Nervous System—Memory
Lecture 13
Today we’re going to nish up our section on the nervous system by
looking at all the various things that can go wrong with segments of
the system. We’re going to divide it up basically by categories and see
exactly what can happen to the nervous system to cause certain illnesses
or diseases and malfunctions.
I
n this lecture, we complete our examination of the nervous system with
a look at memory and brain pathology and provide some information
about anesthesia and pain. First, we examine the nature, development,
pathology, and mysteries of memory. We then examine various kinds of
damage to the brain and spinal cord and the results of such damage. We
conclude by discussing anesthesia and referred pain, in which organs that
share nerves with other body parts can cause the brain to report pain in those
body parts.
Memory prevents repeated mistakes and promotes repeated successes. It has
been extensively studied, but relatively little is known about it compared
to other systems of the body. More is known about memory acquisition
than about memory retrieval. Learning is the acquisition of new skills or
information, either through experience or instruction. Memory is the process
of storing that information and retrieving it when needed. The brain has high
plasticity, which is the ability to change learned behavior on receipt of new
information. Anatomically, memory involves changing the interconnection
of neurons by creating, modifying, or destroying dendrites and synapses.
The brain has almost all its neurons from birth, and it does not expand with
new memories.
Memory areas of the brain
The entire brain is involved in memory processes.
Different areas of the brain (the hippocampus, amigdala,
diencephalon, and so on) are primary memory centers for
certain functions.
71
, Centers of the brain devoted to controlling body parts will expand
as those parts are used repeatedly.
The brain stores only about 1% of conscious information in long-
term memory, probably because of space limitations.
Types of memory
Immediate memory is a few seconds long and consists of activities
occurring at the present moment.
Short-term memory lasts between a few seconds and a
few minutes.
The hippocampus, mamillary bodies, and thalamus handle both immediate
and short-term memory. Immediate and short-term memory are probably
chemical and electrical events rather than anatomical changes involving
dendrites and synapses. Repetitive use of information in short-term memory
converts that information into long-term memory, which can last from hours
to a lifetime.
Memory storage
Verbal or written information is stored across the entire cerebral
Lecture 13: Nervous System—Memory
cortex. Individual ideas and memories cannot be excised
or ablated.
Physical activities are stored in the areas corresponding to the body
parts used and in the basal ganglia.
Brain scans show an increase in the number and size of presynaptic
terminals in corresponding areas when information is retrieved
repeatedly and a decrease in number and size when information is
infrequently used.
72
Lecture 13
Today we’re going to nish up our section on the nervous system by
looking at all the various things that can go wrong with segments of
the system. We’re going to divide it up basically by categories and see
exactly what can happen to the nervous system to cause certain illnesses
or diseases and malfunctions.
I
n this lecture, we complete our examination of the nervous system with
a look at memory and brain pathology and provide some information
about anesthesia and pain. First, we examine the nature, development,
pathology, and mysteries of memory. We then examine various kinds of
damage to the brain and spinal cord and the results of such damage. We
conclude by discussing anesthesia and referred pain, in which organs that
share nerves with other body parts can cause the brain to report pain in those
body parts.
Memory prevents repeated mistakes and promotes repeated successes. It has
been extensively studied, but relatively little is known about it compared
to other systems of the body. More is known about memory acquisition
than about memory retrieval. Learning is the acquisition of new skills or
information, either through experience or instruction. Memory is the process
of storing that information and retrieving it when needed. The brain has high
plasticity, which is the ability to change learned behavior on receipt of new
information. Anatomically, memory involves changing the interconnection
of neurons by creating, modifying, or destroying dendrites and synapses.
The brain has almost all its neurons from birth, and it does not expand with
new memories.
Memory areas of the brain
The entire brain is involved in memory processes.
Different areas of the brain (the hippocampus, amigdala,
diencephalon, and so on) are primary memory centers for
certain functions.
71
, Centers of the brain devoted to controlling body parts will expand
as those parts are used repeatedly.
The brain stores only about 1% of conscious information in long-
term memory, probably because of space limitations.
Types of memory
Immediate memory is a few seconds long and consists of activities
occurring at the present moment.
Short-term memory lasts between a few seconds and a
few minutes.
The hippocampus, mamillary bodies, and thalamus handle both immediate
and short-term memory. Immediate and short-term memory are probably
chemical and electrical events rather than anatomical changes involving
dendrites and synapses. Repetitive use of information in short-term memory
converts that information into long-term memory, which can last from hours
to a lifetime.
Memory storage
Verbal or written information is stored across the entire cerebral
Lecture 13: Nervous System—Memory
cortex. Individual ideas and memories cannot be excised
or ablated.
Physical activities are stored in the areas corresponding to the body
parts used and in the basal ganglia.
Brain scans show an increase in the number and size of presynaptic
terminals in corresponding areas when information is retrieved
repeatedly and a decrease in number and size when information is
infrequently used.
72
