MCAT Psyc/Soc Terms

external validity

validity describing the extent to which the results can be generalized to different experimental situations or real life

construct validity

validity describing the extent to which the study measured what the researchers intended to measure

content validity

validity describing the extent to which the study covers the full scope of content the researchers intend to measure

criterion validity

validity describing the extent to which the measure can predict an outcome

reliability

the extent to which measurements are consistent

\*\*also called precision

social desirability bias

tendency of respondents to answer in a way that seems socially acceptable

acquiescence bias

tendency to agree or answer “yes” when asked a question, especially when unsure of the answer

experiment

study in which a variable is manipulated in order to observe the effects it has on another variable

independent variable

variable that goes on the x-axis

dependent variable

variable that goes on the y-axis

confounding variable

variable that affects both the independent variable and the dependent variable, potentially obscuring the true relationship between them

moderating variable

variable that affects the intensity of a relationship between two variables

mediating variable

variable that provides a causal link between two variables in an observed relationship

observational study

study in which a pre-existing relationship between variables is analyzed without any manipulation

negative controls

controls that do not receive the treatment/intervention of interest

positive controls

controls that receive a treatment that is known to induce the outcome of interest

cross-sectional study

observational study in which researchers take a set of people representative of the population and measure various things at a single point in time (and then look for correlations among the measurements)

correlational study

observational study in which there is a focus on the relationship between two variables (can’t determine directionality though)

longitudinal study

observational study in which multiple measures are taken over time

risk factors

independent variables associated with a higher risk of a negative outcome

protective factors

independent variables associated with a lower risk of a negative outcome

cohort study

observational study in which a group of subjects is assembled according to some organizing principle (often age) and followed up with over time

case-control study

observational study in which a group containing the outcome of interest is compared to a group of people who don’t have the outcome of interest → goal is to identify differences that may shed light on the phenomena in question

validity

extend to which a study’s results are both genuine/accurate and generalizable

\*\*also called accuracy

internal validity

validity describing the extent to which causal conclusions can be drawn from the data → no confounding variables

instinctual behaviours

behaviours that are hard-coded and shaped by genetics

adaptive traits

traits or behaviours that have been selected for because they promote reproductive success

epigenetics

changes that affect how genes work that don’t involve changing the actual nucleotide content

patellar reflex

reflex in which your leg will jerk in response to your knee being hit

palmar grasp reflex

reflex in babies where if you stroke the palm of their hand, they will grab onto your finger

rooting reflex

feeding reflex in babies where if a baby’s mouth or cheek is touched by something, it will search for the object that brushed by it

sucking reflex

feeding reflex in babies where if something grazes a baby’s mouth, it will automatically start making sucking motions

Moro reflex

reflex in babies in which they startle in response to sudden movement or loud sounds by extending their arms and legs, pulling them back in, and throwing their head back before crying

Babinski reflex

reflex in babies in which if the bottom of their foot is stroked, they will extend their toes outward

hypothalamus

structure in the endocrine system that converts input from the nervous system into endocrine signals, also releases various tropic hormones

\*\*releases GnRH, CRF, and TRH

anterior pituitary gland

structure in the endocrine system that is located below the hypothalamus and receives hypothalamic hormonal input through the hypophyseal portal system

\*\*releases LH, FSH, ACTH, TSH, prolactin, endorphins, and growth hormone

hypophyseal portal system

system of blood vessels connecting the hypothalamus to the anterior pituitary in the endocrine system

posterior pituitary gland

structure in the endocrine system that receives input from the hypothalamus in the form of neuronal signals

\*\*releases ADH and oxytocin

oxytocin

hormone secreted by the posterior pituitary gland that has roles in uterine contractions, social bonding, and mood

prolactin

hormone secreted by the anterior pituitary gland that has roles in lactation and modulating the stress response, anxiety, and depression

melatonin

hormone secreted by the pineal gland of the brain that has roles in inducing sleep

leptin

hormone involved in hunger that reduces hunger and tells the body to stop eating → primarily released by adipose/fat cells and acts on the hypothalamus

ghrelin

hormone involved in hunger that promotes hunger → released by cells in the gastrointestinal tract and acts on the hypothalamis

neuropeptide Y

hormone involved in hunger that stimulated appetite to increase food intake

epinephrine

hormones secreted by the adrenal medulla that are responsible for the acute stress (fight or flight) response

cortisol

hormone secreted by the adrenal cortex that is responsible for the chromic/long-term stress response

thyroid hormone

hormone released by the thyroid gland that has roles in metabolism and neurological development

hypothyroidism

condition in which abnormally low levels of thyroid hormone cause fatigue and depression

hyperthyroidism

condition in which abnormally high levels of thyroid hormone cause irritability

sensory neurons

neurons that carry information about stimuli to the central nervous system

afferent neurons

sensory neurons

motor neurons

neurons that carry signals to react from the central nervous system to the target cell

efferent neurons

motor neurons

acetylcholine

neurotransmitter responsible for activating muscle contraction at the neuromuscular junction and has a role in the ‘rest-digest’ functions of the parasympathetic nervous system

glutamate

excitatory neurotransmitter → depolarizes postsynaptic neurons to push them closer to the action potential threshold

GABA

inhibitory neurotransmitter → hyperpolarizes postsynaptic neurons to push them further away from the action potential threshold

agonist

compound that activates a certain receptor, causing some kind of response

antagonist

compound that bind to a receptor, blocking it, so that it is not activated and no response is triggered

central nervous system

system that consists of the brain and spinal cord

peripheral nervous system

section of the nervous system containing everything but the brain and spinal cord

somatic nervous system

section of the peripheral nervous system that is responsible for carrying out voluntary activities

autonomic nervous system

section of the peripheral nervous system that is responsible for unconscious activities

sympathetic nervous system

section of the autonomic nervous system that is responsible for the fight or flight (acute stress) response

\*\*dilates pupils and bronchioles, raises heart rate, and inhibits the activity of the digestive organs

parasympathetic nervous system

section of the autonomic nervous system that is responsible for the rest and digest response

\*\*constricts pupils and bronchioles, reduces heart rate, and stimulates the activity of the digestive organs

enteric nervous system

section of the autonomic nervous system that regulates the activity of the gut

hindbrain

part of the central nervous system consisting of the cerebellum, pons, and medulla oblongata → responsible for basic functions like breathing

midbrain

part of the central nervous system consisting of the substantia nigra, superior colliculus, and inferior colliculus → responsible for intermediate functions like eye movements

brainstem

part of the central nervous system consisting of the midbran, medulla oblongata, and pons

forebrain

part of the central nervous system consisting of the diencephalon and the telencephalon → responsible for more advanced functions like reasoning

diencephalon

part of the central nervous system consisting of the thalamus, hypothalamus, posterior pituitary gland, and pineal gland

cerebellum

structure in the hindbrain responsible for coordinated movement

amygdala

structure in the brain that is involved in episodic memory, attention, and emotion

frontal lobe

lobe involved in voluntary movement, memory processing, planning, motivation, and attention

parietal lobe

lobe involved in sensory processing

occipital lobe

lobe involved in vision

temporal lobe

lobe involved in meaning, making visual memories, attaching meaning to information, and language

electroencephalography

measures brain activity through electrodes placed on the scalp

computed tomography

brain imaging mechanism in which x-rays are taken at 360 degrees to form a 3D image of the brain

magnetic resonance imaging

brain imaging mechanism in which magnetic fields are used to image structures → often used to look at soft tissues

positron emission tomography

technique in which radiolabeled glucose (in FDG) emits positrons as it decays, revealing where more metabolism is being done → reveals brain activity

functional magnetic resonance imaging

technique in which differences in magnetic properties of oxygenated and deoxygenated blood are used to look at activity in the brain (tracks oxygen movement)

tonic receptors

receptors that adapt slowly and continuously fire in response to stimulip

phasic receptors

receptors that adapt quickly and fire when the stimulus is first presented

chemoreceptors

receptors that respond to chemical stimuli

photoreceptors

receptors that respond to light

mechanoreceptors

receptors that respond to touch

proprioreceptors

receptors that respond to stretch in muscle to tell the body where its limbs are

baroreceptors

receptors that respond to pressure

nociceptors

receptors that respond to pain

osmoreceptors

receptors that respond to (blood solute) concentrations

absolute threshold

lowest level of stimulus detectable by sensory neurons

just noticeable difference

minimum percentage change in a stimulus that is detectable as being difference

Weber’s Law

law stating that for any given sensory input, the just noticeable difference will be a constant proportion of the original input (doesn’t apply to extremes)

hit

aspect of signal detection theory in which a stimulus is perceived and present

miss

aspect of signal detection theory in which a stimulus is present, but not perceived

false alarm

aspect of signal detection theory in which a stimulus is perceived, but isn’t present

correct rejection

aspect of signal detection theory in which a stimulus is not detected or present

cones

photoreceptors that are concentrated in and around the fovea to detect colour and details

rods

photoreceptors that are used to night vision due to high sensitivity to light

bipolar cells

cells in the retina that cones and rods directly synapse onto