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Attention and Automaticity

Lecture Supplement   JamesAttention.JPG
          (128880 bytes)William James, in the Principles (1890), gave attention a natural interpretation in terms of consciousness:    

Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration, of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrained state which in French is called distraction, and Zerstreutheit in German. James further distinguished between various kinds of attention:
Sensorial attention, which is directed toward objects of sense, vs. Intellectual attention, directed toward ideal or represented objects;
Immediate attention, in which the object of attention is intrinsically interesting, vs. Apperceptive attention, in which our interest in the object is derived from our interest in some other thing; and Passive attention, which is captured by an object in a reflexive or involuntary way, vs. Active attention, which occurs by virtue of a deliberate, voluntary act. Later in the same chapter, James argued that real consciousness was based on what he called primary memory (what we now sometimes call short-term or working memory), as opposed to long-term "memory proper" -- what James called secondary memory..  

[F]or a state of mind to survive in memory it must have endured for a certain length of time....  All the intellectual value for us of a state of mind depends on our after-memory of it. Only then is it combined in a system and knowingly made to contribute to a result. Only then does it count for us. So that the EFFECTIVE consciousness we have of our states is the after-consciousness....  

For James, and for others, "all introspection is retrospection".  

In a very real sense, modern scientific research on consciousness began with studies of attention and short-term memory inspired by James' introspective analyses.  Consciousness has a natural interpretation in terms of attention, because attention is the means by which we bring objects into  conscious awareness.  Similarly, maintaining an object in primary (short-term, working) memory is the means by which we maintain an object in conscious awareness after it has disappeared from the stimulus field.  Attention is the pathway to primary memory, and primary memory is the product of attention.


The Architecture of Attention

ChunAspects.JPG
              (76470 bytes)Modern descriptions of attention are very much in James' mold.  For example, Chun (2011) described three aspects of attention:



Limited capacity -- The stimulus environment presents more information than we can possibly process. Selection -- So we have to select among the multiple stimuli that complete for our attention. Modulation -- Directing attention facilitates processing of some stimuli, but inhibits processing of others. Vigilance -- In addition to momentary shifts of attention, we must sustain our attention over extended periods of time.

ChunArch.JPG (76771
              bytes)Like James, Chun suggests that there are different types of attention, though his list is somewhat different.  

 

 

External attention focuses on objects in the external world, including sensory modality, spatial location, at different points in time, and on objects and their individual features. In this view, visual attention is different from auditory attention, attention to a point in space is different from attention to a point in time, we can attend to objects as well as to locations, and we can attend to local features of objects as well as to the objects themselves. Internal attention focuses on memory ("working" and "long-term"), on current tasks, and the selection of responses. We attend to long-term memory when we intentionally retrieve knowledge from it.

 Based on a wide variety of behavioral and physiological studies, William Prinzmetal (at UCB) has drawn a different distinction (anticipated earlier by Wundt (1902) and Posner (1978) between two types of attention.




Voluntary attention (what Posner calls endogenous attention) is goal-directed and deliberately paid to some cue.  When you're walking across campus, you look at some people but not others, depending on your goal. Voluntary attention can be paid to either external or internal cues.Voluntary attention can be paid to either external or internal cues. Involuntary attention (what Posner calls exogenous attention is stimulus driven and captured by some cue.  When you pass a person on the street, you usually can't help looking at the logo or slogan on their shirt.  But it can be impolite to look at people's chests, so we then voluntarily direct our attention elsewhere. 
Prinzmetal believes that involuntary attention can only be captured by external cues, though there may be an exception when "involuntary" memories rise up out of consciousness and capture attention just as a surprising external stimulus does.

 

The Evolution of Theories of Attention

After James, most work on attention focused on the problem of the span of apprehension, or the question of how many objects could be kept in the field of attention at the same time -- for example, the work of R.S. Woodworth

Research on attention faded into the background during the heyday of the behaviorist revolution, but was revived in the context of applied psychological research conducted around World War II, well prior to the outset of the cognitive revolution.  Research on such problems as air traffic control and efficient processing of telephone numbers made two facts clear:

attention was limited, in that people could pay attention to only a few things at a time (this had been apparent as well from Woodworth's work on the span of apprehension); and attention could be controlled, so that consciousness was not necessarily dominated by the most salient stimulus in the sensory field.  There was also a general intuition that attention was the path to primary (short-term) memory, and that both attention and primary memory were closely bound up with consciousness.

Filter Models of Attention

The  earliest psychological theories of attention were based on the idea that attention represents a "bottleneck" in human information processing: by virtue of the bottleneck, some sensory information gets into short-term memory, and the rest is essentially cast aside.  

BroadbentFilter.JPG (58597 bytes)The first formal theory of attention was proposed by Broadbent (1958): aside from its substantive importance, Broadbent's theory is historically significant because it was the first cognitive theory to be presented in the form of a flowchart, with boxes representing information-storage structures, and arrows representing information-manipulation processes.  

 

 

CherryCocktail.JPG (67190 bytes)Broadbent's theory, in turn, was based on Cherry's (1953) pioneering experiments on the cocktail party phenomenon.  At a cocktail party, there are lots of conversations going on, and individual guests attend to one and ignore the others.  Cherry argued that attentional selection in such a situation was based on physical attributes of the stimulus, such as location, voice quality, etc.  He then simulated the cocktail-party situation with the dichotic listening procedure, in which two different auditory messages are presented to different ears over earphones; subjects are instructed to repeat one message as it is played, but to ignore the other.  The general finding of these experiments was that people had poor memory for the message presented over the unattended channel: they did not notice certain features, such as switch in language, or a switch from forwards to backwards speech.  However, they did notice other features, such as whether the unattended channel switched between a male and a female voice.

BroadbentFilter2.JPG (88372 bytes)From experiments like this Broadbent concluded that attention serves as a bottleneck, or perhaps more accurately as a filter.  The stimulus environment is exceptionally rich, with lots of events, occurring in lots of different modalities, each with lots of different features and qualities.  All of this sensory information is held in a short-term store, but people can attend to only one "communication channel" at a time: Broadbent's is a model of serial information processing.  Channels are selected for attention on the basis of their physical features, and semantic analysis occurs only after information has passed.  Attentional processing is serial, but people can shift attention flexibly from one channel to another.

Broadbent's model has two important implications for consciousness:

Perceptual analysis can be unconscious: if we pay attention to channels on the basis of their physical features, then we must have processed information about these physical features before we pay attention to them. Semantic analysis must be conscious: if semantic analysis is performed after information has passed through the attentional bottleneck, then it cannot be performed unconsciously. Basically, filter theories of the type proposed by Broadbent entail two important sets of equivalencies:
Preattentive = Preconscious = Perceptual; Attentive = Conscious = Semantic. In other words, preattentive processing is limited to perceptual analysis of the physical features of the stimulus.

Multi-Store.JPG
              (71876 bytes)Broadbent's filter model of attention laid the foundation for the earliest multi-store models of memory, such as those proposed by Waugh & Norman (1965) and Atkinson & Shiffrin (1968).  In these models, stimulus information is briefly held in modality-specific sensory registers.  A limited amount of sensory information is transferred to short-term memory by means of attention, and is maintained in short-term memory by means of rehearsal.  Under certain circumstances, information in short-term memory can be copied into long term memory, and information in long-term memory can, in turn, be copied into short-term memory.   

Broadbent's filter model of attention was a good start, but it was not quite right.  For one thing, at cocktail parties our attention may be diverted by the sound of our own name -- a phenomenon confirmed experimentally by Moray (1959) in the dichotic listening situation.  In addition, further dichotic listening experiments by Treisman (1960) showed that subjects could shift their shadowing from ear to ear to follow the meaning of the message; when they caught on to the fact that they were now shadowing the "wrong" ear, they shifted their attention back to the original ear.  But the fact that they shifted their attention at all suggested that they had processed the meaning of the unattended message to at least some extent.  These findings from Moray's and Treisman's experiments meant that there had to be some possibility for preattentive semantic analysis, permitting people to shift their attention in response to the meaning and implications of a stimulus, and not just its physical structure.  

Treisman.JPG (80934
              bytes)For these reasons, Treisman (1964) modified Broadbent's theory.  In her view, attention is not an absolute filter on information, but rather something more like an attenuator or volume control.  Thus, attention attenuates, rather than prohibits, processing of the unattended channel; but this attenuator can also be tuned to contextual demands.  

 

At a cocktail party, you pay most attention to the person you're talking to -- attentional selection that is determined by physical attributes such as the person's spatial location.  At the same time, you are also attentive for people talking about you -- thus, attentional selection is open to semantic information.

The bottom line is that attention is not determined by physical attributes, but rather can be deployed depending on the perceiver's goals.  This situation is analogous to signal detection theory, where detection is not merely a function of the intensity of the stimulus, and the physical acuity of the sensory receptors, but is also a function of the observer's expectations and motives.

Like Broadbent's model, Treisman's model is historically important because it is the first truly cognitive theory of attention.  It departs from the image of bottom-up, stimulus-driven information processing, and offers a clear role for top-down influences based on the meaning of the stimulus.  Broadbent (1971) subsequently adopted Treisman's modification.

Treisman's revised filter model has important implications for consciousness.  In her model, preattentive processing is not limited to information about physical structure and other perceptual attributes.  Semantic processing can also occur preattentively, at least to some extent.  The question is: 

How much semantic processing can take place preattentively?


Late-Selection Theories of Attention

Treisman's theory altered the properties of the filter/attenuator, but retained its location early in the sequence of human information processing.  The next stage in the evolution of theories of attention was to move the filter to a later stage, and then to abandon the notion of a filter entirely.  

 



LateSelection.jpg (66070 bytes)Late-selection theories of attention (Deutsch & Deutsch, 1963; Norman, 1968) held that all sensory input channels are analyzed fully and simultaneously, in parallel.  Once sensory information has been analyzed, then attention is deployed based on the pertinence of analyzed information to ongoing tasks.



In early-selection theories, attention is required for the selection of input for further processing. In late-selection theories, attention is required for the selection of a response. For this reason, late-selection theories are also sometimes called response-selection theories.  The implications of late-selection theories for consciousness are clear: late-selection theories permit complex semantic analyses to occur preattentively or preconsciously.

LateEarlyCompare.jpg (85107 bytes)The debate between early- and late-selection theories formed the background for the controversy, which we will discuss later, concerning "subliminal" processing -- i.e., processing of stimuli presented under conditions where they are not detected. The conventional view, consistent with early-selection theories, is that subliminal processing either is not possible, or else is limited to "low level" perceptual analyses. The radical view, consistent with late-selection theories, is that subliminal processing can extend to semantic analyses as well -- because semantic processing, as well as perceptual processing, occurs preattentively.

The debate between early-selection and late-selection theories was very vigorous, and you can still see vestiges of it today.  But, like so many such debates, it seemed to get nowhere (similar endless, fruitless debates killed structuralism; in modern cognitive psychology, similar debates have been conducted over "dual-code" theories of propositional and analog/imagistic representations).


Capacity Theories of Attention

Some theorists cut through the seemingly endless debate between early- and late-selection theories by altering the definition of attention from some kind of filter (with the debate over where the filter is placed) to some kind of mental capacity. 

 

 


Capacity.jpg (60945
              bytes) In particular, Kahneman (1973) defined attention as mental effort.  In Kahneman's view, the individual's cognitive resources are limited, and vary according to his or her level of arousal.  These resources are allocated to information-processing according to a "policy", which in turn is determined by other influences:



Enduring dispositions, innate or overlearned tendencies, which are applied automatically; Momentary intentions, conscious, goal-directed decisions, applied deliberately. In Kahneman's theory, a person's ability to carry out a particular process depends on the resources required by it.  If the tasks are undemanding, several can be carried out in parallel; if the tasks are demanding, resources are focused on one task at a time, serially.  Spotlight.jpg (82204
            bytes)Another  version of capacity  theory likened attention to a spotlight (Posner et al., 1980; Broadbent, 1982).  In the spotlight metaphor, attention illuminates a portion of the visual field.  This illumination can be spread out broadly, or it can be narrowly focused.  If spread out broadly, attentional "light" can be thrown on a large number of objects, but not too much on any of them.  If focused tightly, attentional "light" can provide a detailed image of a single object, at the expense of all the others.  As the information-processing load increases, the scope of the attentional beam contracts correspondingly.  


ZoomLens.jpg (59949
              bytes)Similarly, attention can be likened to the zoom lens on a camera (Jonides, 1983; Eriksen & St. James, 1986). As load increases, the lens narrows, so that only a small portion of the field falls on the "film".  But at low loads, a great deal of information can be processed, though there will be some loss of detail.    




SplittingBeam.jpg (39958 bytes)The  spotlight metaphor also raised the question of whether the attentional beam can be split to illuminate two (or more) non-contiguous portions of space.  





Posner's spotlight metaphor has been particularly valuable in illuminating (sorry) various aspects of attentional processing.  For example, Posner has described three different aspects of attention, each associated with its own brain system:


Attention and Consciousness

I began these lectures by noting the close relationship between attention and consciousness -- so close, they seem synonymous.

We become conscious of something by paying attention to it.And even if we identify consciousness with working memory, as opposed to attention per se, attention is the route to working memory -- and thus the route to consciousness as well.Mack and Rock (1998, p. ix), have gone so far as to assert that "there seems to be no conscious perception without attention" (emphasis in the original). 

For example, there are a number of phenomena in which subjects are not consciously aware of events in the environment that are clearly perceptible -- simply because they are not paying attention to them.


Neglect

A dramatic case in point is one a neurological syndrome known as hemispatial neglect, in which the patient ignores regions of space contralateral to the site of the lesionPatients who show hemispatial neglect typically have brain damage localized near the junction of the temporal and parietal lobes in their right hemisphere -- meaning that they will neglect objects in their left visual field.   



Neglect is a complicated syndrome, and it presents in many forms.  

There is no visual impairment as such -- neglect is really a deficit of attention.  Posner and his colleagues have analyzed this attentional deficit in terms of his "spotlight" model of attentionBriefly, Posner argues that the executive control of attention requires that we disengage attention from its current focus, shift it elsewhere, and then engage with some new object or region of spaceAccording to this model, neglect patients have a particular difficulty disengaging attention -- in this case, from the right side of personal space.


Parafoveal Vision and Dichotic Listening

Similar sorts of findings have been obtained in neurologically intact subjects.

Earlier in these lectures, I discussed the dichotic listening paradigm developed by Cherry to study the cocktail-party phenomenon.  Subjects shadow an auditory passage presented to one ear, and ignore a competing message presented to the other ear.  And subjects can do this quite well, failing to notice much about the unattended passage -- unless, at least sometimes, when it contains highly relevant material such as the subject's own name. 

In parafoveal vision, subjects may be asked to detect the appearance of targets presented in the center of a screen.  At the same time, words can be presented on the periphery of the screen.  Typically, subjects do not notice these peripheral targets.  But they can induce semantic priming effects.  One such experiment was conducted by Bargh and PIetromonaco (1982), and discussed later in the Lecture Supplement on "Automaticity and Free Will".

 

Inattentional Blindness

In the classic instances of preattentive processing, the subject's attention is deliberately focused elsewhere -- on one channel of a dichotic listening task rather than the other, or to some portion of the visual field rather than somewhere else.  However, there are also other circumstances in which people do not consciously see or hear things, even when their attention is not distracted by a competing task.  Although some of these phenomena appear to reflect the fact that subjects' attention is focused on one aspect of a stimulus rather than another, in every case the subjects appear to be blind to some object or feature, despite the fact that they are staring right at it. 

 

The Inattention Paradigm

One of these phenomena was discovered by Mack, Rock, and their colleagues, as part of a large study of the limits of preattentive processing (e.g., Rock et al., 1992; Mack & Rock, 1998).  Their experiments employed an inattention paradigm in which subjects were presented with a seemingly straightforward but actually rather difficult task: to determine which of two crossed lines, one horizontal and one vertical, was larger.  Subjects focused on a central fixation point, the cross appeared briefly (200 milliseconds) either at fixation or in the parafoveal region, and then the subjects made their response.  Of course, this was just a cover task.  On the first two or three trials, the subjects were simply presented with lines of different length, and asked to identify which was the longer.  After establishing this attentional set, the subjects were unexpectedly presented with a new stimulus which also appeared briefly, somewhere in the region marked by the contours of the cross.  After reporting their length judgment, the subjects were also are asked whether there was another object presented, and if so where it was.  Because the subjects were not expecting the new stimulus, and were focusing their attention on the crossed lines (in order to make the comparative judgment of length), this trial is called the inattention trial.  It is important to know that this target was presented within one of the quadrants created by the cross -- so that, if subjects were scanning the lines to compare their lengths, as they were instructed to do, they should also have noticed its appearance.  Nevertheless, about 25% of the time, subjects failed to note the presence of the target.  Regardless of their response, they were then given a recognition test in which they were asked to select, from a set of alternatives, the one that most closely resembled the new stimulus. 

At this point, now that subjects had been effectively warned by the inattention trial that some other stimulus might also appear, the task shifted.  In addition to making a judgment about the cross, the subjects were asked report whether another stimulus appeared as well.  After two trials with only the cross, the new object dutifully appeared.  These are called divided attention trials: the subjects had to pay attention to the cross, in order to complete their manifest task, but they were also looking out for any target.  Finally, there were full attention trials in which subjects were instructed to ignore the cross entirely and simply detect the presence of a target. Subjects also performed the recognition task after the divided attention and full attention trials, just as they had after the inattention trial.

For technical reasons, the cross was masked after 200 milliseconds, but this did not prevent it from being clearly seen by the subjects.  The judgment task was complicated somewhat by the well-known horizontal-vertical illusion, in which a vertical line appears longer than a horizontal line of the same length.  For symmetry, it might have been interesting if the subjects had been surprised by a request to make a length judgment on a subsequent full attention trial, which would effectively would have been an inattention trial with respect to the cross.  But because the judgment task is only a cover for the real experiment, none of this really matters.     

In performing these experiments, Rock et al. (1992) were initially interested in asking a question about the relation between perception and attention -- to wit, which aspects of perception require attention, and which do not?  Studies of a phenomenon known as pop out had already indicated that such elementary features as color, motion, and simple shape (e.g., distinguishing between Ts and Os -- could be perceived independent of attention (Treisman, 1988), but at the time there was a dispute over whether location was also processed preattentively.  The Rock et al. (1992) studies showed that targets were successfully detected and located about 75% of the time on the inattention trials, a rate that was not significantly different from that observed on the divided attention or full attention trials.  Accordingly, they concluded that location was also processed preattentively -- a reasonable enough conclusion, given the fact that -- as they themselves noted -- you have to know where something is before you can direct your attention to it. 

On the other hand, if 75% of subjects detected the target, then 25% missed it.  Initially, Rock and Mack dismissed this phenomenon merely as noise" in their data.  But the 25% "miss" rate continued to appear, in experiment after experiment.  Moreover, the rate of misses on inattention trials increased to as much as 80% when the new object was presented right at the point of fixation, rather than when it was presented a little off-center, in the parafoveal region.  Because a substantial number of misses occurred when clearly supraliminal stimuli were presented in that portion of the visual field where visual acuity is optimal, they realized that the misses were a substantive phenomenon in and of themselves.  And because they attributed the misses to the fact that subjects were focusing their attention on the contours of the crosses, they named the phenomenon inattentional blindness (IB).

It may seem difficult to accept that subjects will entirely miss an object that it entirely within their field of vision, just because they are paying attention to something else.  However, an experiment by Neisser (1979) obtained similar effects: when subjects viewed a videotape of people passing a basketball back and forth, counting the number of passes, only 21% reported seeing a clearly visible woman who walked through the basketball court carrying an open umbrella.  A replication experiment substituted a chest-thumping gorilla for the woman: fully half of subjects failed to report the presence of the beast (Simons & Chabris, 1999, 2009).  Inattentional blindness is theoretically important because it shows that attention can be directed to specific objects, not just to particular locations in space.  But in the present context, the phenomenon is mostly interesting as a dramatic lapse of conscious perception.

Inattentional blindness may be defined as the failure to consciously perceive an object, otherwise salient, when the subject's attention and expectation are otherwise engaged.  Mack and Rock's subjects' attention is focused on the horizontal and vertical lines, and they miss the third object presented within their contours.  Inattentional blindness has at least two implications:

Once the phenomenon of IB itself was established to their satisfaction, Mack and Rock (1998) conducted an extensive series of studies designed to discover its properties and limits).  For example, in a series of studies paralleling Cherry's (1953) work on the cocktail party phenomenon, these investigators determined that blindness occurred less frequently when the new stimulus was the subject's own name (12.7% of trials), compared to someone else's name (35%) or a common noun (50%).  If the subject's name was even slightly modified -- e.g., for example substituting Kon for Ken -- the rate of IB rose considerably.  On the other hand, similar modifications to common nouns -- e.g., substituting teme for time -- had little effect on the rate of IB.  These studies were exceptionally arduous and time-consuming, because -- unlike the usual experiment in psychology -- the subjects can provide data for only a single inattention trial.  After that first trial, they know that the new stimulus can appear, and they are "spoiled" for future research.  Based on such findings, Mack and Rock gravitated toward a late-selection view of attention that allowed for preattentive analysis of meaning as well as of physical features -- or, at least, a multilevel attentional system that allowed for both early and late selection. 

 

Inattentional Blindness and the Attentional Bugaboo

Mack and Rock (1998) began their program of research with the view that conscious perception requires attention, and thus that inattention produces a kind of blindness -- a state of "looking without seeing" (p. 1).  From their point of view, attention is "the process that brings a stimulus into consciousness... that permits us to notice something" (p. 25).  Accordingly, there is "no conscious perception at all in the absence of attention" (p. 227).  Objects may capture attention involuntarily, or attention may be deliberately directed to an object (by virtue, for example, of expectations, intentions, or mental set); in either case they enter into phenomenal awareness.  

But are Mack and Rock really right, that attention is required for consciousness?  And did their ostensibly blind subjectws really fail to see the stimuli in question?  There are reasons to be doubtful on both points.  Writing in the tradition of Eriksen (1960) and Holender (1986), Cuylany (2001) emphatically denies both claims. 

The term "demand characteristics" was introduced into psychological discourse by Orne (1962), as part of a broad critique of methodology in social-psychological research (see also Orne, 1969, 1972, 1973, 1981).  By "demand characteristics", Orne meant the totality of cues available in the experimental situation that communicate to the subject the experimenter's design, hypotheses, and predictions {for an analysis, see Kihlstrom, 2002).  Many social psychologists employ deception to hide their real intentions, but as Mack and Rock's experiments show, social psychologists are not the only ones to do so.  By fabricating the cover task of comparing the lengths of crossed lines, when they are really interested in identification of the extraneous stimulus, Mack and Rock engaged in no less a deception than did Milgram (1963) in his famous experiments on obedience to authority.  And just as Milgram's subjects may have caught on to his deception (1968), so Mack and Rock's subjects may have caught on to theirs. 

Certain details of Mack and Rock's procedures and results lend weight to Dulany's critique. 

As attractive as the notion of inattentional blindness might be, it has to be said that there are as yet no good answers to many of Dulany's criticisms.  To a great extent, the intransigence of Dulany's arguments stems from the fact that, like Eriksen before him, he resists the identification of conscious awareness with introspective self-report. (In fact, Dulany was a graduate student of Eriksen's at the University of Illinois before joining him on the faculty there.  In their one joint publication, Dulany and Eriksen (1959) argued that verbal self-reports were no more than accurate than covert psychophysiological responses as indices of stimulus discrimination.)

Dulany expresses a positivist's reserve about introspection, but he is no radical behaviorist.  Far from denying the existence or importance of consciousness, Dulany has asserted a thoroughgoing mentalism that identifies consciousness with symbolic representation, and he has defined symbolic processing so broadly -- encompassing everything that happens after sensory transduction and before motor transduction (Dulany, 1991, 1997).  Some symbolic codes are literal, close to a perceptual representation, while others are symbolic, more abstract and full of meaning, but none of them are any more or less conscious than the others because from his point of view all symbolic codes are represented in consciousness. 

In the end, Dulany adheres to the "grand principle" {Dulany, 1997, p. 184} that "mental episodes consist of nonconscious operation upon conscious intentional states, yielding other conscious intentional states".  In other words, mental processes may be unconscious, but mental contents are conscious.  This position comports well with the traditional view, in cognitive psychology, that procedural knowledge is unconscious, inaccessible to introspective conscious access in principle, but that declarative knowledge is accessible to conscious awareness.  But a major thrust of this course is that mental contents -- percepts, memories, and thoughts -- can also be unconscious, in the sense that they can interact with ongoing experience, thought, and action in the absence of, or independent of, conscious awareness.  That is what implicit memory, implicit perception, and other, cognate phenomena (yet to be discussed) are all about. 

It is possible that Dulany is right, that only mental processes are unconscious, and that mental states, as symbolic representations, are always conscious.  But there is a danger here, and it is of the same kind that Eriksen's arguments posed for studies of subliminal perception.  Eriksen identified consciousness with discriminative behavior; but if the evidence for unconscious percepts, memories, and the like consists in observations of discriminative behavior in the absence of self-reported awareness, he has ruled the psychological unconscious out of existence by definitional fiat.  Similarly, Dulany identifies consciousness with symbolic representations; but if the evidence for unconscious percepts, memories, and the like consists in observations like priming outside of awareness, then he too has ruled the psychological unconscious out of existence.  We are left with the traditional view in cognitive psychology, which identifies the unconscious with automaticity and procedural knowledge, and consciousness with all mental states and contents and states. 


Varieties of Attentional Blindness

Like Eriksen's (1960) before them, Holender's (1986) critique of preattentive semantic processing and Dulany's (1997) criticisms of inattentional blindness are not trivial, and should have the effect of forcing researchers to clean up their methodologies, putting evidence for preattentive, preconscious processing on ever-firmer empirical grounds.  This exactly what happened with research on subliminal perception (Greenwald et al.,1996; Draine & Greenwald, 1998).  In the meantime, other investigators have opened several new lines of research on the general questions of attention, conscious awareness, and preattentive, preconscious processing.  The studies described previously in this chapter examined processing when subjects' attention was directed elsewhere -- to one channel in dichotic listening, to foveal rather than parafoveal regions, to some objects but not others.  By contrast, these studies document anomalies of awareness even when subjects are directing their attention right at the target.  For this reason, I classify these studies as concerned with attentional blindness -- deficits in conscious visual processing that occur despite the subject's appropriate deployment of attention, and accurate expectations (see also Kanai et al., 2010). 

Paralleling the conclusions of Mack and Rock (1997) concerning inattentional blindness, we can conclude from the phenomena of attentional blindness that Attention does not guarantee conscious perception.  But again, in the present context, we are interested not so much in the blindness itself -- though that's interesting.  What we're interested in is whether there is unconscious, implicit perception of the stimuli in question.  Can you get priming from a stimulus for which a subject is attentionally blind?


Repetition Blindness

The phenomena of attentional blindness are most commonly observed in laboratory conditions employing a technique called rapid serial visual presentation, or RSVP (Potter, 1969; Forster, 1970), in which subjects view a series of visual stimuli presented one after another in very quick succession -- about 100 milliseconds each.  In an early experiment by Kanwisher and her colleagues, subjects viewed sentences such as It was work time so work had to get done, presented one word at a time, and then were asked to report verbatim what they had seen.  Note that the sentence contains a repetition of the word work.  We can call the first instance of the repeated word R1, and the second instance R2.  Under RSVP conditions, streaming about 10 words per second, a large number of subjects -- about 60% -- omit R2: they report "It was work time so had to get done", despite the fact that the sentence is obviously incomplete (Kanwisher, 1987).  When R2 is not the same as R1, it is missed only about 10% of the time.

The procedure here is a little tricky: because most skilled readers do not read every word in a sentence, there is a tendency for them to fill in the gaps with meaningful words -- just as we generally ignore misspellings, missed words, and other typographical errors.  To counteract this tendency, Kanwisher carefully instructed subjects to report what they saw verbatim.  And she also included a number of sentences that actually had words missing, so that subjects would not be surprised when they reported an incomplete or anomalous sentence.

A later experiment by Kanwisher and Potter(1990, Experiment 1) makes the effect even clearer.  In this study, subjects saw three different kinds of sentences. 

  • In the repeated condition, the sentence was a standard RB stimulus, such as We were anxious for autumn well before autumn arrived.
  • In the synonym condition, R1 was replaced by a synonym, as in We were anxious for fall well before autumn arrived.
  • In the unrepeated condition, R1 was replaced by a semantically unrelated word that made sense in the context of the sentence, such as
    We were anxious for apples well before autumn arrived.

Across the three conditions, subjects correctly reported R1 approximately 94% of the time; however, they reported R2 only 40% of the time in the repeated condition, compared to an average of about 88% for synonyms and unrepeated condition.  The fact that RB occurs for a repetition, but not a synonym, indicates that RB occurs at the level of a perceptual (or possibly lexical) representation, but not at the level of meaning. 

RB occurs when one instance of a word -- a token of the type -- appears fairly quickly after the first -- within one or two words, in fact, corresponding to a lag of about 200-300 milliseconds at a presentation rate of eight words per second.  If the repeated word is delayed by about 500 milliseconds, either by positioning the word later in the sentence or by slowing the rate of presentation, RB does not occur. 

Such findings led Kanwisher (1987, 2001) to propose a type-token individuation hypothesis of RB.  According to this hypothesis, conscious awareness requires both the activation of a memory representation of an event (the type) and the individuation of that activated structure as the representation of a discrete event (a token of the type).  The first time the subject sees the word autumn, the perceptual representation of that word is activated and a token individuated; but when autumn is repeated so quickly, individuation does not occur, and so the subject does not see it as a different, discrete event -- as another token of the type.  The event need not be a word: RB has also been observed for digits and letters, pictures, and simple and complex shapes -- including impossible figures  According to Kanwisher, the lack of individuation creates a failure of conscious perception: the subject is not consciously aware of the token's repetition.  


The Attentional Blink

Another phenomenon of attentional blindness is known as the attentional blink (AB), -- a phenomenon initially noticed by Broadbent and Broadbent (1987), but given its name by Raymond, Shapiro, and their associates (Raymond et al., 1992; Shapiro et al., 1994; for a review, see Shapiro, 1994, 1997}.  In AB experiments, subjects view a series of stimuli (such as letters) presented in rapid succession -- say, 30 items over a period of a three seconds, or a rate of about 100 milliseconds per item (this is roughly the same rate as in RB experiments). On each trial, the subject's task is to report the identity of a distinctive target letter -- for example, the one printed in red as opposed to black.  However, the subjects are also asked to detect whether a second probe -- for example, the letter "R" -- also appeared in the letter series.  Of course, the presence of the primary target (T1) and secondary probe (T2), and their locations within the string of letters, varied from trial to trial.  Control subjects performed the probe-detection task only, without the target-identification task.  In a typical experiment (Shapiro et al., 1994), control subjects showed a high level of accuracy, approximately 85%, regardless of where in the sequence T2 was placed.  However, the experimental subjects missed T2 about half the time when it was presented within about 500 milliseconds (i.e., within five items) after T1.  If T2 was presented six to eight items later, outside the 500-millisecond interval, detection rates for experimental subjects were essentially the same as those of the controls. 

Of course, the attentional blink is not an actual eyeblink: subjects rarely blink their eyes during an RSVP trial.  Nor is the attentional blink a phenomenon of visual masking, because it does not occur if the subject is not instructed to identify (i.e., pay attention to) the preceding T1.  Instead, it is as if the subject has blinked, by analogy to the actual eye-blinks that occur after subjects shift their gaze from one location to another.  Shapiro and Raymond suggested that T1 is identified preattentively, on the basis of its physical characteristics -- e.g., that it is red as opposed to black.  Attention is then directed toward T1 in support of the identification process (e.g., that it is a T rather than an L), but it takes time for attention to shift back to the stream of RSVP stimuli, giving T2 time to be lost through decay or interference.  If T2 occurs soon enough after the target, then, it is likely to be missed.  However, T2 probe is not missed if the subject is instructed to ignore T1 -- thus supporting an attentional interpretation of the effect. 

Although AB is not an actual eyeblink, it is nonetheless a real blink.  Sergeant and Dehaene (2004) asked subjects to rate the visibility of the T2 at various lags after T1.  After presentation of T1, the visibility of T2 decreased immediately at a lag of 2 (that is, with only a single stimulus between T1 and T2, and returned to baseline immediately at a a lag of six (that is, with five stimuli between the two targets).  The disappearance and reappearance of T2 occurred in a discontinuous, all-or-none fashion, with not even a hint of continuous degradation and recovery.  This pattern was quite different from that observed with backward masking, which produced an immediate degradation of the preceding stimulus (that is, at a lag of 1), and a gradual increase as the SOA lengthened.  Sergent and Dehaene suggest that their results are most compatible with a two-stage model of the AB in which each stimulus in the RSVP display is subject to automatic, preconscious pickup, but conscious processing of T1 consumes cognitive resources that are necessary for conscious required for conscious processing of T2 (Chun & Potter, 1995).

 

Change Blindness

Another variant on attentional blindness is change blindness (CB) , which occurs when subjects fail to notice rather large alterations in familiar scenes (Rensink, 1997; for comprehensive reviews, see Rensink, 2004; Simons, 2000; Simons, 2005; Simons, 1997).  In the flicker paradigm, subjects are presented with a picture of a natural scene rapidly alternating with a slightly modified picture in which there has been some change in the presence or absence of some object or feature, its color, orientation, or location -- about 240 msec per stimulus.  In this case, subjects will readily detect the change, apparently because the alteration creates a "luminance transient" that draws attention to the spatial location in which the change has occurred.  But if the two images are separated by a blank gray field, presented for only 80 msecs, images the situation is a little different.  In the laboratory, the difference between the two stimuli is typically restricted to only a single modification in appearance (i.e., the presence or absence of some object or feature), color, or location. The two versions alternate  back and forth on a random schedule, each version appearing for only a very short time (typically 240 msec), and separated by a gray field that appears for an even shorter period of time (typically 80 msec).  On a single trial, presentation continues in this manner for 60 seconds, or until the subject detects the change.  The purpose of this procedure is to simulate the situation in real-world vision, in which the observer must integrate information across saccadic eye movements -- in this case, simulated by the gray field interposed between the two versions of the stimulus.  In the absence of the gray field, subjects will immediately notice the change

Change blindness falls under the rubric of attentional blindness because the subject is not aware that the second image is different from the first. That is a lapse of consciousness. 


Can Attention and Consciousness Be Dissociated?

 

Automaticity

Kahneman's theory laid the foundation for current interest in automaticity: in his view, enduring dispositions influenced allocation policy automatically, outside awareness and voluntary control, while momentary intentions were applied consciously.  

The traditional view, associated with early-selection "filter" theories, was that elementary information-processing functions are preattentive, performed unconsciously (or, perhaps better put, preconsciously), and requiring no attention.  By the same token, complex information-processing functions, including (most) semantic analyses, must be performed post-attentively, or consciously.

The revisionist view, associated with late-selection theories and capacity theories, agreed that elementary information-processing functions were preattentive, performed unconsciously or preconsciously.  But it asserted that complex processes, including semantic analyses, could be performed unconsciously too, so long as they were performed automatically. 


Early Approaches to Automaticity

Early in the history of cognitive psychology, there was a tacit identification of cognition with consciousness.  Elementary processes might be unconscious, in the sense of preattentive, but complex processes must be conscious, in the sense of post-attentive.  But the evolution of attention theories implied that a lot of cognitive processing was, or at least might be, unconscious.

LaBerge & Samuels (1974; LaBerge, 1975) argued that complex cognitive and motoric skills cannot be executed consciously, because their constituent steps exceed the capacity of attention. Thus, at least some components of skilled performance must be performed automatically and unconsciously. LaBerge & Samuels defined automatic processes as those which permit an event to be immediately processed into long-term memory, even if attention is deployed elsewhere.



LaBerge and Samuels illustrated their concept of automaticity with a model of the hierarchical coding of stimulus input in reading. 




Feature detection is intrinsically automatic, and occurs regardless of the deployment of attention.  All the other levels of reading require conscious effort at early stages, but can become automatized through practice.  After overlearning, the recognition of letters, spelling patterns, words, and word-groups occurs automatically.

StroopControl.jpg (92210 bytes)The StroopColor.jpg
              (100610 bytes) automatization of word-reading is illustrated by the Stroop effect.  In the Stroop experiment, subjects are presented with an array of letter strings printed in different colors, and their task is to name the color of the ink in which the string is printed. 



In Stroop's Experiment 1, subjects were asked to read color names.  Reading was slowed compared when the words were printed in a different color (blue) than when they were printed in black (blue), but the difference was not statistically significant.

Stroop1935.JPG
              (44711 bytes)The classic Stroop effect emerged in Experiment 2, where subjects were asked to name colors.  In the experimental condition, the color was presented as a word (blue), which named a different color than that in which the word was printed, as above.  In the control condition, the color was presented simply as a solid block of color (||||||||||).


 

In a third experiment, the subjects practiced color-naming over a period of 14 days.  The usual Stroop interference effect was apparent on Day 1, not surprisingly.  Interference diminished over the subsequent two weeks, but was still apparent on the final day of testing.

In the Stroop effect, the presence of a word interferes with color-naming -- especially if the word is itself a contradictory color name (but, interestingly, even if the word and the color are congruent).  The "Stroop interference effect" occurs regardless of intention: Clear instructions to ignore the word, and focus attention exclusively on the ink color, do not eliminate the interference effect.  The explanation is that we can't help but read the words -- it occurs automatically, despite our intentions to the contrary.  

StroopAlternate.jpg (66211 bytes)The Stroop effect comes in many forms, not all of which involve colors and color words.  For example, Stroop interference can be observed when subjects are asked to report the number of elements in a string, and the elements themselves consist of digits rather than symbols that have nothing to do with numerosity.  In the emotional Stroop test, subjects show particular interference with color-naming if the words refer to some topic that is personally meaningful to the subject.

 

The more recent roots of automaticity are to be found in the literature on skill acquisition.  For example, Fitts and Posner (1967) identified three stages that subjects went through when acquiring a new skill:

Posner & Snyder (1975a, 1975b) contrasted automatic and strategic processing. Automatic processes:

Schneider & Shiffrin (1977; Shiffrin & Schneider, 1977; Shiffrin & Schneider, 1984) distinguished between automatic and controlled information processing. Their experiments compared performance in "easy" memory-scanning tasks that are highly practiced by subjects, against "harder" novel tasks. Automatic processes entail perception through routines stored in long-term memory, and which require no attentional effort or cognitive capacity. Controlled processing entails novel sequences of processing steps that have not been previously stored in memory, and which require attentional effort or cognitive capacity to be carried out deliberately.

Schneider & Shiffrin argued that while processing specific pieces of information could be automatized, generalized skills could not. 

Spelke.jpg (61577
              bytes) In contrast, Spelke, Hirst, & Neisser (1976) demonstrated that a generalized skill (taking dictation while reading at a high level of comprehension) could be automatized, given sufficient practice. In their experiment, subjects (actually paid as work-study students!) performed a divided attention task in which they read prose passages, and simultaneously took dictation for words.  The subjects practiced this task for 17 weeks, 5 sessions per week -- with every session employing different stories and lists.  The result was that reading speed progressively improved, with no decline in comprehension.  Apparently, the subjects automatized the dictation process, so that it no longer interfered with reading for comprehension.

But what about the dictated lists?  Initially, the subjects had very poor memory for the words presented on the dictation task.  On later trials, they showed better memory for the dictation list, and were able to report when the list items contained rhymes or sentences.  They also showed integration errors, such that they remembered lists like The rope broke Spot got free Father chased him as Spot's rope broke.  Integration errors indicate that the subjects processes the meaning of the individual sentences and the relations among the sentences automatically -- ordinarily this would be considered to be a very complex task.

Although Spelke et al. wished to cast doubt on the whole notion of attention as a fixed capacity, they also expanded the boundaries of automaticity by showing that even highly complex skilled performance could be automatized, given enough practice.

The general notion of automaticity has attracted a great deal of interest, based on the widely shared belief that there are cognitive processes which generally share the following properties:




Later, Hasher & Zacks also postulated other, novel features of automaticity:





Hasher & Zacks listed frequency and spatial location as attributes of events which are encoded automatically. Automatic processes are unconscious in the strict sense of the term, in that they operate outside phenomenal awareness and voluntary control.  They are not subject to introspection, and can be known only by inference from human performance.  Automatic processes are unconscious in the strict sense of that term.


The Roots of Automaticity

The concept of automaticity seems very modern, but in fact its roots go far back in scientific psychology and even further back in the philosophy of mind.  For example, William James devoted an entire chapter of the Principles (1880) to refuting "The Automaton Theory" that consciousness is epiphenomenal and plays no causal role in behavior.  James agreed that certain habits were automatic, in some sense, but he didn't believe that automaticity was everything.


Reflex and Conditioned Response

Automaticity plays an important role in Descartes' notion of the reflex.  In his view, the reflex was the basis of the mechanical behavior of beasts: stimulus energy from the environment, falling on sensory surfaces, was reflected by the nervous system and sent back to the environment through the skeletal musculature.

In modern psychology, reflexes have two primary characteristics:

Of course, not all animal behavior is reflexive.  Beginning with Pavlov, psychologists have been interested in conditioned responses that free behavior from control by innately preprogrammed stimuli. 
In the conditioning metaphor, the organism's behavior is under stimulus control, and the implication of the metaphor is that these learned behaviors are performed automatically.  

Early conditioning theorists, such as Pavlov and Watson, lacked a detailed technical concept of automaticity.  But they had the underlying idea of automaticity -- that certain response processes were automatically elicited by appropriate stimulus conditions, independent of other activities, including the organism's "intentions".


Unconscious Inferences

Among the most influential advocates of unconscious mental processes was the German physiologist Hermann von Helmholtz (1821-1894).  In his Treatise on Physiological Optics (Helmholtz, 1866/1968; Warren & Warren, 1968) , he argued that our conscious perceptions are determined by unconscious inferences concerning the stimulus environment:           
The psychic activities that lead us to infer that there in front of us at a certain place there is a certain object of a certain character, are generally not conscious activities, but unconscious ones.  In their result they are the equivalent to conclusion, to the extent that the observed action on our senses enables us to form an idea as to the possible cause of this action....  But what seems to differentiate them from a conclusion, in the ordinary sense of that word, is that a conclusion is an act of conscious thought....  Still it may be permissible to speak of the psychic acts of ordinary perception as unconscious conclusions... (p. 174).

For Helmholtz, then, perception results from a kind of syllogistic reasoning, in which the major premise consists of knowledge about the world acquired through experience, and the minor premise consists of the information provided by the proximal stimulus.  The perception of this proximal stimulus, then, is the conclusion of the syllogism -- except, in the case of perception, we are not aware of the reasoning process.  Hence, Helmholtz's phrase, "unconscious conclusions".  The fact that the reasoning underlying perception is unconscious is what makes us feel that we are seeing the world directly, the way it really is.  But our percepts are not, in fact, immediate products of stimulation -- they are mediated by unconscious reasoning processes.

With the notion of unconscious inferences, Helmholtz broke down the distinction between "lower" mental processes, like sensation and perception, that are closely tied to the stimulus, and "higher" mental processes, like memory and reasoning, that go on in the absence of a sensory stimulus.  Reasoning is involved in perception as well as in thinking and problem-solving.  But Helmholtz never suggested that perception involved conscious, deliberate, acts of reasoning.  These days, Helmholtz might not have described the reasoning as unconscious. Instead, he would probably have described it as automatic.


Theories of Automaticity

By 1984, the notion of automaticity had gained widespread acceptance. But while the criteria for automaticity were clear, the underlying mechanisms were not: what makes an automatic process automatic? 

One prominent theory (actually, a whole class of theories) of automaticity is the memory-based view, according to which automaticity reflects a change in the cognitive basis of task performance:

There are at least two prominent versions of this theory.


The Instance-Based Theory of Automaticity

In Logan's (1988) instance-based theory of automaticity, practice with a task encodes an increasingly strong memory trace of the appropriate response.  Practice, then, doesn't just speed up processing.  Rather, repeated practice lays down an increasingly strong memory for the correct response to a stimulus.  Actually, there is not just one such memory, strengthened through practice.  Instead, there is a separate memory for each repeated instance.  As these instances accumulate, so does the strength of the memory.  

Instance theory makes the seemingly paradoxical prediction that automatic processes can be controlled by varying the retrieval cues present in the environment, which in turn make the underlying memory more or less accessible.  So, automatic processes aren't so automatic after all -- they are executed only if the appropriate retrieval cues are available in the environment, but also only if the person processes them as such.


Automaticity in the ACT Theory

In Anderson's (1992) ACT theory of cognition, conscious processes are represented in declarative memory by sentence-like propositions, while automatic processes are represented in procedural memory by systems of "If-Then" conditional productions. 

Productions, representing procedural knowledge, consist of three elements:

If the goal and the state are simultaneously represented in working memory, then the action is executed.

Most procedural knowledge is comprised of whole systems of productions, rather than of a production.  In this way, the output of each production, which changes the current state of the actor, serves as input to the next production in the system.  

Both the processing goal and the current state are represented in working memory as activated bits of declarative knowledge, such as: I desire to shift into first gear and My foot is pressing down on the clutch.  

The production consists of a conditional rule, such as:

But the production itself is part of procedural knowledge, not of declarative knowledge.  Thus the production itself is not represented in working memory, and so the production itself is not accessible to consciousness.

Of course, the whole process is more complicated than a single production, which is why we speak of production systems.

The transformation of declarative knowledge into procedural knowledge, through extensive practice, is known as proceduralization.

Automaticity, Proceduralization and Being-in-the-World

UCB philosophy professor Hubert Dreyfuss, and his brother Stuart, UCB professor of engineering sciences, have traced the process of automatization in the Dreyfus skill model (in their book Mind Over Machine: The Power of Human Intuition and Expertise in the Era of the Computer, 1986).  According to their model, the acquisition of a skill proceeds through five stages:

  • Beginner
  • Advanced Beginner
  • Competent
  • Proficient
  • Expert

Basically, skill acquisition begins with conscious, deliberate rule-following, and proceeds to the point where a person can perform the skilled activity without thinking about it at all.  As illustrations, they point to driving a standard-shift car, playing basketball, playing chess, and what the psychologist Mikhail Csikszentmihalyi (1990) calls flow.

Up to this point, the Dreyfus skill model is pretty standard cognitive psychology.  Both Logan's instance-based theory of automaticity and Anderson's ACT theory of proceduralization say pretty much the same thing.  But Hubert Dreyfus is is a noted scholar of the German philosopher Martin Heidegger, author of the pretty-much-unreadable Being and Time (see his Being-in-the-World, 1991, based on a course Dreyfus still offers at Berkeley), and he takes the argument one step further: automaticity is the way of being-in-the-world.  Like Heidegger, Dreyfus opposes the Cartesian model of rational man using his mind to know the world.  Like Heidegger, Dreyfus believes that automatic, intuitive behavior breaks down the distinction between the external world and internal mental representations of it.  Through automaticity, we don't think about the world: we are just in it.  The Cartesian model only applies to beginners.  For Dreyfus, automatization isn't just a matter of internalizing a set of rules, like shift into second gear when you get to 10 miles per hour -- because there are lots of circumstances, like going up a hill or carrying a heavy load, when that rule doesn't apply.  Expert drivers of standard shift cars don't follow rules -- they just intuitively know when it's right to shift.  When we become experts, we behave automatically and intuitively, absorbed in what we are doing, not thinking about it at all.  


Dual-Process Theories in Psychology

General acceptance of the distinction between automatic and controlled processes has led to the development of a large number of dual-process theories in psychology and cognitive science.  The basic feature of all these theories is that any cognitive task -- reading, impression-formation, whatever -- can be performed in either a controlled or automatic manner -- that is, performed either consciously or unconsciously.  (In this respect, dual-process theories could be considered to be a form of conscious inessentialism, as defined by the philosopher Owen Flanagan.) 


Precisely how these two processes are characterized depends on the theory.  Perhaps the most detailed description has been provided by Smith and DeCoster (1999, 2000).


As an example of a dual-process theory, consider consider Kahneman's view of dual systems in thinking, based on his Nobel Prize-winning research on judgment and decision-making.




Whenever a person is presented with a judgment task, or a problem to solve, these two systems go into operation, and essentially "race" to a conclusion.  But because System 1 is inherently faster than System 2, System 1 almost always wins the race.  If we slow the process down, System 2 can take over -- but in the ordinary course of everyday living, this doesn't happen very often.


The Process-Dissociation Procedure

Most work on automaticity assumes that there are two categories of tasks (and, correspondingly, two categories of underlying cognitive processes), automatic and controlled. An alternative view, proposed by Larry Jacoby, is that every task has both automatic and controlled components to it, in varying degree.  Jacoby has developed a process-dissociation procedure, based in turn on the method of opposition, to determine the extent to which performance reflects the operation of controlled and automatic processes.



SchoenfieldAgeDiff.jpg (50718 bytes)To see how the process-dissociation procedure works in practice, consider the matter of age differences in memory.  It is widely known that old people have poorer memories than the young.  Moreover, it turns out that age differences in memory are greatest on tests of free recall; recognition testing often abolishes the age difference entirely.  

 

The question is why this is so, and there are lots of theories.  One, based on Mandler's (1980) two-process theory of recognition, is that recall requires active, conscious retrieval of trace information from memory.  By contrast, recognition can be mediated by two quite different processes:

In Mandler's theory, retrieval requires deliberate, conscious recollection.  But familiarity is the product of an automatic process closely related to priming.  

One explanation of the age difference in memory, then, is that aging impairs retrieval but spares familiarity.  This will produce a decrement in recall among the elderly, but not in recognition -- not so long as the elderly rely on the automatic familiarity process, anyway.  

To determine whether age differences in memory reflected age differences in the controlled or automatic components of memory processing, Jacoby and his colleagues put young and old subjects in the stem-completion task, under both Inclusion and Exclusion conditions. 

Note that, in this case, the stem-completion procedure constitutes a test of what is known as cued recall.  That is, the stem serves as a cue for the retrieval of the corresponding word from the study list.  As a general rule, cued recall tests are less difficult than free recall tests (because they supply additional cue information to support retrieval), but more difficult than a recognition test (because recognition tests supply a lot of information, in the form of a copy of the studied item itself).  

To get concrete, assume that the word density was in the study list.  Then they might receive a stem-completion test, in which they are presented with three-letter stems, and asked to complete these stems with the first word that comes to mind. 

A typical finding is that subjects are more likely to complete old stems with items from the study list, such as density (as opposed to dentist).  This is known as a priming effect.  Priming is often held to be an automatic consequence of stimulus presentation.  And, at least according to some theories, this priming effect is the basis of the automatic feeling of familiarity.

Jacoby contrasted stem-completion performance under two different experimental conditions.

JacobyAgeDiff.jpg (38494 bytes)Here are the results of the experiment.  

 


In other words, the elderly performed more poorly than the young in two different ways:

The process-dissociation procedure is a set of mathematical formulas that allow task performance to be decomposed into its automatic and controlled components.  You will not be responsible for memorizing these formulas, but you should understand the logic of the process-dissociation procedure.



To begin with, Jacoby assumes that targets can be generated on the Inclusion task either deliberately or automatically.  That is to say, either the subject consciously remembers the corresponding completion from the study list or the completion comes immediately to mind by virtue of automatic priming.  Thus,

Inc = C + A(1 - C),

where 

Inc

= the proportion of targets produced on the inclusion task;

C

= the strength of the controlled process, represented by the proportion of targets produced through controlled retrieval;

(1 - C)

= the proportion of targets not consciously retrieved.

A

= the strength of the automatic process, represented by the proportion of target items produced through automatic priming;

Notice that Jacoby assumes that any single item is either consciously or automatically generated.  Thus, the pool of items available for automatic generation is 1 - C, or the proportion of items not generated through conscious retrieval.   Because not all items available for automatic generation are actually generated automatically, the value (1 - C) has to be multiplied by the strength of the automatic process, A.

Similarly, Jacoby assumes that targets can appear on the Exclusion task only by virtue of automatic priming.  If the subject consciously remembered that the item had been on the study list, he would have excluded it from his stem-completion.  Thus,

Exc    = A(1 - C).

By simple algebra, then,

C  = Inc - Exc;


this is the estimate of conscious, controlled component of task performance

A = Exc / (1 - C);

And this is the estimate of the automatic component of task performance.

JacobyAgeDiffPDP.jpg (64790 bytes)Transforming the percentages into proportions, and applying the formulas above, we get the following estimates of controlled and automatic processing for young and old subjects, respectively:



Group

Controlled

Automatic

Young

.44 .46

Old

.16 .46


In other words, recognition in the young subjects was mediated by a mix of controlled and automatic processes.  But recognition by the elderly was mediated mostly by automatic processes.  Put another way, the age difference in memory performance is due entirely to the conscious, strategic component (where the old have lower values than the young).  There are absolutely no age differences in the automatic component (as Hasher & Zacks would predict).


Alternatives to the Process-Dissociation Procedure

Since its introduction in the 1990s, Jacoby's process-dissociation procedure has become very popular as a means of teasing apart the differential contributions of automatic and controlled processes to task performance (Yonelinas & Jacoby, 2012). Most of these applications have been in memory and closely related domains, which is natural enough, but there have been uses outside the confines of cognitive psychology, as we'll see in the next set of lectures, on Automaticity and Free Will.


At the same time, the process-dissociation procedure has been challenged in terms of its underlying assumptions. For example, Jacoby assumes that automatic and controlled processes are independent of each other. On the other hand, it might be that they are redundant -- specifically, that automatic processes are components of controlled processes. Moreover, the PDP assumes that there are only two categories of processes, automatic and controlled. If there are more than two component processes, then the traditional formulas of PDP won't work..

On theoretical grounds, the most important criticism has been of the independence assumption. Formal comparisons show that "independence" and "redundancy" models can give somewhat different parameter estimates for automatic and controlled processes, but the differences are, admittedly, not great.

Personally, I find a version of the redundancy view more appealing than the independence assumption. It seems to me that automatic processes are embedded in controlled processes, which is why dissociations between them go only one way: you can reduce controlled processing without affecting automatic processing, but you can't reduce automatic processing without reducing controlled processing (and, truth be told, you can't reduce automatic processing at all). Still, Yonelinas and Jacoby (2012) summarize evidence from two other paradigms -- employing "remember/know" judgments and signal-detection theory -- that seem to support the independence assumption. Their findings are pretty persuasive. But still, if automatic and controlled processes are really independent of each other, you'd like to see a dissociation in which you can get controlled processing without automatic processing. Which, just to repeat, you can't.

As for the possibility that there might be more than two processes involved, Jeffrey Sherman at UC Davis (interestingly, a colleague of Andy Yonelinas) has developed an alternative QUAD model that has four parameters, not just two (e.g., Sherman et al., 2008). Discussion of this model makes more sense in the lectures on Explicit and the Implicit Emotion and Motivation, so I'll defer until then.

For present purposes, however, the PDP serves as an excellent example of how investigators have gone about differentiating between controlled, conscious processing and automatic, unconscious processing.

 

The Automatic and the Unconscious

In the context of this course, automatic processes are of interest because they were the first landmark in the rediscovery of the unconscious.  Scientific psychology began as the study of consciousness, but fairly quickly the earliest psychologists began to talk about the nature of unconscious mental life.  In particular, Helmholtz argued that conscious perception was mediated by unconscious inferences about the object of perception -- it's location, motion, and shape.  

Watson and other radical behaviorists attempted to take consciousness out of psychology, and to redefine psychology as a science of behavior.  And when psychology lost consciousness, to paraphrase R.S. Woodworth, the unconscious went with it.  

True, Freud put unconscious mental life at the center of his psychoanalytic theory of mind, personality, and mental illness.  But Freud was uninterested in experimental psychology, and the disregard was largely returned.  Those who were interested in unconscious mental life found themselves tainted with the Freudian brush, and had a very difficult time making careers in academic psychology.

As discussed in the Introduction, one of the consequences of the cognitive revolution in psychology was a renewed interest in consciousness -- in attention, in short-term memory, and in mental imagery.  Even if cognitive psychologists rarely used the word, they were talking mostly about conscious perception, memory, and thought; and they were talking about attention as a means for bringing some information into consciousness, to the exclusion of other information.  

The introduction of the concept of automaticity into cognitive psychology completed the cycle, by reviving interest in unconscious processes mediating conscious cognition.  

Automatic processes are unconscious processes, 

executed outside of conscious awareness and outside of conscious control.

 

For more, continue to the Lecture Supplement on Automaticity and Free Will.

 

This page last revised 10/20/2014.