Unit 1: Biological Bases of Behaviour part 2

brain stem

the central core of the brain, beginning where the spina cord swells as it enters the skull; the brain stem is responsible for automatic survival functions.

medulla

the hindbrain’s structure that is the brainstem’s base; controls heartbeat and breathing

cerebellum

the hindbrain’s “little brain” at the rear of the brainstem; its functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory. 

cerebral cortex

the intricate fabric of interconnected neural cells covering the forebrain’s cerebral hemispheres; the body’s ultimate control and information-processing center. 

limbic system

neural system located mostly in the forebrain—below the cerebral hemispheres—that includes the amygdala, hypothalamus, hippocampus, and pituitary gland; associated with emotions and drives.

thalamus

the forebrain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla. 

hypothalamus

a limbic system neural structure lying below the thalamus; it directs several maintenance activities, helps govern the endocrine system, and it is linked to emotion and reward.

hippocampus

a neural center located in the limbic system; helps process explicit memories—of facts and events—for storage.

amygdala

two lima-bean-sized neural clusters in the limbic system; linked to emotion

corpus callosum

the large band of neural fibres connecting the two brain hemispheres and carrying messages between them

motor cortex

a cerebral cortex area at the rear of the frontal lobes that controls voluntary movements

somatosensory cortex

a cerebral cortex area at the front of the parietal lobes that registers and processes body touch and movement sensations.

frontal lobes

the portion of the cerebral cortex lying just behind the forehead. They enable linguistic processing, muscle movements, higher order thinking, and executive functioning.

occipital lobes

the portion of the cerebral cortex lying at the back of the head; it includes areas that receive information from the visual fields.

temporal lobes

the portion of the cerebral cortex lying roughly above the ears; it includes the auditory areas, each of which receives information primarily from the opposite ear. They also enable language processing. 

parietal lobes

the portion of the cerebral cortex lying at the top of the head and toward the rear; it receives sensory input for touch and body position.

Broca’s area

A frontal lobe area, usually in the left hemisphere, that helps control language expression by directing the muscle movements involved in speech.

Wernicke’s area

a brain area, usually in the left temporal lobe, involved in language comprehension an expression.

aphasia

impairment of language, usually caused by left hemisphere damage to Broca’s area or to Wernicke’s area.

EEG

an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp.

fMRI

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans, fMRI scans show brain function as well as structure.

Brain’s award system

Collection of structures key to experience pleasure, motivation, learning

Pituitary gland

Endocrine system’s most influential gland

Hemispheres

Left: controls right side of body, language

Right: controls left side, touch, visual

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The affected person may lapse directly into REM sleep, often of inopportune times

Insomnia

Recurring problems in falling or staying asleep

Sleep apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings

Somnambulism

A sleep disorder where a person walks or does other actions during NREM stage 3 sleep

REM Sleep behavior disorder

A sleep disorder in which normal REM paralysis does not occur; instead, twitching, talking, or even kicking or punching may occur, often acting out one’s dream

Sleep disruption effects

Impairs attention, memory, mood, and physical health

Sleep function

Sleep serves key functions like restoration and consolidation

Consolidation/information processing dream theory

Proposes that dreams help the brain process, organize, and store memories from daily experiences

Dreaming

A sequence of images, emotions, and thoughts passing through a sleeping person’s mind

Activation synthesis dream theory

Dreams are the brain’s attempt to make sense of random neural activity during sleep

REM rebound

The tendency for REM sleep to increase following REM sleep deprivation

REM Sleep (paradoxical)

Rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical but other body systems are active

Hypnagogic sensations

Bizarre experiences, suck as jerking or a feeling of floating weightlessly, while transitioning to sleep

NREM Stage 2

A deeper light sleep marked by slower brain waves, sleep spindles, and harder but still possible awakening

NREM Stage 1

The lightest stage of sleep, when you’re off and can be easily awakened; it includes slowed breathing and irregular brain waves

Consciousness

Our subjective awareness to ourselves and our environment

Distributions to circadian rhythm

When your 24-hour cycle is out of sync with you environment, often causing sleep and alertness problems

Types of consciousness (wake)

Wakefulness is the state of being alert, aware, and conscious of your surroundings

Types of consciousness (sleep)

A periodic, natural loss of consciousness-as distinct from unconsciousness from a coma, general anesthesia, or hibernation

Circadian rhythm

Our biological clock; regular bodily rhythms that occur on a 24-hour cycle

Lesion

Tissue destruction that may occur naturally, during surgery, or experimentally in the brain

Brain plasticity

The brain’s ability to change or reorganize itself by forming new neural connections after learning or injury. If one region is damaged, the brain can reorganize to take over its function.

Split brain patient

Someone whose corpus callosum has been surgically cut, preventing direct communication between the left and right hemispheres

split brain research

Studying people with a severed corpus callosum to see how the two hemispheres work independently

Reticular activating system

Controls arousal and attention by filtering sensory information and alerting the brain to important stimuli

NREM Stage 3

Brain emits large delta waves and hard to awaken. (sleepwalking and night terrors)