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Computational Neuroscience



Introductiontothesubject

Theresearchonthebrainandnervoussystemhasalonghistory.Bytheendofthe18thcentury,peoplerealizedthatthebrainisdividedintodifferentparts,performingdifferentfunctions.Cajalfoundedtheneurontheoryin1891,whichbelievedthattheentirenervoussystemiscomposedofrelativelyindependentnervecellsinstructure.OnthebasisofCajal'sneurontheory,Sherringtonproposedtheconceptofsynapsebetweenneuronsin1906.Adrianproposedneuralactionpotentialsinthe1920s.TheM-PneuralnetworkmodelproposedbyMcCullochandPittsin1943.In1949,Hebbproposedtherulesofneuralnetworklearning.ThePerceptionmodelproposedbyRosenblattinthe1950s.Sincethe1980s,progresshasbeenmadeinneuralcomputingresearch.HopfieldintroducedtheLyapunovfunction(called"calculatedenergyfunction")togiveanetworkstabilitycriterion,whichhasadirectcorrespondencewithVLSI,andlaidthefoundationforthedevelopmentofneuralcomputers.Atthesametime,itcanalsobeusedforassociativememoryandoptimizedcalculations,openingupnewwaysforneuralnetworkstobeusedincomputers.Amarihasdonealotofresearchonthemathematicalbasictheoriesofneuralnetworks,includingstatisticalneuraldynamics,dynamictheoryofneuralfields,associativememory,andhasdonesomegroundbreakingworkespeciallyininformationgeometry.Theresearchofcomputationalneurosciencestrivestoreflectthefollowingbasiccharacteristicsofthehumanbrain:①Thecerebralcortexisahugeandcomplexsystemwithextensiveconnections;②Thecalculationofthehumanbrainisbasedonlarge-scaleparallelsimulationprocessing;③ThehumanbrainisverypowerfulGoodatgeneralization,analogy,andpromotion;④Thebrainfunctionisrestrictedbyinnatefactors,butacquiredfactors,suchasexperience,learningandtraining,etc.,playanimportantrole,whichshowsthatthehumanbrainisverystrongSelf-organizationandself-adaptability.Manyhumanintellectualactivitiesarenotcarriedoutinlogicalreasoning,butformedbytraining.

Atpresent,theunderstandingofhowthehumanbrainworksisstillverysuperficial,andtheresearchofcomputationalneuroscienceisstillinadequate.Wearefacinganewfieldfullofunknowns,andwemustfocusonbasicprinciplesandcomputationaltheories.Makeadeeperexploration.Throughtheanalysisandresearchonthestructure,informationprocessing,memoryandlearningmechanismofthehumanbrainandnervoussystem,simulationiscarriedoutontheworkingmechanismofthehumanbrain,andnewideasandnewmethodsofintelligentscienceareproposed.

Thescientificquestionsofcomputationalneuroscienceareasfollows:

  • Thebasicprocessofneuralactivity:thestudyofneuronalionchannelsandtheirregulation,synaptictransmissionandregulation,Neuronreceptors,signaltransduction,andthesynchronizationmechanismofneuralactivity.

  • Thecalculationmodelofasingleneuron:Asingleneuronisthebasicunitthatconstitutesaneuralnetwork.Itiscomposedofnervecellbodies,dendritesandaxons.Synapticconnection

  • Theneuralmechanismoflearningandmemory:thenervoussystemchangesinstructureandfunctionduetofactorssuchasactivityandenvironment.ThischangeislearningandmemoryAndotheradvancedbrainfunctions.Investigatethemechanismsandlearningrulesthatproducethisplasticity,especiallytheplasticityofnervesynapses.Studytheinformationencodingandprocessingmechanismofneuroncircuits.

  • Themolecularmechanismofneuronandnervoussystemdevelopment:nervecellsaredifferentiatedfromneuralstemcellsduringbraindevelopment,andthenmigrate,growprotrusions,andformsynapses.Theconnectionandotherprocessesgraduallyformacomplexandsophisticatedbrain.Tostudytheneurotrophicfactorsthatregulatethedifferentiationofneuralstemcells,maintainthesurvivalofnervecells,regulatethemigrationofnervecells,processgrowthandsynapseformation,andstudytheirfunctionsandmechanisms.

  • Neurotransmitters:studythecompositionofneurotransmitters,thesynthesis,maintenance,releaseofneurotransmitters,andtheinteractionwithreceptors.

Historicalorigin

Theviewofcognitiveneurosciencebelievesthatspecificbrainareasareresponsibleforspecificcognitivefunctions.Thisviewstemsfrommanydifferenttheories,suchasPhrenology.Althoughphrenologywasfinallyabandonedbecauseoflackofscientificbasis,theviewthatspecificbrainregionscontrolspecificcognitivefunctionsisstilladopted.Now,afterdiscardingtheunscientificwayofobservingtheappearanceoftheheadshell,itisreplacedbyelectrophysiologicalmeasurementsofthescalp,ormoreobservationsofthebrainitself.

Phrenology

TheoriginofcognitiveneurosciencehasalottodowithPhrenology.Phrenologyisessentiallyapseudoscienceandclaimsthattheshapeofthescalpaffectsbehavior.Intheearly19thcentury,FranzJosephGallandJ.G.Spurzheimbelievedthatthehumanbraincanbedividedinto35differentregions.InGore'sbook"IntroductiontotheAnatomyandPhysiologyoftheNervousSystemandIn-depthStudyoftheBrain",heclaimedthatthelargerbulgeontheskullmeansthatthisareaisusedmorefrequently.Thephrenologyhasbeenwidelynoticedbythepublic,andperiodicalsonthesubjectofphrenologyhavebeenpublished.Evenacraniophagographwasinventedtomeasurethebulgeonthehead.

Totalism

TheFrenchexperimentalpsychologistPierreFlourensquestionedtheviewsofphrenologylikemanyscientists.Althoughhisexperimentalsubjectswererabbitsandpigeons,hefoundthataspecificpartofthebraininjurydidnotcauseachangeinbehavior.Therefore,hebelievesthatbehavioralperformanceisjointlyparticipatedbydifferentbrainregions,whichistheviewoftotalism.

Locationtheory

SomeEuropeanscientistssuchasJohnHughlingsJackson(JohnHughlingsJackson)conductedsomeresearchtomakelocationtheorybackintothemainstreamview.Jackson'sresearchisparticularlyfocusedonpatientswithbraininjurieswhohaveepilepsysymptoms.Hefoundthatpatientsoftenhavethesameclonusandmuscletensionduringepilepticseizures.Therefore,hebelievesthateveryseizuremustoccurinthesamebrainarea,andheputsforwardtheviewthatspecificbrainareasareresponsibleforspecificfunctions.Inthefollow-upresearchonthebrainlobe,theregionalizationpointofviewhasagreatinfluenceandhelp.

Rise

FrenchneuroscientistPaulBrocareportedthesymptomsofapatientin1861.Thepatientcouldunderstandlanguage,butcouldnotspeak,andcouldonlymakethesoundof"talk"(tan).Thispatientwaslaterfoundtohaveabraininjuryinthefrontallobeofhisleftbrain,andthisbraininjuryareaisnowcalledBroca'sarea.Anotherneuroscientist,CarlWernicke,discoveredthatastrokepatientwasunabletolistentoverbalmessagesandreadtext,butcouldspeakfluently(althoughthewordsweremeaningless).Thispatienthadabraininjuryatthejunctionoftheleftparietallobeandthetemporallobe.AndthisareaisnowcalledtheVenekiarea.Thesetwocasesareimportantevidencetosupportthetheoryoflocationalization,becauseaspecificareaof​​braininjurycausedspecificbehaviorchanges.BrocaandVeneki’sresearchledtothebirthofneuropsychology,andthisnewfieldstudiestherelationshipbetweenpsychologicalphenomenaandbraininjuries.

Brainfunctionpositioning

In1870,twoGermanphysicians,EduardHitzigandGustavFritsch,publishedtheirfindingsinanimalexperiments.Theyenergizedifferentpartsofthecerebralcortexofthedog,whichcancausedifferentcorrespondingactions.Therefore,theybelievethattheperformanceofbehaviorisderivedfromthelevelofoperationofbraincells.GermanneuroanatomistKorbinianBrodmannusedthetissuestainingtechniqueinventedbyFranzNissltoobservecelltypesinthebrain.In1909,hepublishedhisconclusion:Thebrainismadeupof52differentparts.ThesepartitionsarenowcalledBrodmanpartitions.Itnowappearsthatsomedivisionsareveryprecise,suchasBrodman17andBrodman18.

Neuraldogma

Intheearlytwentiethcentury,SantiagoRamonyCajalandCamilloGolgibegantostudynervecellstructure.Golgidevelopedasilverstainmethod,whichcanstaincellsinaspecificareatogether.UsingthistechniquetoobservenervecellsmakesGolgibelievethatthereisadirectconnectionbetweenthecellsinthecommoncytoplasm.Cajalopposedthisview.Hestainedthepartsofthebrainthatcontainedlessmyelinandfoundthatthenervecellswerenotcloselyconnected,butseparated.Hefurtherdiscoveredthatnervecellstransmitelectricalsignalsinonedirection.Thesefindingsarecalledneuraldogmas,andprovideabasictheoryforunderstandingthefunctionofnervecellsinthefuture.Forthiscontribution,GorkyandKahabothwontheNobelPrizeinPhysiologyorMedicinein1906.

TheBirthofCognitiveScience

OnSeptember11,1956,theCognitiveScienceConferencewasheldattheMassachusettsInstituteofTechnology.Attheconference,GeorgeA.Miller(GeorgeA.Miller)publishedhisfamousresearch"TheMagicNumber7+/-2".NoamChomskyandAlanNewellandHerbertAlexanderSimonpublishedtheirresultsincomputerscience.UlricNeissercommentedonmanyoftheresultspublishedinthisconferenceinhis1967book"CognitivePsychology".Theterm"psychology"graduallydeclinedinthe1950sand1960s,replacingthebeginningofcognitivescience.BehavioristscientistssuchasGeorgeA.Millerbegantoattachimportancetotheinternalrepresentationoflanguage,notjustexternalbehavior.DavidMarr(DavidMarr)proposedthehierarchicalrepresentationofmemory,andmanypsychologistshaveacceptedthatmentalfunctionsneedtobeprocessedbyspecialalgorithmsinthebrain.

CognitiveNeuroscience

Beforethe1980s,therewasalmostnointeractionbetweenthetwofieldsofneuroscienceandcognitivepsychology.Inthelate1970s,theterm"cognitiveneuroscience"wasborninthebackseatofataxiandwasco-foundedbyGeorgeA.MillerandMichaelGazzaniga.Cognitiveneurosciencebegantouseexperimentalpsychology,neuropsychologyandneuroscienceresearchmethodstolaythefoundationforcognitivescience.Inthelate20thcentury,newscienceandtechnologybecameanimportantresearchmethodincognitiveneuroscience.Thesetechniquesgenerallyincludetranscranialmagneticstimulation(TMS),functionalmagneticresonanceimaging(fMRI),electroencephalography(EEG)andmagnetoencephalography(MEG).Sometimesotherbrainimagingtechniquesareused,suchaspositrontomography(PET)andsingle-photoncomputedtomography(SPECT).Single-unitrecordingusedonanimalsisalsoanimportanttechnique.Inaddition,othertechnologiesincludemicroneurography,facialelectromyography(EMG)andeyetracking.Integrativeneuroscienceattemptstointegrateresearchresultsobtainedindifferentfieldsandatdifferentscales(suchasbiology,psychology,anatomy,andclinicalexperience)intoanintegrateddescriptivemodel.

Theme

Attention,awareness,decision-making,judgment,learning,memory

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