Psychology 4090 Cognitive Neuroscience Exam 2 Study Guide

75 flashcards covering action systems, memory structures, emotion theories, language processing, and cognitive control based on the PSYC 4090 Exam 2 Study Guide.

Alpha motor neuron

A lower motor neuron that innervates extrafusal skeletal muscle fibers; it serves as the final common pathway for voluntary movement, reflex movement, and posture.

Gamma motor neuron

A lower motor neuron that innervates intrafusal muscle spindle fibers, adjusting spindle sensitivity to detect stretch during contraction.

Stretch reflex

A mechanism where muscle stretch activates Ia afferent fibers to excite alpha motor neurons of the same muscle while inhibiting antagonist muscles.

Central pattern generators

Spinal or brainstem networks that produce rhythmic patterns such as walking, chewing, or breathing without requiring a command for every micro-step.

Corticospinal tract / pyramidal tract

A voluntary motor pathway from M1, premotor cortex, and SMA through the brainstem pyramids; essential for fine, fractionated hand and finger movements.

Extrapyramidal tract

Motor systems outside the pyramidal tract, including brainstem pathways and those influenced by basal ganglia, which regulate posture, tone, and vigor.

Hemiplegia

Paralysis on one side of the body, usually caused by damage to the contralateral motor cortex or corticospinal tract.

Primary motor cortex (M1)

The cortical area that executes voluntary movement and codes direction, force, and synergies through overlapping populations of neurons.

Premotor cortex

A region important for externally guided action, cue-based selection, reaching, grasping, and action goals.

Supplementary motor area (SMA)

An area critical for internally generated movement, learned sequences, bimanual coordination, and movement preparation.

Posterior parietal cortex

The region that transforms sensory coordinates into action coordinates, determining where objects and effectors are in space.

Affordance competition hypothesis

The theory that objects automatically activate multiple possible actions represented in parietal/premotor circuits, while the PFC/basal ganglia bias selection.

Motor program

An abstract movement plan that can be executed with different muscles or effectors while maintaining the same identity, such as a signature.

Apraxia

The inability to perform skilled voluntary actions despite intact strength and comprehension, often following left parietal or premotor damage.

Mirror neurons

Neurons that fire both when performing an action and when observing another person perform a similar action, linking perception and action.

Population vector

A method of decoding movement direction based on the summed activity of many M1 neurons.

Efference copy

An internal copy of a motor command sent to predictive circuits, especially the cerebellum, to model sensory consequences.

Forward model

A cerebellar process that uses efference copies and body state to predict the sensory consequences of an ongoing action.

Sensory prediction error

The mismatch between predicted and actual feedback that the cerebellum uses to update future movements.

Ataxia

A condition characterized by uncoordinated movement, intention tremors, and a wide-based gait, often resulting from cerebellar damage.

Basal ganglia

An action-selection and gating system consisting of nuclei like the striatum, globus pallidus, and STN.

Striatum

The input structure of the basal ganglia, composed of the caudate nucleus, putamen, and ventral striatum.

Caudate nucleus

A nucleus within the striatum involved in cognitive and associative loops with the PFC for rule use and goal-directed action selection.

Putamen

A component of the striatum primary involved in the motor loop, supporting movement habits and sequences.

Subthalamic nucleus (STN)

An excitatory nucleus in the basal ganglia that helps brake actions through the indirect and hyperdirect pathways.

Direct pathway

The "Go" circuit: cortex $(+)$ $\rightarrow$ striatum D1 neurons $(-)$ $\rightarrow$ GPi/SNr inhibited $\rightarrow$ thalamus disinhibited $\rightarrow$ thalamus $(+)$ cortex, facilitating action.

Indirect pathway

The "No-Go" circuit: cortex $(+)$ $\rightarrow$ striatum D2 neurons $(-)$ $\rightarrow$ GPe inhibited $\rightarrow$ STN disinhibited $\rightarrow$ STN $(+)$ GPi/SNr $\rightarrow$ GPi/SNr $(-)$ thalamus, suppressing action.

Parkinson’s disease

A disorder caused by the loss of SNc dopamine, leading to an underactive direct pathway and overactive indirect pathway, resulting in overinhibition of the thalamus.

Bradykinesia

Slowness of movement, a negative symptom of Parkinson's disease.

Huntington’s disease

An inherited disease causing striatal degeneration (especially the indirect pathway early), leading to reduced braking of unwanted motor programs.

Chorea

Irregular, unpredictable, flowing involuntary movements characteristically found in Huntington's disease.

Dystonia

Sustained muscle contractions or abnormal postures resulting from abnormal basal ganglia output and muscle co-contraction.

Encoding

The process of converting a sensory experience into a neural representation within the brain.

Storage

The phase of memory focused on maintaining information over time.

Retrieval

The process of reactivating stored information to guide current thought or behavior.

Iconic memory

The very brief high-capacity sensory memory for visual information.

Partial report procedure

Sperling’s method proving that iconic memory has a high capacity but decays rapidly by using a cue after a display is removed.

Central executive

A working memory controller that allocates attention, updates, shifts, and inhibits information.

Phonological loop

A verbal/acoustic maintenance system consisting of a phonological store and articulatory rehearsal.

Visuospatial sketchpad

A maintenance system in working memory for images, locations, and spatial relations.

Declarative / explicit memory

Conscious memory for facts and events that depends on the medial temporal lobe for formation.

Episodic memory

Autobiographical memory for events occurring in a specific context with a what-where-when structure.

Semantic memory

General knowledge about facts, concepts, and word meanings.

Nondeclarative / implicit memory

Memory expressed through performance without requiring conscious recollection, such as procedural skills or priming.

Anterograde amnesia

A pathological impairment in forming new long-term memories after the onset of brain damage.

Retrograde amnesia

The loss of memories for events that occurred before the time of brain damage.

Temporal gradient

The phenomenon where recent memories are more vulnerable to loss than remote memories, often seen in retrograde amnesia.

Patient H.M.

Henry Molaison, who had bilateral medial temporal resection, resulting in severe anterograde declarative amnesia but intact intelligence and procedural learning.

Patient M.S.

A patient with impaired visual priming after occipital damage but spared declarative recognition, showing a double dissociation with H.M.

Hippocampus

The MTL structure that binds item, context, and time relations into episodic memory and supports cognitive maps.

Entorhinal cortex

The gateway between the neocortex and the hippocampus that routes information through different hippocampal subfields.

Perirhinal cortex

An MTL region specifically involved in item/object memory and familiarity.

Parahippocampal gyrus/cortex

A region within the MTL involved in context, scenes, spatial layout, and environmental associations.

Standard consolidation theory

The theory that the hippocampus is needed for new memories, but over time, they are represented in the neocortex and become hippocampus-independent.

Multiple-trace theory

The theory that the hippocampus remains necessary for vivid episodic recollection indefinitely, even as facts may become semanticized.

Hebbian learning

A fundamental principle of plasticity summarized as: "cells that fire together wire together."

Long-term potentiation (LTP)

A long-lasting increase in synaptic strength following correlated or high-frequency neural activity.

NMDA receptors

Glutamate receptors that act as coincidence detectors by requiring both glutamate and postsynaptic depolarization to allow calcium influx.

James-Lange theory

The emotion theory stating that bodily/behavioral responses come first and the subjective feeling is the interpretation of those changes.

Cannon-Bard theory

The theory that central brain processing triggers a conscious feeling and a bodily response simultaneously and in parallel.

Schachter-Singer theory

The theory that emotion results from physiological arousal paired with a cognitive label based on the context.

Amygdala

A structure that detects biologically significant stimuli, supports fear conditioning, and modulates attention and memory.

Patient S.M.

A patient with bilateral amygdala damage who exhibited impaired fear recognition and reduced fear responses.

Insula

The brain region associated with interoception, visceral feeling, pain awareness, and specifically the emotion of disgust.

Orbitofrontal cortex (OFC)

An area that represents expected value, reward/punishment, and supports reversal learning and flexible updating.

Valence

A dimension of emotion representing how positive or negative the experience is.

Arousal

A dimension of emotion representing the level of activation or excitement versus calmness.

Somatic marker hypothesis

The theory that bodily value signals associated with options bias decision making prior to explicit reasoning.

Reappraisal

An emotion regulation strategy that involves reinterpreting a situation early to reduce feelings and physiological responses.

Phoneme

The smallest unit of sound in a language that can distinguish meaning.

Morpheme

The smallest meaning-bearing unit of language, such as a root word or a prefix (e.g., "un-," "dog").

Syntax

The hierarchical word and phrase structure that determines grammatical roles and relations in a sentence.

Broca’s aphasia

A non-fluent aphasia characterized by effortful, agrammatic speech with relatively preserved comprehension, linked to the left inferior frontal gyrus.

Wernicke’s aphasia

A fluent aphasia characterized by meaningless speech, paraphasias, and poor comprehension, linked to the posterior superior temporal region.

Conduction aphasia

An impairment characterized by fluent speech and good comprehension but poor repetition, classically linked to arcuate fasciculus damage.

Arcuate fasciculus

The white-matter tract that links the posterior temporal language regions with the frontal speech production areas.

N400

An event-related potential (ERP) around 400 ms that is larger in response to semantic mismatches or low semantic expectancy.

P600

An event-related potential (ERP) around 600 ms associated with syntactic reanalysis, repair, or integration difficulty.

Cognitive control

The process of guiding thought and action according to internal goals rather than automatic impulses.

Anterior cingulate cortex (ACC)

A medial frontal region that detects conflict, error likelihood, and the need for increased cognitive control.

Error-related negativity (ERN)

A negative event-related potential occurring shortly after an error is committed, linked to performance monitoring.

Lateral PFC

The area of the prefrontal cortex responsible for the active maintenance and manipulation of rules, goals, and task representations.

Perseveration

The tendency to repeat a response or follow a rule that is no longer correct, often seen following frontal lobe damage.

Utilization behavior

The stimulus-driven use of objects regardless of intention, resulting from impaired frontal inhibitory control.

Phineas Gage

A classic case of vmPFC/OFC damage that resulted in significant changes to personality and social decision making.