PSYC 4320 Final Exam 2025

What is the term for year-long rhythms that are internally generated? - -Endogenous Circannual Rhythms Endogenous Circadian Rhythms - -Self-generated rhythms that lasts about a day. True of false: Circadian rhythms affect only the wake/sleep cycle - -False. Circadian rhythms affect eating and drinking, hormone secretion, metabolism, etc. At what point in the day is your body temperature highest? Lowest? - -Highest: late afternoon (6 hours before sleep) Lowest: 2 hours after sleep onset (night) When do humans experience their most pleasant mood? Least? - -Most: late afternoon Least: early morning Mood increases from time of wake through the late afternoon and then decreases slightly until bedtime. Zeitgeber - -Translates to "time-giver," this is a stimulus which resets the circadian rhythm. True of false: without something to reset your circadian rhythm, it would gradually drift away for the correct time. - -True What is the dominant zeitgeber for land animals? - -Light Are social stimuli effective or ineffective zeitgebers? - -Ineffective unless they induce vigorous activity. Which is an easier transition, traveling west or traveling east? - -West; this is known as phase-delay. What is the best way to adjust to working night shifts? - -Sleep during the day under as much darkness as possible; work under very bright lights. True or false: The circadian rhythm remains surprisingly steady despite external stimuli. - -True. The biological clock is insensitive to most forms of interference. What is the main driver of rhythms for sleep and body temperature? - -The suprachiasmatic nucleus (SCN) of the hypothalamus. PSYC 4320 PSYC 4320 After damage to the SCN, the body's rhythms become erratic. How does the SCN produce circadian rhythms? What happens if SCN neurons are disconnected from the rest of the brain? - -In a genetically controlled manner; they continue to produce a circadian rhythm of action potentials. What is the name of the path by which retinal cells communicate with the SCN, altering its settings? - -The retinohypothalamic path. Where does the retinohypothalamic path start? What is special about these types of cells? - -The retinohypothalamic path to the SCN comes from a special population of retinal ganglion cells that have their own photopigment, called melanopsin, unlike the ones found in rods and cones. What type of light do melanopsin-containing retinal ganglion cells respond to? - -Short wavelength (blue) light. What is the biochemical basis of the SCN's production of circadian rhythms? - -PER and TIM genes. Explain the action of PER and TIM genes. - -PER and TIM genes produce proteins, which have their respective names. These proteins promote sleep and inactivity. As the day progresses Per and tim mRNA synthesize these proteins on delay. As protein levels increase, synthesis is inhibited. During the night protein concentration is high, and mRNA concentration is low. By morning, protein levels are low and the cycle begins again. What hormone does the pineal gland release? - -Melatonin When does melatonin secretion begin? - -2-3 hours before bedtime This means that taking a melatonin pill prior to bed has little effect. Instead, melatonin pills may be helpful when trying to fall asleep during a phase-advance. What tends to be characteristic of teenagers who are extreme "evening" types? - -They get worse grades in school than their abilities would predict. What evidence strongly indicates that the SCN produces circadian rhythms itself? - SCN cells isolated from the body continue to produce a circadian rhythm. PSYC 4320 PSYC 4320 Coma - -An extended period of unconsciousness caused by head trauma, stroke, or disease. Someone in a coma has a low level of brain activity and little or no response to stimuli. Vegetative state - -Characterized by alternating periods of sleep and moderate arousal. Lacks purposeful behavior and awareness of surroundings; only minimal autonomic response to stimuli. Minimally conscious - -Characterized by brief periods of purposeful action and limits speech comprehension. Brain death - -A condition with no sign of brain activity and no response to any stimulus. Alpha waves - -Characteristic of relaxed wakefulness Frequency ________________ and amplitude _______________ as you move from wake state to deeper sleep stages. - -Decreases; increases. Sleep stages 3 and 4 are known as... - -Slow-wave sleep (during which waves are highly synchronized). What are the two characteristics of stage 2 sleep? - -1. Sleep spindles 2. K-Complexes (high amplitude neg. wave followed by slower pos. wave) REM sleep - -Rapid eye movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active. What are the characteristics of REM sleep? - -Irregular, low-amplitude, fast EEG waves (analogous to wake-state); Postural muscles relaxed; Blood flow to genitals increased. Reticular formation - -Network of neurons that extends from the medulla through the midbrain to the forebrain. Pontomesencephalon (in RF) - -Maintains arousal in wide regions of forebrain (hypothalamus, thalamus, etc) by releasing ACh and Glutamate. Receive input from many sensory areas and generate spontaneous activity. Stimulation causes awakening, arousal, EEG beta-waves. Locus coeruleus - -Located in the pons; Emits bursts of impulses in response to meaningful events. Inactive during sleep. PSYC 4320 PSYC 4320 Strengthens memory storage. What two neurotransmitters does the hypothalamus release which contribute to wakefulness and what are there functions? - -1. Histamine (arousal) 2. Orexin (staying awake) Basal forebrain - -A region, ventral to the basal ganglia, that is the major source of acetylcholine (released during wakefulness and REM sleep) in the brain. What is REM sleep triggered by? - -"PGO-waves" (Pons — LGN nucleus of Thalamus — Occipital Lobe). REM deprivation leads to PGO-waves in stages 2-4. At which time is stage 4 sleep most common? - -Not immediately, but during the early part of the night's sleep. Norepinephrine, released by the locus coeruleus, has which effect on behaviors? - -It increases attention to important information. Narcolepsy is linked with a deficit in which neurotransmitter? - -Orexin Classical conditioning - -A type of learning in which pairing two stimuli changes the response to one of them. Instrumental (operant) conditioning - -A type of learning in which an individual's response leads to a reinforcer or punishment. What is the primary difference between classical and instrumental conditioning? - -In instrumental conditioning the individual's response determines the outcome (reinforcer or punishment), whereas in classical conditioning the CS and UCS occur at the same time regardless of the individual's behavior. Engram - -The physical representation of what has been learned. What are Lashley's two nervous system principles? What do they hold? - -1. Equipotentiality: all parts of the cortex contribute equally to complex behaviors such as learning, and any part of the cortex can substitute for any other. 2. Mass action: the cortex works as a whole, and more cortex is better. What effect did cutting sections of rats' brains have on their maze performance? - -No significant impairment in performance. PSYC 4320 PSYC 4320 What area of the brain did Thompson identify as essen