Cognition Processes

Ari Sudan Tiwari, Ph. D.

Sensory Processes: Registration of sensory inputs

Transduction: Conversion of physical energy into electric voltage by receptor cells (Receptor Potential)

Sensation: Identification of physical energy

Generator Potential (Nerve Impulse) : Transmission of nerve impulse through afferent codes to the respective region of the brain

Vision: Structure and function of eye

Cornea

Pupil

Iris

Lens

Ciliary Muscles

Vitreous Humors

Retina (Cone and Rods)

Fovea Optic Disc

Occipital Lobe of the Neo-cortex

Hearing: Structure and function of ear

Pinna

Auditory canal

Eardrum (Tympani membrane)

Ossicles:

Malleus, Incus, Stapes

Oval window

Cochlea

Cochlear nerve

Temporal lobe of neo-cortex

Smell

Smell Receptors: reactive to chemical energy

Location of smell receptors: In the roots of nasal

passages leading from the nostrils to the throat

Olfactory bulb

Taste

Taste Receptors (Taste buds): Reactive to chemical energy

Location of Taste Buds : Mostly on the tongue; Some of them at the

back of mouth and in the throat,

Primary Tastes: Salty, Sour, Sweet and Bitter

Location

Tip and sides of the tongue

Sides of the tongue

Tip of the tongue

Back of the tongue

Responsive to

Salty solutions

Sour stimuli

Sweetness

Bitter

Taste

Skin

The skin senses: Touch and pressure sensation

Sensitivity variation in various parts of the body: Tongue, lips, face, hands most sensitive; arms, legs, trunks least sensitive

Temperature (Cold and warmth) Sensation:

Variation in temperature of skin surface

COLD WARMTH

Pain Sensation:

Skin and interior of the body

32°C-----33°C

Attention

Attention is a selective process to bring certain stimuli into focus of consciousness among a number of stimuli present in the

perceptual field.

Attention is selective process

Limited capacity perceptual system

Selection of certain stimuli for deeper level perceptual analysis

Filtering of other stimuli

State of readiness and responsiveness

Limited span

Fluctuation and shifting

Division of attention

Characteristics of attention

Perception

Perception is the process of organizing and interpreting patterns of stimuli in the environment.

Form perception

Figure- Background: Perception of a figure/object standing out of a

background

Contours: A marked or abrupt change in brightness or colour in the

visual field which separates figure from the background

Physiological process in contour formation: Differential distribution of

light energy across the retina

Camouflage: Continuous change in brightness and colour; contours

broken up; difficult to distinguish object from the background

Gestalt principles of perceptual organization

1. Law of proximity

2. Law of similarity

3. Law of symmetry

4. Law of continuation

5. Law of closure

6. Law of common fate

Gestalt (Whole): Tendency to perceive the sensory field as organized as possible/situation allows

Visual depth perception

Meaning

Relative distance of the objects

Depth in the surface of the objects

Paradox of sensory process

Flat retinal surface : Perception of depth and distance

Use of cues coming from sensory inputs

Cues in depth perception

Binocular Cues Retinal disparity Accommodation and adjustment

Monocular Cues Linear perspective Clearness Interposition Aerial perspective Texture gradient Size of the retinal image

Perceptual constancy

Brightness Constancy

Size Constancy

Unconscious Inference

A ratio between the retinal image and distance of the object is

calculated unconsciously

This ratio is constant across situations; therefore, perceptual

constancy

Movement perception

Real movement: Movement of stimulation across the retina despite steady eyes (movement of retinal image)

Apparent movement: Perception of movement in the absence of physical of an image across the retina

Stroboscopic motion: Successive pictures of a moving scene: perception of a smooth action (kind of perception in the movies)

Auto kinetic effect: Staring at a small stationary spot of light in a completely dark room: The spot appears to move

Induced movement: Movement in the framework induces perception of movement in the object

Plasticity of perception

Modifiability of perceptual ability along the

developmental period

Sensitive period of perceptual development

Individual Differences in Perception

Perceptual learning: Environmental richness

Set

Motives and needs

Cognitive styles: Field dependent-independent

Learning

Change in behaviour: Adaptive or maladaptive

Occurs through practice and experience

Does not occur through maturation, fatigue or species-specific

behaviour

Relatively permanent

Theory of classical conditioning: Ivan P. Pavlov

When a neutral stimulus (conditioned stimulus, CS) is

paired with a natural stimulus (unconditioned stimulus,

UCS), neutral stimulus alone acquires the ability to elicit

the response (conditioned response, CR) which naturally

occurs (unconditioned response, UCR) after natural

stimulus

Paradigm of classical conditioning

Stimulus Response

Neutral/Conditioned Stimulus No response

Natural/Unconditioned Stimulus Unconditioned response

Continuous pairing of the two stimuli

Neutral/Conditioned Stimulus (alone) Conditioned response

Experimental phenomena of classical conditioning

Extinction

Spontaneous recovery

Reconditioning

Stimulus generalization and discrimination

Theory of instrumental conditioning: B. F. Skinner

BehaviourChange in the environment

Desirable

Undesirable

Increases the likelihood of behaviour

Decreases the likelihood of behaviour

Paradigm of instrumental conditioning

Nature of the event following a response

Appetitive Aversive

Consequence of a

response

Onset of event

Positive reinforcement (Increases the likelihood

of behaviour)

Punishment(Decreases the likelihood

of behaviour)

Termination of event

Omission of reinforcement

(Decreases the likelihood of behaviour)

Negative reinforcement (Increases the likelihood

of behaviour)

Cognitive learning

Learning without being involved in any active process

Selection of information from the environment

Making alterations in the selected information

Associating the items of information with each other

Elaborating information in thought

Storage of information

Retrieval of information when needed

Observervational learning: Albert Bandura

Attention

Retention

Motivation

Production

LATENT LEARNING

Memory

Sensory Register Short Term Memory Long Term Memory

DurationVision: Up to 1 second; Auditory: Up to 5 Seconds

Up to 30 Seconds Days, months, years or lifetime

Capacity Relatively large: Up to 16 items

Relatively small: Up to 7±2 chunks

Unlimited

Transfer Process

Attention and recognition: Attended and eecognized items transfer into STM

Rehearsal: Rehearsed items transfer into LTM -

Type of Information

Copy of input Sounds, visual images, words, sentences

Semantics, life events

Process of Forgetting

Decay of trace Displacement of old information by new one

No real forgetting; Faulty organization of information, Inappropriate retrieval cue, Interference

Type of long term memory

Semantic memory

Words and meanings; relations among words; rules of use in

language and thinking

Storage in highly organized and associative manner

Stable in nature

Episodic memory

Memory of events in our lives in relation to the time and place

of their occurrences

Forgetting

Loss of information from the memory store

Process of forgetting

Decay of trace

Displacement of information

Retrieval problems

Interference

Forgetting B(Proactive interference)

Learning A Learning B

Forgetting A (Retroactive interference)

Amnesia

Loss of memory which remains unexplained with the normal process of forgetting

Childhood Amnesia

Childhood thought characterized by guilt: arousing sexual and aggressive urges: Repressed and forgotten

Retrieval cue failure

Childhood brain is not mature enough for Long Term Memory

Dream Amnesia

Freudian explanation

Retrieval cue failure

Different biological states

Psychological amnesia

Biological amnesia

Global amnesia: Global loss of memory

Retrograde amnesia (Forgetting of events previously exposed to) and anterograde amnesia (Inability to encode and store new information)

Alcoholic amnesia

State dependent forgetting, prolonged alcoholism (Korsakoff syndrome) vitamin-B deficits, chemical imbalances and irreversible brain damages

Diseases of brain

Senile dementia and Alzheimer’s disease

Improving memory

Mnemonics: Acronyms

The Method of Loci

Deeper level of analysis: Association and elaboration of

information

Chunking

Making story by relating items

Thinking and language

Thinking

Cognitive rearrangement and manipulation of

Information from environment

Symbols stored in LTM

Cognitive process mediating between stimuli and

responses

Thinking and language

Images and thinking

Images are mental representation of environmental objects

We use images in our thought process as replacement of

the environmental objects

Thinking and language

Language and thinking

Language is the representative symbol

Stored in semantic LTM

Talking to oneself under ones breath

Linguistic Relativity Hypothesis: Whorf (1956)

Creative thinking

A novel and unique way of conceptualizing the world

Insight: Sudden appearance of new ideas

Stages of creative thinking

1. Preparation: Formulating problem and collecting facts

2. Incubation: Obstruction in thinking; Lack of motivation

3. Illumination: Insight; Sudden solution

4. Evaluation: Testing whether idea works or not

5. Revision

Creative thinking

Nature of creative thinking and thinkers

Divergent and autistic thinking

Prefer complexity

Greater independence in judgment

Self-assertive and dominant

Suppressed mechanism for the control of impulses

Origence

Concepts

Development of concepts

Discrimination learning

Observing examples in different contexts

Definitions of concepts

A symbolic construction of group of objects or events

representing some common features combined according to

specific rules.

Problem solving

Problem: Obstruction or difference between present and goal status

Problem solving: Behaviour targeted to remove obstruction and

difference between present and goal status

Rules in problem solving

Algorithms: Set of rules, if followed correctly guarantee solution

Heuristics: Strategies based on past experiences with problems, likely

to lead to solution; but do not guarantee solution

Decision making

Making choice among several alternative solutions

Comparative evaluation of alternatives

Theory of bounded rationality: Satisfycing decisions

(Sufficiently Satisfactory Decisions)

Thank You