2. Outline (Focus on Psychological Aspects of Memory)
• Introduction
• Physiology of Memory
• Theories Of Memory
• Organisation of Long Term Memory
• Retrieval from Long Term Memory
• Forgetting
• Amnesia
3. Introduction
• Defined As: “Encoding, Storage, and retrieval of
what was learned earlier.”
• Study of Memory emphasises on cognitive, or
mental processes.
• Based upon synaptic plasticity.
4. • Types of memory:
▫ Declarative Memory (Explicit Memory)
▫ Non Declarative Memory (Implicit Memory)
(Memory for
Recognition of
Words)
5. Physiology of Memory
▫ The basis of memory is synaptic plasticity
Increase in response to repeated activity of the
synapse leads to sensitization and long term
potentiating
Decrease in response to repeated activity of
synapse leads to Habituation and Long Term
Depression.
▫ Hippocampus which is important part for memory
STM consolidation (Long term Potentiation) leads to
LTM
6. CA1 Neurons of Hippocampus activated by different
pathway which helps in consolidation (Long Term
Potentiation).
Sensory input pathway to hippocampus also called
preforant pathway.
7. Theories of Memory
• Theory of General Memory Functions
• Information Processing Theory
• Level of Processing theory
8. • Theory of General Memory Functions
▫ Most agreed theory
▫ Divided in three phases
Encoding: Process of receiving sensory input
and transforming it into a form, or code, which
can be stored.
Storage: Process of putting coded information
into memory.
Retrieval: Process of gaining access to stored,
coded information when it is needed.
10. ▫ Sensory Register or Memory:
Storage function of sensory channel
Information that is given attention is sent to
Short term memory, rest is lost.
▫ Short term Memory:
Information retained for up to 30 Sec, However
lengths of retention depends upon multiple
factors.
11. Glanzer and Cunitz (1966) gave experiment to
demonstrate features of Short Term memory.
They used the technique named “Free Recall”.
Subjective Experiment; List of 15 noun
Three Conditions:
▫ Zero Delay
▫ 10 Sec Delay
▫ 30 Sec Delay
▫ Delay interval filled with mental activity
(Counting)
12. Recall Depends upon serial position of Noun
Better recall in beginning called Primacy effect
Better recall at end is called Recency effect
Recency effect affected in Delay Interval due to
interference of transfer from short term to long
term memory due to Mental activity
13. ▫ Rehearsal: Keeping items of information in the
centre of attention.
Two Types
Maintenance Rehearsal: Just going over and
over information to be remembered
Elaborative Rehearsal: Giving Information/
material Organisation and meaning as it is
rehearsed.
14.
15. • Level of processing Theory
▫ Given by Craik and Lockhart 1972, Elaborated by
Craik and Tulving
▫ Information can be worked at different Three
levels
Perception: Immediate awareness of
environment.
Structural Level: Structural features of the
Inputs are analyzed (sound, look, other details)
Meaning Level: deeper Meaning of the input.
16. ▫ Greater the elaboration of Information more likely
it is to be remembered.
17. Organisation of Long Term Memory
• Conscious Long Term memory is divided into
Semantic and Episodic Memory.
• Semantic
▫ “What words means, about the ways they are
related to one another, and about the rules for
using them in communication and thinking.”
▫ Stored in highly organised manner in two possible
ways
Logical hierarchy from general category to specific
ones.
Clusters of words with related meaning
18. • Episodic Memory
▫ Memory of specific things that happened to us at a
particular place and time.
▫ Less organised then semantic memory
▫ More Susceptible to be forgotten then semantic
memory.
• Encoding and Storing of Long Term Memory
▫ Encoding and storage are facilitated by organisation of
materials to be remembered.
▫ Organisation: can be Objective i.e. from Material/
Information to be remembered or Subjective i.e.
Imposed by us upon the information.
19. ▫ Forming Images: during Encoding can also
helps in storage of Information.
▫ Constructive Process: Especially with complex
information or Life events details are often
modified or changed or inferences rather then
exact details are stored in memory.
20. Retrieval From Long Term Memory
• Retrieval Cues
▫ Finding information in the organised long term
memory is aided by retrieval cues
▫ More are cues for any encoded memory better are
chances of its retrieval.
▫ There can be state depended memory and cues
as well, e.g. Memory encoded during alcohol
intoxication may only be retrieved under alcohol
intoxication.
21. • Reconstructive Processes in retrieval Memory
▫ Unconscious modification of memory during
retrieval.
▫ Seen in persons with organic memory disorders
when gaps in memory are filled unconsciously by
false information
22. Forgetting
• Most of things we think are forgotten were never
actually encoded and stored in memory.
• Curve of Forgetting
▫ Curve of forgetting depends upon many factors
23. • Interferences
▫ Appears to play role in problems in forming new
memory
▫ Two types
Retroactive interference: New information
interfere in memory retrieval of old information.
Proactive interference: Old information interfere
in memory retrieval of new information.
▫ Exact mechanism of interference is still unclear
24. Amnesia
• Amnesia: “Profound Memory deficit due to either
loss of what has been stored or the inability to form
new memories”.
• Broad two Types:
▫ Psychological Amnesia: without any structural or
molecular brain malfunction
▫ Biological Amnesia: with structural or molecular
brain malfunction
25. • Psychological Amnesia
▫ Childhood Amnesia
Poor early Childhood memory.
Three Hypothesis
Repression of forbidden (Sexual/ Aggressive)
memories that may cause anxiety or guilt if brought
into awareness, Freud 1938
Difference in Encoding and storage of Information in
adults vs. Children; Adults encode memory using
language but children may encode memory using
unknown organisation making retrieval of information
difficult, Schachtel 1959
26. Lack of maturation of brain structures responsible for
maturation in children so that memory is not stored properly
▫ Dream Amnesia
Inability to remember all dreams had during sleep
As per Freud due to repression of forbidden urges seen in
dreams just like childhood amnesia.
May also be due to different organising of memory in dreams
in comparison to awake state. (State Dependent Memory)
▫ Defensive Amnesia
Defensive repression of intense, intolerable life situations and
conflicts to prevent anxiety, guilt or other negative emotions.
27. • Biological Amnesia
▫ Transient Global Amnesia
Profound memory problem with intact
consciousness
Acute onset and usually short period condition
Both anterograde as well as retrograde amnesia
Due to temporary alteration in pattern of blood
flow in brain.
28. ▫ Substance Use and Amnesia
Cannabis can cause minor problems in encoding
and storage of memory.
Alcohol
Known to cause problems in encoding and
storage of memory, can lead to gap in memory
for period of heavy alcohol intoxication.
Long term alcohol use can also cause difficult
to treat Korsakoff Syndrome due to Thiamine
deficiencies leading to anterograde amnesia.
29. ▫ Senile Dementia
Old age onset deficit in intellectual abilities like
memory, attention, judgement etc.
Mostly anterograde amnesia
Result of reduction of blood flow in brain.
▫ Alzheimer’s Dementia
It is a type of Primary degenerative dementia
Due to Acetylcholine deficiencies in brain areas
Progressive mental deterioration from mild
anterograde to profound anterograde and retrograde
amnesia.
