AP Psychology: Biological Bases of Behavior, Sensation, Perception, and States of Consciousness

Comprehensive review flashcards covering biological psychology, genetics, neuroanatomy, the endocrine system, research methods, consciousness, sleep, sensory processing, and perceptual mechanisms.

Nature

The influence of inherited genetic characteristics and biological predispositions on human development and behavior.

Nurture

The environmental variables, upbringing, life experiences, and cultural context that shape human development and behavior.

Heritability

The proportion of variation among individuals within a population that can be attributed to genetic differences.

Epigenetics

The study of environmental mechanisms that alter gene expression without altering the underlying DNA sequence.

Identical (Monozygotic) Twins

Twins that develop from a single fertilized ovum that splits in two, resulting in two genetically identical individuals.

Central Nervous System (CNS)

The primary decision-making and control center of the nervous system, consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

The division of the nervous system comprising all sensory and motor neurons connecting the central nervous system to the rest of the body.

Autonomic Nervous System

The branch of the peripheral nervous system that controls involuntary, automatic activities of internal organs and glands.

Sympathetic Nervous System

The division of the autonomic nervous system that mobilizes body systems during activity and stress (fight-or-flight response).

Parasympathetic Nervous System

The division of the autonomic nervous system that conserves energy and calms the body (rest-and-digest response).

Neural Impulses (Action Potential)

A brief electrical charge that travels down an axon when a neuron is stimulated past its excitatory threshold.

All-or-None Response

The principle that a neuron either fires completely at full strength or does not fire at all once threshold is reached.

Refractory Period

A brief pause after a neuron fires during which it resets its resting state and cannot trigger another action potential.

Reuptake

The process by which excess neurotransmitter molecules are reabsorbed back into the presynaptic terminal buttons.

Myelin Sheath

A layer of fatty tissue that encloses segments of axons, insulating them and speeding the transmission of neural impulses.

Glial Cells

Cells in the nervous system that support, insulate, nourish, and protect neurons, and play key roles in synaptic transmission.

Acetylcholine (ACh)

A neurotransmitter that facilitates muscle contraction, learning, and memory; its deterioration is linked to Alzheimer's disease.

Dopamine (DA)

A neurotransmitter regulating motor movement, motivation, pleasure, and attention; excess is linked to schizophrenia and a deficit to Parkinson's disease.

GABA

The primary inhibitory neurotransmitter in the brain; an undersupply is associated with seizures, tremors, and insomnia.

Glutamate

The major excitatory neurotransmitter involved in memory formation; an oversupply can produce migraines or seizures through overstimulation.

Endocrine System

The body's slow chemical communication system, comprised of glands that release hormones directly into the circulatory system.

Pituitary Gland

The master gland of the endocrine system that produces growth hormone and signals other endocrine glands under the direction of the hypothalamus.

Electroencephalogram (EEG)

A technique recording the amplified electrical waves across the surface of the brain using scalp electrodes.

Positron Emission Tomography (PET Scan)

A brain-imaging method that tracks brain metabolic activity by monitoring where a radioactive form of glucose is consumed.

Axon

Neuron's output wire—a long fiber that carries electrical signals away from the cell body to other cells, muscles, or glands.

Functional MRI (fMRI)

A neuroimaging technology that detects active brain regions by monitoring shifts in blood flow and oxygen consumption.

Medulla

The lower base of the brainstem responsible for vital automatic bodily functions, including heartbeat, respiration, and blood pressure.

Reticular Formation

A nerve network running through the brainstem into the thalamus that plays a vital role in regulating autonomic arousal and alertness.

Thalamus

The sensory relay hub located atop the brainstem, directing incoming sensory information (except smell) to corresponding cortex regions.

Cerebellum

The hindbrain structure responsible for balance, fine-motor coordination, nonverbal learning, and procedural memory.

Amygdala

Two almond-shaped neural clusters located in the limbic system that are primarily involved in the processing of fear and aggression.

Hypothalamus

A limbic system structure that oversees maintenance functions (hunger, thirst, body temperature) and governs the endocrine system via the pituitary gland.

Hippocampus

A structure within the limbic system essential for processing, encoding, and consolidating conscious (explicit) memories.

Frontal Lobes

The anterior cerebral cortex lobes involved in expressive speech, voluntary muscle execution, decision-making, and executive planning.

Broca's Area

An area located in the left frontal lobe that orchestrates the muscle movements required for the physical production of speech.

Wernicke's Area

An area located in the left temporal lobe that is essential for the comprehension and meaningful expression of language.

Corpus Callosum

The wide bundle of neural axon fibers linking the left and right cerebral hemispheres, facilitating interhemispheric communication.

Split Brain

A medical condition occurring after surgical sectioning of the corpus callosum, effectively isolating each cerebral hemisphere.

Plasticity

The capacity of the brain to structurally and functionally reorganize itself in response to learning, experience, or neurotrauma.

Neurogenesis

The biological generation and development of new neurons within the nervous system.

Dual Processing

The principle that sensory information is simultaneously processed along conscious, deliberate pathways and unconscious, automatic tracks.

Blindsight

A phenomenon wherein an individual responds to visual cues within their visual field without having any conscious visual perception.

Circadian Rhythm

The endogenous 24-hour biological cycle governing physiological patterns such as body temperature and the sleep-wake cycle.

REM Sleep (Paradoxical Sleep)

A sleep stage characterized by rapid eye movements, elevated physiological brain activity, vivid dreaming, and temporary skeletal muscle paralysis.

Suprachiasmatic Nucleus (SCN)

A hypothalamic cluster of cells that regulates the body's circadian clock by instructing the pineal gland to modulate melatonin production.

Sleep Apnea

A sleep disorder involving recurring pauses in breathing during sleep that cause brief, repeated awakenings.

Narcolepsy

A chronic neurological sleep disorder characterized by sudden and uncontrollable episodes of falling directly into REM sleep.

Manifest Content

In Freudian psychoanalysis, the remembered literal storyline and events of a dream.

Latent Content

In Freudian psychoanalysis, the underlying, disguised psychological meaning and unconscious wishes driving a dream.

Activation-Synthesis Theory

The proposition that dreams represent the brain's cognitive synthesis and narrative interpretation of random neural discharges from the brainstem.

Tolerance

The physiological reduction in responsiveness to a drug after repeated exposure, requiring increased dosages to achieve the initial effect.

Agonists

Chemical substances that mimic, stimulate, or enhance the neurochemical activity of a particular neurotransmitter.

Antagonists

Chemical agents that bind to receptor sites and inhibit or block the physiological response of a neurotransmitter.

Transduction

The biological transformation of external environmental sensory stimuli into electrical nerve impulses interpretable by the brain.

Absolute Threshold

The smallest level of physical stimulus intensity necessary for a sensory system to register detection at least $50\%$ of the time.

Difference Threshold

The minimum level of stimulation difference required for a subject to detect a change between two stimuli $50\%$ of the time (Just Noticeable Difference).

Weber's Law

The psychological principle establishing that to be perceived as different, two stimuli must vary by a constant percentage, not a constant numerical amount.

Sensory Adaptation

A progressive decline in receptor sensitivity following persistent, invariant sensory exposure.

Perceptual Set

A cognitive predisposition or mental expectation that predisposes an individual to interpret sensory data in a particular manner.

Top-Down Processing

Information interpretation driven by higher-level cognitive structures, contextual knowledge, memories, and previous experiences.

Rods

Retinal photoreceptors specialized for peripheral vision, low-light detection, and monochromatic perception.

Cones

Retinal photoreceptors concentrated in the fovea responsible for high visual acuity and daylight chromatic perception.

Fovea

The central focal point of the retina consisting entirely of densely packed cones, affording maximal visual sharpness.

Feature Detectors

Specialized visual cortex neurons that selectively discharge in response to specific elemental visual properties like lines, edges, angles, and motion.

Young-Helmholtz Trichromatic (Three-Color) Theory

The model asserting that color vision relies upon the comparative activation of three types of retinal cone receptors (red, green, and blue).

Hering Opponent-Process Theory

The theory proposing that color perception is mediated by antagonist receptor systems (red-green, blue-yellow, and black-white).

Gestalt Psychology

A perceptual framework stating that the brain organizes raw sensory inputs into unified, meaningful, holistic perceptions greater than the sum of their parts.

Cochlea

A fluid-filled, coiled inner-ear structure containing receptor cells that transduce acoustic mechanical vibrations into auditory neural signals.

Basilar Membrane

A membrane lining the cochlea lined with auditory hair cells (cilia) that vibrate and trigger neural action potentials.

Sensorineural Hearing Loss

Auditory impairment stemming from structural damage to the cochlea's hair cell receptors or the auditory nerve.

Conduction Hearing Loss

Hearing impairment caused by physical problems in the mechanical system conducting sound waves through the outer ear, eardrum, or ossicles.

Place Theory

The pitch-perception model proposing that the pitch heard corresponds to the specific location stimulated along the cochlear basilar membrane.

Frequency Theory (Temporal Theory)

The pitch-perception model proposing that the frequency of the acoustic waveform matches the firing rate of impulses traveling along the auditory nerve.

Kinesthetic Sense

The somatic sensory system that detects and provides feedback about the position and movement of individual bodily limbs.

Vestibular Sense

The sensory system operating through fluid-filled semicircular canals and vestibular sacs that governs balance and head orientation.

Gate-Control Theory

The conceptual model asserting that a neural mechanism in the spinal cord can open or close to regulate the transmission of pain signals to the brain.

Smell (Olfaction)

The chemical sensory process triggered when airborne molecules bind to olfactory receptor neurons lining the nasal cavity.

Synesthesia

A neurological condition wherein stimulation of one sensory or cognitive modality produces involuntary experiences in another distinct modality.