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131 Cards in this Set
- Front
- Back
What is a neuron |
nerve cell specialized for communication |
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The cell body (soma): 1. structure 2. function(3) 3. location |
1. contains the nucleus 2. manufactures new cell components - the nucleus is involved in protein manufacture - provides continual removal of cell components 3. central region of neuron |
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Dendrites |
branchlike extensions for receiving information from other neurons
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Portion of neuron the receives signals |
dendrites |
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Axon 1.Structure 2. function |
- very thin near the cell body (narowness creates area that's easily activated by incoming signals) - specialized for sending messages to other neurons |
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Define synaptic vessicles |
- spherical sac containing neurotransmitters |
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Movement of synaptic vesicles: |
- travels length of axon on their way to axon terminal - once reaches synaptic terminal -> bursts -> releases neurotransmitters |
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What is a neurotransmitter? |
chemical messenger specialized for communication from neuron to neuron |
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once neurotransmitters are released from the synaptic vesicles ... |
they enter the synapse and quickly picked up by dendrites |
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Define synapse |
space between two connecting neurons through which messages are transmitted chemically |
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The synapse consists of: |
synaptic cleft: gap into which neurotransmitters are released from axon terminal |
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The synaptic cleft is surrounded by: |
- sending axon of the first neuron and receiving dendrite of the second neuron |
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Define glial celll: |
cell in NS that plays key role in formation of myelin and BBB, responds to injury, removes debris and enhances learning and memory |
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What are the most abundant glial cells? (5) |
Astrocytes - control blood flow to the brain - play vital role in development of embryo - communicate CLOSELY with neurons - abundant in BBB |
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The blood brain barrier is (2) |
a protective shield that protects brain from infection by bacteria and intruders - consists of tiny blood vessels wrapped w/ fatty coating |
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The BBB blocks (3) |
- large molecules - highly charged particles - molecules that dissolve in water |
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oligodendrocyte (2) |
- promotes new connection among nerve cells and releases chemicals to aid in healing - produces myelin sheath |
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What is myelin sheath? - what is its function? (3) total |
- glial cells wrapped around axons that act as insulators of the neurons signals - sheath contains gaps along axon (nodes) - signal jumps from node to node (electricity is conducted more efficiently) |
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Multiple sclerosis (2) |
-autoimmune disease where myelin sheath "eaten away" results in progressive loss of insulation of neural messages - messages become scrambles - results in wide variety of physical and emotional symp. |
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neurons respond to neurotransmitters by |
generating electrical activity |
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basis of all electrical responses in neurons depends on |
uneven distribution of charged particles across membrane surrounding neuron |
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when no neurotransmitters are acting on a neuron, membrane is at |
resting potential: electrical charge diff. across mem. when neuron is not being stimulated (-60 to -70mV) |
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During resting potential more positive particles are inside than outside the neuron? T of F |
FALSE: during resting potential more negative particles are inside than outside the neuron |
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When electrical charge inside neuron reaches high enough level compared to outside (_____________) ... what happens |
(threshold) --> action potential triggered |
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Define action potential (3) |
- electrical impulse that travels down the axon, triggering the release of neurotransmitters - language of neurons (communication b/w) - abrupt waves of electrical discharge triggered by a change in charge INSIDE AXON |
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Neurons obey the "all or none" rule meaning |
they either fire or they don't |
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Action potential originates where?
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- in the trigger zone near the cell body - moves towards axon/axon terminal |
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Flow of charged particles in and out of axon during action potential |
(+) charged particles flow rapidly into axon --> then flow back out rapidly --> causes spike in (+) charge then sudden decrease in charge --> inside charge ends up slightly more (-) than original resting value |
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When electrical charge reaches axon terminal ... |
triggers release of neurotransmitter into synapse |
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What is the absolute refractory period? |
- each action potential followed by absolute refractory period: time during which another action potential is impossible (this limits firing rate) |
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Graded potentials are |
- postsynaptic potentials that can be excitatory or inhibitory |
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graded potentials depend on: (2) |
- whether positive or negative charged particles flow across neuronal mem.
- which direction they flow |
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neurotransmitter binds to appropriate receptor causing receptor to open.. if positive ions allowed in... |
EPSP - excitatory postsynaptic potential - depolarizes neuron |
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neurotransmitter binds to appropriate receptor causing receptor to open.. if negative ions allowed in... |
IPSP - inhibitory postsynaptic potential
- hyperpolarizes neuron |
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Graded potentials of same type
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add together |
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graded potentials of different types |
cancel out |
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Long term potential: |
when graded potential becomes larger than it was prior to stimulation (mechanism for memory) |
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Define receptor sites |
location that uniquely recognizes a neurotransmitter |
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Lock and key analogy :
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neurotransmitter (key) that fits only its own type of receptor (lock) |
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Glutamate: (3) |
- rapidly excite neurons - release of ti associated with enhance learning and memory - when abnormally elevated - high doses can be toxic/damage neural receptors by overstimulation (schizophrenia) |
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GABA: (3) |
- inhibits neurons - anti-anxiety drugs activate GABA receptors - suppress overactive brain areas linked to worrying - workhorse in NS -> role in learning, memory and SLEEP |
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Acetylcholine (2) |
- roles in arousal, selective attention, sleep and memory - neurons that connect directly to muscle cells release acetylcholine (allows to trigger movement) |
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Acetylcholine and alzheimers |
neurons containing acetylcholine progressively destroyed |
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What are the monoamines? |
norepinepherin, dopamine and serotonin |
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Dopamine:
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rewarding experiences that occur when we seek out or anticipate goals (areas rich in dopamine activate when hear a joke) |
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Norepinepherine and serotonin |
activate or deactivate parts of brain influencing arousal and readiness to respond to stimuli |
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Anandamide |
roles in eating, motivation, memory and sleep (explains symptoms of marijuana bc has same receptors as THC) |
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Neuropeptides
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- short strings of amino acids in ns - act like neurotransmitters but tend to be more narrowly targeted in their jobs |
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Endorphines: |
chemical in brain that plays role in pain reduction |
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Morphine: |
binds to endorphine recpetors and mimick their effects |
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Psychoactive drugs: |
drugs that interact w/ neurotransmitter systems (affect mood, arousal or behaviour) |
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Opiates: |
Reduce emotional response to painful stimuli by binding with opoid receptors and mimicking endorphines |
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Ranquilizers (Xanax): |
diminish anxiety by stimulating GABA receptors -> driving down neuronal activity (opiate) |
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Receptor anatagonists |
decrease receptor site activity |
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Antidepressants (prozac/paxil) inhibit
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- inhibit reuptake by allowing neurotransmitter to stay in synapse longer (enhance neurotransmitter effects on receptor sites) |
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Plasticity: |
ability of nervous system t change |
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Network of neurons in brain changes over the course of development in 4 primary ways: |
1. growth of dendrites and axons 2. synaptogensis -formation of new synapse 3. pruning - death of certain neurons and retraction of axons to remove useless connections 4. myelination - insulation of axons w/ myelin sheath |
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Infantile autism theory |
suggests that it is caused by inadequate pruning (they have large brains)
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How is pruning helpful? |
- it streamlines neural organization (enhances communication among brain structurs) |
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Neurogenesis |
creation of new neurons in adult brian |
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Stem cells: |
cell often originating in embryos - potential to differentiate into more specialized cell |
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CNS composed of |
brain and spinal cord (controls mind and behvaiour) |
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PNS composed of |
all nerves that extend outside of the CNS - somatic NS: controls voluntary behaviour - autonomic NS: controls non-voluntary functions |
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Cortex consists of
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Frontal, parietal, temporal, occipital lobes |
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Frontal lobe |
performs executive functions that coordinate other brain area, motor planning, language and memory |
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Parietal lobe |
process touch information, integrate vision and touch |
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Temporal lobe
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process auditory info, language and autobiographical memory |
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Occipital lobe |
visual information |
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Basal Ganglia |
control movement and motor plannin |
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Limbic system consists of (4) |
1. thalamus: conveys sensory information to cortex (relay station) 2. hypothalamus: oversees endocrine and autonomic NS - key role in homeostasis 3. amygdala: regulates arousal and fear 4. hippocampus: processes memory for spatial locations |
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Cerebellum: |
controls balance and coordinated movement
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Brain stem consists of
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Midbrain: tracks visual stimuli and reflexes triggers by sound (role in movement) Pons: conveys information b/w cortex and cerebellum (connects them as well) Medulla: regulates breathing and heartbeats |
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Spinal cord role in CNS
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conveys information b/w brain and rest of body |
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Meninges:
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3 thin layers of membrane |
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Cerebral ventricle and CSF |
ventricle: fluid filled pockets that extend throughout brain and spinal cord - contains CSF which bathes our brains and spinal cord - CSF provides nutrients and cushioning against injuring (CNS shock absorber) |
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The cerebrum consists of |
2 cerebral hemispheres connected by corpus callosu |
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Outermost part of the cerebrum |
cortex |
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Central suculus |
deep groove that separates frontal lobe from rest of cortex |
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Motor cortex structure (2) |
- part of frontal lobe - lies next to central suculus |
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Prefrontal cortex 1. location 2. function |
1. lies in front of motor complex 2. - responsible for thinking, planning and language - contain broca's area - plays key role in language production - also contributes to mood, personality and self-awareness |
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Location of frontal lobe |
lie in forward part of cerebral cortex (touch forehead) |
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Parietal lobe location |
upper middle part of cerebral cortex (lies behind frontal) |
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Primary sensory cortex (3) |
- part of parietal lobe - behind motor cortex - sensitive to touch: pressure, pain and temp |
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Lateral fissure: |
horizontal groove that separates temporal lobe from rest of cortex |
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Auditory cortex |
- part of temporal lobe (top of temp lobe) - devoted to hearing |
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Wernick's area (3) |
- language area in temporal lobe and includes lower parietal lobes as well - located slightly above and behind left ear - damage to: results in difficulty with understanding speech/speak gibberish |
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Occipital lobe location |
very back of brain |
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Association cortex: |
integrate simpler functions to perform more complex functions (pulling together size, shape, colour and location information to identify an object) |
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Limbic system |
process informaiton about internal states: bp, heart rate, perspiration emotion |
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Sensory information first passes through _________ -> undergoes ___________ before travelling to ___________ |
Sensory information first passes through thalamus -> undergoes some processing before travelling to cortex |
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Which part of limbic system plays role in fear conditioning |
Amygdala: fear conditioning: predict when something scary is about to happen |
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Damage to hippocampus
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- causes problems with forming new memories but leaves of memories intact hypothesis: hippocampus temporarily stores memories before transferring it to other sites |
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Relay station between cortex and rest of NS |
brain stem |
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what part of the brain plays a role in tiggering dreams? |
pons |
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Reticular activating system (RAS) |
- connects to forebrain and cerebral cortex - key role in arousal |
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Sensory info carried from brain to body by
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motor nerves |
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Interneurons: |
neurons that send messages to other neurons nearby |
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How do reflexes work |
interneurons connect sensory nerves with motor nerves within spinal cord w/o having to report back to brain |
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Stretch reflex relies only on the _____ |
relies only on the spinal cord carrying books -> over time grasp slightly releases w/o our noticing -> sensory nerve detects muscle stretch -> relay info to spc -> interneurons intervene -> motor neurons automatically send msgs -> arm muscles contract to prevent books from falling |
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Somatic NS conveys information b/w |
CNS and the body - controls and coordinates voluntary movement |
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Autonomic NS controls |
involuntary actions of internal organs and glands along with limbic system (participates with emotion regulation)
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Autonomic NS divided into
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1. sympathetic NS: fight or flight response 2. parasympathetic NS: controls rest and digestion - kicks in when no threat detected |
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Endocrine system:
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system of glands and hormones that controls secretion of blood-borne chemical messengers |
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How do hormones differ from neurotransmitters? (2) |
- hormones carried in blood - neurotransmitters carried in nerves - hormones slower in their actions but tend to last longer |
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Pituitary gland: (3) |
- master gland that controls other glands in body - is controlled by hypothalamus - regulating physical growth, control bp, determines how much water we retain in kidney |
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Oxytocin (2) |
- pituitary hormone - stretching cervix in vagina during birth and aiding milk flow in nursing mothers |
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Adrenal gland |
- tissue located on top of kidneys that releases adrenalin and cortisol during states of emotional arousal |
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Adrenalin: |
boosts energy production in muscle cells while conserving as much energy as possible |
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What signals adrenal glands to release adrenalin |
nerves of the sympathetic NS
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Adrenaline triggers (6) |
1. contraction of heart muscles/constriction of blood vessels (provide more blood to body) 2. opening of bronchioles to allow inhalation of more air 3. breakdown of fat into fatty acids (energy) 4. breakdown of glycogen into glucose (energize muscles) 5. opening pupils to enable better sight during emergencies 6. inhibits gastrointestinal secretions |
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Cortisol: |
increase in response to physical and psychological stressors (elevated levels in ppl w/ anxiety disorders) |
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Phrenology (3)
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first attempt to map mind onto brain - incorrect map of the mind - assessed bumps of the head (attributed to personality and intellectual characteristics) |
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Electroencephalograph (EEG) (5) |
- measure electrical activity generated by brain - patterns and sequences allow scientists to infer whether a person is awake or asleep (dreaming or not) - tell which regions of brain active during specific tasks - multiple electrodes placed on scalp surface to record electrical activity - noninvasive |
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Disadvantage of EEG |
show averaged neural activity that reached the surface of scalp - tells little about what is happening inside neurons |
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Computed tomography (CT Scans) |
scanning technique using multiple X-rays to construct 3D image |
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Magnetic Resonance Imaging (MRI) (3) |
technique that uses magnetic fields to indirectly visualize brain structure - measures release of energy from H atoms in tissues following exposure to magnetic field - superior t CT for detecting (brain tumors) |
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CT and MRI show
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brain structure only |
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Positron Emission Tomography (PET) |
imaging technique - measures consumption of glucose-like molecules, yielding a picture of neural activity in diff. regions of brain - figure out where regions most active during a task (most glucose consumed) |
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Functional MRI (fMRI) (2) |
- uses magnetic fields to visualize brain activity - measures change in blood oxygen level (brain cells require more oxygen as they do work) |
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Strength and disadvantage of fMRI |
Strength: ability to provide detailed images of activity in small brain regions and over brief time intervals Disadvantage: extremely sensitive to motion (patients can't move too much) |
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Transcranial magnetic stimulation (TMS) |
technique that applies strongly and quickly changing magnetic fields to the surface of the skull (can either enhance or interrupt brain function) |
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What is the only noninvasive brain imaging technique that can infer causation? |
TMS Ex: if TMS interrupts functioning in temporal lobe and subject displays temporary language impairment as result - can conclude that temporal lobe plays role in language processing |
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Magnetoencephalography MEG |
measures brain activity by detecting tiny magnetic field generated by the brain - extremely small intervals |
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Lateralization: |
cognitive function that relies more on one hemisphere than the other |
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Split brain surgery: (2) |
severing the corpus callosum to reduce spread of epileptic seizures - difficulty integrating information presented to separate hemispheres |
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Pheotype
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observable traits |
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According to evolutionary psychologists, aggressive behaviour is
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an adaption |
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Behaviour genetics |
to examine influence of nature and nurture on psychological traits and examine heritability of traits and diseases |
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Heritability:
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percentage of the variability in a trait across individuals that is DUE to genes |
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Misconceptions about heritability (3) |
1. heritability applies to a single individual rather than to a difference among individuals [fact: tells about the causes of differences among people not within a person] 2. heritability tells us whether a trait can be changes [fact: tells little to nothing about changeability] 3. heritability is a fixed number [fact: if reduce range of env. heredity will increase (vice verse)] |
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Scientists estimate heritability using 1 of 3 behavioural genetic designs |
1. family studies: analysis of how characteristics run intact families 2. twin studies: analysis of how traits differ in identical vs. fraternal twins 3. adoption studies: analysis of how traits vary in individuals raised apart from their biological relative |