the origin and nature of emotions-第4节

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le　of　discharging　vast　amounts　of　energy　are　the　lateral　chest…wall；　the　abdomen；　the　loins；　the　neck；　and　the　soles　of　the　feet。　　The　type　of　adequate　stimuli　of　the　soles　of　the　feet；　the　distribution　of　the　ticklish　points　upon　them；　and　the　associated　response；　leave　no　doubt　that　these　ticklish　points　were　long　ago　established　as　a　means　of　protection　from　injury。　Under　present　conditions　they　are　of　little　value　to　man。

The　adequate　stimulus　for　the　ticklish　points　of　the　ribs；　the　loins；　the　abdomen；　and　the　neck　is　deep　isolated　pressure；　probably　the　most　adequate　being　pressure　by　a　tooth…shaped　body。　The　response　to　tickling　in　these　regions　is　actively　and　obviously　self…defensive。　The　horse　discharges　energy　in　the　form　of　a　kick；　the　dog　wriggles　and　makes　a　counter…bite；　the　man　makes　efforts　at　defense　and　escape。

There　is　strong　evidence　that　the　deep　ticklish　points　of　the　body　were　developed　through　vast　periods　of　fighting　with　teeth　and　claws　（Fig。　9）。　Even　puppies　at　play　bite　each　other　in　their　ticklish　points　and　thus　give　a　recapitulation　of　their　ancestral　battles　and　of　the　real　battles　to　come　（Fig。　10）。　The　mere　fact　that　animals　fight　effectively　in　the　dark　and　always　according　to　the　habit　of　their　species　supports　the　belief　that　the　fighting　of　animals　is　not　an　intellectual　but　a　reflex　process。　　There　are　no　rules　which　govern　the　conduct　of　a　fight　between　animals。　　The　events　follow　each　other　with　such　kaleidoscopic　rapidity　that　the　process　is　but　a　series　of　automatic　stimulations　and　physiologic　reactions。　Whatever　their　significance；　therefore；　it　is　certain　that　man　did　not　come　either　accidentally　or　without　purpose　into　possession　of　the　deep　ticklish　regions　of　his　chest　and　abdomen。　Should　any　one　doubt　the　vast　power　that　adequate　stimulation　of　these　regions　possesses　in　causing　the　discharge　of　energy；　let　him　be　bound　hand　and　foot　and　vigorously　tickled　for　an　hour。　What　would　happen？　　He　would　be　as　completely　exhausted　as　though　he　had　experienced　a　major　surgical　operation　or　had　run　a　Marathon　race。

A　close　analogy　to　the　reflex　process　in　the　fighting　of　animals　is　shown　in　the　role　played　by　the　sexual　receptors　in　conjugation。　Adequate　stimulation　of　either　of　these　two　distinct　groups　of　receptors；　the　sexual　and　the　noci；　causes　specific　behavior　the　one　toward　embrace；　the　other　toward　repulsion。　　Again；　one　of　the　most　peremptory　causes　of　the　discharge　of　energy　is　that　due　to　an　attempt　to　obstruct　forcibly　the　mouth　and　the　nose　so　that　asphyxia　is　threatened。　　Under　such　conditions　neither　friend　nor　foe　is　trusted；　and　a　desperate　struggle　for　air　ensues。　It　will　be　readily　granted　that　the　reactions　to　prevent　suffocation　were　established　for　the　purpose　of　self…preservation；　but　the　discharge　of　nerve…muscular　energy　to　this　particular　end　is　no　more　specific　and　no　more　shows　adaptive　qualities　than　do　the　preceding　examples。　Even　the　proposal　to　bind　one　down　hand　and　foot　excites　resentment；　a　feeling　originally　suggested　by　the　need　for　self…preservation。　No　patient　views　with　equanimity　the　application　of　shackles　as　a　preparation　for　anesthesia。

We　have　now　considered　some　of　the　causes　of　those　discharges　of　nervous　energy　which　result　from　various　types　of　harmful　physical　contact；　and　have　referred　to　the　analogous；　though　antithetical；　response　to　the　stimulation　of　the　sexual　receptors。　The　response　to　the　adequate　stimuli　of　each　of　the　several　receptors　is　a　discharge　of　nerve…muscular　energy　of　a　specific　type；　that　is；　there　is　one　type　of　response　for　the　ear；　one　for　the　larynx；　one　for　the　pharynx；　another　for　the　nose；　another　for　the　eye；　another　for　the　deep　ticklish　points　of　the　chest　and　the　abdomen；　quite　another　for　the　delicate　tickling　of　the　skin；　and　still　another　type　of　response　to　sexual　stimuli。

According　to　Sherrington；　a　given　receptor　has　a　low　threshold　for　only　one；　its　own　specific　stimulus；　and　a　high　threshold　for　all　others；　that　is；　the　doors　that　guard　the　nerve…paths　to　the　brain　are　opened　only　when　the　proper　password　is　received。　According　to　Sherrington's　law；　the　individual　as　a　whole　responds　to　but　one　stimulus　at　a　time；　that　is；　only　one　stimulus　occupies　the　nerve…paths　which　carry　the　impulses　as　a　result　of　which　acts　are　performed；　_i。　　e_。；　the　final　common　path。　As　soon　as　a　stronger　stimulus　reaches　the　brain　it　dispossesses　whatever　other　stimulus　is　then　occupying　the　final　common　path　the　path　of　action。　　The　various　receptors　have　a　definite　order　of　precedence　over　each　other　（Sherrington）。　For　example；　the　impulse　from　the　delicate　ticklish　points　of　the　skin；　whose　adequate　stimulus　is　an　insect…like　contact；　could　not　successfully　compete　for　the　final　common　path　with　the　stimulus　of　a　nociceptor。　The　stimulus　of　a　fly　on　the　nose　would　be　at　once　superseded　by　the　crushing　of　a　finger。　　In　quick　succession　do　the　various　receptors　（Sherrington）　occupy　the　final　common　path；　but　each　stimulus　is　for　the　time　the　sole　possessor；　hence　the　nervous　system　is　integrated　（connected）　to　act　as　a　whole。　　Each　individual　at　every　moment　of　life　has　a　limited　amount　of　dischargeable　nervous　energy。　This　energy　is　at　the　disposal　of　any　stimulus　that　obtains　possession　of　the　final　common　path；　and　results　in　the　performance　of　an　act。　Each　discharge　of　energy　is　subtracted　from　the　sum　total　of　stored　energy　and；　whether　the　subtractions　are　made　by　the　excitation　of　nociceptors　by　trauma；　by　tickling；　by　fighting；　by　fear；　by　flight；　or　by　the　excitation　of　sexual　receptors；　by　any　of　these　singly　or　in　combination　with　others；　the　sum　total　of　the　expenditure　of　energy；　if　large　enough；　produces　exhaustion。　Apparently　there　is　no　distinction　between　that　state　of　exhaustion　which　is　due　to　the　discharge　of　nervous　energy　in　response　to　trauma　and　that　due　to　other　causes。　　The　manner　of　the　discharge　of　energy　is　specific　for　each　type　of　stimulation。　On　this　conception；　traumatic　shock　takes　its　place　as　a　natural　phenomenon　and　is　divested　of　its　mask　of　mystery。


The　Discharge　of　Energy　through　Stimulation　of　the　Distance　Receptors；　or　through　Representation　of　Injury　（Psychic）


We　will　now　turn　from　the　discussion　of　the　discharge　of　nervous　energy　by　mechanical　stimuli　to　the　discharge　of　energy　through　mental　perception。　_Phylogenetic_　association　may　result　from　stimulation　of　the　distance　receptors　through　sight；　hearing；　smell；　or　by　a　representation　of　physical　experiences；　as　well　as　from　physical　contact。　The　effect　upon　the　organism　of　the　representation　of　injury　or　of　the　perception　of　danger　through　the　distance　receptors　is　designated　FEAR。　　Fear　is　as　widely　distributed　in　nature　as　is　its　cause；　that　is；　fear　is　as　widely　distributed　as　injury。　　Animals　under　the　stimulus　of　fear；　according　to　W。　T。　Hornaday；　not　only　may　exhibit　preternatural　strength；　but　also　may　show　strategy　of　the　highest　order；　a　strategy　not　seen　under　the　influence　of　a　lesser　stimulus。　In　some　animals　fear　is　so　intense　that　it　defeats　escape；　this　is　especially　true　in　the　case　of　birds　in　the　presence　of　snakes。　The　power　of　flight　has　endowed　the　bird　with　an　easy　means　of　escape　from　snakes；　especially　when　the　encounter　is　in　the　tops　of　trees。　Here　the　snake　must　move　cautiously；　else　he　will　lose　his　equilibrium；　his　method　of　attack　is　by　stealth。　　When　the　snake　has　stalked　its　prey；　the　bird　is　often　so　overcome　by　fear　that　it　cannot　fly　and　so　becomes　an　easy　victim　（Fig。　11）。　The　phenomena　of　fear　are　described　by　Darwin　as　follows：

〃Fear　is　often　preceded　by　astonishment；　and　is　so　near　akin　to　it　that　both　lead　to　the　senses　of　sight　and　hearing　being　instantly　aroused。　In　both　cases　the　eyes　and　mouth　are　widely　opened　and　the　eyebrows　raised。　　The　frightened　man　at　first　stands　like　a　statue；　motionless　and　breathless；　or　crouches　down　as　if　instinctively　to　escape　observation。　　The　heart　beats　quickly　and　violently；　so　that　it　palpitates　or　knocks　against　the　ribs。　　*　*　*　That　the　skin　is　much　affected　under　the　sense　of　great　fear　we　see　in　the　marvelous　and　inexplicable　manner　in　which　perspiration　immediately　exudes　from　it。　This　exudation　is　all　the　more　remarkable　as　the　surface　is　then　cold；　and　hence　the　term；　‘a　cold　sweat'；　whereas　the　sudorific　glands　are　properly　excited　into　action　when　the　surface　is　heated。　The　hairs　also　on　the　skin　stand　erect；　and　the　superficial　muscles　shiver。　　In　connection　with　the　disturbed　action　of　the　heart；　the　breathing　is　hurried。　　The　salivary　glands　act　imperfectly；　the　mouth　becomes　dry；　and　is　often　opened　and　shut。　　I　have　also　noticed　that　under　slight　fear　there　is　a　strong　tendency　to　yawn。　One　of　the　best…marked　symptoms　is　the　trembling　of　all　the　muscles　of　the　body；　and　this　is　often　first　seen　in　the　lips。　From　this　cause；　and　from　the　dryness　of　the　mouth；　the　voice　becomes　husky　and　indistinct；　or　may　altogether　fail。　*　*　*　As　fear　increases　into　agony　of　terror；　we　behold；　as　under　all　violent　emotions；　diversified　results。　　The　heart　beats　wildly；　or　may　fail　to　act　and　faintness　ensues；　there　is　death…like　pallor；　the　breathing　is　labored；　the　wings　of　the　nostrils　are　widely　dilated；　‘there　is　a　gasping