Auditory, Sensory, and Motor Systems Overview

Middle ear and inner ear evolution

To amplify sounds

Auditory receptors location

Along the basilar membrane of the cochlea

Identification of low-pitched sound

The whole basilar membrane vibrates in synchrony with the sound frequency

Identification of high-pitched sound

Each frequency produces a peak response at one point along the basilar membrane.

Auditory cortex vs visual cortex

Damage to the primary auditory cortex does not cause deafness

Tonotopic map

Each location in the auditory cortex responds to a preferred tone.

Localization of sudden sounds

By comparing the time of arrival at the two ears.

Absolute pitch prevalence

More common among people with extensive musical training beginning in early childhood

Hearing aids and older people

Lack of inhibitory transmission in the auditory cortex

Vestibular system behavior observation

You can read a page better while shaking your head than while shaking the page.

Semicircular canals response

When you are moving and changing speed

Nervous system representation of sensations

Different types of sensation remain separate even in the cerebral cortex.

Coldness vs heat receptors

Coldness receptors respond to a change in temperature, not to the absolute temperature.

Anterior cingulate cortex function

It responds to the emotional aspect of the sensation.

Spinal cord injury sensation loss

Pain axons cross the spinal cord at once, but touch fibers do not.

Pain-relieving drugs

Certain drugs that relieve pain also relieve hurt feelings.

Cannabinoids vs opiates in pain relief

Cannabinoids act on the periphery, not the brain.

Placebos and pain relief

A placebo can relieve pain in one body part without affecting another.

Chronic pain after injury

The brain has learned to increase its pain perception.

Sensation that inhibits itch

Pain

Taste receptor type

A modified skin cell.

Evidence of multiple taste receptors

Certain chemicals can modify one taste without affecting others.

Receptors for sweet, bitter, and umami

Resemble metabotropic synaptic receptors.

Variety of bitter tastes

We have 30 or more types of bitter receptors.

Sensitivity to taste or smell

Some people have more taste receptors or odor receptors than others do.

Variety of smells

We have hundreds of types of olfactory receptors.

Olfactory receptor replacement

It finds the correct site by chemical attraction.

Metabotropic synaptic receptors

Receptors that are activated by neurotransmitters and initiate a cascade of cellular events.

Bitter receptors

We have 30 or more types of bitter receptors.

Taste and smell sensitivity

Some people have more taste receptors or odor receptors than others do.

Olfactory receptors

We have hundreds of types of olfactory receptors.

Vomeronasal organ

A. Pheromones.

Effect of pheromones on humans

Women who spend much time together tend to synchronize their menstrual cycles.

Synesthesia behavioral evidence

People with synesthesia can find a 2 among 5s, or a 6 among 8s, faster than usual if they have different synesthetic colors, and slower if they have the same color.

Acetylcholine and muscle movement

Acetylcholine causes the extensor muscle to contract.

Fish movement in colder water

The fish swims at the same speed by recruiting more muscle fibers.

Mammals' slow-twitch muscle fibers

Because they are aerobic, they do not fatigue rapidly.

Stretch reflex

The receptor detects that a muscle is stretched, and sends a signal to contract it reflexively.

Muscle spindle and Golgi tendon organ

Proprioceptors.

Rhythm of a cat's scratching movements

A set of neurons in the spinal cord.

Motor cortex to muscles route

Axons from the motor cortex go to the brainstem and spinal cord, which have axons to the muscles.

Half-second stimulation in the motor cortex

Contraction of whatever muscles are necessary to produce a particular outcome.

Brain area peak activity during movement

The primary motor cortex.

Antisaccade task

The ability to inhibit a movement.

Mirror neurons and imitation

Mirror neurons develop their properties before children start to imitate.

Medial corticospinal tract control

Bilateral movements of the trunk of the body.

Finger-to-nose test

Possible dysfunction of the cerebellum.

Cerebellum and movement timing

The cerebellum is most important for timing.

Parallel fibers and Purkinje cells arrangement

They are perpendicular to them.

Basal ganglia movements

Self-initiated, and generally slower than responses that a stimulus triggers.

Basal ganglia and motivation

The basal ganglia increase vigor of response depending on expected reward value.

Learning dependent on basal ganglia

Motor habits that are difficult to describe in words.

Order of events in voluntary movement

Activity begins in the premotor cortex, and a bit later, people are aware of forming an intention, and finally the movement starts.

Deterioration of which axons leads to Parkinson's disease?

Axons from the substantia nigra to the striatum

People with Parkinson's disease show the greatest impairment with which type of movement?

Spontaneous voluntary movements

Which of these chemicals damages the brain in a way that resembles Parkinson's disease?

MPTP

In what way is L-dopa treatment for Parkinson's disease unusual?

It was based on a theory instead of trial and error.

What is the most common age of onset for Huntington's disease?

Middle age (30 to 50)

Why does damage to the basal ganglia lead to involuntary movements in Huntington's disease?

Basal ganglia damage reduces inhibition of the thalamus.

An examination of C-A-G repeats on one gene enables physicians to predict who will develop Huntington's disease. What else does it help them predict?

The age of onset of symptoms

Workers on certain submarines work 6 hours, relax 6 hours, and then sleep 6 hours. After weeks on this schedule, what happens to their circadian rhythm?

It continues producing the usual 24-hour rhythm.

Why do people in Antarctica during the winter often find it difficult to work together?

Their circadian rhythms drift out of phase with one another

For most young adults, what happens to mood as a function of time of day?

Mood tends to be most pleasant in late afternoon or early evening.

Why do people in eastern Germany awaken earlier, on average, than those in western Germany?

The sun rises earlier in eastern Germany.

Why do many high school students get worse test grades in the morning than in the afternoon?

Teenagers tend to stay up late and awaken late.

What evidence most strongly indicates that the SCN produces the circadian rhythm itself?

SCN cells isolated from the body continue to produce a circadian rhythm.

Light can reset the SCN's rhythm even after damage to all rods and cones. Why?

The SCN receives input from ganglion cells that respond to light.

If you want to get to sleep on time, what should you avoid?

Short-wavelength light late in the evening

After the proteins TIM and PER reach a high level during the day, what causes their level to decrease at night?

High levels of the proteins inhibit the genes that produce these proteins.

When is melatonin mostly released?

At night, for all species

Of the following, which shows the LEAST brain activity?

Coma

Sleep spindles in stage 2 sleep appear to be important for which of the following?

Consolidation of memory

What do the high-amplitude slow waves of slow-wave sleep indicate?

Synchrony among neurons

Why is REM sleep also known as paradoxical sleep?

It is deep sleep in some ways and light in others

At which time, if any, is slow-wave sleep most common?

Not immediately, but during the early part of the night's sleep

What tends to activate the locus coeruleus?

Meaningful information

What is the role of orexin with regard to wakefulness and sleep?

It helps someone stay awake

Why are people unconscious during slow-wave sleep?

Inhibitory transmitters block the spread of activity in the cortex.

If you awaken but find you temporarily cannot move your arms or legs, what is happening?

Most of your brain is awake, but part of your pons and medulla remain in REM sleep.

Of the following, which one is not associated with an increased probability of sleep apnea?

Being female

Narcolepsy is linked to a deficit of which neurotransmitter?

Orexin

Circumstances for little sleep in animals

The environment is about the same 24 hours a day.

Oxygen acquisition in whales and dolphins at night

They sleep in just one hemisphere at a time.

Frigate birds' sleep at sea

They sleep only in brief episodes, and not much overall.

Helpful question for predicting animal sleep hours

What does the animal eat?

Effect of sleep on memory

Certain synapses become weakened, enabling others to stand out by contrast.

Group with highest percentage of REM sleep

Infants

Neurocognitive hypothesis of dreams

Dreams are thinking that occurs under unusual conditions.

Definition of allostasis

Processes that anticipate future needs.

Energy devoted to basal metabolism

Well over half of the human body's energy is devoted to basal metabolism.

Regulation of body temperature in ectothermic animals

They move to a location with a more favorable temperature.

Example of an ectothermic animal

Snake.

Advantage of maintaining constant high body temperature

It keeps the muscles ready for rapid, prolonged activity even in cold weather.

Effect of heating the POA/AH

You would sweat.

Cause of fever during infection

The immune system delivers prostaglandins and histamine to the hypothalamus.

Description of a fever

Fever is one way in which the body fights against bacteria.

Effect of eating something salty

Water flows out of the cells.

Result of adding salt to extracellular fluids

Increased osmotic thirst.

Function of vasopressin

It decreases urination and increases thirst.

Reason for stopping drinking before water reaches cells

Drinking inhibits neurons responsible for thirst.