Biological Bases of Behavior and Sensation

Comprehensive vocabulary flashcards covering heredity and environment, the nervous system, neural firing, brain structures and functions, sleep and dreams, and sensory processes.

Evolutionary perspective

Focuses on how natural selection favored behavioral traits that promoted survival and gene propagation.

Eugenics

The historical and controversial movement aimed at improving the genetic quality of a human population.

Natural Selection

Process where heritable traits that provide a survival advantage are more likely to be passed on.

Twin studies

Behavioral genetic research comparing identical and fraternal twins to determine the relative influence of nature vs. nurture.

Autonomic nervous system

Division of the peripheral nervous system controlling involuntary bodily functions like heart rate and digestion.

Central nervous system

The primary command center of the body consisting exclusively of the brain and spinal cord.

Parasympathetic nervous system

Division of the autonomic nervous system that calms the body and conserves its energy.

Peripheral nervous system

Sensory and motor neurons connecting the central nervous system to the rest of the body.

Somatic nervous system

Division of the peripheral nervous system controlling voluntary movements of skeletal muscles.

Sympathetic nervous system

Division of the autonomic nervous system that arouses the body to mobilize energy during stressful fight-or-flight situations.

Agonist drugs

Chemical substances that mimic or enhance the effects of a specific neurotransmitter by binding to its receptors.

Antagonist drugs

Chemical substances that block or inhibit the action of a specific neurotransmitter at the receptor site.

All-or-nothing principle

Law stating that a neuron fires completely or not at all once threshold is reached.

Depolarization

Change in a neuron's membrane potential where the inside becomes more positive, triggering an action potential.

Depressants

Psychoactive drugs that reduce neural activity and slow down essential body functions.

Excitatory neurotransmitter

Chemical messenger that increases the likelihood that a receiving neuron will fire an action potential.

Inhibitory neurotransmitter

Chemical messenger that decreases the likelihood that a receiving neuron will fire an action potential.

Refractory period

Brief resting pause after a neuron fires during which it cannot generate another action potential.

Resting potential

The stable, negative charge of a neuron when it is inactive and waiting to fire.

Reuptake

Process where excess neurotransmitters are reabsorbed by the sending neuron after transmission.

Stimulants

Psychoactive drugs that excite neural activity and speed up bodily functions.

Aphasia

Impairment of language capabilities usually caused by left-hemisphere brain damage to Broca's or Wernicke's areas.

Brain plasticity

The brain's unique ability to reorganize and adapt by forming new neural pathways after damage.

EEG (Electroencephalogram)

Amplified recording of electrical wave activity sweeping across the brain's surface.

fMRI (Functional MRI)

Imaging technique tracking blood flow to reveal brain activity and functional structures in real time.

Lesioning

Intentional destruction of brain tissue to observe subsequent changes in behavior or function.

Limbic system

Neural network associated with emotions, drives, and memory formatting.

Pituitary gland

The endocrine system's "master gland" that regulates growth and controls other endocrine glands.

Split brain patient

Individual whose corpus callosum has been surgically severed, isolating the left and right hemispheres.

Activation synthesis dream theory

Suggests dreams are the brain's attempt to synthesize random neural activity into a story.

Circadian rhythm

The internal 24-hour biological clock regulating sleep-wake cycles and temperature.

Consolidation dream theory

Proposes that dreams help process, sort, and fix the day's experiences into long-term memory.

Hypnagogic sensations

Vivid, lifelike hallucinatory experiences occurring during the transitional stage into sleep.

Insomnia

Sleep disorder characterized by persistent problems falling or staying asleep.

Narcolepsy

Sleep disorder featuring uncontrollable, sudden daytime sleep attacks directly into REM sleep.

REM rebound

The tendency for REM sleep to increase following periods of sleep deprivation.

Sleep apnea

Sleep disorder where breathing repeatedly stops and starts throughout the night.

Somnambulism

Formal clinical term for sleepwalking, which occurs during deep NREM sleep.

Accommodation

Process where the eye's lens changes shape to focus near or far objects on the retina.

Conduction deafness

Hearing loss caused by structural damage to the mechanical systems conducting sound waves to the cochlea.

Frequency theory

Pitch perception theory stating that the rate of nerve impulses matches the frequency of a tone.

Gate control theory

Theory that the spinal cord contains a neurological gate that blocks or allows pain signals to pass.

Just noticeable difference

The minimum structural change between two stimuli required for detection 50 percent of the time.

Opponent-process color theory

Explains color vision via opposing retinal processes (red-green, yellow-blue, white-black).

Place theory

Pitch perception theory linking the pitch we hear to the specific place stimulated on the cochlea's membrane.

Transduction

Conversion of one form of physical energy into neural impulses the brain can interpret.

Trichromatic color theory

Theory that the retina contains three distinct types of color receptors (red, green, and blue).

Vestibular sense

The sense of body movement, position, and balance, managed by the semicircular canals in the inner ear.

Absolute threshold

The minimum stimulation needed to detect a particular stimulus 50 percent of the time.

Sensation

Process by which sensory receptors and the nervous system receive and represent stimulus energies.

Sensory adaptation

Diminished sensitivity as a consequence of constant, unchanging stimulation.

Synesthesia

Neurological condition where stimulation of one sensory pathway leads to involuntary experiences in a second sensory pathway.

Weber's law

Principle stating that to be perceived as different, two stimuli must differ by a constant minimum percentage.

Sensory interaction

The principle that one sense may influence another, such as smell influencing taste.