Provided by the National Institute of Mental Health
Perception, attention, learning, memory, thought,
and communication—these are processes that are basic to much of our mental life
and behavior, and they are all encompassed under the term cognition. The
National Institute of Mental Health (NIMH) supports research on many facets of
cognition, seeking to identify their underlying mechanisms and discover how they
relate to mental disorders. Several scientific disciplines, foremost among them
psychology, neuroscience, and computer science, are contributing to this
cognitive research. Interdisciplinary studies involving all three of these
fields permit researchers to develop sophisticated models of cognition and make
detailed predictions of the outcome of cognitive processes. Most of these
studies involve normal human subjects or animals, but all are ultimately
relevant to the problem of mental disorders.
Among the areas being actively investigated with NIMH and other National
Institutes of Health support are:
The physical basis of memory and learning
Research in the past decade has finally begun to reveal the physical basis for
the storage of memories. There is increasingly strong evidence that physical
changes in the structures called synapses, which allow communication between
neurons in the brain, and the functional consequence of those changes, called
long-term potentiation, are the physical basis of important forms of learning
and memory.
Neuroimaging in cognitive research
Neuroimaging techniques that allow scientists to peer inside the living,
functioning human brain, are immensely powerful tools for cognitive research.
One particularly valuable technique, functional magnetic resonance imaging, or
fMRI, promises to make it possible for researchers to discover which brain
circuits are responsible for specific cognitive processes.
The effect of hormones on learning and memory
Estrogens, the female sex hormones that are so important in menstruation and
other bodily functions, may also modulate cognitive processes such as memory.
There is preliminary evidence that estrogen maintenance therapy enhances memory
in post-menopausal women and delays memory loss related to Alzheimer's disease.
Generation of new nerve cells in the adult brain
For many years it was believed that the brain, once formed, could not produce
new nerve cells. But adult generation of new nerve cells, found first in birds,
then in rats, then in monkeys, has now been found in humans as well. The nerve
cell regeneration occurs in the hippocampus, a portion of the brain essential to
the formation of memories. NIMH-supported scientists are attempting to learn
what role nerve cell regeneration plays in the normal memory function of the
hippocampus.
Role of stress in nerve cell regeneration
Recently, work with animals has shown that nerve cell generation is affected by
stress: stress appears to decrease the capacity for generation of new nerve
cells. Scientists supported in part by NIMH funds are working intensively to
understand the factors linking stress and decreases in nerve cell regeneration.
Understanding these effects is critical because stress can be such a major
factor in life events and because the brain areas affected play an important
role in basic memory functions.
Role of emotion in cognition
Emotion plays a major role in determining how memories are stored. Strong
emotion, such as fear, can mark a memory so that it retains its vividness in a
very persistent way, as in post-traumatic stress disorder. NIMH-supported
scientists are studying how such memories are formed, stored and retrieved, in
the hope of obtaining information that can be used in the development of new
treatments for memory-related disorders.
Extension of cognitive research to depression and anxiety disorders
Research in this area is expanding rapidly. For example, NIMH-supported
researchers have found that a depressive mental "schema"—a tendency to "view the
glass as half empty rather than half full" even when in a normal mood,
predisposes a person to depression and plays a role in the active illness.
Cognition in schizophrenia
NIMH-supported research has contributed to the development of an influential
model of the cognitive problems that are a prominent feature of schizophrenia.
The model says that people with schizophrenia have difficulty taking account of
the context of events and information and making an appropriate response. The
neurotransmitter dopamine is thought to play a role in this problem.
Infants
The process by which infants acquire language has long been of interest to
scientists and parents alike. NIMH-supported researchers have now shown that
infants 3 to 4 months old have greater ability to comprehend speech than
previously thought. Other studies focus on infants of depressed mothers. These
children, who are at risk for depression later in life, may be affected by their
mothers' speech patterns: the researchers have shown that depressed mothers of
infants use flat, unanimated tones in speaking to their babies. This research
suggests that intervention to treat depression in mothers of infants, and to
improve their interaction with their babies, may pay off in reduced rates of
depression as the children grow up.
Decision-making
The process by which people choose between different options has long been of
interest to cognitive psychologists. In addition, decision-making is often
impaired in mental illness. With NIMH support, these studies are now going
beyond tightly controlled laboratory experiments into the real world.
Researchers will study the mental processes that underlie decision-making.
Conditioning in animals
NIMH-supported investigators are learning more about the perceptual, memory, and
attentional mechanisms underlying classical conditioning (the process by which
an animal learns to associate two stimuli, such as a light and a shock) and
operant conditioning (the process by which an animal learns to relate certain
external events to its own behavior, such as gaining a food reward by pressing a
lever). The researchers are developing cognitive models to explain these
phenomena. This work will have applications for understanding phobias and for
the development of treatments.
Plasticity: the integration of "nature" and "nurture"
The physical changes in the brain resulting from new memories, the addition of
new neurons, changes in hormones, and stress and trauma all point to constant
remodeling of the brain itself. Through this plasticity, experience is
constantly changing the brain. Neuro-scientists are beginning to glimpse how the
mind might alter its substrate, the brain.
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