Chapter 2 - The Neural Basis for Cognition Flashcards
Amygdala
- almond-shaped structure in the limbic system
- plays a central role in emotion and in the evaluation of stimuli
Prefrontal cortex
- outer surface of the frontmost part of the brain
- crucial for the planning of complex or novel behaviours
- main site for brain’s executive funcitons
Hindbrain
- sits atop the spinal cord
- includes several structures crucial for controlling key life functions
Cerebellum
- largest area of the hindbrain
- crucial for coordination of bodily movements and balance
Midbrain
- plays an important role in coordinating movements
- contains structures that serve as relay stations for information arriving from the sensory organs
Forebrain
- plays a crucial role in supporting intellectual functioning
Cortex
- outermost surface of an organ in the body
- psychologists are most commonly interested in the cerebral cortex
Convolutions
- wrinkles visible in the cerebral cortex
- allows surface area of the brain to fit into a small volume in the skull
Longitudinal fissure
- separation diving the left cerebral hemisphere from the right
Cerebral hemisphere
- left and right cerebral hemisphere
- constitute the major part of the forebrain in mammals
Frontal lobes
- lobe that includes the prefrontal area and the primary motor projection area
Central fissure
- separation dividing the frontal lobes from the parietal lobes
Parietal lobes
- lies between occipital and frontal lobes
- includes the primary sensory projection areas and circuits that are crucial for the control of attention
Lateral fissure
- separation dividing the frontal lobes from the temporal lobes
Temporal lobes
- lies inward and down from the temples
- includes the primary auditory projection area, Wernicke’s area, amygdala, and hippocampus
Occipital lobes
- rearmost lobe
- includes the primary visual projection area
Subcortical structures
- pieces of the brain underneath the cortex
- includes the thalamus, hypothalamus, and various components of the limbic system
Thalamus
- part of the lower portion of the forebrain
- major relay and integration center for sensory information
Hypothalamus
- small structure at the base of the forebrain
- plays a role in the control of motivated behaviours (eg. eating, drinking, sexual activity)
Limbic system
- includes amygdala, hippocampus, and parts of the thalamus
- involved in the control of emotional behaviour, motivation, learning, and memory
Hippocampus
- structure in the temporal lobe
- involved in the creation of long-term memories and spatial memories
Commisures
- thick bundle of fibre along which information is sent back and forth between the cerebral hemispheres
Corpus callosum
- largest of the commissures linking the left and right hemispheres
Lesion
- a specific area of tissue damage
CT scans
- computerized axial tomography
- uses X-rays to construct a 3D image
PET scans
- positron emission tomography
- determines how much glucose is being used by specific areas of the brain at a particular moment in time
MRI scans
- magnetic resonance imaging
- uses magnetic fields to construct a 3D representation of brain tissue
- more precise than CT scans
fMRI scans
- functional magnetic resonance imaging
- uses magnetic fields to construct a 3D representation of the activity levels in different areas of the brain at a particular moment in time
EEG
- electroencephalogram
- recording of voltage changes occuring at the scalp that reflect activity in the brain underneath
Event-related potentials
- changes in an EEG in the brief period just before, during, and after an explicitly defined event
- usually measured by averaging together many trials in which this event has occurred
Fusiform face area (FFA)
- a brain area apparently specialized for the perception of faces
TMS
- transcranial magnetic stimulation
- technique in which a series of strong magnetic pulses at a specific location on the scalp causes temporary disruption in the brain region directly underneath
Localization of function
- the research endeavor of determining what specific job is performed by a particular region of the brain
Primary motor projection areas
- located at the rear of the frontal lobe
- departure point for nerve cells that send signals to lower portions of the brain and spinal cord
- result in muscle movement
Primary sensory projection areas
- main points of arrival in the cortex for information arriving from the eyes, ears, and other sense organs
Contralateral control
- pattern in which the left half of the brain controls the right half of the body, and vice versa
Association cortex
- traditional name for the portion of the human cortex outside the motor and sensory projection areas
Apraxis
- disturbance in the capacity to initiative or organize voluntary action, often caused by brain damage
Agnosias
- disturbance in a person’s ability to identify familiar objects
Neglect syndrome
- pattern of symptoms in which individuals ignore all inputs coming from one side of space
Aphasias
- disruption to language capacities, often caused by brain damage
Neurons
- an individual cell within the nervous system
Glia
- type of cell in the central nervous system
- functions = support of neurons, repair of neural connections, development of neural connections
- specialized glia provide electrical insulation for faster transmission of neural signals
Cell body
- area of biological cell containing the nucleus and metabolic machinery that sustains the cell
Dendrites
- part of the neuron that usually detects the incoming signal
Axon
- part of the neuron that typically transmits a signal away from the neuron’s cell body and carries the signal to another location
Neurotransmitter
- one of the chemicals released by neurons to stimulate adjacent neurons
Synapse
- area that includes the presynaptic membrane of one neuron, the postsynaptic membrane of another neuron, and the gap between them
- presynaptic membrane releases a small amount of neurotransmitter that drifts across the gap and stimulates the postsynaptic membrane
Presynaptic membrane
- cell membrane of the neuron sending information across the synapse
Postsynaptic membrane
- cell membrane of the neuron receiving information across the synapse
Threshold
- activity level at which a cell or detector responds, or fires
Action potential
- brief change in the electrical potential of an axon
- physical basis of the signal sent from one end of a neuron to the other
- usually triggers a further chemical signal to other neurons
Myelin sheath
- layer of tissue formed by specialized glial cells
- provides insulation around the axons of many neurons
- gaps in the insulation allowing the neuronal signal to jump from one gap to the next
- increases speed of neurotransmission
All-or-none law
- a neuron or detector either fires completely or does not fire at all
- no intermediate responses are possible
- graded responses are possible based on frequency and timing
