MCAT Psychology Review

Franz Gall (1758 - 1828)

One of the earliest psychologists, developed idea of phrenology

Pierre Flourens (1794-1867)

First person to study the functions of the major sections of the brain through extirpation/ablation on rabbits and pigeons

William James (1842 - 1910)

Founder of American psychology, formed the foundation of functionalism, which studies how mental processes help individuals adapt to their environment

John Dewey (1859 - 1952)

Article is attributed to the inception of functionalism, criticized reflex arc as he believes the organism must be studies whole

Paul Brocca (1824 - 1880)

First person to demonstrate that specific functional impairments could be linked with specific brain lesions

Hermann von Helmholtz (1821 - 1894)

First person to measure the speed of a nerve impulse and related it to reaction time

Sir Charles Sherrington (1857 - 1952)

First person to infer the existence of synapses

Neuropsychology

Study of the connection between the nervous system and behavior, most often focuses on the functions of various brain regions

Reflex arcs

Use the ability of interneurons in the spinal cord to relay information to the source of stimuli while simultaneously routing it to the brain

Central nervous system (CNS)

Brain and spinal cord

Peripheral nervous system (PNS)

Most cranial and spinal nerves, divided into somatic (voluntary) and autonomic (automatic) divisions

Autonomic system

Divided into the parasympathetic (rest-and-digest) and sympathetic (fight-or-flight) branches

Hindbrain

Contains the cerebellum, medulla oblongata, and reticular formation

Midbrain

Contains the inferior and superior colliculi

Forebrain

Contains the thalamus, hypothalamus, basal ganglia, limbic system, and cerebral cortex

Thalamus

Relay station for sensory information

Thypothalamus

Maintains homeostasis and integrates with the endocrine system through the hypophyseal portal system that connects it to the anterior pituitary

Basal ganglia

Smooths movements and helps maintain postural stability

Limbic system

Controls emotion and memory, contains the septal nuclei, amygdala, and hippocampus

Septal nuclei

Limbic system structure involved with feelings of pleasure, pleasure-seeking behavior, and addiction

Amygdala

Limbic system structure that controls fear and aggression

Hippocampus

Limbic system structure that consolidates memories and communicates with other parts of the limbic system through an extension called the fornix

Frontal lobe

Cerebral cortex structure that controls executive function, impulse control, long-term planning, motor function, and speech production

Parietal lobe

Cerebral cortex structure that controls sensations of touch, pressure, temperature, and pain, spatial processing, orientation, and manipulation

Occipital lobe

Cerebral cortex structure that controls visual processing

Temporal lobe

Cerebral cortex structure that controls sound processing, speech perception, memory, and emotion

Neurotransmitters

Released by neurons and carry a signal to another neuron or effector

Acetylcholine

Neurotransmitter used by the somatic nervous system (to move muscles), the parasympathetic nervous system, and the central nervous system (for alertness)

Dopamine

Neurotransmitter that maintains smooth movements and steady posture

Endorphins and enkephalins

Neurotransmitters that act as natural painkillers

γ-Aminobutyric acid (GABA) and glycine

Neurotransmitters that act as brain “stabilizers”

Epinephrine

Neurotransmitter that maintains wakefulness and alertness and mediate fight-or-flight responses, released by the adrenal medulla

Norepinephrine

Hormone that maintains wakefulness and alertness and mediate fight-or-flight responses, released by the adrenal medulla

Glutamate

Excitatory neurotransmitter in the brain

Serotonin

Neurotransmitter that modulates mood, sleep patterns, eating patterns, and dreaming

Cortisol

Stress hormone released by the adrenal cortex

Testosterone

Hormone that mediates libido, increases aggressive behavior, released by the adrenal cortex, and produced by the testes in males

Estrogen

Hormone that mediates libido, released by the adrenal cortex, and produced by the ovaries in females

Family studies

Looks at the relative frequency of a trait within a family compared to the general population

Twin studies

Compares concordance rates between monozygotic (identical) and dizygotic (fraternal) twins

Adoption studies

Compares similarities between children who were adopted and their adoptive parents, relative to similarities with their biological parents

Neural tube

Becomes the central nervous system

Neural crest

Cells spread out through the body, differentiating into many different tissues

Primitive reflexes

Exist in infants and should disappear with age, most serve a protective role and can reappear in certain nervous system disorders

Rooting reflex

Infants turn their head toward anything that brushes the cheek

Moro reflex

Infants extend the arms, then slowly retracts them and cries in response to a sensation of falling

Babinski reflex

Infants’ big toe is extended and the other toes fan in response to the brushing of the sole of the foot

Grasping reflex

Infants grab anything put into their hands

Age 0 language developments

Laughs aloud (4 mo)

Repetitive responding (8 mo)

“Mama, dada” (10 mo)

Age 1 language developments

Great variation in timing of language development

Uses 10 words

Age 2 language developments

Use of pronouns

Parents understand most

Two-word sentences

Uses 250 words

Identifies body parts by pointing

Age 3 language developments

Complete sentences

Uses 900 words

Understands 3600 words

Strangers can udnerstand

Recognizes common objects in pictures

Can answer “Tell me what we wear on our feet?” and “Which block is bigger”

Age 0 Social developments

Parental figure central

Issues of trust are key

Stranger anxiety (7 mo)

Play is solitary and exploratory

Pat-a-cake, peek-a-boo (10 mo)

Age 1 social developments

Separation anxiety (12 mo)

Dependency on parental figure

Onlooker play

Age 2 social developments

Selfish and self-centered

Imitates mannerisms and activities

May be aggressive

Recognizes self in mirror

“No” is favorite word

Parallel play

Age 3 social developments

Awareness of assigned gender

Gender-stereotyped play

Understands “taking turns”

Knows full name

Age 0 motor developments

Puts everything in mouth

Sits with support (4 mo)

Stands with help (8 mo)

Crawls, fear of falling (9 mo)

Pincer grasp (10 mo)

Follows objects to midline (4 wk)

One-handed approach/grasp of toy

Feet in mouth (5 mo)

Bang and rattle stage

Changes hands with toy (6 mo)

Age 1 motor developments

Walks alone (13 mo)

Climbs stairs alone (18 mo)

Emergence of hand preference (18 mo)

Kicks ball, throws ball

Pats pictures in book

Stacks three cubes (18 mo)

Age 2 motor developments

High activity level

Walks backward

Can turn doorknob, unscrew jar lid

Scribbles with crayon

Stacks six cubes (24 mo)

Stands on tiptoes (30 mo)

Able to aim thrown ball

Age 3 motor developments

Rides tricycle

Stacks nine cubes (36 mo)

Alternates feet going up stairs

Bowel and bladder control (toilet training)

Draws recognizable figures

Catches ball with arms

Cuts paper with scissors

Unbuttons buttons

Sensation

Conversion or transduction of physical, electromagnetic, auditory, and other information from the internal and external environment into electrical signals in the nervous system

Perception

Processing of sensory information to make sense of its significance

Sensory receptors

Nerves that respond to stimuli and trigger electrical signals, examples include photoreceptors, hair cells, nociceptors, thermoreceptors, osmoreceptors, olfactory receptors, and taste receptors

Sensory ganglia

Collections of sensory neuron cell bodies outside the CNS

Projection areas

Brain areas which analyze sensory input transmitted from sensory stimuli

Threshold

Minimum stimulus that causes a change in signal transduction

Absolute threshold

Minimum of stimulus energy that is needed to activate a sensory system

Threshold of conscious perception

Minimum of stimulus energy that will create a signal large enough in size and long enough in duration to be brought into awareness

Difference threshold/Just-noticeable difference (jnd)

Minimum difference in magnitude between two stimuli before one can perceive this difference

Weber’s law

The jnd for a stimulus is proportional to the magnitude of the stimulus, and this proportion is constant over most of the range of possible stimuli

Signal detection theory

Refers to the effects of nonsensory factors, such as experiences, motives, and expectations, on perception of stimuli

Response bias

A stimuli may or may not be given, and the subject is asked to state whether or not the stimulus was given

Four possible outcomes: hits (signal + detected), misses (signal + no detection), false alarms (no signal + detected), and correct negatives (no signal + no detection)

Adaptation

Decrease in response to a stimulus over time

Cornea

Eye structure that gathers and filters incoming light

Iris

Eye structure that divides the front of the eye into the anterior and posterior chambers, contains two muscles, the dilator and constrictor pupillae, which opens and closes the pupil

Lens

Eye structure that refracts incoming light to focus it on the retina and is held in place by suspensory ligaments connected to the ciliary muscle

Aqueous humor

Clear watery fluid in the front of the eye produced by the ciliary body and drained through the canal of Schlemm

Rods

Retinal structure that detects light and dark

Cones

Retinal structure that comes in short-, medium-, and long-wavelength forms to detect colors

Macula

Retinal area corresponding to the central visual field containing mostly cones

Fovea

Retinal area in the center of macula containing only cones

Path of visual input

Photoreceptors (rods and cones) → horizontal cells → bipolar cells → amacrine cells → retinal ganglion cells → nerve fibers

Vitreous

Clear gel-like substance that supports most of the eye on the inside

Sclera and choroid

White and colored part of support for the outside eye

Path of visual signals

Optic nevers → optic chiasm → optic tracts → lateral geniculate nucleus (LGN) of the thalamus → visual radiations → visual cortex

Optic chiasm

Contains fibers crossing from the nasal side of the retina (temporal visual fields) of both eyes

Visual radiations

Run through the temporal and parietal lobes

Parallel processing

Ability to simultaneously analyze and combine information regarding color, form, motion, and depth, all sense utilize this

Parvocellular cells

Neurons that detects form with high spatial resolution and low temporal resolution

Magnocellular celsl

Neurons that detects motion with low spatial resolution and high temporal resolution

Binocular neurons

Neurons that detect depth

Outer ear

Consists of the pinna (auricle), external auditory canal, and tympanic membrane

Middle ear

Consists of the ossicles (malleus/hammer, incus/anvil, and stapes/stirrup), the footplate of the stapes rests on the oval window of the cochlea, connected to the nasal cavity by the Eustachian tube

Inner ear

Consists of the bony labyrinth filled with perilymph, within which is the membranous labyrinth filler with endolymph and consists of the cochlea which detects sounds, utricle and saccule which detect linear acceleration, and semicircular canals, which detect rotational acceleration

Auditory pathway

Cochlea → vestibulocochlear nerve → medial geniculate nucleus (MGN) of the thalamus → auditory cortex in the temporal lobe

Superior olive

Brain stem nuclei that localizes sound

Inferior colliculus

Brain region involved in the startle reflex

Olfactory chemoreceotors/nerves

Olfactory epithelium cells that detects volatile or aerosilized chemicals

Olfactory pathway

Olfactory nerves → olfactory bulb → olfactory tract → higher-order brain areas

Pheromones

Chemicals given off by animals that have an effect on social, foraging, and sexual behavior in other members of that species