Ch 2 Psy

• study links btwn our biology and our behavior
• also call themselves: behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologist, or biopsychologist

• a nerve cell; the basic building block of the nervous system
• Each has cell body and dentrite

• Receives impulses
• the neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body

• sends impulses away from cell... can be very long
• the neuron's extension that passes messages through it's branching terminal fibers that form junctions with other neurons, muscles, or glands.

speak, listen

a neural impulse; a brief electrical charge that travels down an axon

the level of stimulation required to trigger a neural impulse

• the junction btwn the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. 
• the tiny gap at this junction is called the synaptic gap or synaptic cleft 

• chemical messengers that cross the synaptic gaps btwn neurons
• When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

a process in which the sending neuron reabsorbs the excess neurotransmitters

• (ACh) ~ one of the best understood neurotransmitter
• enables muscle action, learning and memory
• is the messenger at every junction btwn a motor neuron and skeletal muscles
• if blocked (like with anesthesia), we are paralyzed. 
• Malfunctions: alzheimers disease, ACh-producing neurons deteriorate

"morphine within" - natural, opiatelike neurotransmitters linked to pain control and to pleasure

• neurotransmitter
• influences movement, learning, attention, and emotion
• Excess linked to schizophrenia, insufficient amount linked to Parkinsons

• affects mood, hunger, sleep, and arousal
• insufficient linked to depression. prozac is one that will rise levels

• helps control alertness and arousal
• undersupply can depress mood

• molecules which may be similar enough to neurotransmitter to bind to receptor and mimic it's effects
• some opiate drugs are agonists and produce a temporary "high" by amplifying normal sensations of arousal or pleasure

molecules which bind to receptors but their effect is instead to block a neurotransmitter's functioning.

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

• CNS ~ brain and spinal cord. 
• the body's decision maker

• PNS ~ the sensory and motor neurons that connect the CNS to the rest of the body
• responsible for gathering info and transmitting CNS decisions to other body parts
• two components: somatic and autonomic

bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs

sensory, motor, and interneurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord for processing

neurons that carry outgoing info from the brain and spinal cord to the muscles and glands

• neurons within the brain and spinal cord that communicate internally and intervene btwn the sensory inputs and motor outputs
• process info

• VOLUNTARY CONTROL
• the division of the peripheral nervous system that controls the body's skeletal muscles.
• Also called skeletal nervous system

• involuntary; auto-piolet
• the part of the peripheral nervous system that controls the glands and muscles of the internal organs (such as the heart)
• it's sympathetic division arouses; it's parasympathetic division calms

division of autonomic nervous system; arouses and spends energy

division of the autonomic nervous system that calms the body, conserving it's energy

work groups of clusters of brain neurons

information highway connecting the peripheral nervous system to the brain

a simple, automatic response to a sensory stimulus, such as a knee-jerk

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress

• most influential endocrine gland
• under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
• sort of master gland

• tissue destruction
• a brain lesion is a naturally or experimentally caused destruction of brain tissue

electroencephalogram ~ an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp

• positron emission tomography scan ~ a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
• sugar glucose is the brains chemical fuel

• magnetic resonance imaging ~ a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. 
• shows brain anatomy

• functional magnetic resonance imaging ~ a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans.
• show brain function

the base of the brainstem; controls heartbeat and breathing

• oldest and innermost region, begins where the spinal cord swells slightly after entering the skull (slight swelling is medulla)
• is crossover point, where most nerves to and from each side of the brain connect with the body's opposite side

just above the medulla, helps coordinate movements

• sits at top of brainstem, egg shaped. receives info from all senses except smell
• the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

"netlike" ~ a nerve network in the brainstem that plays an important role in controlling arousal

*experiment involving electrically stimulating this made a sleeping cat instantly awake & alert

• "little brain" at rear of brainstem;
• functions include some nonverbal learning, processing sensory input, and coordinating movement output and balance
• Ex: Helps us judge time, modulate our emotions, and discriminate sounds and textures, also coordinates voluntary movement

the two halves of the brain

• neural system (including the hippocampus, amygdala, and hypothalamus) 
• located below the cerebral hemispheres
• associated with emotions (as fear and anger) and drives (as for food and sex)

• part of the limbic system
• processes memory

• part of the lumbic system, two lima-bean neural clusters
• linked to emotions, influence aggression and fear

• just below thalamus
• directs several maintenance activities (hunger, thirst, body temp, sexual behavior)
• also monitors blood chemistry & takes orders from other parts of brain (ex: hormones for sexual arousal)
• helps govern the endocrine system via the pituitary gland
• linked to emotion and reward

• a genetically disposed deficiency in the natural brain systems for pleasure and well-being that leads people to crave whatever provides that missing pleasure or relieves negative feelings
• EX: addictive disorders such as alcohol, substance abuse, and binge eating

sustain basic life functions and enable memory, emotions, and basic drives

• the two large hemispheres which contribute 85% of the brain's weight
• contain newer neural networks which form to specialized work teams that enable our perceiving, thinking and speaking

• a thin surface layer of interconnected neural cells
• covers the two hemispheres of the cerebrum like bark on a tree
• Is brains thinking crown, body's ultimate control and information processing center

four lobes: frontal, parietal, occipital, and temporal

"folds" on the brain which geographically subdivide each lobe

• portion of cerebral cortex lying just behind the forehead
• involved in speaking and muscle movements and in making plans and judgments

• portion of the cerebral cortex laying oat the top of the head and toward the rear
• receives sensory input for touch and body position

• portion of the cerebral cortex lying at the back of the head
• includes areas that receive information from the visual fields

• portion of the cerebral cortex lying roughly above the ears
• includes the auditory areas, each receiving information primarily from the opposite ear

• an area at the rear of the frontal lobes that controls voluntary movements
• discovered by 2 german physicians who elect. stimulated a dogs cortex; stimulating regions in left or right hemisphere caused body parts to move on opposite side of body

sensory receptors

occupied the greatest amount of cortical space

• area at the front of the parietal lobes, parallel to and just behind the motor cortex
• specializes in receiving info from skin senses and from movement of body parts
• the more sensitive the body region, the larger the sensory cortex area devoted to it

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather they are involved in higher mental functions such as learning, remembering, thinking, speaking, and integrating info.

impaired use of language, usually caused by left-hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding)

• area of left frontal lobe; 
• damage disrupts speaking; would cause a person to struggle to speak works while still being able to sing familiar songs and comprehend speech

• area of left temporal lobe; involved in language comprehension and expression
• damage would cause a person to speak only meaningless words; disrupts understanding

• involved in reading aloud
• receives visual info from visual area and decodes it to auditory form
• leaves a person able to speak and understand, but unable to read

• a) hearing words ~ auditory cortex and Wernicke's area
• b) Seeing words ~ visual cortex and angular gyrus
• c) speaking words ~ Broca's area and the motor cortex

the brain's ability to modify itself.. to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

the formation of new neurons

hemispheric specialization; each side serves differing functions

the wide band of axon fibers connecting the two hemispheres and carrying messages btwn them

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

• Info from L half of field of vision goes to the R hemisphere, which controls voluntary movement
• Info from R half of field of vision goes to the L hemisphere, which controls speech