Intro to Psychology

• Psychology's history includes studying brain function localization using phrenology.
• Phineas Gage's case demonstrated that frontal lobe damage can lead to impulsivity.
• Wilhelm Wundt is credited with initiating contemporary psychology.
• Structuralism aimed to understand consciousness by breaking it down into basic elements.
• Functionalism focuses on the study of the purpose and function of behavior.
• Behaviorism is defined as the study of behavior.
• Cognitive psychology explores mental processes and their impact on behavior.
• The psychoanalytical approach investigates how unconscious processes influence behavior.
• Cross-cultural psychology compares behaviors across different cultures.
• WEIRD stands for Western, Educated, Industrialized, Rich, Democratic, and is often a limitation in research samples.
• Basic research is conducted for the purpose of gaining general knowledge.
• Applied research aims to solve practical, real-world problems.
• Translational research bridges the gap between general knowledge research and its application to real-world psychological issues.
• Hindsight bias is the belief that an outcome is foreseeable after it has already occurred.
• A variable is a factor whose values can vary across individuals or over time.
• An operational definition defines a property in measurable terms.
• Correlational designs measure how closely two variables vary together.
• Positive correlation means that both variables increase or decrease together.
• Negative correlation means one variable increases as the other decreases.
• Zero correlation indicates no predictable relationship between two variables.
• Pearson's r is a correlation coefficient that ranges from -1 to 1.
• Experimental designs manipulate an independent variable (IV) to observe its impact on a dependent variable (DV) with random assignment.
• The independent variable is the factor that is varied or manipulated by the researcher.
• The dependent variable is the behavior that is measured and expected to change as a result of manipulating the independent variable.
• Quasi-experimental designs rely on existing group memberships (e.g., gender, marital status, age groups).

Brain Structure and Function

• The hindbrain includes the cerebellum, medulla, reticular formation, and pons.
• The cerebellum is responsible for motor coordination and control.
• The medulla coordinates vital functions such as heart rate, circulation, and respiration.
• The reticular formation regulates sleep, wakefulness, and arousal.
• The pons relays information from the cerebellum to the rest of the brain.
• The forebrain includes the limbic system, which is involved in emotion, motivation, and memory.
• The hypothalamus regulates the "4 F's": feeding, fighting, fleeing, and reproduction.
• The amygdala plays a role in emotional processes.
• The hippocampus is crucial for creating and integrating new memories.
• The basal ganglia direct intentional movement and play a role in reward processing.
• The cerebral cortex has a large surface area that is folded to fit within the limited volume of the skull.
• The size of the somatosensory cortex corresponds to the sensitivity of the corresponding body area.
• Broca's area is responsible for language production.
• Wernicke's area is responsible for speech comprehension.

Hemispheric Specialization and Neurons

• The two cerebral hemispheres are connected by the corpus callosum.
• Contralateral organization means the left hemisphere controls the right side of the body, and vice versa.
• A neuron is a cell that specializes in receiving and transmitting information.
• The cell body coordinates information-processing tasks and keeps the cell alive.
• Dendrites receive information from other neurons and relay it to the cell body.
• The axon carries information to other neurons, muscles, or glands.
• The synapse is the region between the axon of one neuron and the dendrite of another.
• The myelin sheath is a fatty sheath that insulates axons, speeding up signal transmission.
• An action potential is an electrical signal that is conducted along the length of a neuron's axon to a synapse.
• The resting potential of a neuron is -70mV.
• Depolarization occurs when sodium channels open and positive ions rush into the cell.
• Repolarization occurs after the sodium gates close and potassium moves out.
• When an action potential reaches the terminal buttons, it causes the release of neurotransmitters into the synaptic cleft.
• Excitatory neurotransmitters increase the likelihood of an action potential.
• Inhibitory neurotransmitters decrease the likelihood of an action potential.

Neurotransmitters and Brain Study Methods

• The binding of neurotransmitters is specific; they cannot bind randomly.
• Acetylcholine is involved in voluntary motor control.
• Dopamine regulates motor behavior, motivation, pleasure, and emotional arousal.
• Parkinson's disease involves uncontrolled, involuntary movement and can be treated by enhancing dopamine levels.
• Serotonin is involved in regulating sleep, wakefulness, and eating behavior.
• Selective Serotonin Reuptake Inhibitors or SSRIs, are a treatment for depression
• An agonist is a drug that increases the action of a neurotransmitter (e.g., increasing dopamine in Parkinson's disease).
• An antagonist is a drug that diminishes the function of a neurotransmitter (e.g., Botox, an acetylcholine antagonist, blocks voluntary motor movement).
• MRI (magnetic resonance imaging) uses a magnetic field to produce high-quality images of the brain structure, but limits movement within the machine.
• fMRI (functional MRI) examines changes in brain activity by measuring changes in blood oxygen levels, indicating how the brain functions.
• Electroencephalography (EEG) records electrical activity from large populations of neurons at the scalp with millisecond resolution, providing good timing information but limited spatial resolution.

Sensation and Perception

• Sensation: physical processing of environmental stimuli by sense organs.
• Perception: psychological process of interpreting sensory information.
• Psychophysics: relates physical stimulus characteristics to perception.
• Absolute threshold: minimum stimulation needed for detection 50% of the time.
• Just noticeable difference (JND) or difference threshold: minimum difference between two stimuli for detection 50% of the time.
• Top-down processing: perceptions influenced by expectations or prior knowledge.
• Bottom-up processing: constructing complex messages from individual sensory bits.
• Signal detection theory: response depends on sensitivity and decision criteria.
• Sensory adaptation: diminished sensitivity due to constant stimuli.
• Selective attention: focusing on one task or event.
• Inattentional blindness: failure to perceive unattended objects.
• Change blindness: failure to detect changes in visual details.

Vision

• Photoreceptors: transform light into neural signals (transduction).
• Ganglion cells: gather information from photoreceptors.
• Trichromatic color theory: 3 cones sensitive to different wavelengths (short, medium, long).
• Opponent process theory: perceive color in opposing pairs (red/green, yellow/blue, white/black).
• Monocular depth cues: pictorial cues, depth using one eye.
  • Relative height.
  • Relative size.
  • Linear perspective.
  • Interposition: closer objects block further objects.
  • Light and shadow.
• Retinal disparity: different retinal images from each eye's perspective.
• Convergence: eye muscles turn inward when viewing nearby objects.
• Constancy: brains automatically recognize the stability of things despite changing conditions.
  • Size constancy.
  • Color constancy.
• Binocular depth cues: using both eyes for visual signals.

Audition and Multimodal Perception

• Audition: sense of hearing.
• Hearing loss.
  • Conduction: sound not loud enough; treatment: hearing aid.
  • Sensory neural: cochlea damage; treatment: cochlear implant.
• Sound localization: cues to determine the source of sound.
• Multimodal perception: concurrent stimulation in multiple modalities affects perception. Example: "ba" face mouthing "fa" results in hearing "fa".
• Synesthesia: perceptual activities trigger exceptional sensory experiences.

Learning: Classical Conditioning

• Ivan Pavlov (1906) discovered classical conditioning.
• Neutral stimulus (NS): doesn't initially cause a response (e.g., bell).
• Unconditioned stimulus (US): causes an unconditioned response (e.g., dog food).
• Conditioned stimulus (CS): the neutral stimulus becomes the conditioned stimulus after conditioning.
• Conditioned response (CR): the response triggered by the conditioned stimulus.
• Unconditioned response (UR) and Conditioned Response (CR) are the same, but triggered by different events; conditioning was/was not necessary.
• Neutral Stimulus and Conditioned Stimulus are the same.
• Acquisition: the process of NS + US pairing.
• Second-order conditioning: a conditioned stimulus is paired with another stimulus.
• Extinction: the conditioned stimulus is repeatedly presented without the unconditioned stimulus, leading to the elimination of the learned response.
• Spontaneous recovery: the reappearance of an extinguished conditioned response after a period of rest.
• Generalization: similar stimuli elicit the same response.
• Discrimination: the ability to distinguish between similar but distinct stimuli.
• John B. Watson: father of behaviorism, believed behaviors can be explained by conditioning.
• Little Albert experiment: used classical conditioning to make Albert fear rats.
• Preparedness: organisms are biologically predisposed to learn certain associations more easily than others.
• Conditioned taste aversions: developing a dislike for a food or drink after it has been associated with feeling ill.

Learning: Operant Conditioning

• Operant conditioning: behavior is modified by its consequences (differs from classical conditioning).
• B.F. Skinner: pioneer of operant conditioning.
• Edward Thorndike's law of effect: behaviors followed by favorable consequences become more likely, and behaviors followed by unfavorable consequences become less likely.
• Reinforcement: meant to increase behavior.
  • Positive: ADDING something to increase behavior.
  • Negative: REMOVING something to increase behavior.
• Punishment: meant to decrease behavior.
  • Positive: ADDING something (aversive) to decrease behavior.
  • Negative: REMOVING something to decrease behavior.
• Shaping: using operant conditioning to gradually guide behavior toward a desired response.
• Reinforcement schedules: impact how long behaviors last.
  • Fixed vs. variable: predictable, stable vs unpredictable.
  • Interval vs. Ratio: time vs number of behaviors. - Fixed interval: Reinforced after a given amount of TIME. - Variable Interval: Reinforced after an AVERAGE amount of time. - Fixed Ratio: Reinforcement after an average number of responses. - Variable Ratio: Reinforced after an average number of responses.

Memory: Encoding and Storage

• Encoding: transforming perception into memory.
• Levels of processing: information processed deeply is better remembered.
• Mnemonics: strategies for remembering large amounts of information (e.g., method of loci).
• Storage: holding information for later retrieval.
• Atkinson-Shiffrin model proposes 3 different states of memory.
• Sensory memory: Briefly holds perceptual information in accurate form.
  • Iconic memory: visual information.
  • Echoic memory: auditory information.