Mechanism of memory

1. PHYSIOLOGY OF MEMORY
FATIMA WAHID MANGRIO
fatimawahid1234@gmail.com

2. PHYSIOLOGY OF MEMORY
• Memory is the process by which information
acquired through learning is stored and
retrieved.
• For an experience to become part of memory,
it must produce persistent structural and
functional changes that represent the
experience in the brain.

3. • This capability for change associated with
learning is termed plasticity.
• Nervous system plasticity underlies our
ability to change our behavior in response to
stimuli from the external and internal
environments. It involves changes in individual
neurons—for example, synthesis of different
proteins or sprouting of new dendrites—as
well as changes in the strengths of synaptic
connections among neurons.

4. • The parts of the brain known to be
involved with memory include the
association areas of the frontal,
parietal, occipital, and temporal lobes;
parts of the limbic system, especially
the hippocampus and amygdala; and the
diencephalon.

5. Association Areas
• The somatosensory association area (areas 5
and 7) is just posterior to and receives input
from the primary somatosensory area, as well as
from the thalamus and other parts of the brain.
• Role of the somatosensory association area is
the storage of memories of past somatic
sensory experiences, enabling you to compare
current sensations with previous experiences.
For example, the somatosensory association
area allows you to recognize objects such as a
pencil and a paperclip simply by touching them.

6. • The primary somatosensory and primary
motor areas in the brain also exhibit
plasticity. If a particular body part is
used more intensively or in a newly
learned activity, such as reading Braille,
the cortical areas devoted to that body
part gradually expand.

7. IMMEDIATE MEMORY
• Immediate memory is the ability to
recall ongoing experiences for a few
seconds.
• It provides a perspective to the present
time that allows us to know where we
are and what we are doing.

8. PROCEDURAL MEMORY
• Memory of how to do things.
• Skills or habits once acquired become
automatic & unconscious.
• Very stable memory.
• Memory of skilled behavior without any
understanding e.g riding a bicycle.
• Sensorymotor cortex, basal ganglia, and
cerebellum are involved in this memory.

9. Short-term memory
• Short-term memory is the temporary
ability to recall a few pieces of
information for seconds to minutes. One
example is when you look up an
unfamiliar telephone number, cross the
room to the phone, and then dial the
new number. If the number has no
special significance, it is usually
forgotten within a few seconds.

10. • Brain areas involved in immediate and
short-term memory include the
hippocampus, the mammillary bodies,
and two nuclei of the thalamus (anterior
and medial nuclei).

11. Long Term Memory
• Information in short-term memory may
later be transformed into a more
permanent type of memory, called long-
term memory, which lasts from days to
years.

12. • If you use that new telephone number
often enough, it becomes part of long-
term memory.
• Information in long-term memory
usually can be retrieved for use
whenever needed.

13. • Long-term memories for information
that can be expressed by language, such
as a telephone number, apparently are
stored in wide regions of the cerebral
cortex.
• Memories for motor skills, such as how
to serve a tennis ball, are stored in the
basal nuclei and cerebellum as well as in
the cerebral cortex.

14. • Although the brain receives many
stimuli, we pay attention to only a few
of them at a time.
• It has been estimated that only 1% of
all the information that comes to our
consciousness is stored as long-term
memory.

15. • Moreover, much of what goes into long-
term memory is eventually forgotten.
Memory does not record every detail as
if it were magnetic tape. Even when
details are lost, we can often explain
the idea or concept using our own words
and ways of viewing things.

16. Biological Basis of Memory
• Memory does not reside in neurons-it is
change in pattern/ alteration of signals
transmitted across selected synapses in a
neuronal network.
• This alteration involve protein synthesis &
gene activation.
• Different mechanisms are responsible for
short-term and long-term memory.

17. • Short-term memory involves transient
modification in functions of pre-existing
synapses.
• Long-term memory involves permanent
functional & structural changes between
existing neurons in the brain.
• New neurons continously being formed in
olfactory bulb & the hippocampus, a process
called neurogenesis.
• Neurogenesis plays role in learning memory in
hippocampus.