cognitive neuroscience exam 1 study guide
cognitive neuroscience exam 1 study guide 507
Popular in Cognitive Neuroscience
verified elite notetaker
BIO 1000 & 1060
verified elite notetaker
MATH 105 - 75
Etana Garfinkle Plymesser
verified elite notetaker
ARTH 2302 - 001
verified elite notetaker
verified elite notetaker
verified elite notetaker
Popular in Psychology (PSYC)
This 15 page Study Guide was uploaded by mallorylong59 Notetaker on Monday September 12, 2016. The Study Guide belongs to 507 at University of South Carolina taught by Allie Pierce in Fall 2016. Since its upload, it has received 4 views. For similar materials see Cognitive Neuroscience in Psychology (PSYC) at University of South Carolina.
Reviews for cognitive neuroscience exam 1 study guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/12/16
Cognitive Neuroscience Exam 1 Study Guide Chapter 1: A Brief History of Cognitive Neuroscience What is Cognitive neuroscience? - Cognitive neuroscience: the scientific study of the neural basis of mental processes - Neuroscience: the scientific study of the nervous system - Cognitive psychology: the scientific study of mental processes o Encompasses perception, attention, learning, memory, problem solving, decision making What is Phrenology? - Phrenology: the idea that character could be divined through palpating the skull. Phrenology came about due to this inference that the brain is the foundation of cognitive (and other) function. It was also thought that specific functions can be localized to specific brain regions (localizationist view), therefore, changes in brain structure influence skull development - Thomas Willis foreshadowed cognitive neuroscience with the notion that isolated brain damage could affect behavior (Localizationist view) Aggregate Field Theory - A theory that proposes that the whole brain participates in behavior. Flourens lesioned bird brains in order to observe the notion that certain brain structures were responsible for certain functions - Alternative to localizationist view What does having a “localization of function” perspective mean? - Localization of function perspective essentially composes this idea that specific functions can be localized to specific brain regions - John Hughlings Jackson proposed a topographic organization in the cerebral cortex- a map of the body was represented across a particular cortical area, where one part would represent the foot, another lower leg, and so on. - This view is also seen in various brain lesions: o Broca: Patient “Tan”-specific language impairment (speech production)- lesion to inferior frontal cortex o Wernicke: specific language impairment (speech comprehension)- lesion to different cortical region than Broca’s patient Cryoarchitechtonic Mapping - Cryoarchitechtonics: or cellular architecture, is the study of how cells differ between brain regions - Different functional regions of the brain should look different at the cellular level o Brodmann map: organized into 53 distinct areas based on cell structure- some area names are still used today The Neuron Doctrine: - The Neuron Doctrine is the concept that the nervous system is made up of individual cells - Golgi: proposed that the whole brain was a syncytium, a continuous mass of tissue that shares common cytoplasm - Ramon y Cajal: proposed the Neuron Doctrine o Golgi- developed new staining method o Ramon y Cajal: used Golgi stain to identify neurons as distinct entities Main Contribution of Camillo Golgi to this field - Golgi developed a new staining method Chapter 2: Structure and Function of the Nervous System Cell Types in The Brain - Neurons: Basic signaling unit- transmits information in the nervous system - Glial Cells: Non-neuronal cells, structural support, electrical insulation, modulating neuronal activity Know the Different Parts/Terminology of a Neuron and Their Functions - Dendrites: receive information - Axon: sends information - Cell Body/Soma: produces proteins and other cellular macromolecules - Dendritic Spines: where synapses form, Important for learning and neural plasticity - Myelin: fatty substance wrapped around axons that provides insulation for signaling - Synapse: where transmission occurs, a specialized structure where two neurons come in close contact so that chemical or electrical signals can be passed from one cell to the next - Pre-synaptic: when neuron’s axons make their connections onto other neurons - Post-synaptic: when neurons make a connection onto their dendrites Know the Processes of Graded Potentials and Action Potentials - Neurons at rest o Cell membrane is made of fatty material- it is impermeable to water soluble molecules (Na+,K+,protiens) o Also contains transmembrane proteins that allow molecules to pass through Ion Channels: Passive (non-gated K+ and Na+ channels), ions go down the concentration gradient (high to low) Ion Pumps: Active (Na+/K+ pump), Ions go against the concentration (low to high) o At rest these maintain an electrochemical equilibrium- the cells resting potential - Resting Membrane Potential o Difference between intracellular and extracellular charge o Resting Membrane Potential: -70 mV (inside of the cell is more negative) - Passive Signaling (Ion Channels) o Sensory stimulation or synaptic activity opens ion channels- this generates an electrical current o Current is passively conducted throughout the neuron o Depolarizing or EPSPs (making the inside of the cell more positive, closer to threshold) o Hyperpolarizing or IPSPs (making the inside of the cell more negative, farther from threshold) o Passive post-synaptic potentials- EPSPs bring membrane potential closer to threshold. IPSPs bring it farther away from threshold o All passive currents in cell sum together o When threshold is reached, an action potential is generates - Active Signaling o Passive currents depolarize patches of axonal membrane o Action potential is generates if threshold is reached o All-or-none response o Always has the same amplitude- stimulation can modulate the rate of firing but not amplitude o Always depolarization - Action Potentials o Change in membrane permeability o Depolarization opens Na+ channels o K+ channels open a few milliseconds later- repolarization phase mediated by K+ o Undershoots resting potential, preventing new action potential o Current flows passively from areas of positive to negative voltage o Depolarizes next area of membrane, activates voltage gates Na+ channels o The appearance of one action potential is jumping down the axon from one node of Ranvier to the next is called Saltatory Conduction o Nodes of Ranvier are the gaps between myelin located along the length of the axons Know the Process of the transmission of a neurotransmitter across the synapse - Gap junctions: ion channels in pre- and postsynaptic membrane aligned - Synaptic Cleft: gap between the neurons at the synapse (neurotransmitter releases at the synapse, into the synaptic cleft) - Chemical Synapses o How most neurons communicate, large variety of chemicals, can be inhibitory or excitatory - Synaptic Transmission o Vesicles created in cell body, travel down the axon to the terminal bouton o Depolarization from action potential opens voltage-gated calcium channels o Calcium causes vesicles to fuse with membrane and release neurotransmitter into the synaptic cleft - Neurotransmitter Receptors o Directly coupled Ligand-gated/ionotropic: binding with neurotransmitter causes ion channel to open o Indirectly Coupled G-protein coupled/metabotropic: binding with neurotransmitter causes cascade of changes inside cell Opens ion channel a short distance from the binding site - Classes of Neurotransmitters o Amino Acids GABA Glutamate Glycine o Biogenetic amines Dopamine (DA) Norepinephrine (NE) Epinephrine Serotonin (5-HT) Histamine o Neuropeptides: 5 groups Over 100 types Oxytocin, vasopressin, corticotrophin-releasing hormone, endorphins Tachykinins Substance P (spinal neurotransmitter involved in pain) Neurohypophyseal hormones Oxytocin (mammary functions; bonding/maternal behaviors) Vasopressin (antidiuretic hormone) Hypothalamic releasing hormones Corticotropic-releasing hormone (stress response) Opioid peptides Endorphins (similarity to opiate drugs) Other neuropeptides - Typical Effect of Neurotransmitters o Effect is determined by post-synaptic receptor, not just NT itself- the same NT could have excitatory or inhibitory effect depending on the receptor o Typical effects Acetylcholine (Ach)- Excitatory Glutamate- excitatory GABA- inhibitory Catecholamines (epinephrine, norepinephrine, dopamine)- excitatory Serotonin (5-HT)- excitatory Histamine- excitatory Neuropeptides- excitatory and inhibitory - Removal of Neurotransmitter from synapse o Reuptake with active transporters DA,NE,5-HT, GABA, glutamate o Degradation via Enzymes Acetylcholine (Ach) o Diffusion Neuropeptides Know the different types of glial cells and their functions - Four main types o Astrocytes o Microglial cell o Oligodendrocytes o Schwann cell - ~50% of brain volume - Astrocytes o Maintenance of the blood-brain barrier (BBB) o End feet attach to blood vessels in brain o “astrocytes, through active uptake of K+, improved the signal-to-noise ratio of synaptic transmission o Active control of the extracellular K+ concentration thus provides the astrocytes with a simple yet powerful mechanism to rapidly modulate network activity - Microglia o Remove damaged/sick cells o Help prune synapses during development - Oligodendrocytes (CNS) and Schwann cells (PNS) o Provide myelination for neurons o Cell wraps around axon, squeezing out cytoplasm in glial cell o Creates multiple lipid bilayers that insulate cell Myelin integral for rapid neural communication, loss of this function= MS Neuroanatomy directional terminologies - Rostral (anterior)- toward beak, caudal (posterior)- toward tail - Dorsal (superior)- top, ventral (inferior)- bottom - Lateral- more left/right, medial- center Slices of the brain - Horizontal (sub sandwich) - Sagittal (hot dog bun) - Coronal (loaf of sliced bread) What makes up grey matter/white matter - Grey matter: collections of cell bodies - White matter: collections of axons: whiteness is due to myelination of axons - Cortex is not the whole brain, only its outermost cellular layer o Everything that is not cortical is said to be subcortical Terminology - Afferent= inputs (to a brain structure) - Efferent= projections (from a brain structure) - Contralateral= on the opposite side - Ipsilateral= on same side Divisions of the brain - Hindbrain o Myelencephalon Medulla Pyramidal tracts - Corticospinal motor projections - These axons cross: pyramidal decussation- contralateral muscle control Respiratory, cardiac control o Metencephalon Pons Some eye, face, and mouth movements Modulates arousal (reticular formation) Generates REM sleep Fiber tracts - cortical projections to spinal cord, brainstem, cerebellum pontine nuclei - auditory information (superior olive) - vestibular functions - visuomotor nuclei (extraocular muscles) - reticular formation Cerebellum “little brain” Subdivisions: - Cerebellar cortex - White matter - Deep nuclei Cerebellar peduncles Modifies motor output - Maintaining posture, walking, performing coordinated movements - Midbrain o Mesencephalon Fiber tracts from forebrain to spinal cord, cerebellum, and brain steam Tectum (roof) Superior colliculus Inferior colliculus Tegmentum (floor) - Forebrain o Diencephalon Thalamus One thalamus per hemisphere “gateway to the cortex” Composed of groups of nuclei with interconnections to many areas Nuclei to know: - Lateral Geniculate - Medial Geniculate - Ventral posterior - Pulvinar Hypothalamus Small group of nuclei below the thalamus Endocrine control - Control release of growth hormone, TSH,ACTH, gonadotropic hormones from pituitary - Stimulate release of vasopressin and oxytocin from posterior pituitary Direct projections to cortex and neuromodulatory via peptide hormones o Telencephalon Limbic system Cingulate gyrus Parahippocampul gyrus Subcallosal gyrus Fornix Dentate gyrus Hippocampal formation Amygdala - Emotion - Heavily connected to orbitofrontal cortex Hippocampus - Learning and memory Basal Ganglia Integral for control of movement Caudate, putamen, Globus pallidus Substantia nigra - Produces dopamine - Diminished substantia nigra is seen in Parkinson’s disease Does not control motor activity directly Cortico-spatial loop - Monitoring motor activity Cerebral cortex Interhemispheric connections - Hemispheres connected by white matter tracts o Corpus callosum o Anterior commissure o Posterior commissure Lobes of the brain - Visual cortex o Occipital lobe o Topographically organized Calcarine fissure separates visual fields - Auditory Cortex o Superior temporal gyrus o Tonotopically organized (sound frequency) o Proximity to language areas in left hemisphere Broca’s area, Wernicke’s Area - Somatosensory Cortex o Primary Somatosensory Cortex (S1) Information about: touch, pain, temperature, limb proprioception o Anterolateral system Pain Temperature o Dorsal column-medial lemniscal system Touch Proprioception o Secondary somatosensory cortex (S2) Receives most of its input from s1 - Olfactory System o Only system that projects directly to the cortex o Closely linked to orbitofrontal cortex and limbic system - Frontal Lobe o DLPFC Executive function, attention, memory o VLPFC Attention, memory, language o OFC Decision making, emotion, reward o M1- primary motor cortex o Motor cortex Precentral gyrus Axons project to spinal cord and brainstem, synapse on motor neurons o Premotor Cortex o Supplementary motor area Arterial System - Active neurons require oxygenated blood - PET and MRI Ventricular System - CSF o Brain floats in liquid, reduces pressure and shock formation Neurobiology of development - Prenatal Development o Week 1- blastocyst forms o Week 2-3- gastrula forms Three distinct layers (ectoderm, mesoderm, endoderm) - Prenatal stages o Zygote: fertilization to 2 weeks o Embryo: 2 to 8 weeks o Fetus: 9 weeks to birth - Neural Plate o Thickened region of the ectodermal layer that gives rise to the neural tube - Neural Tube o Structure in the early stage of the brain development from which the brain and spinal cord develop - Major Events o Day 49: embryo begins to resemble a miniature person o Day 60: sexual differentiation o Day 100: Brain looks distinctly human o 7 months (gestation) Gyri and sulci begin to form o 9 months (gestation) Brain looks like an adult brain - Origins of Neurons and Glia o Neural Stem Cell A self-renewing multipotential Cell o Progenitor Cell Precursor cell derived from a stem cell; it migrates and produces a neuron or a glial cell o Neuroblast Product of a progenitor cell that gives ride to different types of neurons o Glioblast Product of a progenitor cell that gives rise to different types of glial cells - Stages of Brain Development o Cell Birth A chemical compound acts to support growth and differentiation in developing neurons; begins about 7 weeks after conception Largely complete by 5 months Exception: Hippocampus makes new cells throughout life Subventricular Zone Neuronal Proliferation When are neurons “born”? Inject radioactive label - Incorporated into dividing cells - Remains in mature neurons - Autoradiographic visualization Humans: middle third of gestation Birth of New Neurons Neurogenesis occurs in adults - Olfactory bulb - Hippocampus - Possibly other areas Terminally ill patients injected with BrdU (synthetic thymidine) Evidence of new neurons in hippocampus and caudate o Cell Migration Begins approximately 8 weeks after conception Largely complete by 29 weeks Radial glial cells Path-making cell that a migrating neuron follows to its appropriate destination Ventricular zone Contains a primitive map of the cortex that predisposes cells to migrate to certain locations Cells migrate to inner layers then to outer layers Deeper cortical layers show cell development earlier in gestation in all brain areas Time course various but sequence does not o Cell Differentiation Begins after cells have begun to migrate Largely complete by 29 weeks Essentially complete at birth Differentiation is dependent upon genetic instructions, timing, and signals from other cells in the local environment All cortical cells emerge from ventricular zone But not all cells are the same Different cortical layers have different cells Generated at different times in neuronal proliferation Time of genesis that matters, not time of migration Transplanted cells migrate to the region of cortex specified by stage of their development o Neuronal Maturation Begins about week 20 and continues long after birth Mature in 2 ways: Axonal Growth Dendritic Growth - Arborization (Branching) - Growth of dendritic spines where most synapses occur - Slower (micrometer/day) than axonal growth (millimeter/day) o Synaptic Development 10^14 synapses in the adult human cerebral cortex Combination of genetic programming and environmental cues and sthnals 5 gestational month Simple synaptic contacts 7 gestational month Synaptic development of deep cortical neurons After birth Synaptic development increases rapidly during the first year of life o Cell Death and Synaptic Pruning We are born with an overabundance of neurons and synaptic connections Synaptic connections that are not part of a functional network are pruned away in an experience-dependent manner o Myelogenesis Birth of astrocytes and Oligodendrocytes begins after most neurogenesis is complete and continues throughout life Oligodendrocytes from myelin in CNS Myelination provides a useful rough index of cerebral maturation Myelination starts late in gestation and continues well into childhood and adolescence Myelination develops first in sensory regions then in association cortex Develops last in prefrontal region - Postnatal Development o Critical periods of development o Modifying input during critical period permanently changes function o Modifying input later has little or no effect - Experience and Brain Development o Cognitively stimulating environments help maximize intellectual development o Compared with rats raided in standard lab cages, those raised in “enriched environments” have: Larger and more synapses Larger and more astrocytes Neural Plasticity - Most neural changes in adults result from changes in neural connections, not new neurons - Experience can modify connections - Short-term changes o Release of inhibition on synaptic connections - Long-term changes o Change in strength and number of synaptic connections o Possibly growth of new axons - Changes in cortical representations - Musicians who play string instruments have modified representations of the fingers - Individuals born blind use visual cortex for processing other sensory modalities - Changes can occur with short-term training - With amputation, surrounding cortex “invades” no unused area - Phantom limb sensation o Also pain Chapter 3: Methods of Cognitive Neuroscience Methods of Studying Cognition - Cognitive processes don’t generally occur in isolation o Individual processes occur simultaneously or in rapid succession o Each main process can usually be broken down into a number of smaller sub- processes - To understand individual cognitive processes we need to isolate the process of interest o True for both behavioral and neuroscience studies - Two Key Concepts: o Information processing depends on internal representations o The mental representations undergo transformations Mental Chronometry - How long does a cognitive process take? - Simple reaction time o How long does it take to perceive the light and generate a response to it? - Choice Reaction time o How long does it take to perceive the light, make a decision about which button to press, and generate a response to it? - Choice RT-Simple RT o How long it took to make a decision about where the light was Behavioral Methods - Reaction time o How long does it take to respond - Response accuracy o Percentage of correct responses - Counts o Number of attempts needed to complete a task, number of items remembered from a list - We infer changes in cognitive processes from these measures - Can also directly ask participants what they are thinking o Exit questionnaires o Think-aloud protocols Structural Neuroimaging - Correlate brain structure with cognitive functions o Individual differences between brain structure o Structural damage due to trauma, disease, etc. - Neurological Disorders o Use structural imaging to evaluate changes in soft tissue o Vascular disorders o Tumors o Degenerative and infectious disorders o Trauma o Epilepsy (EEG) - Vascular Disorders o Stroke Occlusion of blood flow, deprives tissue of oxygen and glucose o Ischemia Partial occlusion or sudden drop in blood pressure o Hemorrhage Sudden ride in blood pressure, breakage of blood vessels o Cerebral arteriosclerosis Thickening and hardening of arteries-persistent ischemia o Aneurysm Weak spot in a blood vessel-can burst o Tumors Mass of tissue that grows abnormally Benign Do not recur or spread Malignant Recur, spread to other area Symptoms and prognosis depend on size and location o Degenerative and infection diseases Degenerative Huntington’s-genetic, atrophy of interneurons in basal ganglia Alzheimer’s- tangles and plaques in limbic and temporo-parietal cortex Parkinson’s- loss of dopaminergic neurons Pick’s- fronto-temporal atrophy Infectious AIDS-related dementia- diffuse white matter lesions Herpes simplex virus- destruction of temporal and limbic neurons Gradual onset of symptoms MS- slight disturbances in sensation or double vision Alzheimer’s- memory problems difficult to distinguish from normal aging Parkinson’s- difficulty standing up or initiating movement Often not detectable by structural imaging in early phases o Trauma Closed-head injury Coup- injury at region of impact Countercoup- injury opposite region of impact ( due to brain bouncing around) Open-head injury Skull is penetrated - Neuropsychological Method o Associating brain structures with specific mental operations If operation A depends on brain area X, then damage to area X should eliminate operation A Must design tasks to diagnose fundamental operations, not just complex behaviors o Single and double dissociations - Structural Imaging Techniques o CT (computed tomography) Tomography means imaging by sections or slices Disadvantages: Radiation Not great spatial resolution o MRI (Magnetic resonance imaging) Magnetic properties of hydrogen proton used to generate images Orientation of protons is normally random The MRI magnet causes the axes to align with the external magnetic field Apply a Radio Frequency (RF) pulse to perturb the protons The MRI scanner measure the energy release when the protons return to their normal state Different tissues return to normal at different rates, allowing for the differentiation of grey matter, white matter Disadvantages: Projectiles (if safety guidelines are not followed) Some patients/participants may not be MR-safe o CT versus MRI Advantages of MRI over CT Higher resolution; brain more easily visualized No radiation Advantages of CT over MRI More comfortable environment No danger of foreign materials in body or MRI room o Voxel-Based Morphometry Uses high0resolution structural MRI Segment brain into different tissues White matter, grey mater Measure structural features of individual brain areas Amount of grey matter in a given volume of brain tissue Compare across participants/groups o Diffusion Tensor Imaging Measures motion of water in axons Diffusion of water in brain is anisotropc (not equal in all directions) Restricted by axon membranes Modify MRI to be sensitive to diffusion of water Two pushes - 1) measures initial position of protons in water - 2) measures how far they’ve moved in space (in a specific direction) Measures lots of directions Color code base on principle direction Trace white-matter tracts - Functional neuroimaging: temporal resolution o Single-unit Recording Usually in non-human animals Rare in humans Tumor removal Epilepsy o EEG (Electroencephalography) Registers post-synaptic potentials in dendrites Graded potentials Pyramidal neurons perpendicular to cortical surface Electrodes pick up activity of neurons perpendicular to scalp surface Harder to pick up activity from neurons in sulci Interpretation Polarity of EEG/ERPs - Positive voltage does not mean an increase in activity - Negative voltage does not mean a decrease in activity ERPs (event-related potential) Get an ERP waveform for every scalp channel Plot scalp topography Examine changes in topography over time ERP Analysis Difference in activity between conditions plotted on the scalp Estimated neural location of the scalp activity The inverse problem o MEG (magnetoencephalography) MEG is only sensitive to tangential sources (parallel to scalp surface) EEG sensitive to all sources, but most sensitive to radial sources (perpendicular to scalp surface) Analyses similar to EEG More expensive (on par with fMRI) Magnetic signal unimpeded by skull Source estimation easier - Functional Neuroimaging: Spatial Resolution o Positron Emission Tomography (PET) Radioactive tracer injected into blood stream Blood flow to active brain regions Radioactive substance begins to decay and emits positrons (hence, positron emission tomography) Variety of radiotracers Radiolabeled fluordeoxyglucose (glucose metabolism) Drugs that will specifically react with certain receptors or neurotransmitters Radiation is cumulative Limits to research participation o fMRI uses same equipment as structural MRI Measures the Blood-Oxygenation Level Dependent (BOLD) o PET versus fMRI Advantages of MRI over PET Higher spatial and temporal resolution No radiation Advantages of PET of MRI More comfortable environment No danger from foreign material in body o Subtraction technique Important points: All parts of the brain are active all the time - Very small changes in blood flow during cognitive processes aren’t always readily apparent - Need to use a good control condition to isolate the cognition-related activity Every individual’s brain activity will be a little different - Need to run multiple subjects and look at brain activity that is common across them Potential problems with cognitive subtraction - Assumes pure insertion (or deletion) - Can be interactions where addition of a cognitive component changes how other parts of the system function Alternatives to subtraction - Factorial design (can look at interaction between process) - Parametric design (varying degrees of the process of interest) o Other techniques fNIRS Functional Near Infrared Spectroscopy Visible light spectrum ~400-750 Nm NIR spectrum ~700-900nm - Will pass through skin, tissue, bone unimpeded - Oxy-Hb and deoxy-Hb have different absorption spectra - Use light that responds differently based on amount of oxy/deoxy hb Only able to image depth of 3-4 cm Lower spatial resolution Less expensive and more comfortable /convenient than fMRI Transcranial magnetic stimulation (TMS) Electrical current running through TMS coils produces magnetic field that can stimulate neurons Can produce temporary lesions by over stimulating neurons Can be used with neuroimaging methods to look at changes in brain activity Transcranial Direct Current Stimulation Low-level currents that result in action potentials under the anodes TMS and TDCS increasingly used for treatment in neuropsychiatric disorders - Methods with Non-Human Animals o Animal Behavior Place learning Rats must find platform using external cues Matching-to-place-learning- platform is in the same location each trial, but a different location each day Landmark version- platform is identified by a cue on the wall Train monkeys on complex tasks Decision making Reward o Lesions in non-human Animals We can modify the brain and see how behavior is altered Two reasons for doing so: - Develop hypothesis about how the brain affects behavior - Test hypothesis Brain lesions Ablation: removal or destruction of tissue Stereotaxic apparatus - Surgical instrument that permits the researcher to target a specific part of the brain Surgical lesions - Possibility of damaging neighboring tissue/axons - Ambiguity in interpretation - Compensatory strategies Neurochemical lesions - Injection of neurotoxins - Improved specificity Temporary/reversible lesions - Chemical - Within-subject comparisons Chemical methods - Microanalysis Technique used to determine the chemical constituents of extracellular fluid - Administration of chemicals via cannula Animal electrophysiology Measuring single-neuron action potentials with final electrodes - Electrodes placed next to cells (extracellular recording) or inside them (intracellular recording) - Usually extracellular recording - Small number of cells not a single cell - Cells are always active Different regions/different cells within a region, have different baseline firing rates Can look at what actions/stimuli/behaviors increase or decrease firing relative to baseline - Very thin metal electrode inserted into cortex Major surgery to implant electrode holder, animal has to recover before experimentation - Only tip conducts electricity - Records action potentials that occur nearby - Mapping sensory receptive fields - Cells specific to orientation, color, shape, direction of motion Multi-unit recording Stimulation - First used by Wilder Penfield to stimulate the cerebral cortex of humans during neurosurgery - Stimulate brain areas, observe resulting behaviors - Rats with electrodes in the lateral hypothalamus will eat whenever the stimulation is turned on Self-stimulation: given the opportunity, rats will press a lever to obtain the current The stimulation affects a neural circuit involving both eating and pleasure
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'