the origin and nature of emotions-第21章

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e　type　of　the　contact。　　Powerful　response　is　made　to　crushing　injury　by　environmental　forces；　to　such　injuring　contacts　as　resemble　the　impacts　of　fighting；　to　such　tearing　injuries　as　resemble　those　made　by　teeth　and　claws　（Fig。　9）。　On　the　other　hand；　the　sharp　division　of　tissue　by　cutting　produces　no　adaptive　response；　indeed；　one　might　imagine　that　the　body　could　be　cut　to　pieces　by　a　superlatively　sharp　knife　applied　at　tremendous　speed　without　material　adaptive　response。

These　examples　indicate　how　the　history　of　the　phylogenetic　experiences　of　the　human　race　may　be　learned　by　a　study　of　the　position　and　the　action　of　the　nociceptors；　just　as　truly　as　the　study　of　the　arrangement　and　variations　in　the　strata　of　the　earth's　crust　discloses　to　us　geologic　history。

These　adaptive　responses　to　stimuli　are　the　result　of　the　action　of　the　brain…cells；　which　are　thus　continually　played　upon　by　the　stimuli　of　environment。　　The　energy　stored　in　the　brain…cells　in　turn　activates　the　various　organs　and　parts　of　the　body。　If　the　environmental　impacts　are　repeated　with　such　frequency　that　the　brain…cells　have　no　time　for　restoration　between　them；　the　energy　of　the　cells　becomes　exhausted　and　a　condition　of　shock　results。　Every　action　of　the　body　may　thus　be　analyzed　into　a　stimulation　of　ceptors；　a　consequent　discharge　of　brain…cell　energy；　and　a　final　adaptive　activation　of　the　appropriate　part。　Walking；　running；　and　their　modifications　constitute　an　adaptation　of　wonderful　perfection；　for；　as　Sherrington　has　shown；　the　adaptation　of　locomotion　consists　of　a　series　of　reflexes　ceptors　in　the　joints；　in　the　limb；　and　in　the　foot　being　stimulated　by　variations　in　pressure。

As　we　have　shown；　the　bene…　and　nociceptors　orientate　man　to　all　forms　of　physical　contactthe　former　GUIDE　HIM　TO　the　acquisition　of　food　and　to　sexual　contact；　the　latter　DIRECT　HIM　FROM　contacts　of　a　harmful　nature。　　The　distance　ceptors；　on　the　other　hand；　adapt　man　to　his　distant　environment　by　means　of　communication　through　unseen　forcesethereal　vibrations　produce　sight；　air　waves　produce　sound；　microscopic　particles　of　matter　produce　smell。　The　advantage　of　the　distance　ceptors　is　that　they　allow　time　for　orientation；　and　because　of　this　great　advantage　the　majority　of　man's　actions　are　responses　to　their　adequate　stimuli。　As　Sherrington　has　stated；　the　greater　part　of　the　brain　has　been　developed　by　means　of　stimuli　received　through　the　special　senses；　especially　through　the　light　ceptors；　the　optic　nerves。

We　have　just　stated　that　by　means　of　the　distance　ceptors　animals　and　man　orientate　themselves　to　their　distant　environment。　As　a　result　of　the　stimulation　of　the　special　senses　chase　and　escape　are　effected；　fight　is　conducted；　food　is　secured；　and　mates　are　found。　It　is　obvious；　therefore；　that　the　distance　ceptors　are　the　primary　cause　of　continuous　and　exhausting　expenditures　of　energy。　On　the　other　hand；　stimuli　applied　to　contact　ceptors　lead　to　short；　quick　discharges　of　nervous　energy。　　The　child　puts　his　hand　in　the　fire　and　there　is　an　immediate　and　complete　response　to　the　injuring　contact；　he　sees　a　pot　of　jam　on　the　pantry　shelf　and　a　long　train　of　continued　activities　are　set　in　motion；　leading　to　the　acquisition　of　the　desired　object。

The　contact　ceptors　do　not　at　all　promote　the　expenditure　of　energy　in　the　chase　or　in　fight；　in　the　search　for　food　or　for　mates。　Since　the　distance　ceptors　control　these　activities；　one　would　expect　to　find　that　they　control　also　those　organs　whose　function　is　the　production　of　energizing　internal　secretions。　　Over　these　organsthe　thyroid；　the　adrenals；　the　hypophysisthe　contact　ceptors　have　no　control。　Prolonged　laboratory　experimentation　seems　to　prove　this　postulate。　According　to　our　observations；　no　amount　of　physical　trauma　inflicted　upon　animals　will　cause　hyperthyroidism　or　increased　adrenalin　in　the　blood；　while　fear　and　rage　do　produce　hyperthyroidism　and　increased　adrenalin　（Fig。　44）　（Cannon）。　This　is　a　statement　of　far…reaching　importance　and　is　the　key　to　an　explanation　of　many　chronic　diseases　diseases　which　are　associated　with　the　intense　stimulation　of　the　distance　ceptors　in　human　relations。

Stimuli　of　the　contact　ceptors　differ　from　stimuli　of　the　distance　ceptors　in　still　another　important　particular。　　The　adequacy　of　stimuli　of　the　contact　ceptors　depends　upon　their　number　and　intensity；　while　the　adequacy　of　the　stimuli　of　the　distance　ceptors　depends　upon　the　EXPERIENCE　of　the　species　and　of　the　individual。　That　is；　according　to　phylogeny　and　ontogeny　this　or　that　sound；　this　or　that　smell；　this　or　that　sight；　through　association　recapitulates　the　experience　of　the　species　and　of　the　individual　awakens　the　phylogenetic　and　ontogenetic　memory。　　In　other　words；　sights；　sounds；　and　odors　are　symbols　which　awaken　phylogenetic　association。　If　a　species　has　become　adapted　to　make　a　specific　response　to　a　certain　object；　then　that　response　will　occur　automatically　in　an　individual　of　that　species　when　he　hears；　sees；　or　smells　that　object。　Suppose；　for　example；　that　the　shadow　of　a　hawk　were　to　fall　simultaneously　on　the　eyes　of　a　bird；　a　rabbit；　a　cow；　and　a　boy。　That　shadow　would　at　once　activate　the　rabbit　and　the　bird　to　an　endeavor　to　escape；　each　in　a　specific　manner　according　to　its　phylogenetic　adaptation；　the　cow　would　be　indifferent　and　neutral；　while　the　boy；　according　to　his　personal　experience　or　ontogeny；　might　remain　neutral；　might　watch　the　flight　of　the　hawk　with　interest　or　might　try　to　shoot　it。

Each　phylogenetic　and　each　ontogenetic　experience　by　an　indirect　method　develops　its　own　mechanism　of　adaptation　in　the　brain；　and　the　brain　threshold　is　raised　or　lowered　to　stimuli　by　the　strength　and　frequency　of　repetition　of　the　experience。　Thus　through　the　innumerable　symbols　supplied　by　environment　the　distance　ceptors　drive　this　or　that　animal　according　to　the　type　of　brain　pattern　and　the　particular　state　of　threshold　which　has　been　developed　in　that　animal　by　its　phylogenetic　and　ontogenetic　experiences。　The　brain　pattern　depends　upon　his　phylogeny；　the　state　of　threshold　upon　his　ontogeny。　　Each　BRAIN　PATTERN　is　created　by　some　particular　element　in　the　environment　to　which　an　adaptation　has　been　made　for　the　good　of　the　species。　　The　_*state　of　threshold_　depends　upon　the　effect　made　upon　the　individual　by　his　personal　contacts　with　that　particular　element　in　his　environment。　　The　presence　of　that　element　produces　in　the　individual　an　associative　recall　of　the　adaptation　of　his　speciesthat　is；　the　brain　pattern　developed　by　his　phylogeny　becomes　energized　to　make　a　specific　response。　The　intensity　of　the　response　depends　upon　the　state　of　threshold　that　is；　upon　the　associative　recall　of　the　individual's　own　experiencehis　ontogeny。

If　the　full　history　of　the　species　and　of　the　individual　could　be　known　in　every　detail；　then　every　detail　of　that　individual's　conduct　in　health　and　disease　could　be　predicted。　Reaction　to　environment　is　the　basis　of　conduct；　of　moral　standards；　of　manners　and　conventions；　of　work　and　play；　of　love　and　hate；　of　protection　and　murder；　of　governing　and　being　governed；　in　fact；　of　all　the　reactions　between　human　beingsof　the　entire　web　of　life。　To　quote　Sherrington　once　more：　　〃Environment　drives　the　brain；　the　brain　drives　the　various　organs　of　the　body。〃

By　what　means　are　these　adaptations　made？　　What　is　the　mechanism　through　which　adequate　responses　are　made　to　the　stimuli　received　by　the　ceptors？　We　postulate　that　in　the　brain　there　are　innumerable　patterns　each　the　mechanism　for　the　performance　of　a　single　kind　of　action；　and　that　the　brain…cells　supply　the　energyelectric　or　otherwise　by　which　the　act　is　performed；　that　the　energy　stored　in　the　brain…cells　is　in　some　unknown　manner　released　by　the　force　which　activates　the　brain　pattern；　and　that　through　an　unknown　property　of　these　brain　patterns　each　stimulus　causes　such　a　change　that　the　next　stimulus　of　the　same　kind　passes　with　greater　facility。

Each　separate　motor　action　presumably　has　its　own　mechanism　brain　patternwhich　is　activated　by　but　one　ceptor　and　by　that　ceptor　only　when　physical　force　of　a　certain　intensity　and　rate　of　motion　is　applied。　　This　is　true　bot