refers to a presumed process by which new information is placed
into long-term memory
Incoming information is often placed into
where it can survive for several minutes, or into working
memory, where it can survive for an hour or longer. However,
these forms of memory are essentially transient. At some point,
the information must be established in long-term
memory to survive.
There appears to be a consolidation period,
during which this transition occurs, and during which memory
is still unstable. There are two main reasons to assume that
consolidation is not instantaneous. The first is interference:
if subjects are asked to learn a list of words, and then asked
to learn a second list of words, this later learning interferes
with recall of the first list of words. This suggests that
newly-formed memories can be disrupted by later incoming information.
The second reason to assume that consolidation
is not instantaneous comes from patients who have sustained
brain injury which causes retrograde
amnesia, a loss of memory for events occurring before
the injury. Typically, retrograde amnesia is time-graded,
meaning that there may be near total loss of memory for the
events immediately before the injury, partial loss of events
occurring somewhat before the injury, and little or no loss
of memory for events from the distant past. For example, someone
who sustains a blow to the head in the course of a car accident
may have no memory of the accident itself, sketchy memory
of the drive which led to the crash, and normal memory for
events before the day of the crash. In other cases, memory
disruptions may occur which stretch as far back as several
years before the injury.
These findings suggest that new memories
are vulnerable, and that brain damage can disrupt them before
they are fully stabilized in memory; older memories become
progressively more stable and are more likely to survive.
The biological mechanisms of consolidation
are poorly understood, although long-term
potentiation has been implicated in causing anatomical
changes in the brain which may underlie long-term memory formation.
Article : "MEMORY
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain