AP Psychology Unit 1: Biological Bases of Behavior and Sensation

Comprehensive practice flashcards designed for AP Psychology Unit 1 review, covering biological bases of behavior, neuroanatomy, chemical transmission, sleep and consciousness, and sensory systems.

What is the core distinction between nature and nurture in psychological research?

Nature refers to genetic and biological predispositions, whereas nurture encompasses external environmental factors and experiences that shape behavior and development.

How do twin studies, family studies, and adoption studies help researchers measure heritability?

Twin studies compare identical and fraternal twins to estimate genetic versus environmental contributions; family studies examine phenotypic traits among biological relatives with varying degrees of genetic overlap; and adoption studies compare children to their biological and adoptive parents to isolate environmental influences from genetic effects.

What are the two major divisions of the Peripheral Nervous System (PNS) and their functions?

The somatic nervous system governs voluntary movements of skeletal muscles, while the autonomic nervous system controls involuntary bodily functions such as heart rate, digestion, and respiration.

How do the sympathetic and parasympathetic nervous systems differ in function?

The sympathetic nervous system arouses the body to mobilize energy for action (fight-or-flight), whereas the parasympathetic nervous system calms the body to conserve energy and restore resting homeostasis (rest-and-digest).

What are the roles of sensory neurons, motor neurons, and interneurons within a reflex arc?

Sensory (afferent) neurons carry incoming sensory input to the central nervous system; interneurons in the spinal cord process that input and formulate a response; and motor (efferent) neurons carry outgoing motor instructions from the central nervous system to effectors (muscles or glands).

What sequence of physiological events occurs during the generation of a neural impulse?

A neuron begins at its resting potential, reaches its excitation threshold, undergoes depolarization as positively charged ions rush inward, fires an action potential following the all-or-none principle, enters a refractory period to reset its membrane, and cleans the synapse via reuptake.

What cellular mechanism explains the symptoms of multiple sclerosis?

Multiple sclerosis is caused by disruptions in neural transmission resulting from the degradation or destruction of the protective myelin sheath surrounding axons, which slows or blocks action potential conduction.

How do neurotransmitters differ between excitatory and inhibitory signals?

Excitatory signals depolarize the postsynaptic membrane to increase the likelihood of an action potential firing, whereas inhibitory signals hyperpolarize the membrane to decrease the likelihood of an action potential.

How do the endocrine system and the nervous system compare in terms of operational speed and duration?

The endocrine system is slow-acting with long-lasting effects because it transmits chemical hormones through the bloodstream, whereas the nervous system is fast-acting with short-lived effects because it relies on electrical impulses and neurotransmitters across synaptic gaps.

Why is the pituitary gland referred to as the master gland?

It releases key hormones that stimulate and regulate the hormonal secretions of other endocrine glands throughout the body, working under the direct direction of the hypothalamus.

How do agonists, antagonists, and reuptake inhibitors alter neurotransmitter activity?

Agonists bind to and activate receptor sites to mimic or enhance a neurotransmitter's effects; antagonists bind to receptor sites to block or reduce neurotransmitter activity; and reuptake inhibitors prevent sending neurons from reabsorbing neurotransmitters, increasing their concentration and time in the synaptic cleft.

What are the survival functions regulated by the medulla in the brainstem?

The medulla controls vital autonomic life-support functions, including heartbeat, respiration, and blood pressure.

What functions are carried out by the cerebellum?

The cerebellum governs balance, fine motor coordination, posture, and the procedural memory involved in implicit, skilled physical actions.

What are the primary functions of the hippocampus and amygdala within the limbic system?

The hippocampus is primarily responsible for processing, consolidating, and forming new explicit long-term memories, while the amygdala regulates emotional responses, particularly fear, anger, and threat detection.

What are the four cortical lobes of the cerebrum and their primary specialized functions?

The occipital lobes process visual information; the temporal lobes process auditory signals and language comprehension; the parietal lobes house the somatosensory cortex for touch and body sensation; and the frontal lobes control higher-order executive functioning, decision-making, and voluntary movement via the motor cortex.

How do the language deficits of Broca's aphasia differ from Wernicke's aphasia?

Damage to Broca's area results in expressive aphasia, where speech production is broken and laborious despite preserved comprehension; damage to Wernicke's area results in receptive aphasia, where speech remains fluent but lacks meaning and language comprehension is severely impaired.

What did split-brain research on patients with a severed corpus callosum demonstrate about hemispheric processing?

It confirmed contralateral hemispheric organization (the left hemisphere receives input from and controls the right side of the body/field, and vice versa) and showed that without the corpus callosum, the two hemispheres process information independently without interhemispheric communication.

Why is REM sleep referred to as paradoxical sleep?

It is called paradoxical sleep because the brain displays fast, active EEG beta-like brain waves similar to being awake, accompanied by rapid eye movements and physiological arousal, while the major voluntary muscles remain completely paralyzed.

How does the activation-synthesis theory of dreaming contrast with the memory consolidation theory?

Activation-synthesis posits that dreams are the cerebral cortex's attempt to weave a coherent narrative out of random biological neural bursts from the brainstem, whereas memory consolidation theory suggests that dreaming serves an active cognitive function to process, sort, and store daytime experiences into long-term memory.

How does absolute threshold differ from the just-noticeable difference (JND)?

The absolute threshold is the minimum stimulus energy needed to detect a stimulus 50% of the time, whereas the just-noticeable difference (difference threshold) is the minimum amount of change required to detect a difference between two existing stimuli 50% of the time.

What principle governs stimulus detection according to Weber's law?

Weber's law states that for an observer to perceive a difference, two stimuli must differ by a constant minimum percentage or proportion rather than by a fixed, constant physical amount.

How do rods and cones differ in their distribution and visual specialized functions?

Rods are situated in the retinal periphery, functioning in low-light environments and detecting peripheral movement and black-and-white vision; cones are concentrated in the fovea, operating in well-lit conditions to provide high visual acuity, fine detail, and color vision.

How do the Trichromatic and Opponent-Process theories account for color perception?

The Trichromatic theory states that the retina has three color receptors (red, green, and blue cones) that produce color mixtures, while the Opponent-Process theory explains downstream processing by opposing ganglion/bipolar cell pairs (red-green, blue-yellow, black-white), which accounts for negative afterimages.

What is the structural difference between conduction deafness and sensorineural deafness?

Conduction deafness results from mechanical damage preventing sound waves from traveling through the outer or middle ear (such as the eardrum or ossicles), whereas sensorineural deafness is caused by damage to the cochlea's hair cell receptors or the auditory nerve.

What is anatomically unique about the olfactory pathway compared to other sensory modalities?

Olfactory signals are the only sensory inputs that bypass the thalamus, traveling directly from olfactory receptor cells through the olfactory bulb into limbic system structures such as the amygdala and hippocampus.

How does gate control theory explain the modulation of pain sensations?

It suggests that non-painful sensory inputs can close a neurological 'gate' in the spinal cord, preventing pain signals carried by small nerve fibers from ascending to the brain.

What is the primary difference between the vestibular sense and kinesthesis?

The vestibular sense monitors whole-body balance, equilibrium, and head spatial orientation via the semicircular canals and vestibular sacs in the inner ear, whereas kinesthesis detects the movement and relative position of individual body limbs and joints via proprioceptors.