MCAT - Behavior Sciences

Franz Gall

Earliest theory that behavior, intellect, and personality might be linked to brain anatomy, believed in phrenology(Skull formation = prioritizes important traits)

Pierre Flourens

First person to study functions of the major sections of the brain, through extirpation(also known as ablation) on rabbits and pigeons

William James

Founder of American psychology, studied how the mind adapts to environment, formed foundation of functionalism(Mental processes help people adapt to environment)

John Dewey

Important name in functionalism, believed that psychology should focus on the study of the organism as a whole as it functioned to adapt to environment

Paul Broca

Examined behavioral deficits of people with brain damage, showed that specific issues could be linked to certain brain damage, discovered Borca's area(language part of brain)

Hermann Von Helmholtz

First to measure the speed of a nerve impulse, provided one of the earliest measurable links between psychology and Physiology

Sir Charles Sherrington

First inferred existence of synapses, though they were an electrical process(It is chemical)

Neurons - Afferent

Sensory neurons

Neurons - Efferent

Motor neurons

Interneurons

Communicate between sensory and motor

Reflex Arcs

Ability of interneurons in the spinal cord to replay info to source of stimuli while simultaneously routing it to brain

Peripheral Nervous System(limbs)

Divided into somatic(voluntary) and autonomic(automatic)

Central Nervous System

Spinal cord and brain, Parasympathetic and sympathetic

Connective tissue in brain name

Meninges, resorb cerebrospinal fluid

3 layers of brain tissue

Outer Layer = Dura mater

Middle = Arachnoid mater

Inner(connected to brain) = Pia mater

Brainstem

Hindbrain + midbrain, first developed, forebrain developed later including the limbic system, most recent evolutionary development of human brain is the cerebral cortex(problem solving, language, long term planning)

Forebrain

Contains cerenral cortex, basal ganglia, limbic system, thalamus, hypothalamus

• Complex perceptual ,cognitive, behavioral processes, emotion and memory

• * Prosencephalon divides to form telencephalon(cerebral cortex, basal ganglia, limbic system) and diencephalon(Thalamus, hypo, posterior pituitary gland, pineal gland)

Telencephalon

Part of forebrain, comes from prosencephalon

• Cerebral cortex, basal ganglia, limbic system

Diencephalon

Part of forebrain, comes from prosencephalon

• Thalamus, hypo, posterior pituitary gland, pineal gland

Neuropsychology

Study of functions and behaviors associated with specific parts of the brain

EEG

Electroencephalogram, shows electrical activity generated by larger groups of neurons

rCBF

Regional cerebral blood flow, Detects broad patterns of neural activity based on increased blood flow increases

CT

Also known as CAT scan, multiple X-rays are taken at different angles and processed by computer to show tissue

PET

Radioactive sugar injected and absorbed, dispersion and uptake throughout target tissue is imaged

MRI

Magnetic field that interacts with hydrogen atoms is used to map out hydrogen dense regions of body

fMRI

Same technique but specifically measures changes associated with blood flow, useful for monitoring neural activity

Hindbrain

Controls balance, motor coordination, breathing, digestion, arousal like sleeping and waking

• Myelencephalon becomes medulla oblongata, metencephalon becomes pons and cerebellum

• Cerebellum - Maintains posture and balance and coordinates body movements

• Medulla oblongata - Breathing, heart rate, digestion

• Reticular formation, pons(Sensory and motor pathways between cortex and medulla)

Midbrain

Mesencephalon, receives sensory and motor info from rest of body

• Two nuclei, colliculus, superior and inferior, superior = visual sensory input, inferior = receives sensory info from auditory system

Thalamus

Part of Diencephalon - Relay station for incoming sensory info except smell, filters them

Hypothalamus

Part of Diencephalon - Homeostatic functions, key player in emotional experiences during high arousal states, aggressive behavior, and sexual behavior

• Later hypothalamus - Hunger center, detects when body needs food or fluids

• Ventromedial hypothalamus - Satiety center

• Anterior Hypothalamus - Controls sexual behavior

Posterior Pituitary

Part of Diencephalon - Release of Antidiuretic hormone and oxytocin for hypothalamic hormones

Pineal Gland

Part of Diencephalon - Melatonin, regulates circadian rhythms

Basal Ganglia

Part of Telencephalon - Coordinates muscle movement, receive info from cortex and relay info to brain/spinal cord

• Extrapyramidal system - Gathers info about body position

• Parkinson’s Disease = Destruction of portions of basal ganglia

Septal Nuclei

One of primary pleasure centers

Amygdala

Defensive and aggressive behaviors, fear and rage

Hippocampus

Vital role is learning and memory processes, helps consolidate info to form long-term memories and can redistribute remote memories to the cerebral cortex, fornix communicates with other brain areas

Anterograde Amnesia

Cannot establish new long term memories, can remember memories before brain injury

Retrograde Amnesia

Memory loss of events that transpired before brain injury

Anterior Cingulate Cortex

Higher order cognitive processes, regulation of impulse control and decision-making, maintains connections to other parts of the limbic system

Cerebral Cortex

Has gyri and sulci, increases surface area, two halves with 4 lobes

• Frontal Lobe - Motor cortex, Prefrontal cortex: Executive function by supervising and directing operations of other brain regions, Broca's Area - Speech production

• Parietal lobe - Somatosensory cortex(on postcentral gyrus), where all incoming sensory signals for touch, pressure, temp, and pain goes

• Occipital Lobe - Visual cortex

• Temporal Lobe - Auditory cortex and [[Wernicke's Area]] - Language reception and comprehension, also functions in memory processing, emotion, language(hippocampus in temporal lobe)

• Dominant hemisphere(Usually left) - Analytic in function, logic, language, math

• Nondominant(right) - Intuition, creativity, music cognition

Association Area

Area that integrates input from diverse regions of the brain

Projection Area

More rudimentary perceptual and motor tasks, example is primary motor cortex

Broca’s Area

Speech production

Wernicke’s Area

Speech comprehension

Frontal Lobe

Function - Voluntary movement, speech, attention, reasoning, problem-solving, and impulse control

• Motor cortex, Prefrontal cortex: Executive function by supervising and directing operations of other brain regions

• Broca's Area - Speech production

Parietal lobe

Somatosensory cortex(on postcentral gyrus), where all incoming sensory signals for touch, pressure, temp, and pain goes

Occipital Lobe

Visual information

Temporal Lobe

Auditory cortex and Wernicke's Area - Language reception and comprehension, also functions in memory processing, emotion, language(hippocampus in temporal lobe)

Neurotransmitter

Sends signals from neuron to neuron, drug that mimics action of neurotransmitter = agonist, antagonist - Drugs that can block action

Acetylcholine

Transmits nerve impulses to muscles, used in parasympathetic nervous system, some function for learning

Epinephrine and Norepinephrine

Known as Catecholamines(all play roles in experience of emotions), Involved in controlling alertness and wakefulness

Dopamine

Help with smooth movements and postural stability , imbalances = schizophrenia]overproduction) and Parkinson's Disease(Too little), also helps with learning

Serotonin

Regulates mood, eating, sleeping, dreaming

GABA

Inhibitory effects, stabilizes neural activity

Glycine

Inhibitory neurotransmitter in CNS, increasing chloride influx into neuron

Glutamate

Excitatory neurotransmitter in CNS

Neuromodulators

Peptide neurotransmitters, slow, endorphins are natural pain killers

Endocrine System

Uses chemical messengers called hormones, hypothalamus links endocrine and nervous system

Hypophyseal Portal System

Connects hypothalamus and pituitary gland

Pituitary Gland

Releases hormones that regulate activities of endocrine glands elsewhere in body

Anterior portion(master) hormones:

• Adrenocorticotropic Hormone(ACTH)

• Follicle-Stimulating Hormone(FSH)

• Growth Hormone(GH)

• Luteinizing Hormone(LH)

• Prolactin

• Thyroid-Stimulating Hormone(TSH)

  Posterior Hormones:

• Antidiuretic Hormone(ADH/vasopressin)

• Oxytocin

Adrenocorticotropic Hormone(ACTH)

Stimulates adrenal glands to make cortisol - Cortisol regulates metabolism, blood glucose levels, maintains blood pressure, reduces inflammination

Follicle-Stimulating Hormone(FSH)

Male = Sperm production, Female = stimulates ovaries to make estrogen, role in egg development

Growth Hormone

Helps children grow taller, adult = maintains muscles, bone, fat distribution, metabolism

Luteinizing Hormone(LH)

Stimulates ovulation, stimulates testosterone if male - Gonadotrophic hormone

Prolactin

Stimulates breast milk production

Thyroid-Stimulating Hormone(TSH)

Stimulates thyroid to make hormones, manages metabolism, energy levels, and nervous system

Antidiuretic Hormone

Regulates water balance, sodium levels

Oxytocin

Helps labor to progress, causes release of breast milk, role in moving sperm

Adrenal Glands

Releases epinephrine and norepinephrine

• adrenal cortex: Produces many hormone called corticosteroids - Cortisol, also produces sex hormones like testosterone and estrogen

Gonads

Sex glands of body, produces sex hormones

Innate Behavior

Genetically programmed as a result of evolution, learned behaviors are based on experience

Adaptive Value

Extent to which a trait or behavior positively benefits a species by influencing evolutionary fitness

Family vs Twin vs Adoption Studies

Family studies - Genetically related individuals are more similar genotypically than unrelated

Twin studies - Comparing concordance rates(likelihood that both twins exhibit same trait)

Adoption Studies - Understands environmental and genetic influences on behavior

Neural Tube

Becomes CNS

Neural Crest

Spreads throughout the body, differentiating into many different tissues

Rooting Reflex

Infants turn heads toward anything that brushes cheek

Moro Reflex

Infant extends arms, slowly retracts and cries in response to falling sensation

Babinski Reflex

Big toe is extended and other toes fan in response to brushing of the sole of foot

Grasping Reflex

Infants grab anything put into their hands

Sensory Ganglia

Collections of cell bodies outside the CNS

Weber’s Law

The difference threshold for a stimulus is proportional to the magnitude of the stimulus, this proportion to 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

Stimulus Adaptation

Refers to a decrease in response to a stimulus over time

Cornea

Gathers and filters incoming light

Iris

Divides the front of the eye into anterior and posterior chambers, two muscles, dilator and constrictor papillae which open and close pupil

Lens

Refracts incoming light to focus it on the retina and is held in place by suspensory ligaments connected to the ciliary muscle

Ciliary Body

Produces aqueous humor, which drains through the canal of Schlemm - In eye

Retina

Contains rods and cones, rods detect light and dark, cones(short, medium, long) detect colors

Macula(central visual field)

Mostly cones, center is fovea which contains only cones

Ganglion Cells

Neurons that receive visual information, integration of signals from ganglion cells is performed by horizontal and amacrine cells

Eye support muscles

Bulk of eye supported by the vitreous on the inside and the sclera and choroid on outside

Visual Pathway

Eye, through optic nerves, optic chiasm, optic tracts, lateral geniculate nucleus of the thalamus, and visual radiations to get the visual cortex

Optic Chiasm

Contains fibers crossing from the nasal side of retina of both eyes

Visual Radiations

Run through temporal and parietal lobes

Visual Cortex

In occipital lobe

Parvocellular Cells

Detects form, high spatial resolution, low temporal

Magnocellular Cells

Low spatial, high temporal

Binocular Neurons

Detects depth

Outer Ear Structure

Pinna, external auditory canal, tympanic membrane

Middle Ear Structure

Ossicles: malleus, incus, stapes, footplate of stapes rests on oval window of cochlea, middle ear connected to nasal cavity by Eustachian tube