Key Concepts in Psychology: Heredity, Brain, and Behavior

Heredity

Genetic predispositions influence physical, behavioral, and mental traits.

Environment

External factors (e.g., family, education) shape behavior and cognition.

Evolutionary Perspective

Explains behavior via natural selection (survival/reproduction).

Criticism of Evolutionary Perspective

Misused in eugenics (discriminatory practices).

Research Methods

Twin studies, family studies, adoption studies compare genetic vs. environmental influences.

Central Nervous System (CNS)

Brain + spinal cord; processes all bodily functions.

Peripheral Nervous System (PNS)

Connects CNS to body; includes Autonomic NS and Somatic NS.

Autonomic Nervous System

Involuntary functions (e.g., heartbeat).

Sympathetic Nervous System

"Fight or flight" response.

Parasympathetic Nervous System

"Rest and digest" functions.

Neurons vs. Glial Cells

Neurons transmit info; glial cells support neurons.

Reflex Arc

Sensory → Interneuron → Motor neuron (e.g., knee jerk).

Neural Transmission

Steps: Resting potential → depolarization → action potential → refractory period.

All-or-nothing principle

Neurons fire fully or not at all.

Neurotransmitters

Excitatory (e.g., glutamate) vs. inhibitory (e.g., GABA).

Key Neurotransmitters

Dopamine (reward), serotonin (mood), acetylcholine (muscles).

Hormones

Similar to NTs; e.g., adrenaline (stress), oxytocin (bonding).

Psychoactive Drugs

Agonists (boost NT effects) vs. Antagonists (block NTs).

Types of Psychoactive Drugs

Stimulants (cocaine, caffeine), depressants (alcohol), hallucinogens (LSD, marijuana), opioids (heroin, pain relief).

Effects of Psychoactive Drugs

Tolerance, addiction, withdrawal.

Brain Structures

Brainstem: Medulla (breathing/heart rate), Cerebellum: Balance/motor coordination.

Limbic System

Amygdala (fear), hippocampus (memory).

Cerebral Cortex

Frontal lobe (decision-making, motor cortex), Parietal (somatosensory cortex), Occipital (vision), Temporal (hearing).

Hemispheric Specialization

Left: Language (Broca's/Wernicke's areas), Right: Spatial skills.

Plasticity

Brain's ability to reorganize after damage.

Circadian Rhythm

24-hour sleep/wake cycle.

Sleep Stages

NREM: Stages 1-3 (deep sleep), REM: Paradoxical sleep (dreaming, brain active/body paralyzed).

Sleep Disorders

Insomnia, narcolepsy, sleep apnea.

Vision

Rods (low light), cones (color).

Hearing

Pitch theories: Place, frequency, volley.

Chemical Senses

Olfaction (smell), gustation (taste: sweet, salty, umami).

Touch/Pain

Gate-control theory (pain modulation).

Vestibular/Kinesthetic

Balance (semicircular canals) vs. body movement sense.

Absolute threshold

The minimum level of stimulus intensity needed for a stimulus to be detected.

Sensory adaptation

The process by which sensitivity to a stimulus decreases over time when the stimulus remains constant.

Trichromatic theory

A theory of color vision that proposes three types of cones in the retina, each sensitive to different wavelengths of light.

Opponent-process theory

A theory of color vision that suggests color perception is controlled by the activity of two opponent systems: a blue-yellow mechanism and a red-green mechanism.

Gate-control theory

A theory that explains how the nervous system can block or allow pain signals to pass to the brain.

Phantom limb

The sensation that an amputated or missing limb is still attached and functioning.

Bottom-up processing

A type of perception that starts with the sensory input and builds up to the final perception.

Top-down processing

A type of perception that starts with the brain's prior knowledge and expectations to interpret sensory information.

Gestalt Principles

Principles that describe how we organize visual elements into groups or unified wholes.

Closure

The Gestalt principle that describes the tendency to perceive incomplete shapes as complete.

Figure-ground

The ability to distinguish an object from its background.

Proximity

The Gestalt principle that suggests objects that are close together are perceived as a group.

Similarity

The Gestalt principle that suggests objects that are similar are perceived as a group.

Cocktail party effect

The ability to focus on a single conversation in a noisy environment.

Inattentional blindness

The failure to notice a fully visible but unexpected object because attention was engaged on another task.

Binocular cues

Depth cues that require the use of both eyes, such as retinal disparity and convergence.

Monocular cues

Depth cues that can be perceived with one eye, such as relative size and interposition.

Prototype

The best example of a category, such as 'robin' as a prototype for 'bird'.

Algorithms

Step-by-step procedures that guarantee a solution to a problem.

Heuristics

Mental shortcuts that often involve focusing on one aspect of a complex problem and ignoring others.

Confirmation bias

The tendency to search for, interpret, and remember information in a way that confirms one's preconceptions.

Sunk-cost fallacy

The tendency to continue an endeavor once an investment in money, effort, or time has been made.

Divergent thinking

A thought process or method used to generate creative ideas by exploring many possible solutions.

Functional fixedness

The cognitive bias that limits a person to using an object only in the way it is traditionally used.

Explicit memory

Memory that involves conscious recall of facts and events.

Implicit memory

Memory that does not require conscious thought and is often demonstrated through performance.

Multi-store model

A model of memory that describes memory as consisting of three stores: sensory memory, short-term memory, and long-term memory.

Working memory

A system for temporarily holding and manipulating information.

Levels of processing

The theory that deeper levels of analysis produce more elaborate, longer-lasting memories.

Chunking

A memory strategy that involves grouping information into larger, more manageable units.

Method of loci

A mnemonic device that involves visualizing items to be remembered in specific physical locations.

Spacing effect

The phenomenon where information is better retained when study sessions are spaced out over time.

Context-dependent memory

The improved recall of specific information when the context present at encoding and retrieval are the same.

Mood-congruent memory

The tendency to recall experiences that are consistent with one's current mood.

Ebbinghaus curve

A graph that depicts the decline of memory retention over time.

Proactive interference

When old information interferes with the retrieval of new information.

Retroactive interference

When new information interferes with the retrieval of old information.

Misinformation effect

The phenomenon where a person's recall of episodic memories becomes less accurate because of post-event information.

Primacy effect

The tendency to better remember the first items in a list.

Recency effect

The tendency to better remember the most recent items in a list.

Anterograde amnesia

A condition where a person cannot form new memories after a brain injury.

Retrograde amnesia

A condition where a person cannot recall past memories before a brain injury.

General intelligence (g)

A construct that represents the overall cognitive ability of an individual.

Multiple intelligences

Howard Gardner's theory that proposes eight distinct types of intelligence.

Validity

The extent to which a test measures what it claims to measure.

Reliability

The consistency of a measure, often assessed through test-retest or split-half methods.

Stereotype threat

The risk of confirming negative stereotypes about an individual's racial, ethnic, gender, or cultural group.

Flynn effect

The observed rise over time in standardized intelligence test scores.

Aptitude

The potential to learn or perform in a specific area.

Aptitude tests

Assess potential.

Achievement tests

Assess knowledge.

Nature vs. Nurture

Genetic vs. environmental influences.

Continuity vs. Discontinuity

Gradual growth vs. distinct stages.

Stability vs. Change

Do traits persist or evolve over time?

Cross-sectional research

Compares different age groups at one time.

Longitudinal research

Tracks same group over time.

Teratogens

Harmful agents (e.g., alcohol, drugs) causing birth defects.

Gross motor skills

Large movements, e.g., walking.

Fine motor skills

Small movements, e.g., grasping.

Reflexes

Rooting (turn toward touch), Moro (startle).

Visual Cliff

Tests depth perception in infants.

Critical Periods

Time-sensitive learning (e.g., language).

Imprinting

Rapid attachment (e.g., ducklings to Lorenz).

Puberty

Primary (reproductive organs) and secondary (body hair, voice) sex characteristics.

Menopause

End of reproductive ability in women.

Crystallized Intelligence

Knowledge (stable).

Fluid Intelligence

Problem-solving (declines).