MCAT: Psychological, Social, and Biological Foundations of Behavior

Threshold

The minimum level of stimulus intensity needed to detect a stimulus (absolute threshold) or notice a change between two stimuli (difference threshold)

Weber’s Law

The principle that the just noticeable difference (jnd) of a stimulus is a constant proportion rather than a constant amount. Ex: If you are holding a 10-pound dumbbell, you will likely notice if 1 pound is added (a 10% change). If you are holding a 100-pound barbell, adding 1 pound will be undetectable. You would need to add 10 pounds (still a 10% change) for the difference to feel noticeable.

Signal detection theory

A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise)

Psychophysics

The study of the quantitative relationships between physical characteristics of stimuli and our psychological experience of them

Sensory receptors

Specialized cells or nerve endings that respond to specific physical or chemical stimuli and initiate neural impulses

Visual processing

The complex manipulation of neural signals from the retina through the lateral geniculate nucleus (LGN) of the thalamus to the primary visual cortex

Parallel processing

The brain's ability to simultaneously analyze and combine separate pieces of visual information (such as colorr, shape, motion, and depth) all at once;

Feature detection

Specialized neurons in the visual cortex that respond maximally to specific aspects of a visual stimulus

Auditory processing

The pathway of sound signals from the cochlea via the vestibulocochlear nerve to the medial geniculate nucleus (MGN) of the thalamus and into the auditory cortex of the temporal lobe

Sensory reception by hair cells

The mechanism where sound waves bend the stereocilia of hair cells on the basilar membrane

Somatosensation

The broad mix of tactile senses including touch

Olfactory cells

Specialized chemoreceptors in the olfactory epithelium that bind specific volatile chemical ligands to trigger a G-protein coupled receptor cascade

Pheromones

Volatile chemical messengers released by an animal that affect the behavior or physiology of other members of the same species

Olfactory pathways in the brain

The neural route of smell from olfactory receptors to the olfactory bulb

Kinesthetic sense

Also known as proprioception: the body's ability to perceive its own movement, weight, and limb positions in space without relying on sight

Vestibular sense

The sense of balance

Bottom-up processing

Data-driven processing where the brain constructs a mental perception by piecing together individual

Top-down processing

Concept-driven processing where the brain uses existing knowledge

Perceptual organization

The cognitive process of grouping visual elements together to perceive stable

Gestalt principles

A set of specific rules describing how the human brain naturally structures and groups ambiguous visual elements into a meaningful patterns, groups, and unified wholes rather than seeing them as isolated parts.

Selective attention

The cognitive process of focusing on one specific stimulus or task while filtering out and ignoring irrelevant background stimuli

Divided attention

The ability to attend to and perform multiple tasks or process multiple streams of information simultaneously

Information-processing model

A cognitive framework describing how the human mind takes in

Piaget’s stages of cognitive development

A four-stage theory detailing how children construct a mental model of the world: sensorimotor (0–2 years), preoperational (2–7 years), concrete operational (7–11 years), and formal operational (11+ years)

Cognitive changes in late adulthood

Age-related cognitive shifts where fluid intelligence and recall memory generally decline

Role of culture in cognitive development

The principle that social and cultural contexts dictate which cognitive skills are valued

Influence of heredity and environment on cognitive development

The complex interaction where genetic potential sets the baseline range for cognitive development

Biological factors that affect cognition

Physiological influences on thinking

Types of problem-solving

Structural methods used to find solutions

Barriers to effective problem-solving

Cognitive hurdles that prevent finding a solution

Approaches to problem-solving

Distinct cognitive strategies utilized to tackle a dilemma

Heuristics and biases

Mental shortcuts that ease cognitive load but can lead to systematic errors

Theories of intelligence

Explanatory models of intellectual capability

Influence of heredity and environment on intelligence

The realization that intelligence is highly heritable (as shown by twin studies)

Variations in intellectual ability

The spectrum of human intellectual performance

States of consciousness

The distinct levels of awareness and physiological arousal that an individual experiences

Alertness

A state of consciousness characterized by wakefulness

Stages of sleep

The four distinct electroencephalogram (EEG) phases of sleep: Stage 1 (NREM1

Sleep cycles and changes to sleep cycles

The predictable 90-minute progression through NREM and REM stages that repeats 4 to 6 times per night

Sleep and circadian rhythms

The internal biological clock that regulates the 24-hour cycle of sleep and wakefulness

Sleep-wake disorders

Clinical disruptions in sleep patterns or quality

Hypnosis and meditation

Altered states of consciousness where hypnosis involves a state of deep relaxation and heightened suggestibility

Consciousness-altering drugs

Chemical substances that alter psychological processes

Types of consciousness-altering drugs and their effects

Functional classes of psychoactive drugs: depressants (alcohol/barbiturates

Drug addiction and the reward pathway in the brain

A state of compulsive drug use driven by the activation of the mesolimbic pathway

Encoding

The initial process of transforming raw sensory inputs and information into a structural mental representation that can be committed to memory storage

Processes that aid in encoding memories

Cognitive strategies that improve storage success

Types of memory storage

The structural layers of memory including sensory memory (extremely brief visual/auditory traces), working memory (active workspace holding roughly 7 items for immediate use), and long-term memory (unlimited, permanent storage)

Semantic networks and spreading activation

An organizational model of long-term memory where concepts are stored as interconnected nodes

Retrieval

The process of accessing

Retrieval cues

Environmental prompts

Recall

recognition

The role of emotion in retrieving memories

The phenomenon where emotional intensity enhances memory vividness via amygdala activation

Aging and memory

Age-related memory shifts where episodic memory

Memory dysfunctions

Clinical disorders causing severe memory loss

Memory decay

The gradual fading and structural weakening of physical memory traces (engrams) in the brain over time when the stored information is not actively used or retrieved

Interference

The phenomenon where different memories compete with and disrupt one another

Memory construction and source monitoring

The reconstructive nature of memory where retrieval can be distorted by misinformation

Changes in synaptic connections underlie memory and learning

The biological mechanism of memory formation where repetitive neural stimulation leads to long-term potentiation (LTP)

Three components of emotion

The distinct dimensions that make up an emotional state: Physiological Response: The involuntary physical changes your body undergoes. This includes altered brain activation, hormonal changes, and nervous system responses (e.g., an increased heart rate, sweating, or muscle tension).Cognitive Component: Your mental assessment and conscious interpretation of a situation. This includes the personal meaning you assign to an event, your memories, and your expectations. Behavioral Component: The outward expression of the emotion. This involves your body language, facial expressions, tone of voice, and physical actions

Universal emotions

The seven distinct facial expressions that are recognized and expressed across all human cultures regardless of upbringing: fear

Adaptive role of emotion

The evolutionary purpose of emotions to guide quick decision-making

James-Lange theory

A theory of emotion stating that a physiological response occurs first

Cannon-Bard theory

A theory of emotion asserting that a triggering stimulus causes a physiological response and a conscious

Schachter-Singer theory

Also known as the two-factor theory

The role of biological processes in perceiving emotion

The physiological infrastructure used to process feelings

Brain regions involved in emotion

Key structures including the amygdala (fear

The role of the limbic system in emotion

The brain regions that constitute this system are:

Limbic cortex. Cingulate gyrus. Parahippocampal gyrus.

Hippocampal formation. Inlcudes the dentate gyrus, Hippocampus, Subicular Complex, Amygdala, Septal area, and the Hypothalamus.

Emotion and the autonomic nervous system

The immediate physical control system where the sympathetic division drives the physiological arousal of negative or high-energy emotions (fight-or-flight)

Physiological markers of emotion

The specific physiological patterns associated with distinct emotional states

The nature of stress

The physiological and psychological response to an environmental threat or challenge (stressor) that taxes an individual's coping resources

Cognitive Appraisal Theory

The Lazarus theory of emotion states that our emotional experience is directly determined by how we evaluate or interpret a situation. We don't just react to an event; our brain first assesses its significance to our well-being, which then triggers the specific emotion.

Different types of stressors

Categories of stress-inducing events

Effects of stress on psychological functions

The cognitive and behavioral consequences of chronic high-stress levels

Physiological response to stress

The body’s physical reaction to a stressor

Emotional response to stress

The psychological affect caused by prolonged stressors

Behavioral response to stress

The actions and coping mechanisms adopted to deal with stress

Forebrain

The largest and most complex region of the brain containing the cerebral cortex

Midbrain

A small brain region above the hindbrain containing the superior colliculus (visual reflexes) and inferior colliculus (auditory reflexes) that acts as a relay station for sensory and motor information

Hindbrain

The evolutionarily older division of the brain consisting of the medulla oblongata

Lateralization of cortical functions

The division of labor between the two brain hemispheres

Components of the endocrine system

A network of glands that secrete hormones directly into the bloodstream to regulate physiology

Effects of the endocrine system on behavior

The modulation of mood and actions via systemic hormones

Genes

temperament

Adaptive value of traits and behaviors

The evolutionary benefit a specific behavioral trait provides

Interaction between heredity and environmental influences

The principle that nature and nurture do not act independently but interact

Experience and behavior

The process by which repeated environmental stimuli

Regulatory genes and behavior

Non-coding genetic sequences and epigenetic mechanisms (like DNA methylation) that control the expression of structural genes

Genetically based behavioral variation in natural populations

The presence of diverse behavioral phenotypes within a wild species driven by genetic mutations and polymorphisms

Prenatal development

The highly structured three-stage biological sequence of growth in the womb: the germinal stage (zygote formation and implantation)

Motor development

The predictable

Developmental changes in adolescence

The transition period from childhood to adulthood marked by a massive surge in sex hormones

Psychoanalytic perspective

Freud’s personality theory asserting that behavior is driven by unconscious conflicts between ancestral urges (id)

Humanistic perspective

A personality theory championed by Rogers and Maslow that focuses on free will

Trait perspective

A personality framework focused on identifying

Social cognitive perspective

Bandura's personality theory emphasizing reciprocal determinism

Biological perspective

The viewpoint that personality characteristics are heavily dictated by an individual's genetic inheritances

Behaviorist perspective

Skinner’s theory, known as operant conditioning, dictates that behaviors are shaped and maintained by their consequences, specifically through reinforcements and punishments.

Anxiety disorders

A class of psychological disorders characterized by excessive

Obsessive-compulsive disorder

A psychological disorder characterized by intrusive