Biopsychology, Research Design, and Sensation & Perception (Fill-in-the-Blank Flashcards)

Experimental Design

  • Correlational designs
    • Look at the relation between two or more variables
    • Can show positive or negative correlations
    • Important caution: correlations do not show causation
    • Students should go back over these concepts; they’ll be revisiting them soon
  • Experimental design (to demonstrate cause and effect)
    • Can demonstrate some cause and effect when set up correctly
    • Key terms:
    • Independent variable (IV): the manipulated variable by the researcher
    • Dependent variable (DV) / outcome variable: what changes as a result of the manipulation
    • Experimental condition: intended treatment
    • Control condition: comparison group (often a placebo or standard treatment)
    • Randomization: process for assigning participants to groups; computer programs give everyone an equal chance
  • Example: new drug for depression vs standard treatment
    • Experimental condition: new drug (intended treatment)
    • Control condition: standard drug already on the market
  • IV and DV in a published example
    • IV: what’s changed/manipulated by the researcher
    • DV: changes or outcomes observed
  • Outcome variable terminology
    • Also called the dependent variable
    • In many psychology experiments, the DV is a measurable performance or symptom change
  • Hypothetical study: intro psych in-person vs online
    • IV: learning environment (in-person vs online)
    • DV: grades or test scores
  • Random assignment and experimental control
    • Randomization ensures equal chance of allocation to each group
    • Aims to control for confounding variables
  • Recap of key terms
    • Independent variable: manipulated by researcher
    • Dependent variable / outcome variable: measured outcome
    • Experimental condition: receives the intended treatment
    • Control condition: receives a comparison or placebo
    • Randomization: equal-probability assignment to groups
  • Additional notes
    • Placebo effect can be part of the control condition to isolate the effect of the treatment
    • A properly designed experiment can support causal inferences when confounds are controlled

Biopsychology and Neuroscience: Foundations

  • Biopsychology definition
    • Studies the interaction of biology, behavior, and environment
    • Neuroscience is a major subfield focusing on the brain and psychological processes
  • The cell and the neuron
    • The human body has trillions of cells; the neuron is the basic signaling unit
    • Neuron: a cell that carries messages between the brain and body
  • Core brain communication pathway (neural signaling)
    • Axon: transfers nerve impulses from the cell body to a synapse with another cell
    • Dendrites: branch projections that spread stimulation received from other neurons to the soma (cell body)
    • Synapse: gap where signals pass from one neuron to another
    • Neurotransmitters: chemical messengers that convey signals across the synapse
  • Prominent neurotransmitters and relations to behavior
    • Serotonin and norepinephrine
    • Low levels linked to depression
    • Influenced by genetics, biology, environmental factors
    • Dopamine
    • Involved in movement control, emotional responses, and pleasure/pain experience
    • Hyperactivity (overactive receptors) linked to schizophrenia (e.g., hallucinations, delusions)
    • Hypoactivity linked to risk-taking and addictions (drug or behavioral)
    • Dopamine relates to the sensation of pleasure; examples of under/overactivity affecting mood and behavior
    • GABA (Gamma-aminobutyric acid)
    • Inhibits neurotransmitter firing; contributes to motor control and vision; promotes sleep
    • Long-term alcohol use reduces GABA and disrupts sleep; can contribute to insomnia and anxiety when deficient
    • Other practical notes
    • Sleep aids and supplements sometimes target GABA to improve sleep or reduce anxiety
  • Endocrine system and stress hormones
    • Endocrine organs release hormones into the bloodstream (e.g., cortisol)
    • Cortisol: involved in the stress response system
  • Stress and the mind-body loop
    • Stress response is designed for two purposes: fight or flight, and sometimes productive task performance
    • Excessive or chronic stress can dysregulate cortisol release and the stress response system
    • Real-world example: veterans experiencing chronic stress exposure linked to PTSD due to repeated stress activation
  • Genetics and predisposition
    • Humans have 2323 pairs of chromosomes; genes influence inherited traits and predispositions
    • Bipolar disorder and schizophrenia are described as biological disorders with genetic components
    • Environment can affect severity and expression, but a genetic predisposition is often necessary for these disorders
    • Even with a genetic predisposition, stress management and resilience can influence whether a disorder develops
    • Example of gene-environment interaction: two individuals with similar trauma can have different outcomes depending on serotonin/norepinephrine regulation and coping strategies
  • Brain anatomy: major structures and functions (overview)
    • Brain stem: communication highway; basic life-sustaining functions
    • Cerebellum: coordinates movement and motor control
    • Limbic system: emotions, motives, and motivational behavior
    • Cerebrum: largest brain region; higher-order thinking; divided into lobes and hemispheres
    • Thalamus: sensory relay center; processes senses (seeing, touching, tasting, hearing); smell is processed elsewhere
    • Pons: helps regulate sleep cycle
    • Hypothalamus: command center for stress response and bodily regulation; monitors blood and hormones
    • Amygdala: emotions (fear, aggression); initiates the stress response
    • Hippocampus: involved in establishing long-term memories
    • Cerebral cortex: outer gray matter; logical reasoning and language; left-right hemispheric specialization
    • Corpus callosum: connects left and right hemispheres
  • Left vs. right hemispheres: functional distinctions (general patterns)
    • Left hemisphere: spontaneous speaking and writing; language-focused; memory for words and numbers; complex command processing; descriptive labeling of experiences
    • Right hemisphere: repetitive or automatic actions; memory for shapes and music; spatial interpretation; emotional processing and negative focus tendencies
    • Additional nuance: most people are not strictly left- or right-dominant; many show bilateral or mixed patterns
  • Four lobes of the brain and their primary functions
    • Frontal lobe: movement and thinking; high-level planning and executive function
    • Parietal lobe: touch, spatial relations, depth perception; handles somatosensory processing
    • Occipital lobe: visual processing (visual cortex)
    • Temporal lobe: processing sound and speech; auditory processing and language comprehension
  • Note on brain anatomy and learning contexts
    • The instructor emphasizes you do not need to label brain regions for this course, but you should know the general functions
  • Einstein and parietal lobe data example
    • Study comparing Einstein’s brain to control brains
    • Finding: Einstein’s parietal lobe was about 15 ext{%} larger than average in the control condition
    • Experimental condition: Einstein’s brain; Control condition: control brains
    • Link to creativity and spatial reasoning; parietal lobe size associated with creative capacity in this discussion

Sensation and Perception: Basics of Sensing the World

  • Sensation vs. perception
    • Sensation: process by which sensory receptors and nervous system detect external stimuli
    • Perception: the interpretation and labeling of sensory information to give it meaning
    • Note: our perceptions are not always accurate; perceptual errors occur and will be explored further in class
  • The five basic senses and typical brain processing
    • Senses: sight, touch, taste, smell, hearing
    • Except for smell, sensory information travels to the thalamus for processing
    • Smell is processed directly by olfactory structures (olfactory bulb) rather than the thalamus
  • Absolute thresholds (weakest detectable stimulus half the time)
    • Examples discussed:
    • Touch: a bee’s wing on the cheek
    • Hearing: ticking of a clock at 20 feet
    • Smell: one drop of perfume across a six-room apartment
    • Vision: candle flame seen from 30 miles away on a clear night
    • Taste: one teaspoon of sugar in two gallons of water
  • Difference threshold (Just Noticeable Difference, JND)
    • Minimum difference between two stimuli noticed half the time
    • Examples:
    • Sand added to a hand until weight difference is noticed
    • Radio volume adjusted by a few notches until it’s noticed
  • Sensory adaptation
    • Ongoing, steady stimuli become less noticeable over time
    • Example: braces becoming less noticeable after initial adjustment
  • Pheromones and olfactory sense
    • Pheromones: chemical signals in animals (and possibly humans) that can communicate or influence behavior
    • Smell is crucial for newborns to identify caregivers; smell can drive emotional responses later in life
  • Olfaction and newborns
    • Newborns rely on smell and touch to recognize mothers; vision develops later in infancy
  • Vision and perception of smell as a combined experience
    • Flavor perception requires both taste and smell (and some visual input)
    • A thought experiment with jelly beans demonstrated how presence or absence of sight and smell alters flavor perception
    • The chest of factors affecting flavor also includes genetic and cultural influences
  • Kinesthetic and vestibular senses
    • Vestibular sense: balance and orientation relative to gravity
    • Kinesthetic sense: body position and movement relative to body parts
    • Examples of high kinesthetic or vestibular ability: athletes, dancers, and people with exceptional balance
  • The role of taste (gustation) and flavor interaction
    • Taste buds on the tongue detect basic tastes; flavor is a combination of taste, smell, and sight
    • A classroom demonstration idea described: testing flavor detection under different sensory conditions to illustrate flavor perception
  • The skin senses and somatosensation
    • Parietal lobe is associated with touch; detects temperature, warmth, cold, pain; pain thresholds vary across individuals
    • Psychological factors can modulate pain perception (e.g., distraction, humor, and cognitive reframing can lessen perceived pain)
  • The psychology of sound: pitch, loudness, and timbre
    • Pitch: frequency of sound waves; higher frequency = higher pitch
    • Loudness: amplitude or intensity; higher amplitude = louder sound
    • Timbre: quality or color of the sound; differentiates tones that have the same pitch and loudness
  • Acoustic measures and safety
    • Sound intensity measured in decibels (dB)
    • Absolute hearing threshold: 0extdB0 ext{ dB} (softest sound audible by humans)
    • Extremely loud sounds (e.g., jet engine) can reach extabout140extdBext{about } 140 ext{ dB} and cause immediate damage
  • Practical implications of loud sounds
    • In urban environments, frequent loud noises can trigger the stress response
    • Prolonged exposure to loud sounds can contribute to hearing loss; wearing ear protection and moderating volume on devices is important
  • The vestibular and kinesthetic sense in action
    • Vestibular sense contributes to balance; kinesthetic sense contributes to movement awareness and coordination
  • Smell and taste in flavor and social behavior
    • Olfaction is deeply linked to early development and social/romantic cues via pheromones
    • Testosterone and attraction may have links to olfactory cues; many studies cited are correlational and require caution due to potential third-variable influences
  • Correlation vs. causation in taste, smell, and attraction studies
    • Emphasize the difference between correlational relationships and causal inferences
    • The potential for a third variable to influence both testosterone levels and attraction responses
  • The role of the brain in sensory processing and perception
    • Visual information processing begins in the occipital lobe; image is initially reversed on the retina
    • The brain interprets and reconstructs the visual world from neural input; you do not literally see everything as it is
  • Final reminders and transition to the next class
    • Perception is a process of giving meaning to sensation; it can be error-prone
    • Tomorrow’s topics will cover more on perception processes and sleep-related aspects