Glossary
Amygdala: A
part of the limbic system named for its almond shape. The amygdala is thought
to be involved with emotion and memory formation.
Angular Gyrus:
A section of the left temporal lobe involved in language
processing, integrating information about letter shape, word recognition,
meaning, and sound. It connects the occipital cortex with Wernicke’s Area.
Anterior Cingulate Gyrus:
An area of the brain associated with motor control, pain
perception, cognitive function and emotional arousal. A component of the limbic
system.
Axon: The
fiber like extension of a neuron (neural cell) by which the cell sends
information to target cells, usually by an electrical impulse.
Basal Ganglia:
Clusters of neurons, which include the caudate nucleus,
putamen, globus pallidus and substantia nigra, located deep in the brain that
play an important role in movement.
Broca’s Area:
The central region for the production of speech. Located
in the frontal lobe, typically in the left hemisphere, Broca’s area is
responsible for the production of words, word sound, syntactic comprehension,
and working memory.
Brodmann Area 17:
An area of cortex in the occipital lobe. Also called the
V1, or primary visual cortex, because it receives the earliest information from
the eyes by way of the thalamus. Also called striate cortex because in
cross section, it has a distinct band of white myelin within the cell layer.
CAT (Computerized Axial Tomography) Scan:
A computer-mediated x-ray image depicting a cross-section
of the body.
Central Nervous System (CNS):
Portion of the nervous system that includes the brain and
the spinal cord.
Central Sulcus:
The major groove which divides the frontal lobe from the
parietal lobe
Cerebellum: Structure
located at the base of the brain involved in central regulation of movement,
such as basic movement, balance, and posture; comes from the Latin word meaning
little brain is divided into two hemispheres and has a cortex.
Cerebral Cortex:
The outer covering of the cerebral hemispheres consisting
mostly of nerve cell bodies and branches; involved in functions such as
thought, voluntary movement, language, reasoning, and perception; the right and
left sides of the cerebral cortex are connected by a thick band of nerve fibers
(corpus callosum).
Cerebral Hemispheres:
The two specialized halves of the brain. The left
hemisphere is specialized for speech, writing, language and calculation; the
right hemisphere is specialized for spatial abilities, face recognition in
vision and some aspects of music perception and production.
Cerebro-Spinal Fluid (CSF):
A fluid that surrounds the brain and spinal cord,
providing nutrients to nerve tissue, removing cellular waste products, and
cushioning the brain.
Cingulate Gyrus:
A cortical structure, part of the limbic system, that is
directly over the corpus callosum along the medial side of each hemisphere. It
is involved with emotion and attention.
Cognition: The
process or processes by which an organism gains knowledge or becomes aware of
events or objects in its environment and uses that knowledge for comprehension
and problem-solving.
Contralateral:
Related to the opposite side, as when functions on the
right side of the body are controlled by the left side of the brain.
Corpus Callosum:
The large bundle of axons which connect the two cerebral
hemispheres. It disseminates information from the cerebral cortex on one side
of the brain to the same region on the other side.
Cortex: The
surface of the brain.
Cortical Plasticity:
The ability for connections between neurons to be modified
within the cortex.
Declarative Memory:
Memory for semantic information that can be consciously
(and verbally) recalled.
Dendrite: A
branching extension from the neuron cell body that receives information from
other neurons.
DorsoLateral Prefrontal Cortex:
An area on the lateral aspect of the brain near the front
that is associated with executive function, decision making, and working memory.
Executive Processes:
Cognitive tasks related to decision-making, associated
with the frontal lobe of the brain.
Extrastriate:
Visual areas in the cerebral cortex which are downstream
of primary visual cortex. Extrastriate areas are associated with higher order
features of vision, such as face recognition and spatial awareness.
Frontal Lobe:
One of the four divisions (parietal, temporal, occipital)
of each hemisphere of the cerebral cortex. The most anterior portion of the
cerebral cortex (in front of the central sulcus); The frontal lobe has a role
in reasoning, movement, problem-solving and in the planning and coordinating of
behavior.
Functional Magnetic Resonance Imaging (fMRI):
A technique for imaging brain activity using magnets. FMRI
is able to detect brain activity by taking advantage of the fact that
deoxyhemoglobin has a different magnetic profile than oxyhemoglobin.
Deoxyhemoglobin is concentrated in areas of high cellular metabolism, which
correlates to high cellular activity.
Globus Pallidus:
A nucleus of the basal ganglia, involved in the
coordination of voluntary movement.
Gyrus: Raised
portion of convoluted brain surface
Hemisphere: Half
of the brain, the right or left.
Hippocampus: A
seahorse-shaped structure (in cross section) located within the basal medial
part of the temporal lobe and considered an important part of the limbic
system. This part of the brain is important for learning and memory, for
converting short term memory to more permanent memory, and for recalling spatial
relationships in the world about us
Hypothalamus:
A brain structure providing specific functions such as
regulating the activities of internal organs, monitoring information from the
autonomic (peripheral) nervous system and controlling the pituitary gland.
Infereotemporal Cortex:
The lower part of the temporal lobe, an area of the brain
involved in object and number recognition.
Inferior Parietal Lobe:
A region of the parietal lobe associated with object
recognition.
Ipsilateral: Related
to the same side, as when stimuli presented to the left side of the body are
detected by the left hemisphere of the brain.
Lateral Fissure:
A deep sulcus (groove) within the convolutions of the
cerebral cortex. Delineates the temporal lobe from the rest of the cortex.
Lateral: Anatomical
term meaning toward the side (versus medial)
Limbic System:
A group of brain structures that work to regulate
emotions, memory and certain aspects of movement. Includes the amygdala,
hippocampus, cingulate gyrus and basal ganglia.
Long-Term Memory:
A type of memory that lasts from a few hours to many years.
Longitudinal Fissure:
A deep sulcus (groove) that runs down the middle of the
cortex and provides a prominent landmark for separating the brain into the left
and right hemispheres.
Magnetic Resonance Imaging (MRI):
A technique for imaging soft tissues, especially the
brain, using magnets. While MRI provides a static image of the brain, a related
technique called fMRI(functional magnetic resonance imaging) can image changing
activity within the brain.
Medial: Referring
to a structure that is closer to the midline of another structure, as opposed
to a lateral.
Memory Consolidation:
The physical and psychological changes that take place as
the brain organizes and restructures information in order to make it a
permanent part of memory.
Motor Cortex:
A part of the brain that is responsible for executing
movements of the body. Located in the frontal cortex.
Motor Program:
A plan of action including the sequence of muscles needed
and the level of contraction required for each muscle.
MRI (Magnetic Resonance Imaging):
Non-invasive technique that uses magnetic energy to
generate images that reveal some of the structural details in the living brain.
Neocortex: Literally
meaning anew cortex, I because it evolved later than other brain areas.
Consisting of the recently evolved six-layered portions of the cerebral cortex,
the neocortex occupies the bulk of the cerebral hemispheres. The neocortex is
especially large in higher primates and is responsible for sensory and motor
processing as well as abstract reasoning and association.
Neuroanatomy:
The structure of the nervous system.
Neuron: Nerve
cell, the basic building block of the brain. These cells receive input from
other nerve cells and distribute information to other neurons; the information
integration underlies the simplest and most complex of our thoughts and
behaviors. It is characterized by long fibrous projections called axons and shorter,
branch-like projections called dendrites.
Non Declarative Memory:
A type of memory that cannot be verbally recalled, also
called Procedural Memory. For example, catching a baseball or riding a
bicycle.
Occipital Cortex:
One of the four subdivisions of the cerebral cortex and is
located at the back of the brain. The occipital cortex is primarily responsible
for vision-related functions such as recognizing letters. The occipital cortex
is also referred to as the visual cortex.
Orbitofrontal Cortex (a.k.a Brodmann’s Area 47):
A region of the frontal cortex which is involved in motor
function and communicates with the basal ganglia as well as other limbic
structures. This structure may be involved in mood-related disorders as well as
motor dysfunction.
Parietal Cortex:
One of the four subdivisions of the cerebral cortex and is
located behind the frontal cortex (and central sulcus). The parietal cortex
contains somatosensory areas and sensory integration areas. The parietal lobe
is involved in perception of stimuli related to touch, pressure, temperature,
and pain.
Positron Emission Tomography (PET):
A technique for imaging brain activity using radioactive
dyes injected into the blood stream.
Posterior Parietal Cortex:
Posterior portion of the parietal cortex involved in
transforming visual information to motor commands.
Precentral Gyrus:
Bump of cortex in the frontal lobe located anterior to the
central sulcus, site of the primary motor cortex.
Prefrontal Cortex:
the most anterior region of the frontal cortex; associated
with complex decision-making, behavioral inhibition, and judgement.
Premotor Cortex:
Region of cortex in the frontal lobe involved in the
sensory guidance of movement.
Primary Motor Cortex:
Cortical area in the frontal lobe which is directly
involved in producing muscle contraction.
Primary Somatosensory Cortex:
region which receives tactile information from the body.
Primary Visual Cortex:
Located in the occipital lobe. Receives the earliest
information from the eyes by way of the thalamus. Also called Brodmann Area 17.
Procedural Memory:
A type of unconscious memory for motor skills that does
not require the hippocampus for formation. see also Non Declarative memory.
Psycho-Physical Study:
Psychological tests which determine behavioral responses
to certain physical stimuli such as behavioral responses to tastes or to sounds.
Putamen: A
nucleus of the basal ganglia located deep within the brain. The putamen is
involved in sensorimotor integration and motor control.
Reinforcement:
The use of reward, encouragement, and repetition to
promote learning and memory.
Sagittal: The
plane that bisects the body or brain into right and left halves.
Secondary Motor Cortices:
Regions of cortical motor function besides the primary
motor cortex; posterior parietal
cortex, premotor cortex, supplementary motor area.
Secondary Visual cortex:
Also called V2, responsible for perceiving color and form.
Short-Term Memory:
A phase of memory in which a limited amount of information
may be held for several seconds to minutes.
Soma: The
main part of a neuron cell; term comes from the Greek word for body.
Somatosensory:
Relating to information perceived through sensory organs
in the skin and muscles including tactile, temperature, pressure, and position
information.
Spatial Memory:
A type of memory concerned with representing physical
places.
Spinal Cord: A
large bundle of nerve fibers beginning at the base of the brainstem and
continuing down to the tail bone. The spinal cord is a part of the central
nervous system, and most of the fibers within it serve motor and sensory
functions.
Stimulus: An
environmental event capable of being detected by sensory receptors.
Subcortical: Literally
located beneath the cortex, referring to brain structures that are not a part
of the cerebral cortex.
Substantia nigra:
A nucleus of the basal ganglia named for its dark
pigmentation in cross sections. Parkinson’s disease is characterized by a loss
of cells in this nucleus.
Subthalamic Nucleus:
A group of neurons that resides just below the thalamus
and comprises part of the basal ganglia.
Sulci (singular, Sulcus):
Grooves within the convolutions of cerebral cortex, the
deepest of which are sometimes called fissures.
Superior Temporal Gyrus:
Located within the temporal cortex, the superior temporal
gyrus helps process morphemes that describe syntactic features, such as the s
in dogs and the ed in barked.
Supplementary Motor Area (SMA):
Region of cortex in the frontal lobe involved in the
planning of complex movements and in two-handed movements.
Supramarginal Gyrus:
Located in the parietal lobe, the supramarginal gyrus
recognizes the words formed by written letters.
Synapse: The
physical structure that makes an electrochemical connection between two
neurons. The area between one neuron and the next, through which
neurotransmitters are passed which transmit neural messages.
Temporal Cortex:
One of the four major subdivisions of each hemisphere of
the cerebral cortex, located below the frontal and parietal lobes. Separated
from the frontal lobe by the lateral sulcus, the temporal lobe functions in
auditory perception, speech and complex visual perceptions.
Thalamus: A
structure consisting of two egg-shaped masses of nerve tissue, each about the
size of a walnut, deep within the brain. The key relay station for sensory
information flowing into the brain, the thalamus filters out only information
of particular importance from the mass of signals entering the brain and
distributes that information to appropriate areas of the cerebral cortex.
Transcranial Magnetic Stimulation (TMS):
A cortical stimulation technique. Electromagnets outside
the head create fluctuating magnetic fields that induce electric currents in
specific areas of the brain.
Ventricles: Large
spaces in the brain that are filled with cerebrospinal fluid.
Visuospatial Perception:
The perception of an object and its movement through space.
Wernicke’s Area:
An area of the left temporal lobe that is crucial for
language comprehension, Wernicke’s area is where words are associated with
their meanings.
Working Memory:
The short-duration, limited-capacity memory system that
simultaneously stores and manipulates information in order to accomplish a
task; also called scratch-pad memory.