Midterm Examination

Narrative Review


In the past, my practice has been to conduct a pre-exam review in class, accompanied by some illustrations, followed by a question-and-answer session.  That takes a lot of time, however -- time that might be better devoted to students' questions.  Accordingly, I now prepare written "narrative" review, prior to each exam, which will leave extra time for questions in the review session itself.  

I also encourage students to post pre-exam questions to the Forum in the course website on bCourses.  Because I want all students to have access to each student's questions and my answers, I do not answer such queries sent by private email.

Click here for general information about exams in this course.

Link to slides used in the In-Class Q&A Session


The Exam

The exam is scheduled for Wednesday, March 20, 2013.  Students with disability accommodations should get these to me as soon as possible, so that we can make the appropriate arrangements.



The exam will cover all lectures and required readings to date, including Searle's the Mystery of Consciousness

There are lots of resources available for the examination, in addition to the in-class review session:

In addition, students are encouraged to post questions to the "Midterm Exam" forum in the course website on bCoursesbSpace.  I will do my best to respond to them, provided that they are posted no later than noon on Tuesday, 15.  Do not send questions by private Email to either me or the GSIs: we want to make sure that everybody in class has equal access to the exchanges.


Exam Construction and Scoring

The exam will consist of 15-20 short-answer questions.  Roughly half will be drawn directly from the lectures, roughly half will be drawn directly from the text.  Of course, there is some overlap between lectures and readings. As a rule, I try to have at least one question from each lecture, and at least one question from each of the required readings.  

The exam requires only very short answers.  In no case are more than 3-4 sentences required to answer a question; often, the job can be done in fewer than three sentences. 

Note: In contrast to some previous exams, there will be no choice of questions.  Allowing students to choose their own questions makes it more difficult to insure that the exam has adequate psychometric properties.

Answers should be written in ink on the exam itself.  Exams written in pencil will not eligible for regrading.  No "blue books" are required for the exam.  You will write your answers in the space provided on the exam.

The focus of my exam is on basic concepts and principles.  There are no questions about names or dates of experiments (though names and dates may appear in questions).  There are no questions about picky details.  There are no questions about specific experiments, though you should be able to recognize the implications of the phenomena revealed by some classic experiments.  There are no intentionally tricky questions: I want you to understand basic concepts and principles, not the exceptions to the rules.

The exam will be scored following a guide which I have prepared, and which will be posted to the course website following the exam.  The guide is just that: alternative approaches to answering a question will also be considered.  We will do our best to have grades posted within a week of the exam.  

When grades are posted, there will also be an announcement to this effect, and then students will have an opportunity to correct any errors that may have occurred in the grading process.  Requests must be made in writing, and include an argument about why a particular answer deserves a higher score.  Students should not simply "fish" for extra points, though, because the GSIs have been instructed to regrade each question fresh, and it is possible that they will like your answer even less the second time than they did he first..

Exams will be returned in discussion sections, after which the students will have until the next Monday at 12:00 Noon to request a rescore.  Requests for rescores after that time will not be honored.  



I define consciousness in terms of two aspects: monitoring ourselves and our environment, (phenomenal awareness, or sentience) and controlling ourselves and our environment (voluntary action, raising the problem of free will).  They're related, it seems to me, if only because conscious control would seem to logically require conscious awareness of what we're trying to control.

You should understand some of the history of the scientific study of consciousness, beginning with Rene Descartes, who inferred from his conscious thoughts that he existed ("Cogito, ergo sum"). 

Just as psychology was getting going, Watson and other behaviorists became dissatisfied with introspection, and redefined psychology as the science of behavior, leaving consciousness, and all of mental life, out of the picture.  Nevertheless, an interest in consciousness persisted in Gestalt psychology, research on the span of apprehension, and some "neobehaviorist" learning theories, such as Hull's and especially Tolman's.

Consciousness returned to psychology with the cognitive revolution, in research and theory on attention, primary (short-term) memory, and mental imagery.  But some aspects of cognitive theory, such as Chomskian psycholinguistics, seemed to undermine a focus on consciousness.  the computer metaphor raised the question of whether computers could be conscious, but also suggested that consciousness was not necessary for "human information processing".  Perhaps consciousness is part of "folk psychology", and that a real scientific psychology will dispense with it after all.

You should know something about Owen Flanagan's symptoms of "conscious shyness": 

A scientific approach to consciousness seeks to provide a public, objective description of private, subjective experience.  This course focuses on five major problems: the mind-body problem, the problem of unconscious mental life, altered states of consciousness, consciousness in nonhuman animals and in machines, and the origins of consciousness.



There's not much in the the various section introductions that isn't covered in more detail in the book as a whole, but they do underscore some concepts that are important:  



Nagel points out that there's "something it's like" to be conscious.  And nobody ever provided a better introspective description of consciousness than William James, and you should know what he meant by each of his "five characters of consciousness": subjectivity, change, continuity, intentionality, and attention.

In the classification of conscious mental states, I begin with Kant: that there are three "absolutely irreducible" mental states: knowing, feeling, and desiring.  That may be wrong, and Frith and Rees may be right that I define "cognition" too narrowly, excluding emotion and motivation, but I don't think so.  If you're going to define cognition broadly to include all mental states, including emotion and motivation, there's no point in having an interdisciplinary cognitive science -- because then cognitive science isn't doing anything that psychology doesn't do.  But you won't be asked to choose between F&R and me on any exam.

Anyway, philosophers and others who rely on introspection often define consciousness in terms of three aspects: qualia, intentionality, and subjectivity. 

I talked briefly about Synesthesia, a condition in which stimulation in one modality elicits sensation in another.  Synesthesia underscores Muller's idea that it's not the stimulus that matters in sensation, but rather where the stimulus ends up in the brain.  More important, synesthesia offers us a concrete example of how objective, behavioral methods can be employed to determine whether, for example, a person really sees digits in color.  

Turning to which, the science of consciousness begins with sensation, which returns us to the matter of qualia.



I endorsed Revonsuo's book, but his organization is very different from mine, so I had to fudge sometimes to find chapters that correspond more or less to my lectures.  Half his book is about various aspects of the mind-body problem, and the book is the kind of thing that you really should read from Chapter 1 to the end.

Chapter 1


Chapter 2


Chapter 3:


Mind and Body

The mind-body problem is Descartes' great gift to philosophy, and you should understand why consciousness makes the mind-body problem as difficult as Nagel thinks it is.

This understanding begins with Descartes's doctrines of substance dualism and interactive dualism.  You should know what these terms mean, and you should understand what the Cartesian impasse is, and how it relates to Levine's "explanatory gap" and Chalmers' "hard problem". 

You should understand the vocabulary of the mind-body debate, such as:
After you've read Searle's book of reviews (see below), you should also be able to relate the contemporary debate to the Cartesian categories, so that you know why Dennett looks like an epiphenomenalist, why Chalmers looks like a property dualist, and why Searle looks a little like a dualist too (but also why he actually isn't one).

After running roughshod over 400 years of philosophical debate, I tried to break down the mind-body problem into four quite different problems.

From Body to Mind

How you get from body to mind: We may not understand precisely how the brain generates conscious experience (and we may not care), but there is now a considerable scientific literature that tries, through neuropsychological and neuroimaging research, to identify the neural correlates of consciousness.  The major point of my lecture is that the neural correlate of consciousness you identify will depend largely on how you define consciousness in the first place. 

From Mind to Body

How you get from mind to body: Here we have placebo and other psychosomatic effects, in which people's specific beliefs, e.g., beliefs as to what drugs they are taking, affect the functioning of specific tissues and organs in the brain. 
You should be able to distinguish between three sorts of psychosomatic effects:
  1. The effects of mental state on another mental state, such as pain (which isn't really a psychosomatic effect).
  2. The effects of mental state on central nervous system activity (which is ambiguous as evidence of psychosomatic interactions, because every mental state has to have some kind of neural correlate).
  3. The effects of mental state on anatomy or physiology outside the central nervous system (and why only this last offers convincing evidence for psychosomatic interactions).

Mind Without Body

Whether you can have mind without body: You should know why both 19th-century spiritualism and modern parapsychology are relevant to the mind-body problem.

Bodies Without Minds

Whether you can have body without mind: You should understand the implications of both behaviorism and philosophical functionalism for the idea that consciousness is not essential for behavior, and that consciousness, even if we have it, might even be epiphenomenal -- a proposition that we took up again in the lectures on "Attention and Automaticity".



In these chapters, Revonsuo focuses on the neural correlates of consciousness.


Chapter 7

Don't worry about the technical foundations of brain-imaging such as PET and fMRI, or between EEG.  The important things to know are the limitations on these methods:


Chapter 9

This chapter focuses, where most scientific investigations focus, on visual consciousness -- because we (think we) know more about vision than about any other aspect of mental life.  Don't worry about the technical details, but do use this chapter as a jumping-off point for thinking about Revonsuo's first discussion question: What would be "the best imaginable NCC experiment"?


The Mystery of Consciousness  

You're reading Revonsuo's Chapters 7 and 9 mostly because we're reading the whole book, and you've got to read these chapters sometime.  The meat here is in Prof. Searle's book, which is intended to give you the flavor of the current philosophical debate over consciousness -- not least because the book shows Prof. Searle debating with a number of important figures, as he reviews their books, they respond to his reviews, and he presents rejoinders to their responses.  

On one past exam, I constructed a "matching" test in which students were asked to match particular philosophers with quotations from their work.  Some students complained about the item, but I actually like it a lot, because, in philosophy at least, individual authors have such distinctive points of view that you ought to be able to identify who's writing from what s/he has written.  So, it is possible that such a "matching" test will appear on some exam in the future.  If you've done the reading seriously, you should be able to match philosophers with their words, and that will allow you to keep track of the debate in the future.  And you'll also get the jokes in David Lodge's Thinks... when you read it on the beach over Spring Break.


Attention and Automaticity

You should understand why attention seems so relevant to consciousness, and the various features of attention:

In this course, we focus on the nature of preattentive, or preconscious, processing.  You should understand the evolution of models of attention, beginning with the implications of the filter models, and the ensuing debate over early vs. late selection. Capacity models of attention attempted to transcend this debate, by asserting that even complex semantic processing could be performed outside of conscious awareness and control, so long as the processes in question were automatized -- thus opening a wider door to preconscious semantic processing.  

You should also understand how automaticity is illustrated in such phenomena as the Stroop effect. 

You should be able to define the four canonical features of automaticity (inevitable evocation, incorrigible completion, efficient execution, and parallel processing) that indicate that automatic processes are unconscious in the strict sense of being unavailable to conscious awareness and conscious control.  And you should be able to talk about dual-process theories in psychology, as exemplified by Kahneman's distinction between "System 1" and "System 2" thinking.

You don't need to know the mathematics of the process-dissociation procedure, but you should understand that the PDP is designed to estimate the contributions of automatic and controlled processes by putting them in opposition to each other.  So, for example, if priming occurs automatically, and unconsciously, subjects should not be able to keep primes from intruding into task performance. 

You should also understand how the social-psychological appropriation of the concept of automaticity returns us to arguments over conscious inessentialism and the epiphenomenalist suspicion -- not to mention the debate over free will.  You should recognize the links between this "automaticity juggernaut", and behaviorism on the one hand, and Dennettian functionalism on the other.  And you should understand that, despite overheated claims that social interaction is overwhelmingly mediated by automatic rather than controlled processes, research -- e.g., studies using the PDP -- shows no such thing.  The most that can be said is that there is a balance between automatic and controlled processes, except under very restricted conditions like a short response window.

In this respect, the Libet experiment has played an enormous role in convincing people that we don't have free will after all -- that, in Wegner's terms, it's an illusion and the "actual causal pathway is from an "unconscious cause of action" to action. You don't have to go into the details of Libet's psychophysiology (I didn't), but you should know what the implications are of the readiness potential and the "predecisional negative shift". You should also be aware of Miller's experiment, which strongly suggests that Libet's findings were an artifact of clock-watching.



The readings from Revonsuo's book, here and there, will also give you another perspective on some of these philosophers -- and also on Searle's own position (if I had been the editor of the Mystery of Consciousness, I would have included Thomas Nagel's review of Searle's own book, The Rediscovery of Mind, plus an exchange between Searle and Nagel).  


Chapter 10

You should focus on:

Not that the others aren't interesting, too!  But with only limited amounts of time, I want you to focus on the philosophers who have addressed the Cartesian impasse, and debated the mind-body problem most vigorously.


Chapter 11

Similarly, there is a discussion of theories of mind and body that connect more closely to empirical science, particularly neuroscience.

  1. Crick and Koch, and especially the distinction between the first and second versions of their theory.

  2. Tononi & Edelman, and their notion of "the dynamic core".

  3. Thalamocortical binding theory, which Edelman also embraces (Koch and Tononi have also endorsed this now).

  4. Damasio's "anti-Cartesian" theory (and why it's anti-Cartesian).

  5. Pay attention also to Revonsuo's "analysis" of this material, pp. 221-224.


The Explicit and the Implicit

The thrust of the automaticity is that certain mental processes can be executed outside of conscious awareness and conscious control.  They are unconscious in the strict sense of the word, inaccessible to introspection and knowable only by inference.  But the conventional view is that the mental states on which these processes operate, and which these processes generate-- sensations, percepts, memories, thoughts, and the like -- are accessible to phenomenal awareness, at least in principle.  But experimental studies of both brain-damaged and neurologically intact subjects indicate that the there is a meaningful way to talk about unconscious sensations, percepts, memories, and the like.

In this literature, pride of place goes to studies of priming in the amnesic syndrome (and other amnesias, such as those associated with ECT and sedative drugs).  You should know how priming is defined, and how it is assessed in tasks such as word-stem completion and word-fragment completion.  You should understand how observations of spared priming in amnesia give rise to the distinction between explicit and implicit memory, and the claim that explicit and implicit memory can be dissociated from each other.  You should also understand how savings in relearning show that explicit and implicit memory can be dissociated in neurologically intact subjects, as well as in amnesic patients.  You should understand the distinction between repetition priming and semantic priming, and the implications for the perception-based and meaning-based knowledge representations that mediate these priming effects. 

You don't have to understand the terminological dispute between the explicit-implicit, direct-indirect, declarative-procedural, and declarative-nondeclarative distinctions in memory.  For our purposes, these are all ways to capture the essential distinction between memories that are accessible to conscious recollection and those that are not, and the point that memory traces of past events can influence ongoing experience, thought, and action even though these events are not -- cannot be --consciously remembered.

The basic priming paradigm can serve as a basis for extending the explicit-implicit distinction beyond memory, to other domains of cognition.  

For example, there is implicit perception, where objects and events influence behavior even though they are not consciously perceived. 

In classic demonstrations of subliminal perception, subjects make discriminative responses to stimuli, or differences between stimuli, that they cannot consciously detect.  In the strictest sense, the term "subliminal" refers to stimuli whose intensities lie below the absolute or relative threshold for sensation. Later experiments on subliminal perception employed tachistoscopic presentations which presented (visual) stimuli for very brief periods of time -- as little as 1 msec.  Instead of being too weak to be consciously perceived, these stimuli were too brief to be consciously perceived.  

In either case, the classic demonstrations were criticized in part on the grounds that the investigators may not have determined thresholds properly --i.e., that what seemed to be "subliminal" stimuli were actually "supraliminal" after all, which is why subjects could respond to them.  Whatever the merits of the threshold-setting procedures in any individual case, you should understand that, underlying this criticism, is a behavioral definition of awareness in terms of discriminative response.  That is, conscious awareness is operationally defined in terms of the subject's ability to make a discriminative response to the stimulus -- if the subject responds discriminatively, then the subject is aware, by definition.  You should understand that the problem with this critique is that the evidence "subliminal" perception consists of the subject's discriminative response to a stimulus of which s/he is not consciously aware.  If conscious awareness is defined by discriminative response, then subliminal perception is ruled out by definition -- which doesn't seem fair, does it?

Simple tachistoscopic presentation isn't ideal for studies of "subliminal" perception, because iconic memory can allow a representation of the stimulus to persist after the stimulus itself has been terminated -- thus, effectively lengthening the duration of the stimulus.  Accordingly, the method of choice in modern studies of "subliminal" perception is to employ a "masking" stimulus which effectively erases the iconic representation.  If the stimulus is immediately followed by the mask (e.g., within 50 msec or so), subjects will have no conscious awareness of the stimulus.  At this point, standard priming techniques take over, and priming effects from masked primes constitute the standard evidence for implicit perception.  In part as a holdover from the old debate over the scope of preattentive processing, the best evidence for masked priming is semantic priming -- priming that must be mediated by a meaning-based representation of the stimulus.

I prefer the term "implicit perception" to "subliminal" perception because unconscious perception can occur in situations where the stimulus is in no sense subliminal.

Even though there is good evidence for semantic priming in at least some forms of implicit perception, you should know that implicit perception is limited, both in terms of the duration of the effect, and in terms of the extent of semantic processing that can be performed preattentively.  

There is also there is, or at least there may be, implicit thought, as exemplified by studies in which subjects' behavior is influenced by the solution to a problem, even though they don't know what the solution is.  Implicit thought is so called because the prime, or other knowledge involved in the effect, is neither a percept (a representation of a stimulus in the current environment) or a memory (a representation of a past event). 

Implicit thought may be relevant to the sequence of incubation, intuition, and insight often encountered in studies of problem-solving.  That is, subjects may have an intuition or "gut feeling" about the solution to a problem; after an incubation period of rest or distraction, the solution emerges into consciousness as an insight.  If so, a reliance on intuition may not be such a bad strategy for problem-solving after all.  Although some theorists have cast doubt on the phenomenon of incubation, more recent research suggests that the concept might be viable after all.

And, finally, implicit learning, in which subjects acquire knowledge through experience (the definition of learning), and use this knowledge in various ways (e.g., various forms of discriminative responding), without having conscious access to the knowledge they've acquired.  

You should be able to distinguish between implicit memory (where subjects can't consciously remember events) and implicit learning (where subjects can't consciously remember newly learned facts and skills).  Implicit memory pertains to episodic memory, while implicit learning pertains to semantic and procedural knowledge.  And you should know how source amnesia, and skill learning in amnesia,  illustrates the distinction between implicit memory and implicit learning.  

These lectures focused on priming, and similar effects, as illustrations of unconscious cognition: implicit memory, perception, thought, and learning.  But, as Kant pointed out, there may be other mental states besides cognitive ones -- states of feeling and desiring as well as states of knowing.  If so, it is possible that we can have unconscious feelings and desires, which affect our experience, thought, and action even though we're not consciously aware of them.  

There is only limited evidence for unconscious emotions and motives, but the evidence for unconscious cognitions suggests that we should not dismiss the possibility out of hand.  So, in the last lecture, I talked about this work, focusing more on the case for implicit emotion than for implicit motivation -- for the simple reason that there's more research on implicit attitudes

Implicit motives, measured by tests such as the Thematic Apperception test ('Picture-Story Exercise") appear to be only weakly correlated with explicit motives, measured by traditional self-report personality questionnaires such as the Personality Research Form.  But this is only half the story. It might be that the lack of correlation reflects just "method variance", as opposed to a true dissociation.  And it might be that the explicit and implicit tests actually measure two different constructs.

Implicit emotion is anticipated by the multiple-systems theory of emotion, which suggests that verbal-cognitive (explicit, conscious) expressions of emotion might be dissociated from overt motor and/or covert physiological expressions (which might serve as measures of implicit, unconscious emotion.  This situation, known as desynchrony, is sometimes observed in clinical situations.  And LeDoux has suggested that the three emotional systems might be served by different brain systems. 

Most of the research on unconscious emotional states makes use of the Implicit Attitude Test.  The IAT is based on the principle of stimulus-response compatibility, and is promoted as a means of revealing unconscious attitudes that are different from those which a subject consciously acknowledges.  And, indeed, the correlation between explicit (self-report) and implicit (IAT) measures of the same attitude are relatively low.  But, as with TAT measures of implicit motives, this is only part of the story. 

The bottom line is that dissociations between various aspects of explicit and implicit cognition (especially memory and perception) lend plausibility to the idea of unconscious motives and emotions, the jury's still out on the proposition that the TAT and IAT are valid measures of them.



Revonsuo, like most researchers in this field, focuses Chapters 4-5 on visual consciousness.  There are a lot of interesting phenomena here, and we could spend an entire course on them.


Chapter 4

In my view, Revonsuo's treatment of these neurological syndromes is good, but -- as with his earlier discussion of inattentional blindness and change blindness -- he ignores a crucial question -- to wit, Can the brain-damaged patient process visual information of which he is unaware?  This is the question of the dissociation between explicit and implicit perception.


Chapter 5

Revonsuo takes up the question of unconscious influence in Chapter 11 (but my point is that it's relevant to Chapter 10, as well). 

This whole literature on explicit-implicit distinctions began with work on implicit memory, and I don't understand why Revonsuo doesn't give this phenomenon more attention.  Just two crummy sentences on p. 127!  Still, he does a good job of capturing the gist of how theorists conceptualize the nature of explicit-implicit dissociations, in terms of separate pathways, connections to a consciousness module, or (and much, much less interesting) degraded processing.



Questions and Comments

As you prepare for the exam, feel free to post questions to the "Midterm Exam" discussion board in the course website.  


This page last revised 10/17/2014.