"Define ""homologous structure"", and explain why research involving non-human animals ca sometimes tell us about how the human nervous system works."the similar shapes of our bodies and brain present in different animals can be helpful because these animals can provide an approximate model of the human brain when hypotheses cannot be tested on human participants. Know and describe the two major divisions of the nervous systemCentral NS: brain + spinal cordPeripheral NSSomatic NS - carries signals from organs/body to the CNSAutonomic NS - carried signals from internal organs to CNSParasympathetic - acts to conserve energysympathetic - responds to dangerous situations Name three bilateral animals, and explain what they have in commonspider, butterfly, lobsterall 3 can be split down the middle and display bilateral symmetry Describe the location and function of the corpus callosumConnects left and right hemispherescontralteral - right side of your body is controlled by left side of the brain, vice versalargest cerebral commissure Name 4 lobes of the cerebral cortex, and describe a key function of eachOccipital: visionTemporal: hearing, learning and memoryParietal: bodily sensations (e.g. touch, temperature, pain)Frontal: movement, planning and motivation Toggle Masks Toggle Masks Toggle Masks Toggle Masks Name three components of the limbic system, and describe their key functionhippocampus - memory functionamygydala - fear/fear learninghypothalamus - homeostatsis and controlling the pituitary gland Thalamusrelay stationdivided into different kinds of nuclei specialized to perform certain functionsreceives most of its information from the cortex -> suggesting it plays an important role in many high-level cognitive functions Basal gangliaBasal: located at the base of the brainGanglia: plural of ganglion or cluster of nerve cellsbest known for their role in facilitating movementcomposed of:striatum: caudate and putamenglobus pallidussubthalamic nucleussubstantia nigra Nucleus accumbensmajor component of the ventral striatumpart of the basal ganglia and is a key node in reward systemspart of the striatum along with the caudate and putamendivided into two components: shell -> limbic systemcore -> motor system hippocampusbuilds and retains a mental map in space and timenavigation + memory - how we locate ourselves in space and time amygdalaMemory - associates events and places with good/bad thingsassigns +/- values to stimuli and memories Somatosensory cortexlocated in the postcentral gyrus, behind the central sulcusresponsible for processing somatic sensations (body sensations)divided into 4 regions: 1, 2, 3a, and 3ba somatotopic map of the body is called homunculus Primary motor cortexfound in the precentral gyrusmotor homunculus: motor map of the body neurons enter either corticospinal tract: movement related signals to the spinal cord to cause movement of the body corticobublbar tract: movement related singals to the brain stem to move, neck and face Association areasregions of temporal and partetal lobesprefrontal cortex, which is important:planningvoluntary behaviourinhibition of inappropriate thoughts and actions Prefrontal coretexcommonly linked to executive functionexecutive function: refers to exerting cognitive effort or controlling impulsive behaviour for immediate ends in order to act with a longer-term goal in mind includes:self-controlplanningdecision-makingproblem solvingcannot confidently assign specific roles to PFC subregions Orbitofrontal cortexallow us to understand the relationship between a particular course of action and a particular outcome or result Ventrolateral prefrontal cortexmostly made up of the IFGinhibits inappropriate actions and thoughts that may not be helpful in a given situation Dorsolateral prefrontal cortexmostly made up of the middle frontal gyruscrucial for working memory, or spatial awareness important for holding in mind and maintaing complex sets of rules and other forms of abstract thought Lesion studiesutilizing brain damge to learn about cognitioncan reveal the necessary regions for healthy cogntion + limitations of ability can reveal functions of certain areaadvantages: can show that a region is necessary for a particular functiondisadvantages: the damage is not typically localized to one regionunable to attribute deficit to damage to the region or its connections to other regions Transcranial Stimulation Approaches"can create ""temporary"" lesions BUT poor spatial awarenessuses an electromagnetic coil/electrodes to ramp up or damp down neuron activityinduces weak electric current using rapidly changing magnetic field/direct electrical stimulationtest behaviour/cognitive processesallows us to infer a region is necessary for function" Electronecephalography (EEG) and MEGEEG measure brain waves which reflect the electrical output of cortical neuronsevent-related potentials: averaged EEG signal following stimulus or response -> compared between groups and conditions conclusions: ERP components linked to specific cogntive processes MEGmeasures magnetic detectors surrounding the headtells you when but not where strengths:good temporal resolutioninexpensivenon-invasivedirect measure of brain activityincreasingly portableweaknesses:poor spatial resolution (ok for MEG)correlational: cant infer that activity in a region is necessary for a behaviour. Positron Emission Tomographyold skool PET measured glucose metabolismno radioactive tracers mostly tag neurotransmittersincreasingly used in clinical studiescool but expensive, invasive, and very slowlow spatial resolution (1 cm) but can measure molecular processesallows you to measure neurochemical activity Describe in general terms what fMRI measuresfunctional magnetic resonance imagingindex of cognition in actiondifferences in BOLD between groups or experimental but does not measure neuronal activityBOLD: measure of magnetic properties associated with changes in the ratio of oxygenated:deoxygenated blood Strengths and Limitations of FMRIstrengthsgood spatial precisionnon-invasivelimitationsexpensivepoor temporal precisionindirect measure of brain activitycorrelational relaitonship between cogntition and activation Explain the difference between encoding and decoding approaches to analyzing fMRI data"Encoding: standarduses brain mapping to measure activity that is evoked from stimuluslooks for increased activity during one condition compared to the otherable to infer causality of the function of brain regionswhat parts of the brain ""light up"" when you do something decoding: repreentational look at brain activity to predict what the stimulus or cognitive process producing it iswhat does your brain activity tells us you are doing" Define structural and functional connectivity in the human brain and outline some ways they are measuremap of strctural and functional connectivityrefers to structural and functional connectivity within the brainanatomical/structural connectivitypresence of axonal conncetionsDTI: measures the direction of the diffusion of waterfunctional connectivity:correlation in activation activation between BOLD activity in different areas over timeintrinsic networks - patterns of activity that arise naturally and spontaneously in the brain Retina-geniculate-striate systemConsists of the retina, lateral geniculate nucleus of the thalamus, striate cortex - primary visual cortex How is info organized in the primary visual cortexRetinotopically organized - map of what is on the retina Each neuron receives a small amount of the overall visual field What type of info do V1 neurons respond to?V1 neurons best activate to gabor patches - lines of contrast in edges! Discuss the contribution of classic and more recent fMRI research to our understanding of object processing stages in humansInitially knew about retinotopic maps + V1 neurons liking points/edges Neurons increase their receptive field as we move forward in the visual stream Areas towards the end of the ventral stream were sensitive to whole objects LOC - what are the stages in between moving from parts to wholes? Lateral occipital complex Compare challenges posed to human and computer visionSize invariance: the ability to know an object is the same size when it is a different size on the retina Viewpoint invariance: the ability to recognize objects from different viewpoints Describe the role of the dorsal system in object recognitionFlows from V1 to dorsal prestriate cortex to posterior parietal association cortex The “where/how” pathway -> vision for object-direct actionAction - direct behavioral interaction with objects Describe the role of the Ventral stream in object recognitionFlows from V1 to ventral prestriate cortex to the inferotemporal cortex The “what” pathway -> vision for conscious recognition Perception - mediate conscious perception of objects Damage -> 2 types of agnosia: Apperceptive: problem with perception Failures in object recognition link to problems in perceptual processing Impaired in match objects in “unusual views” Associative: problem with semantics Do well on perceptual tests but cannot access names or other information about objects Toggle Masks Toggle Masks Toggle Masks Toggle Masks