Post on 26-Jun-2015
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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