unit 1: biological bases of behavior

based off of AP Psych's unit 1, discussing the brain, the states of consciousness, and sensation of the body

cerebral cortex

the outer layer of the brain, responsible for higher-level cognitive functions, including thinking, perceiving, and decision-making

-highly folded to increase its surface area, allowing for complex neural processing and integration of information

-highly folded to increase its surface area, allowing for complex neural processing and integration of information

-85% of the brain (choosing between college algebra or pre-calculus; decision weighing)

lobes of the brain

the lobes of the brain refer to the four main regions or sections into which the cerebral cortex, the outer layer of the brain, is divided (frontal lobe, parietal lobe, temporal lobe, occipital lobe)

frontal lobes

located at the front of the brain

-involved in higher-level cognitive functions, including decision-making, problem-solving, planning, and personality expression (making quick decisions about ingredient qualities, cooking times, plating arrangements, prioritizing tasks between orders and kitchen staff, and regulating chef's behavior to make sure they stay professional under pressure)

prefrontal cortex

region of the brain located in the frontal lobe

-involved in higher-level cognitive functions, including decision-making, problem-solving, planning, and personality expression (making quick decisions about ingredient qualities, cooking times, plating arrangements, prioritizing tasks between orders and kitchen staff, and regulating chef's behavior to make sure they stay professional under pressure)

motor cortex

region of the brain located in the frontal lobe

-responsible for planning, executing, and controlling voluntary movements of the body

-send signals to the muscles, enabling us to preform actions such as walking, talking, and grasping objects (basketball player dribbling ball, where the motor cortex orchestrates the complex movements needed to control the ball with hand and feet; signals from cortex travel down into the muscles for precise dribbling, pivoting, and acceleration)

corpus callosum

thick band of nerve fibers that connects the left and right hemisphere of the brain, facilitating communication and information sharing between the two hemisphere (playing piano; brain sends signal to coordinate the movements between fingers on both hands, communicating between the left and right hemispheres of the brain, allowing them to work together seamlessly)

brainstem

the oldest and most primitive part of the brain

-responsible for basic life sustaining functions like breathing, heart rate, and sleep wake cycles

-serves as pathway for neural signals traveling between the brain and the rest of the body, connecting the cerebral cortex to the spinal cord (ADD PICTURE)

medulla

vital structure at the base of the brain stem

-regulates essential autonomic functions such as heartbeat, breathing, and blood pressure

-serves as a relay station for nerve signals traveling between the brain and the spinal cord, controlling involuntary bodily processes crucial for survival (jogging; heart rate increases to supply more oxygen to muscles; medulla sends signals due to this increase in activity, making sure that the cardiovascular system can meet the demands of the exercise)

reticular activating system

network of neurons located in the brain stem that plays a critical role in regulating arousal, attention, and consciousness

-filters sensory information and modulates overall brain activity, helping to maintain wakefulness and alertness

-"arousal" think, "alert" 99% of the time in psychology (peacefully asleep and suddenly jerking awake due to sound of smoke alarm; become very alert to the potential danger)

cerebellum

located at back of the brain, below the cerebral hemispheres

-responsible for coordinating movement, balance, and posture

-receives input from sensory systems and other parts of the brain to fine-tune motor movements and ensure smooth coordination (riding a bike down a winding trail; continuously processing information from eyes, inner ear, and proprioceptive receptors to adjust body position and maintain balance, as well as smoothly steer, and adjust speed to stay upright and avoid falling)

thalamus

relay station in the brain that processes and relays sensory information, such as sight, sound, touch, and taste, to the cerebral cortex

-acts as a gateway for sensory input, directing signals to the appropriate areas of the brain for further processing (body preparing for sleep, so the thalamus sends the signals to the pineal gland, which produces hormone melatonin; when the light levels increase, the thalamus receives signals for start of new day, leading to decreased melatonin production)

hypothalamus

small but powerful structure located below the thalamus

-responsible for regulating various essential bodily functions, including hunger, thirst, body temperature, and sleep-wake cycle

-control center helping to maintain homeostasis in the body

-also controls sexual arousal (activities mechanisms to help cool the body down when signals are received that the body is very warm by initiating sweating and dial acting blood vessels near skin surface to promote heat loss through perspiration and radiation)

refractory period

brief period following an action potential during which a neuron is unable to generate another action potential

-occurs because the neurons sodium channels are temporarily inactive sated and the cell membrane returns to its resting state (like waiting to flush a toilet after its just been flushed; neurons wait to reset before firing another action potential)

myasthenia gravis

chronic autoimmune disorder that affects the neuromuscular junction, where nerve impulses are transmitted to muscles

-occurs when the immune system produces antibodies that block or destroy the receptors for acetylcholine, a neurotransmitter that stimulates muscle contraction (weakness of eye muscles, drooping of one or both eyelids, blurred/double vision)

glutamate

the primary excitatory neurotransmitter in the CNS, playing a key role in synaptic transmission and neuronal communication

-involved in various brain function, including learning, memory, and neural plasticity (studying for a test and learning new information, glutamate activates in certain regions for memory formation, like the hippocampus; binds to receptors on the post synaptic neurons, leading to depolarization and the initiation of action potentials)

GABA

a neurotransmitter that acts as the primary inhibitory near transmitter in the central nervous system; promotes relaxation and reduces anxiety (GABA binds to receptors on the postsynaptic neurons, causing hyper polarization and reducing likelihood of action potentials firing in amygdala when publicly speaking)

acetylcholine

neurotransmitter that plays a fundamental role in both the central nervous system and the peripheral nervous system

-involved in various functions, including muscle contraction, memory, and learning (playing a game of basketball, and when moving across the court, your brain sends signals to your muscles to coordinate movements and perform actions like running or jumping; nerve fibers connect with muscle fibers that help trigger muscle contractions, enabling the coordination of muscle activity)

electrophalogram (EEG)

non-invasive neuroimaging technique used to record the electrical activity of the brain

-involves placing electrodes on the scalp to detect and measure the electrical signals produced by neurons in the brain

-commonly used to diagnose and monitor various neurological conditions

functional magnetic resonance imaging (fMRI)

neuroimaging technique used to measure brain activity by detecting changes in blood flow and oxygen levels

-provides detailed images of the brain's structure and function, allowing researchers to observe with areas of the brain are active during specific tasks or stimuli

absolute threshold

minimum amount of stimulation required for a stimulus to be detected by a sensory system

-represents the point at which a stimulus becomes noticeable to an individual at least 50% of the time (gradually increasing music to where you can barely hear it over the roar of the engine and road; even if faintly perceiving it)

just noticeable difference

the smallest change in a stimulus that can be detected by an individual

-the minimal difference needed for a person to perceive that a change has occurred (the change of the radio is so small you're not entirely sure the volume has increased, so you keep increasing until you're confident the music sounds louder; point when you're certain the volume has increased)

webers law

perceived difference in a stimulus must be proportional to the original intensity of the stimulus

-the bigger something is, the more you need to change it to notice a difference

-between TWO stimuli (a large amount of increase in volume to notice a difference in volume at concert; but decrease would be more evidence as you're used to the music being so loud)

retina

light-sensitive inner surface of the eye containing photoreceptor cells that convert light into neural signals (light rays from an object enter through the cornea and pass through the pupil, then to the lens, then the retina, which converts that light into neural signals)

lens

transparent structure in the eye that focuses light onto the retina

-adjusts its shape to help the eye properly refract light, enabling clear vision as different distances (gazing at distant tree and the lens adjusts to focus on the incoming light rays onto the retina for sharp image of the tree, and then shifting to a flower, the lens changes its shape to once again bring the object closer to focus; clear and detailed)

pitch perception

the brain's interpretation of the frequency of sound waves, determining whether a sound is high or low in tone

-higher frequencies are perceived as higher pitchers

-lower frequencies are perceived as lower pitches (high pitched note may correspond to a string vibrating rapidly with higher frequency wave, while low pitched note may result from slower vibrations and lower frequency wave on guitar)

frequency theory

theory of pitch perception proposing that the frequency of a sound wave directly corresponds to the rate at which auditory nerves fibers fire

-higher frequency->faster firing rates which results in higher perceived pitches (thick bass string vibrating, producing sound waves with a relatively low frequency, which causes the basilar membrane to vibrate at the same frequency, simulating auditory nerve fibers at corresponding rate)

volley theory

theory of pitch perception proposing that groups of auditory neurons fire in rapid succession to encode the frequency of sounds about 1000 Hz

-allows the brain to perceive pitches that exceed the firing rate of individual neurons (neurons in auditory system fire in coordinated manner when the drumbeat happens; groups of neurons fire, which creates volley of neural impulses that match the frequency of the sound wave)

conduction deafness

hearing impairment caused by problems with the outer or middle ear, such as damage to the ear canal, eardrum, or middle ear bones

-typically results in difficult hearing soft sounds and can often be treated medically/surgically(temporary) (development of built up wax, preventing sound waves from reaching the eardrum effectively, resulting in decrease in volume and clarity of sounds heard; muffled or fainter)

sensorineural deafness

hearing loss caused by damage to the inner ear or auditory nerve

-results in difficult hearing soft sounds and understanding speech, and is often permanent

-common causes include aging, exposure to loud noise, and certain medical conditions (noisy industrial environment without proper hearing protection, so overtime, the loudness damages the delicate hair cells in the cochlea, so the person experiences hearing loss in higher frequencies; also from aging, genetics, or certain medical conditions)

vestibular sense

the sense of body orientation and movement, including balance and spatial awareness

-brain waves slow down, muscles relax, and individuals may experience sudden muscle contraction known as hyping jerks

-90 minutes between cycles (nodding off, thoughts wandering, becoming more relaxed, jerking awake; verge of falling asleep but somewhat aware of surroundings)

nrem stage 1

the first stage of non-rapid eye movement sleep characterized by a drifting in and out of sleep, lasting only a few minutes

-brain waves slow down, muscles relax, and individuals may experience sudden muscle contraction known as hyping jerks

-90 minutes between cycles (nodding off, thoughts wandering, becoming more relaxed, jerking awake; verge of falling asleep but somewhat aware of surroundings)

nrem stage 2

the second stage of non-rapid eye movement sleep characterized by light sleep, lasting about 20 minutes (like nap)

-brain waves further slow down, and sleep spindles(short bursts of brain activity) and K-complexes(sudden, sharp waveforms) appear (thoughts become less coherent and more fragmented, muscle twitches [sleep spindles and k-complexes], not fully asleep and can easily be woken up)

nrem stage 3

the deepest stage of non-rapid eye movement sleep characterized by the presence of predominantly delta waves

-restoration of resources: the process during sleep where the body and brain replenishes energy, repair tissues, and remove waste products, promoting physical and mental well-being (someone trying to wake you up but you are still sleeping; breathing is slow and regular, movements are limited, and less responsive to external stimuli)

rem sleep

a stage of sleep characterized by rapid eye movements, vivid dreams, and muscle paralysis

-associated with increased brain activity, including dreaming, and plays a role in memory consolidation and emotional processing

-paradoxical sleep: you go from a super active brain to a paralyzed body (vivid dream where you are flying through a land of exotic colors, where your eyes dart back and forth)

rem rebound

the phenomenon where the body increases the time spent in REM sleep after a period of REM deprivation

-occurs as a compensatory response to the lack of REM sleep, often resulting in more intense and frequent REM sleep episodes (dreams become more vivid and spend more time in rem sleep because the body is making up for the rem sleep missed)

agonists

substances that bind to neurotransmitter receptors and mimic their effects, enhancing neural activity (drugs like heroin and methadone that bind neurons to heighten pleasure/decrease pain)

antagonists

substances that bind to neurotransmitter receptors without activating them, blocking the effects of neurotransmitters (drugs like chlorpromazine block the receptors to limit the uptake of dopamine; blocking to get certain effect)