How
Memory Works
Every
experience generates a memory—whether it last depends on how often it is revisited.
Intricate neural connections allow memories to form, and these can strengthen,
aiding recall, or fade away.
What is Memory?
A memory is formed when a group of neurons fire in a
specific pattern in response to a new experience these neural connections can
then refire in order to reconstruct that experience as a Memory. Memories are
categorized into five types (right). They are briefly stored in the short-term
(working) memory but can fade unless the experience is of emotional value or
importance in which case it is encoded (below) in the long-term memory.
In recalling a memory, the nerve cells that first
encoded it are reactivated. This strengthens their connections and, if done repeatedly,
solidifies the memory. A memory’s component parts, such as related sounds or smells,
reside in different areas of the brain, and in order to retrieve the memory all
of these brain parts must be activated.
During recall a memory can merge accidentally with new
information, which fuses irrevocably with the original (known as confabulation).
How Memories form
The process of laying down (encoding) a memory depends
on many factors. Even once encoded a memory can take two years to be fimly
established.
0.2 SECONDS
1. Attention
Focusing attention on an
event helps to solidify the memory: the thalamus activates neurons more intensely,
while the frontal lobe inhibits distractions.
0.25 SECONDS
2a. Emotion
High emotion increases attention,
making an event more likely to be encoded into a memory. Emotional responses to
stimuli are processed in the amygdala.
0.2-0.5 SECONDS
2b. Sensation
Sensory stimuli are part of
most experiences, and if of high intensity they increase the chances of recollection.
Sensory cortices transfer signals to the hippocampus.
TYPES OF MEMORY
Episodic
Memory-Recalling past events or
experiences, usually closely linked with sensory and emotional information.
Semantic
Memory-Retaining factual information,
such as the name of a capital city.
Working
Memory-Storing information temporarily;
capable of holding between five and seven items at any one time; also known as
short-term memory.
Procedural
(body) Memory-using learned
actions that require no conscious recall, such as riding a bicycle.
Implicit
Memory-Bringing back an
unconscious memory that influences behaviour, such as recoiling from a stranger
reminiscent of someone unpleasant.
“Memory
is the treasury and guardian of all things.”
-Cicero
0.5 SECONDS—10 MINUTES
3. Working Memory
Short -term Memory stores information
until needed-it is kept active by two neural circuits that incorporate the
sensory cortices and the frontal lobes.
10.MINUTES—2 YEARS
4. Hippocampal Processing
Important information transfers
to the hippocampus, where it is encoded. It can then loop back to the brain
area that first registered it, to be recalled as a Memory.
2 YEARS ONWARD
5. Consolidation
The neural firing patterns
that encode an experience carry on looping from the hippocampus to the cortex—this
firmly fixes (consolidates) it as a Memory.
This Article is Taken From How Psychology Works
Written by Arshad. A
