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Learning, the ability to recollect from the storehouse of memory, involves a complex set of processes
whereby experience alters the nervous system. These changes endure and affect subsequent
experience and behavior. Is learning and recollection simply the neuronal residue of experience,
or do other factors play an important role in memory recall? How are significant experiences
selected for later recall? How do past experiences interact with present experiences, and how do they
lead to changes in behavior?
The complexity of the problem may be illustrated by examining what is involved in using a familiar
telephone number. The information is obtained by looking up a telephone number in a directory.
One may see many numbers that are present in the visual field, but only one is selected for use.
The recollection may be indicated by speaking, dialing or pushing buttons, by writing or simply by
identifying the correct sequence of numbers as the correct number. The recollected image can be
discriminated from all other sequence of numbers, including other telephone numbers we are
capable of recalling. The recollection that is rapidly formed is transient, but with repetition can
become long lasting.
This is but one simple example of recollection. We can obtain information through watching,
reading, listening, and through other sensory experiences. We learn and remember
isolated
experiences, complex events and reliable skills. However, recollection does not merely consist of the
particular responses that are made during the course of learning experiences. We readily learn and
perform skills such as language, in which responses occur in novel sequences.
Brain lesions can impair learning and retention. However, such studies are difficult to interpret since
they only reveal how behavior is altered by lesion. In addition, lesion studies have not revealed in
anatomical locus for the storehouse of memory. However, since
neurological changes are induced
during training and recollecting, many scientists assume that an anatomical locus can exist.
Studies of electrical brain activity indicate that training and recollecting alters brain wave patterns
and especially hippocampal theta activity. The hippocampus is a sea-horse like structure found in the
limbic system deep within temporal lobe of the brain. It is a brain structure associated with learning,
mapping, and memory retrieval. Moreover, whenever we are actively visualizing, slow brain waves
of 4 to 8 cycles per second are produced. These slow waves are called theta waves. The firing
pattern of single brain cells and their evoked potential recordings also show characteristic changes
during recollection and learning. However it has not been determined that these correlates of
learning are involved in the mechanisms underlying learning and memory recall. The
electrophysiological changes produced by training and by insight experiences are signs that brain
cell activities are altered.
Training of laboratory animals also produces changes in brain chemistry. Studies suggest that RNA
and protein synthesis are increased by training. Furthermore, in goldfish, patterns of brain protein
synthesis are changed by training. Other studies suggest that learned predispositions to light can be
transferred to untrained animals via brain extracts. These extracts exist as if they were hormones
promoting light avoidance or dark avoidance behaviors. Memory transfer via brain extracts is
highly controversial and many neuroscientists do not feel that such 'memory transfer' studies are
convincing.
The ability to recall experiences can be enhanced or impaired by treatments that alter brain activity.
Such treatments are most effective if administered shortly before or shortly after the experience.
Effective treatments include electrical stimulation, hormones, stimulant drugs, drugs affecting RNA
and/or protein synthesis, and drugs affecting neurotransmitters. The inference drawn from these
results is that normal variations in our ability to recollect may be due to the modulating influence
of hormones and brain chemistry. Since hormone activity and brain metabolism is cyclic, we might
expect to see rhythmic fluctuations in our abilities to recollect experiences.
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Learning is the ability to remember from
the data that has been gathered and stored in the brain. The problem is
a complex one. Taking the use of the telephone as an example, learning
is the using of the senses to absorb the number from a book.
Recollection is when we are able to differentiate the set of numbers
from other numbers in our memory and use it o dial. Usually the rapidly
formed recollection is not remembered for long, but it can be if used
repeatedly. We obtain information, through the senses, when we learn
languages and other skills and remember them when we use them. Even
though many scientists believe that learning causes changes to the brain
and are therefore anatomical, these studies are not final. Studies
indicate that training and recollecting do alter brain wave patterns.
Patterns also reveal themselves in single brain cells showing that there
are changes taking place when we learn or recollect. ( 159 words ) |
