COGNITIVE NEUROSCIENCE EXAM 1

Neuron

A cell that receives, integrates, and sends information through electrical and chemical signals.

Glia

Cells that support neurons, maintain the neural environment, and contribute to myelin and repair.

Dendrite

A branch of a neuron that receives much of its incoming synaptic input.

Axon

The long neuronal process that carries an action potential toward other cells.

Synapse

The junction where one neuron communicates with another cell.

Action potential

A brief electrical change that travels down an axon after the neuron reaches threshold.

Postsynaptic potential

A local change in the receiving neuron; excitatory and inhibitory inputs can combine over time and across locations.

Temporal summation

Inputs arriving close together in time combine.

Spatial summation

Inputs arriving at different locations on a neuron combine.

Myelin

An insulating sheath around axons that helps signals travel faster.

Gray matter / white matter

Gray matter contains many cell bodies and local circuits; white matter contains many connecting axons

Association cortex

Cortical regions that combine or interpret information beyond basic sensory input or motor output.

Structural MRI

An imaging method used to examine brain anatomy.

Diffusion-weighted imaging

MRI-based method that estimates the orientation of white-matter pathways.

Functional connectivity

Statistical similarity in activity patterns between brain regions; it does not by itself establish direct communication.

BOLD signal

The fMRI signal based on changes in oxygenated and deoxygenated blood associated with neural activity

EEG

Recording of electrical activity at the scalp, useful for measuring the timing and rhythms of population-level neural activity.

ERP

An EEG response averaged and time-locked to a particular event.

MEG

Recording of magnetic fields associated with neural electrical activity.

PET

Imaging method using a radioactive tracer to measure metabolism or specific molecular binding.

TMS

Magnetic stimulation used to temporarily perturb cortical activity and test its contribution to performance

tDCS

Weak electrical stimulation used to modulate cortical excitability; effects are relatively diffuse.

Temporal resolution / spatial resolution

How precisely a method measures when an event occurs / where activity occurs.

Converging evidence

Agreement across methods with different strengths and limitations.

Motor tract

A pathway that carries commands from the brain toward spinal motor systems.

Motor plan

An organized representation of an intended action, prepared before movement.

Forward model

A prediction of the likely sensory consequences of a motor command, associated with cerebellar processing

Basal ganglia loop

A circuit linking cortex, basal ganglia, and thalamus that helps regulate action selection and inflation

Apraxia

Difficulty carrying out learned skilled actions that is not explained by basic weakness.

Akinesia

Marked difficulty initiating movement.

Bradykinesia

Slowness of movement.

Tremor

Rhythmic, involuntary movement.

Proprioception

Information about the position and movement of the body.

Callosal disconnection

Interruption of communication between hemispheres through the corpus callosum.

Photoreceptor

A light-sensitive retinal cell; rods and cones are the two main types.

Rod / cone

Rods are highly sensitive in dim light; cones support color and fine detail, especially near the fovea

Fovea

The central retinal region with dense cone representation and high visual acuity.

Receptive field

The region of sensory space where stimulation changes a neuron’s response.

Center-surround organization

A receptive-field arrangement in which stimulation at the center and surrounding area has different effects

Retinotopic map

A neural map that preserves the spatial arrangement of locations on the retina.

LGN

The lateral geniculate nucleus of the thalamus; a major relay in the geniculostriate visual pathway.

Geniculostriate pathway

The route from retina through LGN to primary visual cortex.

Tectopulvinar pathway

A route involving superior colliculus and pulvinar, important for orienting and some residual visual

processing

Binocular disparity

The difference between the images received by the two eyes; a cue to depth.

Blindsight

Above-chance visual responding without the usual conscious visual experience in part of the visual

field

Achromatopsia

A deficit in color perception associated with damage to color-processing regions.

Ventral visual stream

Occipital-to-temporal pathway that contributes to object identity and recognition.

Agnosia

Difficulty recognizing an object or stimulus despite adequate basic sensation.

Apperceptive agnosia

Difficulty forming a coherent visual percept from features.

Associative agnosia

Difficulty connecting a relatively adequate percept with object identity or meaning.

Prosopagnosia

Difficulty recognizing familiar faces.

Invariance

The ability to recognize an object despite changes in size, position, viewpoint, or lighting.

Feature-based processing

Recognition emphasizing individual parts or attributes.

Configural processing

Recognition emphasizing the relationships among parts and the overall arrangement.

Population coding

Representation of information through a pattern of activity across a group of neurons.

Category-specific deficit

Disproportionate difficulty recognizing or understanding one class of items compared with others.

Cross-modal priming

Prior recognition through one sense influences later processing through another sense.

Dorsal visual stream

Occipital-to-parietal pathways supporting spatial processing, visually guided action, and related

functions

Egocentric frame

A representation of location relative to the observer, such as eye-, head-, or body-centered.

Allocentric frame

A representation of location relative to external objects or landmarks.

Categorical relation

A broad spatial relation such as above, below, left, or right.

Coordinate relation

A more precise metric relation, such as exact distance or angle.

Binocular disparity

A depth cue from comparing the two eyes’ slightly different views.

Motion parallax

A depth cue from the relative movement of images as the observer moves.

Optic flow

The patterned movement of visual information across the retina during self-motion.

MT/V5 and MST

Motion-sensitive visual areas; MST is involved in complex motion patterns such as optic flow.

Optic ataxia

Difficulty reaching accurately toward visually perceived targets.

Route-based navigation / map-based navigation

Navigation using learned sequences of turns / navigation using relationships among places.

Numerosity

The quantity or number of items in a set, represented in part by parietal systems.

Anterior / rostral; posterior / caudal

Toward the front; toward the back.

Superior / dorsal; inferior / ventral

Toward the top; toward the bottom.

Medial; lateral

Toward the midline; toward the side.

Spinal cord

Major route carrying information between brain and body; also supports reflexes.

Medulla

Vital functions such as breathing and heart regulation; arousal.

Cerebellum

Coordination, timing, fluent movement, and motor learning; helps predict movement consequences.

Midbrain

Superior colliculus supports visual orienting; inferior colliculus supports auditory processing.

Thalamus

Major relay and routing hub between sensory systems and cortex; also participates in cortex-to-subcortex loops

Hypothalamus

Homeostasis and motivated behaviors.

Basal ganglia

Movement selection/initiation and stopping, motor planning and learning; also connected with broader cognitive functions

Limbic structures

A network with roles in emotion, motivation, and memory, rather than a single-purpose emotion center

Frontal / parietal / temporal lobes

Planning and evaluating behavior / multisensory integration and spatial processing / auditory processing, memory, object recognition, and emotion.

Primary motor cortex

Contributes to execution and control of movement parameters such as force.

Supplementary motor complex

Specifies, prepares, and initiates internally organized motor plans.

Premotor cortex

Selects action types suited to external cues or task demands; frontal eye fields help program voluntary gaze shifts.

Parietal cortex

Combines vision, proprioception, and body-state information to guide and update goal-directed action.

Basal ganglia

Cortical-subcortical loops help initiate or suppress actions; contribute to planning and learning.

Cerebellum

Coordinates timing and smoothness, supports rapid actions with limited feedback, and helps learn/predict sensory consequences

Anterior cingulate cortex

Helps select responses in novel or competing situations and evaluate outcomes/errors.

Right inferior frontal cortex

Contributes to inhibiting a prepotent motor response.