1st Psych Test
Understanding Psychology as a Science 01/24/24
Why do psychology?
Psychology definition: science of behavior and mental processes
Better understand why people think, feel, and act as they do
NOT common sense
Hindsight bias definition: one becomes convinced they accurately predicted an event before it occurred
Ex: Cubs (3) vs. White sox (7). Cubs win. “I knew the cubs were going to win”
Overconfidence definition: being too certain of your abilities or of your chances of success
Scientific attitude → encourages critical thinking
Be skeptical!
Scientific Method 01/26/24
Theory definition: organizes observations to explain behavior
Ex: playing violent video games makes people aggressive
Hypothesis definition: testable predictions based on theory
Ex: if people play violent video games, they become more aggressive
Methods definition: way we test the hypothesis
Ex: experiments
Methods for Studying Behavior
Case study definition: analyze one individual in depth
Pros: you gather a LOT of information
Cons: cannot generalize information to the rest of the population
Naturalistic Observation definition: observe and record behavior in natural setting
Pros: more authentic behavior (go where people are most comfortable)
Cons: act strangely in the laboratory, observing for distance does not allow for context of behavior
Survey (Questionnaires) definition: obtain self- reported behaviors of a sample
Pros: cheap, easy, large data
Cons: people lie
⭐Experimentation definition: manipulate one or more variables to observe effects on behavior
Pros:
Cons:
Correlation
Correlation definition: measures relationships between 2 variables
Variables simply measured (no manipulation)
NEVER imply causation
Correlation can be:
Positive: as one variable increase, other variable also increases
Ex: the more junk food one consumes, the more weight they gain
junk⬆weight⬆
Negative: as one variable increases, other variable decreases
Ex: the more time you spend on the treadmill, the more weight you lose
Treadmill use⬆weight⬇
Experimentation 01/29/24
Obtain “random sample” from population
Random sampling: when getting conclusions, you can generalize the information to the entire population
Ex: (Group of people (games and non-gamers)) Some play GTA and some play Stardew Valley for half an hour. At the end of half an hour measure their aggression in some way (questionnaire, heart rate, etc.)
Variables:
Independent Variable (IV): manipulated variable (Ex: game that they play)
Dependent Variable (DV): measured variable (Ex: aggression levels)
Extraneous Variable (EV): additional variable that may influence DV (Ex: people that come in at 7am are more aggressive but people that come in at 1pm were less aggressive)
Want to control for EV’s
Use “random assignment” to place sample into:
Definition: Everyone has an equal chance of being in each group (Ex: equal chance of playing GTA or Stardew Valley) (Ex: 1,2,1,2,1,2,1,2)
Experimental Condition: exposed to treatment (those playing GTA)
Control Condition: not exposed to treatment (those playing Stardew Valley)
Allows us to establish cause and effect!!
Ethical Consideration
Protect physical and mental well-being of participants
Both human and animals
APA Guidelines for human participants:
Informed consent
Cost- benefit ratio
Confidentiality
Debriefing
Statistical Overview 02/02/2024
Measures of Central Technology
Mean: average
When data is normally distributed, best measure of C.T.
Stable- used to compare samples
BUT, strongly affected by extreme scores
Median: middle score
Unaffected by extreme score
Not as stable across samples
Good alternative to mean if data is skewed
Mode: most frequent score
Unaffected by extreme scores
Used when discussing categorical data
Measures of Variability
Range: distance from the lowest score to the highest score
Problem- based on the two extreme scores
Standard Deviation (SD) definition indicates, how much all the scores in a distribution deviate from the mean
Larger SD = more dispersed
Smaller SD = more clustered around mean
Neuroscience
The Neuron
Parts of Neuron
Soma (cell body)
Dendrites
Axon
Myelin Sheath
Terminal buttons
Facts:
Born with over 100 billion neurons
Do NOT regenerate
Neurogenesis is promising, however!
During the first 2 years:
Dendritic Arborization
Dendritic Spreading
Old age- connectedness between neurons decreases
Stimulation Process:
Resting Potential: voltage inside cell when not stimulated (-)
Action Potential: nerve impulses that disturbs the resting potential
Triggers release of neurotransmitters
All-or-none process
Refractory Period: charge temporarily drops down below baseline
Cannot restimulate
Chemical Process 2/7
Neurotransmitters (NTs) definition: chemical messengers of nervous system
Action potential triggers release of NTs
Released from terminal buttons on axon
Synapse definition: junction between two neurons
NTs cross to bind with next neuron
Bind on specific receptor sites on dendrites
Reuptake definition: excess NTs reabsorbed by sending neuron
Neuron communication
NTs messages can be:
Excitatory
Inhibitory (most impo: endorphins)
Different NTs = Different Effects!
Each NT has its own receptor site- “lock and key”
Other chemicals can interfere with process
Agonist- chemical that mimics NTs
Ex: Morphine and codeine can act like endorphins
Antagonist: chemical that blocks NTs
Plugs up to stop dopamine
Prevent reuptake
Nervous System
Central Nervous System (CNS): brain and spinal cord
Reflexes- word of spinal cord
Peripheral Nervous System (PNS): link CNS with sense receptors, muscles, and glands
Somatic: movement of skeletal muscles
Autonomic: glands and muscles of internal organs
Sympathetic: arouses (fight)
Parasympathetic: calms (flight)
Brain 2/9
About 3 pounds (2% body weight)
Consumes 20% blood oxygen
Among first systems formed during prenatal development
Convolution is more important than size!
Ways of studying the brain:
Effects of disease
Surgical lesioning and electrical stimulation
Brain imaging (e.g. CT, MRI, PET, fMRI)
Important Brain Structures
Brainstem: oldest and innermost region
Medulla: heartbeat and breathing
Reticular Formation: arousal
Thalamus: brain’s sensory switchboard
Cerebellum: muscle movement
Limbic System
Hippocampus: process memories for storage
Amygdala: aggression and fear
Hypothalamus: link between nervous system and endocrine system
Lobes of the Brain 2/12
Frontal Lobe
Planning of future
Emotion
Parietal Lobe
Sense of touch, temperature, pain, and pressure
Logic of mathematics
Occipital Lobe
Vision
Temporal Lobe
Hearing
Brain Hemisphere
Connected by corpus callosum
Left hemisphere functions include:
Speech and language
Logic
Math
Science
Right hemisphere functions include:
Spatial construction
Creative thinking
Art and music appreciation
Fantasy
Sensation and Perception
Basic Principles
Sensation: when info interacts with sensory receptors
E.g., light patterns reflect on retina in eye
Perception: interpretation of the sensed
E.g., when we “see” a tree
Study of Sensation
Psychophysics (Signal Detection Theory)
Absolute Threshold: minimum stimulation needed to detect stimulus 50% of the time
Process some info from stimuli too weak to detect!
Difference Threshold: minimum change in stimulation that can be detected 50% of the time
Weber's Law- larger stimuli need larger differences
Sensory Adaptation: diminished sensitivity due to continued stimulation
Visual Process
Light waves enter through pupil (size regulated by iris)
Lens focuses rays (through accommodation
Image is displayed on the retina
Rods and cones (around fovea) convert light to neutral signals
Signals activate bipolar cells- which activate ganglion cells
Optic nerve carries info to brain cells
Visual Perception 2/14
We do not simply take in visual information
We process information to form representation
How do we know?
Illusions!
Due to our knowledge of the world
Ponzo Illusion: Vertical lines that are “farther away” must be objectively larger
Theories of Color Vision
Young-Helmholtz Trichromatic Theory
Retina has three color cones: red, green, blue
Stimulate combinations of these cones- see color
Additive approach to color (Red + Green + Blue = White)
Trichromatic Theory: works with sensory organs
Opponent- Process Theory
Three additional color processes:
Red vs. Green perception
Yellow vs. Blue perception
Black vs. White perception
Explains afterimage effects
Both theories are correct!
Perceptual Organization: Gestalt Theory 2/16
Principles by which organize our sensations into perceptions.
Organize sensations into wholes
Gestalt Grouping Principles
Proximity: group nearby objects together
Similarity
Continuity: we percieve things as smooth continuous lines
Connectedness: is there is a line connecting two figures, we assume that means they belong together
Closure: if there is a gap in some kind of figure, our brain naturally fills in the gap
Perceptual Organization: Perceptual Constancy
Perceptual Constancy: perceive objects as unchanging even as illumination and retinal image change
Size Constancy: even though retinal image gets smaller as it moves away from us, we still know it is the same size
Shape Constancy: recognize objects as the same, even if the retinal image change
Color Constancy: recognize that things stay the same color, even if the lighting conditions change
Auditory Process
Pressure wave cause vibrations in ear drum
Signal transferred via bones in middle ear (handle, anvil, and stirrup) to the cochlea in inner ear
Vibrations in cochlea cause hairs on basilar membrane to move
Triggers neural message to brain
Sensory Interactions
One sense may influence another
Smell influences taste
Visual information influences auditory perception
McGurk Effect
Visual information trumps auditory information
Other Senses
Touch is a sensation of pressure, warmth, cold, and pain
No one type of stimulus triggers pain
Gate- Control Theory: gate in spinal cord- opens to permit pain signals or closes to prevent them
Smell
5 million olfactory receptor cells recognize individual odor molecules
Taste is sensation of: sweet, sour, salty, bitterness, and umami