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Cognitive Processes


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The term "cognition" refers to all processes by which the sensory input is transformed, reduced, elaborated, stored, recovered, and used. It is concerned with these processes even when they operate in the absence of relevant stimulation, as in images and hallucinations. The presentation discusses various cognitive processes; such as, cognition,concept,language,learning,memory,perception,sensory registration,thinking, etc.

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Cognitive Processes

  1. 1. Cognitive Processes Ari Sudan Tiwari, Ph. D.
  2. 2. 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
  3. 3. 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
  4. 4. 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
  5. 5. 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
  6. 6. 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
  7. 7. 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
  8. 8. 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
  9. 9. Attention Attention is a selective process to bring certain stimuli into focus of consciousness among a number of stimuli present in the perceptual field.
  10. 10.  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
  11. 11. Perception Perception is the process of organizing and interpreting patterns of stimuli in the environment.
  12. 12. 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
  13. 13. 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
  14. 14. 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
  15. 15. 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
  16. 16. 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
  17. 17. 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
  18. 18. 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
  19. 19. Learning  Change in behaviour: Adaptive or maladaptive  Occurs through practice and experience  Does not occur through maturation, fatigue or species-specific behaviour  Relatively permanent
  20. 20. 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
  21. 21. 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
  22. 22. Experimental phenomena of classical conditioning  Extinction  Spontaneous recovery  Reconditioning  Stimulus generalization and discrimination
  23. 23. Theory of instrumental conditioning: B. F. Skinner Behaviour Change in the environment Desirable Undesirable Increases the likelihood of behaviour Decreases the likelihood of behaviour
  24. 24. Paradigm of instrumental conditioning Nature of the event following a response Appetitive Aversive Consequenceofa 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)
  25. 25. 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
  26. 26. Observervational learning: Albert Bandura  Attention  Retention  Motivation  Production LATENT LEARNING
  27. 27. Memory Sensory Register Short Term Memory Long Term Memory Duration Vision: 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
  28. 28. 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
  29. 29. 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)
  30. 30. Amnesia Loss of memory which remains unexplained with the normal process of forgetting
  31. 31.  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
  32. 32. 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
  33. 33. Improving memory  Mnemonics: Acronyms  The Method of Loci  Deeper level of analysis: Association and elaboration of information  Chunking  Making story by relating items
  34. 34. Thinking and language Thinking  Cognitive rearrangement and manipulation of  Information from environment  Symbols stored in LTM  Cognitive process mediating between stimuli and responses
  35. 35. 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
  36. 36. 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)
  37. 37. 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
  38. 38. 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
  39. 39. 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.
  40. 40. 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
  41. 41. Decision making  Making choice among several alternative solutions  Comparative evaluation of alternatives  Theory of bounded rationality: Satisfycing decisions (Sufficiently Satisfactory Decisions)
  42. 42. Thank You