PSYC 201: Biological Psychology Exam 3

Topic 8, 9, 10, 11

Where is the primary motor cortex located?

In the precentral gyrus of the frontal lobe, anterior to the central sulcus.

What is the function of the primary motor cortex?

Execution of voluntary movement.

What does somatotopic organization mean in the motor cortex?

Different part of the brain maped to control specific parts of the body

What is the role of the posterior parietal cortex in movement?

helps you understand where your body is in space and how it’s positioned. It uses this information to help plan movements by sending signals to brain areas involved in decision-making and movement planning.

What does the dorsolateral prefrontal cortex do?

Helps plan movements. It gets information from the posterior parietal cortex and sends signals to motor areas to start action.

What are the two subregions of the secondary motor cortex?

Premotor cortex (plans/organizes movements) and supplementary motor cortex (assembles info for primary motor cortex).

What are mirror neurons, and where are they found?

Neurons active during both performing and observing movement; found in premotor cortex.

What is the role of the basal ganglia in movement?

Fine-tunes and smooths purposeful movement; acts as a filter to block unsuitable movements.

What is the role of the cerebellum in movement?

Coordinates balance, force, direction, duration; regulates learned sequences; also involved in higher-level processes.

What is the lateral corticospinal tract?

Pathway carrying motor commands from primary motor cortex; most fibers cross in the medulla.

What neurotransmitter is released at the neuromuscular junction?

Acetylcholine (ACh), causing muscle contraction.

What causes Multiple Sclerosis (MS)?

Immune system attacks myelin and oligodendrocytes, leading to neuron damage.

What are common MS symptoms?

Numbness, weakness, difficulty walking, tingling/pain, fatigue.

What happens in Amyotrophic Lateral Sclerosis (ALS)?

Motor neurons degenerate, leading to muscle atrophy, stiffness, twitching, and difficulty breathing/swallowing.

What gene causes Huntington’s Disease?

A dominant mutation on chromosome 4 producing abnormal Huntingtin protein.

What is chorea in Huntington’s Disease?

Jerky, random, involuntary limb movement

What neuropathology is seen in Huntington’s Disease?

Loss of GABA cells in striatum, excessive dopamine activity, shrinkage of striatum/cortex/cerebellum/thalamus, enlarged ventricles.

What drug reduces chorea in Huntington’s Disease?

Tetrabenazine (reduces dopamine in synaptic cleft

What are hallmark symptoms of Parkinson’s Disease?

Resting tremor, bradykinesia, muscle rigidity, postural instability, cognitive dysfunction.

What neuropathology underlies Parkinson’s Disease?

Degeneration of dopamine cells in substantia nigra; Lewy bodies formed by misfolded alpha-synuclein.

What is the main treatment for Parkinson’s Disease?

Levodopa (L-DOPA), converted to dopamine in the brain; effective but can cause dyskinesia and loses efficacy over time.

What is language?

Communication of thoughts/feelings using sounds, gestures, or symbols.

Which hemisphere is most involved in language?

Left hemisphere (for most people).

Function of Wernicke’s Area?

Speech comprehension

Function of Broca’s Area?

Speech production

What connects Wernicke’s and Broca’s Areas?

Arcuate fasciculus

Function of Angular Gyrus?

Reading and writing

Function of Primary Auditory Cortex?

Hearing speech.

Function of Primary Visual Cortex?

Seeing words

Function of Primary Motor Cortex (language)?

Controls mouth/larynx muscles for speech

Why is the classical model considered too simple?

Language areas vary across people; many more regions are involved

What is the “language connectome”?

 Diffuse, interconnected networks controlling different aspects of language.

Myth about hemispheric dominance?

“Right-brain vs. left-brain personalities” — not supported by evidence.

Left hemisphere language roles?

Comprehension, production, verbal memory, detail-focused processing.

Right hemisphere language roles?

Prosody (timing/rhythm), emotional meaning of words, holistic processing

Handedness and language lateralization?

 ~95% right-handers → left hemisphere; ~70% left-handers → left hemisphere.

Advantages of lateralization?

Splitting attention, efficient processing, predictable social behavior.

What is hemispatial neglect?

Inability to recognize one side of body/visual field (often left side).

What brain damage causes hemispatial neglect?

Right parietal lobe.

What is the Wada Test used for?

Determines language lateralization before surgery

How does the Wada Test work?

Anesthetize one hemisphere via carotid artery, test speech ability.

What is split-brain surgery?

Severing corpus callosum to treat severe epilepsy.

Do split-brain patients function normally?

Yes, impairments only show in specific tasks.

Does sensory info still cross hemispheres after split-brain surgery?

Yes (via optic chiasm, medulla, spinal cord)

In split-brain experiments, what happens if a hammer is shown to the right visual field?

Patient says “hammer” (left hemisphere processes language).

If a saw is shown to the left visual field, what happens?

Patient draws “saw” with left hand (right hemisphere controls left hand).

What is aphasia?

An acquired communication disorder that impairs language processing or production

Common causes of aphasia? 

Stroke, traumatic brain injury, tumor, dementia, progressive neurological disorders.

Broca’s aphasia main feature?

Impaired speech production (slow, effortful, stilted).

Do people with Broca’s aphasia understand language? 

Yes, mostly but complex sentences can be difficult.

Wernicke’s aphasia main feature?

Impaired comprehension; fluent but nonsensical speech (“word salad”).

Example of Wernicke’s aphasia error?

Saying “chair” instead of “table” or “hat” instead of “cat.”

Conduction aphasia cause?

Damage to arcuate fasciculus.

Conduction aphasia symptom? 

Difficulty repeating words/phrases, but comprehension and speech intact.

What is a stroke?

Sudden change in brain blood flow → cell death.

Stroke risk factors?

Age, family history, high BP/cholesterol, heart disease, diabetes, COVID-19.

Common stroke symptoms? 

Weakness, numbness, altered speech, headache, face drooping

Ischemic stroke cause?

Blocked blood vessel (clot or narrowing).

Most common type of stroke?

Ischemic stroke.

Hemorrhagic stroke cause? 

Vessel rupture → blood pooling in brain.

Hemorrhagic stroke risk factors?

High blood pressure, weak vessel walls.

Transient ischemic attack (TIA)?

Temporary blockage; stroke-like symptoms but no lasting damage.

Why is TIA important? 

Warning sign — 1 in 3 will later have a stroke.

Ischemic stroke treatment? 

Clot removal or open blocked artery.

Hemorrhagic stroke treatment? 

Stop bleeding, remove pooled blood.

Types of stroke rehabilitation?

Physical, speech, occupational, cognitive, behavioral therapy.

What is neuroplasticity in stroke recovery?

Undamaged brain regions take over lost functions.

Prevention strategies? 

Blood thinners, exercise, healthy diet, no smoking, limit alcohol.

What is homeostasis?

The body’s natural/resting state.

What is a stressor?

Any stimulus (psychological or physiological) that disrupts homeostasis.

What is allostasis? 

The process of restoring balance after stress.

Difference between acute and chronic stress? 

Acute = short-term; Chronic = long-term, persistent.

Distress vs. eustress?

Distress = harmful stress; Eustress = positive, short-term stress that can build resilience.

What do adrenal glands regulate?

The body’s response to stress.

What does the adrenal medulla release? 

Epinephrine (adrenaline) & norepinephrine (noradrenaline).

What does the adrenal cortex release?

Cortisol (a glucocorticoid).

What is the “fast” stress pathway?

Sympathomedullary (SAM) pathway — 1–3 seconds.

What is the “slow” stress pathway?

Hypothalamic-Pituitary-Adrenal (HPA) axis — 5–10 minutes.

What happens in the SAM pathway?

Sympathetic nervous system → adrenal medulla → adrenaline/noradrenaline → fight/flight/freeze response.

What happens in the HPA axis?

Amygdala → hypothalamus (CRH) → pituitary (ACTH) → adrenal cortex (cortisol).

Main role of cortisol? 

Raises blood glucose for energy.

How does the HPA axis shut down?

Negative feedback loop: cortisol signals hypothalamus & pituitary to stop releasing CRH/ACTH

What happens when the HPA axis malfunctions under chronic stress?

Excess cortisol or failed negative feedback.

How does chronic stress affect the immune system?

Suppresses protective immune response, increases inflammation, raises cytokines/chemokines → risk of autoimmune conditions.

How does chronic stress affect the hippocampus?

Reduces dendritic branching, neurogenesis, and memory performance.

What are ACEs?

Traumatic/stressful experiences during childhood.

Effects of ACEs?

Higher risk of depression, anxiety, substance use.

 What role do microglia play in ACEs? 

Early adversity “primes” microglia to overreact to later stressors.