PSYCH 111 Exam Review: Research Methods, Biopsychology, Sensation and Learning

Terms in this set (30)

1. Independent vs dependent variableThe independent variable is what the researcher manipulates; the dependent variable is the outcome measured to see whether it changed because of the manipulation.
2. Why doesn't correlation imply causation?A third variable might cause both (third-variable problem), or the causal direction might be reversed (directionality problem). Only experiments with random assignment support causal conclusions.
3. What does a correlation coefficient (r) tell you?r ranges from −1 to +1. The sign shows direction (positive or negative relationship) and the absolute value shows strength; r = 0 means no linear relationship.
4. Random sampling vs random assignmentRandom sampling selects participants so the sample represents the population (helps generalization). Random assignment places participants into conditions by chance so groups are equivalent (supports causal claims).
5. What is an operational definition?A precise description of how a variable will be measured or manipulated in a study, such as defining aggression as the number of times a child hits a doll in 10 minutes.
6. What is a double-blind study, and what problems does it prevent?Neither participants nor the researchers interacting with them know who is in which condition. It controls placebo effects and experimenter bias.
7. What is a confounding variable?A variable other than the independent variable that differs systematically between conditions, so it offers an alternative explanation for the results.
8. Reliability vs validityReliability is consistency: the measure gives similar results across time or raters. Validity is accuracy: it measures what it claims to measure. A measure can be reliable without being valid.
9. Main parts of a neuron and their functionsDendrites receive signals; the cell body (soma) integrates them; the axon carries the action potential; the myelin sheath speeds conduction; axon terminals release neurotransmitter.
10. Describe the action potential.Resting potential is about −70 mV. When stimulation reaches threshold (about −55 mV), Na+ channels open and Na+ rushes in (depolarization), then K+ flows out (repolarization). It is all-or-none: intensity is coded by firing rate.
11. What happens at a chemical synapse?The action potential triggers release of neurotransmitter into the synaptic cleft. It binds receptors on the postsynaptic cell, producing excitatory or inhibitory effects, and is cleared by reuptake or enzymatic breakdown.
12. Key functions of dopamine, serotonin, acetylcholine, GABA and glutamateDopamine: reward and movement (loss in Parkinson's). Serotonin: mood, sleep, appetite. Acetylcholine: muscle contraction and memory (reduced in Alzheimer's). GABA: main inhibitory. Glutamate: main excitatory.
13. Agonist vs antagonist drugsAn agonist mimics or enhances a neurotransmitter's effect. An antagonist blocks or reduces it, for example by occupying receptors without activating them.
14. Sympathetic vs parasympathetic nervous systemSympathetic: fight or flight, raising heart rate, dilating pupils, slowing digestion. Parasympathetic: rest and digest, calming the body and conserving energy.
15. Main function of each cerebral lobeFrontal: planning, decision making, motor control. Parietal: touch and spatial processing. Occipital: vision. Temporal: hearing, language comprehension, and memory (with nearby medial structures).
16. Broca's vs Wernicke's aphasiaBroca's area damage (left frontal) causes halting, effortful speech with relatively intact comprehension. Wernicke's area damage (left temporal) causes fluent but meaningless speech and poor comprehension.
17. Roles of the hippocampus, amygdala and hypothalamusHippocampus: forming new explicit memories. Amygdala: fear and emotional responses. Hypothalamus: hunger, thirst, temperature, and control of the pituitary gland.
18. What did split-brain studies (Sperry and Gazzaniga) reveal?With the corpus callosum cut, an object shown only to the right hemisphere (left visual field) could not be named aloud but could be picked out by the left hand, showing the left hemisphere's dominance for language in most people.
19. Sensation vs perception, and what is transduction?Sensation is detecting physical energy with sense receptors; perception is organizing and interpreting it. Transduction is converting stimulus energy into neural signals.
20. Absolute threshold vs difference threshold, and Weber's lawAbsolute threshold: the minimum stimulus detected 50% of the time. Difference threshold (JND): the smallest detectable change. Weber's law: the JND is a constant proportion of the original stimulus.
21. What does signal detection theory add to the idea of thresholds?Detection depends on both sensitivity and the observer's response bias (criterion). Outcomes are hits, misses, false alarms and correct rejections.
22. Rods vs conesRods are very sensitive to dim light, more numerous in the periphery, and do not detect color. Cones work in bright light, are concentrated in the fovea, and support color and fine detail.
23. Trichromatic vs opponent-process theory of colorTrichromatic: three cone types (short, medium, long wavelength) explain color at the receptor level. Opponent-process: red-green, blue-yellow and black-white channels later in processing explain afterimages.
24. Define UCS, UCR, CS and CR in classical conditioning using Pavlov's dogs.Food is the UCS, which naturally produces salivation (UCR). A tone (initially neutral) paired with food becomes the CS, and salivation to the tone alone is the CR.
25. Extinction vs spontaneous recoveryExtinction: the CR weakens when the CS is repeatedly presented without the UCS. Spontaneous recovery: after a rest period, the extinguished CR briefly reappears.
26. Positive vs negative reinforcement and punishmentReinforcement increases behavior; punishment decreases it. Positive means adding a stimulus; negative means removing one. Removing a headache by taking aspirin is negative reinforcement.
27. Which schedule of reinforcement produces high, steady responding that is most resistant to extinction?Variable ratio, which reinforces after an unpredictable number of responses, like a slot machine.
28. What did Bandura's Bobo doll study show?Children who watched an adult behave aggressively toward a doll were more likely to imitate the aggression, demonstrating observational learning without direct reinforcement.
29. Stimulus generalization vs discrimination, using Little AlbertAfter a white rat was paired with a loud noise, Albert also feared similar white furry objects (generalization). Discrimination is learning to respond only to the specific CS and not similar stimuli.
30. Binocular vs monocular depth cuesBinocular cues need both eyes: retinal disparity and convergence. Monocular cues work with one eye: relative size, interposition, linear perspective, texture gradient and motion parallax.