PSY 3061 Exam 2 Review: Brain, Vision, Movement, Sleep & Motivation

What are the stages of the early formation of the central nervous system?

The embryo begins as a zygote, forming layers including the ectoderm, which develops into the nervous system. A neural plate forms from the ectoderm and folds into a neural tube, which develops into the forebrain, midbrain, hindbrain, and spinal cord.

What are the stages of neuronal development and survival?

1. Proliferation (new cells produced)

2. Migration (cells move)

3. Differentiation (cells develop features)

4. Myelination (axons gain sheaths)

5. Synaptogenesis (synapses form).

What are the diagnostic characteristics of fetal alcohol syndrome?

• Growth and developmental difficulties

• CNS problems

• Characteristic facial features include:

  • small eye openings

  • smooth philtrum

  • thin upper lip

  • flat midface

  • low nasal bridge.

What is the empirical evidence that the brain changes in response to the environment?

Rats in enriched environments develop thicker cortices and more dendritic branching.

Musicians and skilled keyboard players show experience-related brain changes.

How do environmental experiences affect the appearance of neurons?

Experience can change dendritic branching, the number of dendritic spines, and synapse formation and strength. Frequently used connections are maintained; less-used ones may be eliminated.

What are common causes of brain damage in younger and older adults?

• Closed-head injury is common in young adults

• Stroke is common in older adults.

• Other causes include tumors, infections, toxic exposure, and degenerative disease.

What differentiates types of stroke? How do neurons die in each type?

Ischemic stroke: a clot cuts off blood flow, depriving neurons of oxygen.

Hemorrhagic stroke: an artery ruptures, causing bleeding that damages tissue.

What is the difference in neural recovery between the central and peripheral nervous system?

PNS: damaged axons can regrow along myelin sheaths.

CNS: regrowth is limited due to scar tissue and inhibitory substances in myelin.

What is the difference between complete recovery and behavioral compensation?

Complete recovery restores lost neural function; behavioral compensation uses different strategies or remaining abilities without restoring the original pathway.

How is physical energy converted into neural impulses in the eye?

In the rods and cones of the retina, light strikes photopigments, initiating phototransduction, which generates neural impulses sent by ganglion cells through the optic nerve.

What is the function of lateral inhibition?

Sharpens visual contrast by reducing activity in neighboring pathways, enhancing the detection of edges and boundaries.

What are the three types of ganglion cells?

Parvocellular cells: small receptive fields, sensitive to color and detail.

Magnocellular cells: larger receptive fields, sensitive to movement.

Koniocellular cells: send information to the LGN and other visual areas.

What is the visual pathway from the retina to the primary visual cortex?

1) Rods and cones

2) Bipolar cells

3) Ganglion cells

4) Optic nerve

5) Optic chiasm

6) LGN

7) Primary visual cortex (V1)

8) Secondary visual cortex (V2)

9) Additional areas.

What is the difference between parvocellular, magnocellular, and koniocellular pathways?

Parvocellular: processes fine detail, color, and shape; contributes to the ventral pathway.

Magnocellular: processes movement and broad patterns.

Koniocellular: a distinct, parallel visual processing stream in primates consisting of small neurons located between the primary layers of the lateral geniculate nucleus.

• Transmits short-wavelength ("blue-yellow") color information to the primary visual cortex.

• Bridges connections with the superior colliculus to support residual visual functions like blindsight.

What does the magnocellular pathway process?

Movement and broad visual patterns.

What pathway helps track movement and location?

The dorsal ('where') pathway.

What does the koniocellular pathway carry?

An additional channel of visual information.

What area in the visual cortex helps with color constancy?

Area V4.

What can damage to area V4 impair?

Color perception or color constancy.

What does the ventral pathway help recognize?

Shapes and objects.

What is visual agnosia?

Seeing an object but being unable to recognize it.

What is the fusiform region important for?

Recognizing faces.

What condition results from damage to the fusiform region?

Prosopagnosia—difficulty recognizing faces.

What does the dorsal pathway, especially MT/V5, respond to?

The direction of movement.

What can damage to MT/V5 cause?

Motion blindness—difficulty telling whether an object is moving.

What does the MST respond to?

More complex motion, such as expansion and rotation.

What is the role of the posterior parietal cortex?

Tracks body position relative to the world.

What does the prefrontal cortex do?

Uses sensory information to anticipate outcomes and plan actions.

What is the function of the premotor cortex?

Prepares a movement toward a target.

What does the supplementary motor cortex organize?

Sequences of movements in the right order.

What is the primary motor cortex responsible for?

Executing movement.

What are mirror neurons?

Neurons that activate when performing or observing a similar movement.

Where were mirror neurons first discovered?

In the premotor cortex of macaque monkeys.

What is the dorsolateral corticospinal tract important for?

Precise movements of the hands and feet.

What does the ventromedial corticospinal tract control?

Neck, shoulders, and trunk for posture and whole-body movements.

What are the three main structures of the basal ganglia?

Caudate nucleus, putamen, and globus pallidus.

What causes involuntary movements in Huntington's Disease?

Damage to the caudate disrupts circuits that suppress unwanted movements.

What happens when dopamine neurons in the substantia nigra die?

Loss of effective support for initiating voluntary movement.

What are symptoms of Parkinson's Disease?

Tremor, muscle rigidity, slow movement, and difficulty starting movements.

What causes Parkinson's Disease?

Progressive loss of dopamine-producing neurons in the substantia nigra.

What is the treatment for Parkinson's Disease?

L-DOPA to replace dopamine activity.

What are symptoms of Huntington's Disease?

Involuntary jerking movements and possible cognitive changes.

What causes Huntington's Disease?

An inherited mutation involving expanded CAG repeats on chromosome 4.

What are symptoms of Myasthenia Gravis?

Muscle weakness that worsens with use and rapid fatigue.

What causes Myasthenia Gravis?

An autoimmune attack on acetylcholine receptors at the neuromuscular junction.

What treatments improve signaling at the junction in myasthenia gravis?

Medicines such as pyridostigmine, immune-directed treatments, and sometimes thymectomy.

What is the key contrast between Parkinson's, Huntington's, and myasthenia gravis?

Parkinson's: makes wanted movements hard to start

Huntington's: causes unwanted movements

Myasthenia gravis: causes fatigable weakness due to disrupted nerve-to-muscle signals.

What is a circannual rhythm?

A rhythm that runs on an approximately yearly cycle, such as seasonal migration.

What is a circadian rhythm?

A rhythm that runs on an approximately 24-hour cycle, regulating sleep, wakefulness, body temperature, and hormone release.

What happens to the human sleep-wake cycle in a free-running circadian rhythm?

It tends to run slightly longer than 24 hours, causing sleep times to drift.

What are morning types and evening types in terms of sleep patterns?

Morning types prefer earlier sleep and wake times; evening types prefer later times.

What are the EEG stages of sleep?

Relaxed but awake: Alpha waves

Stage 1: Light sleep with irregular waves

Stage 2: Sleep spindles and K-complexes

Stages 3 & 4: Slow-wave sleep; REM sleep: Fast, irregular waves and dreaming.

What characterizes REM sleep?

Fast, irregular EEG waves, rapid eye movements, relaxed postural muscles, and strong association with dreaming.

What initiates REM sleep?

Activity rises in the pons, with acetylcholine promoting the shift into REM and serotonin suppressing it.

What is the role of the pons in REM sleep?

It helps switch REM on, activates visual and other brain areas, and inhibits large muscle movement.

What area in the hypothalamus regulates temperature?

The preoptic area/anterior hypothalamus.

What hormone regulates thirst?

Vasopressin, also called antidiuretic hormone (ADH).

What is osmotic thirst?

Thirst caused by too much salt relative to water.

What triggers osmotic thirst?

Fluid outside cells becomes more concentrated after salty food, drawing water out of cells.

What is hypovolemic thirst?

Thirst caused by too little fluid volume.

What triggers hypovolemic thirst?

Loss of body fluid through bleeding or heavy sweating lowers blood volume.

What is the difference between the lateral and ventromedial hypothalamus?

Lateral hypothalamus promotes eating

The ventromedial hypothalamus regulates how much and how often an animal eats.

What regulates hunger versus satiety?

Hunger pathway: involves hunger-sensitive neurons responding to ghrelin.

Satiety pathway: involves satiety-sensitive neurons responding to signals of food availability.

What are the symptoms of anorexia nervosa?

Eating much less than needed, intense fear of gaining weight, and significant weight loss.

What is the treatment for anorexia nervosa?

Nutritional and medical care to restore health, along with eating-disorder-focused therapy.

What are the symptoms of bulimia nervosa?

Repeated binge eating followed by compensatory behaviors like self-induced vomiting.

What is a common treatment for bulimia nervosa?

Cognitive behavioral therapy for eating disorders (CBT-ED) and nutritional support.

What is the key difference between anorexia and bulimia?

Anorexia involves persistent restriction of food intake; bulimia involves binge-compensate cycles.