AP PSYCH UNIT 1 PART 2: Biological Bases of Behavior

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

psychoactive drug

a chemical substance that alters the brain, causing changes in perceptions and moods.

substance use disorder

a disorder characterized by continued substance use despite significant life disruption.

depressants

drugs that reduce neural activity and slow body functions

tolerance

the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect.

addiction

an everyday term for compulsive substance use (and sometimes for dysfunctional behavior patterns, such as out-of-control gambling) that continue despite harmful consequences.

withdrawal

the discomfort and distress that follow discontinuing an addictive drug or behavior.

barbiturates

drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgment.

opioids

opium and its derivatives; they depress neural activity, temporarily lessening pain and anxiety.

stimulants

drugs that excite neural activity and speed up body functions.

biological psychology

the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.

biopsychosocial approach

an integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.

levels of analysis

the differing complementary views, from biological to psychological to social-cultural, for analyzing any given phenomenon.

neuroplasticity

the brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

lesion

tissue destruction. Brain _____ may occur naturally (from disease or trauma), during surgery, or experimentally (using electrodes to destroy brain cells).

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 (functional MRI)

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

hindbrain

consists of the medulla, pons, and cerebellum; directs essential survival functions, such as breathing, sleeping, and wakefulness, as well as coordination and balance.

midbrain

found atop the brainstem; connects the hindbrain with the forebrain, controls some motor movement, and transmits auditory and visual information.

forebrain

consists of the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activities, sensory and associative functions, and voluntary motor activities.

brainstem

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

medulla

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

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.

reticular formation

a nerve network that travels through the brainstem into the thalamus; it filters information and plays an important role in controlling arousal.

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.

limbic system

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

amygdala

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

hypothalamus

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

hippocampus

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

cerebral cortex

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

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 (such as making plans and judgments).

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.

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

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.

association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

neurogenesis

the formation of new neurons.

corpus callosum

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

split brain

a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.