Higher functions of brain.learning memory

1. DR NILESH KATE
MBBS,MD
ASSOCIATE PROF
ESIC MEDICAL COLLEGE, GULBARGA.
DEPT. OF PHYSIOLOGY
HIGHER
FUNCTIONS OF
BRAIN.

2. LEARNING & MEMORY
 Learning – Neural
mechanism by which
individual changes
behaviour on the basis of
past experience.
 Memory – Acquisition ,
storage & retrieval of
sensory information
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3. LEARNING .
 Reflex learning.
 Associated with
immediate behaviour
change.
 Incidental learning.
 Behaviour change not
immediate
 But person gets
information from
sensory inputs &
develop potential to
behave differently.
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4. REFLEX LEARNING.
 Non- associative .
Person learns about
properties of single
stimulus when
repeatedly exposed to
same stimulus.
 Associative.
Person learns about
relationship between
two stimuli or a
stimulus & behaviour.
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5. NON- ASSOCIATIVE .
 Habituation
Decrease in response
to benign stimulus
when stimulus
presented repeatedly.
 Sensitization.
 Increase in response
to benign stimulus
when stimulus
presented repeatedly.
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6. First time it evokes a novel response (orientation
response or what is it response)
Evokes less & less response when repeated
Subject becomes habituated to the
stimulus & ignores it
Habituation
 If a stimulus is repeated
many times

7. Habituation
 Example
 New clock in the
room.
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8. Cellular basis of Habituation.
 Given by KANDEL
& his collegue.
 Repeated stimulus.
 Inactivation of Ca
influx at axon endings.
 neurotransmitter
release at synapses.
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9. Cellular basis of Sensitization.
 Given by KANDEL
& his collegue.
 Repeated stimulus.
 neurotransmitter
release at synapses.
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10.  Due to Presynaptic
facilitation by third
interneuron ---
facilitatory neuron.
which releases
SEROTONIN.
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Sensitization

11. Pathway in increased release of
Neurotransmitter.
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12. ASSOCIATIVE LEARNING.
 Classical
conditioning.
 Learning relationship
between two stimuli.
 Type I, Type S,
respondant
conditioning or
Pavlovian
conditioning.
 Operant
conditioning.
 Learning relationship
between special
behaviour with a
reinforcement event.
 Type II, type R,
Instrumental or trial &
error condioning.
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13. CLASSICAL CONDITIONING.
 Characteristic features.
 Conditioned reflex is reflex response.
 Acquired by repeatedly pairing given stimulus with
another stimulus which normally produces the response.
 Thus temporal association made between neutral
conditioned stimulus (CS) & unconditioned stimulus. (US)
 It depends upon formation of new functional connections
in CNS.
 Reinforcement -- CS SHOULD FOLLOWED BY US
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14. CLASSICAL CONDITIONING.
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15. Pre-requisites for development of
conditioned reflex.
 Alertness & good health.
 Timing of CS & US – CS US.
 Duration of CS – Should overlap US.
 Reinforcement. CS US.
 No external inhibition.
 Type of US
 Sensory / motor
 Pleasant, unpleasant / Neutral.
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16. Physiological basis of conditioned
reflexes.
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Formation of
new
connections
in the
nervous
system

17. Cellular mechanism of
conditioned reflex.
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18. OPERANT CONDITIONING.
 Reward
conditioning.
Naturally occurring
response is
strengthened by
positive reinforcement
( reward)
 Adversive
conditioning.
Naturally occurring
response is weakened
by negative
reinforcement
( punishment)
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19. Experiment to demonstrate
Operant conditioning.
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20. Experiment to demonstrate
Operant conditioning.
 Positive reinforcement – pressing a lever is
associated with positive reinforcement,
reward i.e. food.
 Negative reinforcement – pressing a lever
is associated with Negative reinforcement,
punishment i.e. electric shock.
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22. MEMORY.
 Memory –
Acquisition ,
storage &
retrieval of
sensory
information
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23. TYPES OF MEMORY.
 Physiologically on
the basis of how
information is stored
& recalled.
 Implicit memory.
 Explicit memory.
 Depending upon
permanency of
storage.
 Short term.
 Intermediate long
term.
 Long term.
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25. TYPES OF MEMORY.
 Implicit memory.
 Non-declarative /
reflexive memory.
 How to perform
something.
 Not associated with
awareness not involve
processing in
hippocampus.
 Explicit memory.
 Declarative / reconition
memory
 Factual knowledge of
people, places & things.
 Associated with
awareness ,Involve
processing in
hippocampus.
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26. IMPLICIT MEMORY.
 How to perform
something.
 Does not depend on
conscious process.
 Includes motor skills,
habits, behavioural
reflexes & learning
procedure & rules.
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27. Implicit memory – reflexive
learning.
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28. EXPLICIT MEMORY.
 Declarative / reconition
memory
 Factual knowledge of
people, places & things.
 Associated with
awareness ,Involve
processing in
hippocampus.
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29. EXPLICIT MEMORY.
 Semantic memory.
 About knowledge of
objects, facts and
concepts.
 Words & their
meanings.
 Episodic memory.
 Memory of events &
personal experience.
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30. MECHANISM OF MEMORY.
 Explicit memory.
 Short term memory.
 Neural substrate for encoding of memory.
 Intermediate long term.
 Long term.
 Consolidation of memory.
 Storage of memory.
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31. Principles of Memory.
 Encoding.
 Elaboration. (Item specific)
 Organization (Inter-item)
 Storage.
 Time-dependency (Interference)
 Retrieval.
 Cue-dependency.
 Encoding specificity.
 Schematic processing.
 Reconstruction.
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32. Neural substrate for encoding
of memory.
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34. RETRIEVAL OF MEMORY.
 Working memory.
 Components.
 Attentional control
system.
 Rehearsal system.
 Articulatory loop.
 Visuospatial sketch pad.
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35. Working
memory.
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37. LEARNING & MEMORY
 Interhemispheric transfer of learning &
memory.
 Experiment to demonstrate importance of corpus
callosum for interhemispheric transfer of
information.
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38. APPLIED ASPECT.
 Drugs facilitating learning & memory.
 Common CNS stimulant.
 Amnesia.
 Antegrade
 Retrograde.
 Alzheimer’s disease.
 Pathophysiology
 Characteristic features.
 Senile dementia.
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39. Alzheimer’s
disease.
 Senile dementia
 Prototypical
neurodegenerative
disease.
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40. Higher intellectual functions of
prefrontal association cortex.
 Thought process.
 Working memory & intellectual functions.
 Episodic memory.
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Thank
You