Consciousness

What’s it all about?

Inattentional Blindness

Linking perception and attention What (if anything) do we perceive w/o attention?

Mack & Rock (1998) Participants engaged in another task have an element added at

one point Example: judge which line is longer, but add a critical stimulus on

a later trial. After critical trial participants are asked if they noticed anything unusual (very quick experiment)

+ +.

Change blindness

Outside world as an external memory to be probed by our senses (O’Regan)

Just like certain memories are not readily available unless ‘looked’ for, elements of the environment may not be perceived without attention How would you check whether you were seeing

all elements in a scene? By attending to them

Although it seems as if we are perceiving the world as is, we are only getting info which is attended to The refrigerator light is always on

Such findings from CB and IB suggest there is no conscious perception without attention There is no sound from the tree falling, if no one is

around to attend to it!

We have looked at the problem of how much info gets through, and know that even without conscious focusing of attention we do in fact perceive and are influenced by information in the environment Recall Mackay and Sternberg studies

Shift focus Of what are we aware?

Perception, Attention and Awareness are intimately related to one another

What does it mean to be aware of something? What is consciousness?

“Its meaning we know so long as no one asks us to define it” (James)

Consciousness

Broad definition: Awareness of both environmental and cognitive stimuli Sensations, thoughts, memories etc.

Minds, Brains, and Consciousness Brain: bunch of goo in our noggins Mind: the sum of brain functioning of the

brain, i.e. what the brain does Consciousness: ?

The Problem of C

How can it be studied? Can it be? What is its function/purpose? Is it unitary? What do we know? What do we not know?

Properties of Consciousness

James starts us off by giving four characteristics of consciousness

Subjective “Every 'state' tends to be part of a personal consciousness.”

Changing “Within each personal consciousness states are always

changing.” Continuous

“Each personal consciousness is sensibly continuous.” Purposeful

“It is interested in some parts of its object to the exclusion of others, and welcomes or rejects -- chooses from among them, in a word -- all the while.”

Properties of Consciousness

Emergent Like the liquidity of water or solidity of objects Not a property that the parts of the system which

create it possess, nor just the sum total of the parts

Irreducible? Some (e.g. Searle) claim that the subjective

nature of C leads to the distinction that it is not able to be reduced to the parts that cause it

The ‘hard’ problem of subjectivity Third-person data

Wakefulness Perceptual discrimination Integrated control Access & self-monitoring Verbal Reports Focused attention

Data re underlying brain processes

“The easy problems”

First-person data Visual experiences e.g.

color, depth, … Other sensory experiences e.g.

sound, taste, … Bodily sensations e.g.

pain, orgasm, … Mental imagery e.g.

recalled visual images, … Emotional experiences

e.g. happiness, anger, … Stream of occurrent thought e.g.

reflection, decision, …

All are states of subjective experience: there is something it is like to have these states.

The “hard problem”.

Example: Musical Processing

Third-person data Sound wave patterns Processes in auditory cortex Behavioral reactions Verbal reports (actual and potential)

First-person data Musical experience

Related: qualia Properties of objects related to the subjective experience of the object (the

redness of red)

Hard Problem

What is it like to be a bat? Nagel, Chalmers and other philosophers suggest in

varying degrees that subjective experience is not reducible, and yet is necessary for a complete account of consciousness

However, does this keep us from even attempting to study Consciousness? Can we construct a theory of C without including what it is

like to have C?

The irreducibility of C

Considerations Does your heart pump blood differently (in kind) than does mine?

Subjective experience is assumed to be at least correlated w/ brain functioning, if our brains are similar one would think our personal experiences are similar though colored by our own history (e.g. your ‘redness of red’ is similar to mine [similar eyes, visual cortices] but will call on different memories, emotions, thoughts etc.)

This would at least allow for the possibility of study/comparison/ generalization

Private experiences can be expressed publicly Now a means for at least some inference is available, verbal report

should have some correlation with subjective experience

So in a sense we do have indirect access to the personal from which insights might be gained Much like electrons, planets in other solar systems etc., we can ‘observe’

the personal indirectly

The irreducibility of C

On the other hand.. How well can we even know our private experience?

The psychological uncertainty principle Observing the contents of consciousness necessarily change that

experience Subjective experience is unable to be verified

PUP Verbal report wouldn’t be completely accurate (our own understanding of the

workings of the mind can be incorrect) No 1 to 1 mapping of verbal report to experience

So on the one hand we have (indirect) access to subjective experience but it is problematic

Suggestion: Construct a theory of consciousness that will allow for evaluation and

testable predictions (like we do with everything else in science)

Properties of Consciousness

Variable States of C Vs. UnC

Serial and limited capacity We can only be conscious of one thing at a time

(which we are attending to) There are a great many things that we are not

conscious of

Properties of Consciousness

Widespread Access In spite of limitations, consciousness has access to wide

variety of knowledge, skills and actions Can influence activation of UnC content and even

physiological functioning (biofeedback) Constructive?

Are UnC states simply in waiting, biding their time until the ‘threshold’ of C is reached?

Or is C some sort of construction of pre-C structures to deal with the present environmental situation? Activated schemas are not themselves C, but contribute to the

C experience

Active, analytic consciousness on a continuum of degrees of consciousness Focal awareness (the focus of attention)

Reflective Primary

Peripheral awareness accessible by a shift of attention

Unconsciousness Subconscious (accessible to conscious awareness) Nonconscious (not accessible)

Levels of Consciousness

Subconscious Not in awareness Not necessarily retrievable into awareness by will Influences current processing

Nonconscious Not in awareness Not retrievable by will Not necessarily influencing current processing

Perhaps better(?) distinction: C and Not-C

Unconsciousness

Conscious vs. Unconscious

On the Relation between Conscious and Unconscious

Freud’s View Active repression of unconscious Conscious distortion

Cognitive View Lack of activation, not active repression No special distortion

Metaphors of Consciousness

Activation threshold Novelty Spotlight Theater

Activation threshold

Activation of UnC content reaches threshold and becomes conscious

Problems Redundancy effect: repeated and predictable

stimulation can lead to UnC processing Automaticity

Goes against idea of C as a construction

Novelty

Novelty Change in the environment (dishabituation) Disconfirmation of expectation (surprise) Violation of skilled routines (interruptions in the flow of

action Consciousness functions to direct attention to

maximize adaptation to novel and significant events Like the activation threshold metaphor, does speak

to a function of C, but doesn’t allow for a complete picture

Spotlight

Bringing things into focus (thoughts, objects in the environment), the selective nature of consciousness

Questions remain: How is the focus determined?

Why this content and not others? Once it is selected, what happens to the info?

Is there further processing (e.g. semantic), does it go to motor systems

What does it mean for content to be conscious?

Theater

Whatever is on the conscious stage is available to a large (UnC) audience

Various processes (e.g. executive:director) operate behind the scenes to control how consciousness plays out.

Functions of Consciousness

Choice and selection of action Modification and evaluation of long-term

plans Adaptation to novel events Retrieval from long term memory Construction of storable representations of

current activities and events Reflective, Self-monitoring Troubleshooting/error detection

Functions of Consciousness

Choice and selection of action Can recruit subgoals to organize and carry out action to the

attainment of a primary goal Prioritizes, makes some info more accessible to

consciousness Executive function

Not an executive system but the executive system has access to it, and so UnC processes are affected

Modification and evaluation of long-term plans Alternative actions considered and different outcomes

evaluated

Functions of Consciousness

Adaptation to novel events More novelty more conscious effort needed to

process Retrieval from long term memory

C not necessary for retrieval but can be used to retrieve information necessary to the situation

Construction of storable representations of current activities and events Information stored and retrieved for future

comparisons of present and past

Functions of Consciousness

Reflective, Self-monitoring Through inner speech and imagery we can control

C and UnC functioning Troubleshooting/error detection

Conscious resources may be activated when other processes (often UnC) are interrupted or breakdown

Scientific Approaches to the Study of Consciousness Consciousness as a variable: studies look at

different types of stimulation (C vs. UnC), memory (C vs. UnC), brain damage, wakefulness vs. other states etc. Attention and automaticity Subliminal perception Implicit learning and memory Neuropsych, neurobiolgical

An inferred construct like attention, working memory etc.

Scientific Approaches to the Study of Consciousness Operational definition (from Baars, 2003).

Conscious processes are events that Can be reported and acted upon With verifiable accuracy Under optimal reporting conditions

Little delay between event and report Which are reported as conscious

Contrast with ‘fringe consciousness’ (e.g. familiarity)

Scientific Approaches to the Study of Consciousness An UnConscious event is that in which

Knowledge of its presence can be verified Even if that knowledge is not claimed to be

conscious And it cannot be voluntarily reported, acted on, or

avoided Even under optimal reporting conditions

Distinctions in cognitive psychology Conscious

Mediated Strategic control Limited capacity Voluntary Declarative memory Supraliminal Novel stimuli Wakefulness, dreaming Episodic Explicit cognition Attended stimuli

UnConscious Immediate Automatic No capacity demands Involuntary Procedural Subliminal Routine, predictable Deep sleep, coma Semantic Implicit cognition Unattended input

Return to subjectivity

Philosophers who suggest that science will never solve the problem of subjectivity essentially do not allow for comparisons of subjective states In doing so are not allowing consciousness to be conceived of as

a variable to be studied However the scientific study of C is studying the subjective

nature of consciousness, assuming what a person reports and the findings seen have at least some correlation to what a person experiences Could we possibly assume that it had no correlation whatsoever?

Regardless of the ‘hard problem’, scientific study of consciousness is routinely carried out and knowledge gained

Some findings: Vision

Blindsight People with damage to visual cortex can

nonetheless ‘see’ objects in their environment

Milner and Goodale (1995) suggest that there are two vision systems: visual perception and visuomotor control. Only the former is involved in conscious

awareness. Example:

Patient shown a circle with lines inside will report not seeing anything

Asked to indicate whether the lines are horizontal or not, patient can respond above chance

Some findings: Vision Split-brain patients

Left half doesn’t know what the right is doing Hemispheric Lateralization

Motor control right brain - left side left brain - right side

Visual field right brain - left visual field left brain - right visual field

Lateralization of function Primary language areas on left, in most people

The split brain

Hemispheric coordination by means of the corpus callosum Disconnecting the Hemispheres

Treatment for Epilepsy Commissurotomy

Now they only snip anterior part of the CC

Normal responses under normal conditions or only subtle effects seen

Unusual responses under laboratory controlled conditions If something is displayed to the LVF, the person cannot name (is

not aware of) the object Information from the right hemisphere does not get to the left

The can however reach for the correct object with their left hand

The split brain

So really, only the left side can report being conscious at all At least initially, the right can learn to speak to some extent also,

and is already implicated in aspects of language such as metaphor and humor

So right brain is largely mute, but inability to speak is not the same as lack of consciousness However the language - consciousness-as-we-know-it link is

strong. Perhaps it is language that allows us to get a sense of self…

"When I learned the meaning of 'I' and 'me' and found that I was something, I began to think. Then consciousness first existed for me". ~Helen Keller

At the very least suggests consciousness-as-awareness is not unitary

Some findings: Vision

Hemineglect Cannot attend to info in half

the visual field Can still make same/different

judgments above chance Can still show priming effects

for stimuli in the neglected hemifield

Some findings: Attention

Mackay (1973) Unattended information is processed for meaningful content,

though this happens subconsiously Schneider & Shiffrin (1977)

Automatic vs. controlled processes Automatic operates independently of subject’s control, and

independent of attention; Does not use up processing resources Findings discussed regarding change blindness and inattentional

blindness suggest attention is a necessary component to consciousness awareness No attention means no awareness However may also suggest that what we think consciousness is

may be way off

Some findings: Memory

Tulving’s (1985) Types of Memory related to Consciousness Anoetic consciousness

Neither awareness of knowledge nor of personal engagement (procecdural)

Remembering how to do things Noetic

Awareness of knowledge based on experience, but without awareness of personal engagement (semantic)

Remembering what it is Autonoetic

Awareness of personal engagement in remembered events and experiences (episodic)

Memory for a specific episode of experience

Some findings: Memory

Schacter et al. (1986) Hippocampal involvement in conscious

recollection of studied words Reber (1989), Shanks & St. John (1994)

Implicit & Explicit learning and memory (or not) Learn materials, skills consciously, the details

may not reach awareness

Some findings: Memory

Retrograde Amnesia Failure to remember events prior to injury Often caused by head trauma

Anterograde Amnesia Failure to remember events experienced after injury

H.M. Korsakoff’s syndrome Selective brain injuries

Priming can be as good for amnesiacs as for controls “Procedural memory” like that in Towers of Hanoi

H.M.

H.M. Surgical removal of hippocampus on both sides of brain to

treat epilepsy Retention of ordinary short-term memory Retention of information from before operation Failure to learn new information Unable to find his way to his new home unless he can see

the location of the house Has normal initial conversations but has no memory of the

meeting if the person leaves and returns Shows learning of mirror-tracing, but has no memory of

doing so

States of Consciousness

Normal Waking State The “stream of consciousness” Daydreaming

Altered States of Consciousness Near Death & Out of Body Experiences Meditation & Sensory Deprivation Hypnosis Sleep Other Induced States

Drugs Activities

States of Consciousness

Anesthesia At what point is Consciousness ‘turned off’? Thalamus (e.g. Alkire, Haier & Fallon, 2000)

Drugs in general produce a wide variety of ‘states of consciousness’, from nicotine to heroin

Activities (sex, running) can also produce changes in brain states and thus conscious states

Sleep and dreams

Dreams Dreams as a form of thinking Mnemonic activation Lucid (LaBerge et al., 1981)

Characteristics Sleep mentation

Thoughts while sleeping Dream qualities

Imagery Temporal progression Narrative coherence

When Dreams Occur

Hypnagogic State Onset of sleep May be characterized by vivid imagery

NREM Sleep 10-40% yield dream reports Often static images or isolated thoughts

REM Sleep 80-90% yield dream reports Usually images in a narrative

Dreams as a Form of Thinking

Dreams are symbolic acts Dreams are based on what we know

Children have simpler dreams than adults (or lack the language to describe the complexity)

Dreams use dissociated pieces of memory and knowledge

Dreams are organized Dreams have realistic features

People are people; objects are real

Diffuse Memory Activation

Dream elements are activated on a haphazard basis, due to residual activation from daytime, passive associations, etc.

In contrast to Freud, elements are not activated by underlying sexual desires

Meditation

Meditation Concentrative meditation

Emphasis on limited attentional focus Mindfulness meditation

Emphasis on heightened attentiveness Common Goal

Break down habitual modes of thinking Lama in the lab (Shambhala Sun, 2003)

Memory test

DogBuildingBridgeCoinShoeMovieLoveDiskYellowGameChairForestThinCowardCarDiamond

How many words do you remember?

Which color was presented?

Fringe of consciousness

Familiarity, tip of the tongue etc. Characteristics: vague, inarticulate, elusive

Menu bar metaphor (Mangan, 2003) Much info available but not currently displayed due to

limited capacity of C Fringe remains on the periphery of what is consciously

attended Tradeoff between the need to articulate detail and the need

to represent the larger context within which it is embedded

Theories of Consciousness

Cognitive Theories As a component of an information processing

system As a process in an information processing

system As a state of activation

Neural Theories As a component of the brain As a process of the brain As a state of activation

Cognitive Theories The Human Information Processing System

based on a computer metaphor the mind as composed of components or modules

Consciousness as a component within the information processing system

Human Information Processing Symbolic Representations/Manipulation Flow of Information Control of Processing Processing Modules

Sensory Register Working Memory Long-term Memory

Elements of Information Processing Sensory Registers Memory

Short-term (active, working) memory Long-term memory

Executive controller attentional focus

Response generator

Senso

ry Reg

isters

Long-TermMemory

Respo

nse Gen

erator

WorkingMemory

Executive Controller

Sensory registers Large capacity Briefly available

Working memory Verbal, Visual-spatial processing Limited capacity

LTM Associative network Retrieval of stored information by retrieval cues

Executive Control Some part of the system needs to set priorities, select actions,

evaluate outcomes Attentional Focus Planning and Selection of Tasks

Cognitive Theories of Conciousness DICE Shallice’s info-processing model Global Workspace

Dissociable Interactions and Conscious Experience Schacter (1989) Distinguish processes involved in conscious identification and

recognition from those involved with other types of information (e.g. linguistic, perceptual)

A number of knowledge modules connect to a conscious awareness system, which is itself connected to an executive system

DICE

Consciousness arises in Conscious Awareness System

Most information processing performed by semi-autonomous cognitive modules

Output from modules may provide input to other modules which influence their functioning, yet no conscious awareness of this process

DICE

Engram Transient or enduring changes in the brain resulting from

encoding and experience

Events are recorded by strengthening connections of those neurons involved in the encoding process, with different parts of the brain involved in different kinds of sensory experience (e.g. occipital for vision)

Each memory associated with many neurons being activated at once

DICE Conscious awareness system can activate otherwise dormant

engrams for conscious recall and then voluntary action by means of the executive Assumes independent memory modules and a lack of direct

conscious access to procedural details. Consciousness interacting with separable knowledge modules

transmits the information from modules to the executive Performs no executive function but serves as gateway to the

executive system Conscious experience results from global awareness of

composite output from these cognitive modules entering CAS

Ok as a starting point, but perhaps not so great as an overall theory of consciousness (e.g. explaining limited capacity, attentional control etc.)

Shallice’s Information Processing Model of Consciousness Consciousness as control of action Aspects of Shallice’s model

Modular (as with DICE) Contention scheduling system that selects among a large

set of action and thought schema based on activation/inhibition factors

A supervisory system that processes the output of the contention scheduling system, correcting for novel or surprising situations

A language system to represent the operations of the supervisory or specialist systems

Episodic memory component containing event-specific information

Shallice

C does not reside in any one component, but instead the contents of C correspond to the info flowing between these systems and the rest of the cognitive system

Baars’ Global Workspace

Based on the theater metaphor

C as a global broadcasting system disseminating info throughout the brain.

More well-developed model of C

Global Workspace: Components Experts

Specialized experts from single neurons to networks or systems of neurons

Efficient, and working together and with other networks, suffer little in the way of capacity limitations

Receive global messages and through various interactions and activations can control perceptual processes that may place content in consciousness

Global Workspace: Components Global Workspace

Architecture capable of system-wide integration and dissemination of information

Corresponds to conscious contents Likely neural correlate is the thalamus

Context Powers backstage Structures that constrain conscious content without being

conscious themselves May involve momentary or long-lasting goals Can shape and be shaped by conscious events

Global Workspace

1.Conscious perception enables access to widespread brain sources; unconscious sensory processing is much more specific. 

2.Conscious perception, inner speech, and visual imagery enable working memory functions;  there is no evidence for unconscious access to working memory.

3.Conscious events enable almost  all kinds of learning: episodic and explicit learning, but also implicit and skill learning.

4.Conscious perceptual feedback enables voluntary control over motor functions, and perhaps over any neuronal population and even single neurons.

5.Conscious contents can evoke selective attention.  6.Consciousness enables access to "self" -- executive

interpreters, located in part in the frontal cortex.

Dennett’s critique

The theater cannot be localized No place in the brain where it all comes together

(like Descartes’ pineal gland) Response:

No one really said it had to be in the first place

Further thinking

http://nivea.psycho.univ-paris5.fr/ASSChtml/kayakflick.gif

The results from such findings as change blindness may suggest a different way of thinking about consciousness

No continuous stream as previously and widely thought?

Blackmore article

Further thinking

During fixation, brain briefly stores the gist of the scene (not the details*) and new info is compared and previous representation updated Leads to feeling of continuity Simons and Levine

No representation stored at all, but instead virtual representations are created of just the object we are paying attention to Nothing else is represented, but we get the impression that

everything is there because a new object can always be made “just in time” whenever we look

Rensink

Further thinking

No internal representations at all because the world is always there to be referred to Seeing is a way of interacting with the world, a kind of

action. What remains between eye movements is not a picture of the world but the information needed for further exploration

O’Regan The underlying theme of these views is that

searching for the neural correlates of the detailed, picture in our heads is fruitless because there is no such picture

Further thinking

“Perhaps the answer here is to admit that there is no stream of conscious experiences on which we act. Instead, at any time a whole lot of different things are going on in our brain at once. None of these things is either “in” or “out” of consciousness but every so often, something happens to create what seems to have been a unified conscious stream; an illusion of richness and continuity” (Blackmore)

It is possible that the experience of consciousness is created the moment we look, and there never was either a conscious self or a stream We can’t ever catch ourselves not being conscious, as soon as we ‘look’ we are The refrigerator light is always on Can’t prove you actually had a dream

So the trick now is not determining how neural firings give rise to consciousness, but instead figuring out how the illusion is created

Philosophical Aside

Mind - Body Problem Monism

Idealism There are only mental things (minds)

Materialism There are only material things (bodies)

Dualism There are both minds and bodies

Questions for Dualism

How are minds and bodies related? interactive substance

Minds and bodies interact with each other psychophysical parallelism

Minds and bodies act in parallel, but do not interact

Cartesian Dualism

Two kinds of substance, mind and matter Mind

Not material substance (Immaterial) Not extended in space

Matter (Body) Physical substance Extended in space

Problems for Descartes

How can non-material mind influence material body? Pineal gland (obviously)

How can mind be localized to body? Why does consciousness vary with variation

in bodily states?

Churchland’s Critique

Dualism is not parsimonious Postulating one kind of thing is simpler than

postulating two kinds of things Dualism is unable to explain the things we

are interested in Understanding perception, memory, and

judgment, as well as physiological states has been made possible in terms of material explanations

Other stances

Emergentism (property dualism) “Mind emerges from brain”

Interactionism Developed by Roger Sperry, who devised the “split brain” procedure If mind “emerges” from the brain at some level of development or

some level of activity, what kind of thing is it? Does mind exert an influence on the body, or is it just another kind of

psychophysical parallelism?

Epiphenomenalism “mind” is caused by brain but has no effects on physical events C as by-product of brain, (zombies!) But… it certainly doesn’t seem that way!

Other stances

‘Cogpsychy’ notions Functionalism

Define mental states and processes in terms of the their causal relations to behavior but stop short of identifying them with their neural realizations

The computational mind “mind is the function of the brain”

Mind is the software; brain is the hardware Dennett Intentional states involve symbolic representations

John Searle’s argument against computational mind mind cannot be computational because a program has only

syntax and no “content”. The Chinese Room analogy

Reductionistic stances

Eliminative materialism Folk psychology is not just off, but wrong All the mental states we take for granted are not there

Identity theory “mind = brain” Denies the existence of non-physical substances Experiences just are brain processes, not merely correlated with

brain processes. Possible problem:

A subjective experience is different from the brain state that is correlated with it E.g., our experience of a dream is not the same thing as the

observation by others of an REM state in our sleep

Other Minds

Does consciousness occur in other entities? Determining if something is conscious

argument from analogy argument from behavior

introspection intelligent behavior self-awareness

argument from theory

Other Minds, cont’d

Origin of consciousness in human development When does a child become conscious?

Origin of consciousness in evolution What animals are conscious? When did hominids become conscious?

Origin of consciousness in functional complexity Can a computer be conscious?

Can consciousness be separated from the biological processes that give rise to it? Can we imagine the consciousness of a bat?

Consciousness as a biological phenomenon John Searle

Other Minds:What’s it like to be a bat?