Emo$on

Emo$on
Emo$on
PSYC*3570:*Lecture*9*
Dr.*J.*Nicol
• Emo$ons*are*organized*behavioural,*autonomic,*and*
hormonal*responses*that*prepare*an*animal*to*deal*
with*exis$ng*situa$ons*in*the*environment,*such*as*
events*that*pose*a*threat*to*the*organism*
• Emo$onal*responses*are*accompanied*by*subjec$ve*
feelings*
• Emo$onal*behaviour*is*what*is*func$onal*to*survival*
and*reproduc$on*M*it*is*the*useful*purposes*served*by*
emo$onal*behaviours*that*guided*evolu$on
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Fear
Amygdala*is*involved*in*the*effects*of*olfactory*
s$muli*on*male*sexual*behaviour
• Emo$onal*responses*involve*behavioural,*autonomic,*
and*hormonal*components*that*are*controlled*by*
separate*neural*systems*
• The*amygdala*integrates*the*components*of*fear*
• The*amygdala*is*cri$cally*involved*in*the*physiological*
and*behavioural*reac$ons*to*objects*and*situa$ons*
that*have*biological*significance
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Amygdala*is*involved*in*the*effects*of*olfactory*
s$muli*on*female*sexual*behaviour
Amygdala*is*involved*in*the*effects*of*olfactory*
s$muli*on*maternal*behaviour*in*female*rats
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The*three*major*regions*of*the*Amygdala
The*Amygdala
• When*threatening*s$muli*are*perceived,*neurons*in*
the*central*nucleus*of*the*amygdala*become*ac$vated*
(Pascoe*&*Kapp,*1985)*
• Animals*no*longer*show*signs*of*fear*when*confronted*
with*s$muli*that*been*paired*with*aversive*events,*
when*the*central*nucleus*has*been*destroyed*
• When*the*central*amygdala*is*s$mulated*the*animal*
shows*physiological*and*behavioural*signs*of*fear*and*
agita$on*(Davis,*1992)
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Kalin*et*al.*(2004)
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McGregor*et*al.*(2004)
Kalin*et*al.*(2004)
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Berdoy*et*al.*(2000)
Berdoy*et*al.*(2000)
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Condi$oning*Fear
The*most*basic*form*of*emo$onal*learning*is*a*condi$oned*
emo$onal*response,*which*is*produced*by*a*neutral*that*
has*been*paired*with*an*emo$onMproducing*s$mulus
• Some*s$muli*automa$cally*ac$vate*the*central*nucleus*of*
the*amygdala*and*produce*fear*responses*
• But*it*is*actually*more*important*to*have*the*ability*to*
learn*that*a*par$cular*s$mulus*or*situa$on*is*dangerous*or*
threatening*
• And*once*learning*has*taken*place,*that*s$mulus*or*
situa$on*will*evoke*fear*
• The*most*basic*form*of*emo$onal*learning*is*a*condi$oned*
emo$onal*response,*which*is*produced*by*a*neutral*that*
has*been*paired*with*an*emo$onMproducing*s$mulus
The*physical*changes*responsible*for*the*
condi$oning*of*a*condi$oned*emo$onal*response*
take*place*in*the*lateral*nucleus*of*the*amygdala
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Hitchcock*&*Davies*(1991)
• During*learning*phase,*a*light*(CS)*is*repeatedly*paired*
with*an*electric*shock*(UCS)*
• Later*fearMpoten$ated*startle*is*measured*by*
presen$ng*a*noiseMburst*while*the*light*is*on,*or*when*
the*light*is*not*on*
• FearMlearning*is*evident*by*a*poten$a$on*of*the*
magnitude*of*the*startle*reflex*when*the*light*is*
present,*compared*to*when*it*is*not*
• Hatched*bars*are*learning:*rats*learned*that*the*light*
meant*gecng*shocked,*so*they*were*already*expec$ng*
pain*when*the*noiseMburst*occurred
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Hitchcock*&*Davies*(1991)
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LeDoux*et*al.*(1990)
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Mather*et*al.*(2004)
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Cook*&*Mineka*(1990)
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Bishop*et*al.*(2004)
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Ohman*&*Soares*(1994)
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Morris*et*al.*(1998)
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Neural*Control*of*Aggression
• Aggressive*behaviours*are*species*typical*and*many*are*
related*to*reproduc$on*
• Aggressive*behaviour*can*consist*of*actual*aeacks,*or*threat*
behaviours*
• In*nature,*threats*of*aeack*happen*far*more*ogen*than*
actual*aeacks*
• Threat*behaviours*are*useful*in*reinforcing*social*hierarchies*
in*organized*groups*of*animals*or*in*warning*intruders*
Canli*et*al.*(2000)
• They*have*the*advantage*of*not*involving*actual*figh$ng,*
which*can*harm*one*or*both*the*combatants
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Neural*Control*of*Aggressive*Behaviour
The*three*principal*regions*of*the*amygdala*and*two*
regions*of*the*hypothalamus*affect*defensive*rage*and*
preda$on,*both*of*which*are*organized*by*the*PAG
• The*par$cular*muscle*movements*that*an*animal*
makes*in*aeacking*or*defending*itself*are*programmed*
by*neural*circuits*in*the*brain*stem*
• Ac$vity*of*the*brain*stem*circuits*is*controlled*by*the*
hypothalamus*and*the*amygdala
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PreMadolescent*males*with*the*lowest*5MHIAA*levels*
tend*to*die*young,*while*those*with*high*levels*survive
Role*of*Serotonin
• Depressed*rate*of*serotonin*release*is*associated*with*aggression*
and*other*forms*of*an$social*behaviour*(Lidberg*et*al.,*1984)*
• Men*with*personality*disorders*with*the*lowest*serotonergic*
ac$vity*most*likely*to*have*close*rela$ves*with*similar*
behavioural*problems*(Coccaro*et*al.,*1994)*
• Higher*rates*of*recidivism*in*parolees*with*lower*serotonin*than*
higher*levels*(Virkkunen*et*al.,*1996)*
• Serotonin*plays*an*important*role*in*dampening**behavioural*
impulses*in*general*(Van*der*Does,*2001)*
• Serotonin*agonists*(e.g,*Prozac)*decrease*irritability*and*
aggressiveness*(Coccaro*&*Kavoussi,*1997)
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Ventromedial*Prefrontal*Cortex*(vmPFC)*plays*
an*important*role*in*emo$on*regula$on
Importance*of*vmPFC*in*the*control*of*emo$onal*
behaviour*is*shown*by*the*effects*of*damage*to*the*region
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Ventromedial*Prefrontal*Cortex
Ventromedial*Prefrontal*Cortex
• People*whose*vmPFC*has*been*damaged*by*disease*or*
accident*are*s$ll*able*to*accurately*access*the*
significance*of*par$cular*situa$ons*but*only*in*a*
theore$cal*sense*
• Researchers*found*a*significant*correla$on*between*
emo$onal*dysfunc$on*and*impairments*in*realMworld*
competencies,*but*no*rela$onship*between*cogni$veM
abili$es*and*realMworld*competencies*(Anderson*et*al.,*2006)*
• The*vmPFC*serves*as*an*interface*between*brain*
mechanisms*involved*in*automa$c*emo$onal*responses*
and*those*involved*in*the*control*of*complex*behaviours*
• This*role*includes*using*our*emo$onal*reac$ons*to*
guide*our*behaviour*and*in*controlling*the*occurrence*
of*emo$onal*reac$ons*in*various*situa$ons
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• Suggests*that*emo$onal*problems*lie*at*the*base*of*the*realM
world*difficul$es*exhibited*by*people*with*vmPFC*damage**
• Evidence*suggests*that*emo$onal*reac$ons*guide*moral*
judgements*as*well*as*decisions*involving*personal*risks*and*
rewards*and*that*the*PFC*plays*a*role*in*these*judgments*as*
well
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Moral*Dilemmas
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vmPFC*pa$ents*make*u$litarian*judgements*even*in*
the*case*of*personal*moral*judgments
Text
Iowa*Gambling*Task
Disadvantageous
A
Advantageous
B
C
$100*gain
$50*gain
$250*M*1250*loss
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D
$25*M*250*loss
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Bechara*et*al.*(1997)
Bechara*et*al.*(1997)
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Developmental*Changes
• Amygdala*plays*an*important*role*in*provoking*anger*and*
violent*emo$onal*reac$ons,*and*the*PFC*plays*an*important*
role*in*suppressing*such*behaviour*by*making*us*see*its*
nega$ve*consequences*
• As*the*PFC*matures*adolescents*show*increases*in*cogni$ve*
abili$es,*and*an*increased*ability*to*inhibit*impulsive*and*
inappropriate*behaviour*(YurgelunMTodd,*2007)*
Best*et*al.*(2002)
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• Aggressive*behaviour*during*adolescence*was*posi$vely*
related*to*the*volume*of*the*amygdala*and*nega$vely*
related*to*the*rela$ve*volume*of*the*right*medial*PFC*
(Whiele*et*al.,*2008)
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Developmental*Changes
• Decreased*PFC*ac$vity*and*increased*subcor$cal*
ac$vity*(including*the*amygdala)*in*brains*of*men*
convicted*impulsive*emo$onal*murder*(Raine*et*al.,*
1998)*
• Increased*ac$va$on*of*the*amygdala*reflects*increased*
tendency*for*display*of*nega$ve*emo$ons,*and*
decreased*PFC*ac$va$on*reflects*a*decreased*ability*to*
inhibit*the*ac$vity*of*the*amygdala*and*control*emo$on*
• People*with*APD*showed*an*11%*reduc$on*in*gray*
maeer*of*the*PFC*(Raine*et*al.,*2002)
Developmental*Changes
• PFC*receives*a*major*projec$on*of*serotonergic*axons,*and*
serotonergic*input*to*the*PFC*ac$vi$es*this*region*
• Abnormally*low*level*of*serotonin*release*can*result*in*decreased*
ac$vity*of*the*PFC*and*increased*likelihood*of*u$litarian*
judgments*and*an$social*behaviour*
• SerotoninMreleasing*drug*increased*the*ac$vity*of*the*OFC*in*
normal*nonMviolent*subjects*but*not*in*the*subjects*with*a*history*
of*impulsive*aggression*(New*et*al.*(2002)*
• Lower*levels*of*serotonin*transporters*in*the*medial*PFC*of*people*
with*impulsive*aggression*(Frankle*et*al.,*2005):*suggests*that*the*
medial*PFC*of*these*people*contains*decreased*serotonergic*input
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Hormonal*Control*of*Aggression
Early*androgeniza$on*has*an*organiza$onal*effect*
that*s$mulates*the*development*of*testosteroneM
sensi$ve*neural*circuits*that*facilitate*aggression
• Many*instances*of*aggressive*behaviour*are*in*some*
some*way*related*to*reproduc$on,*and*like*ma$ng,*many*
forms*of*aggressive*behaviour*are*affected*by*hormones*
• Androgen*secre$on*occurs*prenatally,*decreases,*then*
increases*again*at*the*$me*of*puberty*M*intermale*
aggressiveness*is*controlled*by*neural*circuits*that*are*
s$mulated*by*androgens*
• Indeed,*research*has*shown*that*castra$on*reduces*
aggressiveness*and*injec$ons*of*testosterone*reinstate*
aggression*(Beeman,*1947)
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Hormonal*Control*of*Aggression
Aggression*between*females*is*also*
facilitated*by*testosterone
• Prolonged*administra$on*of*testosterone*will*eventually*
induce*intermale*aggression*even*in*rodents*that*were*
castrated*immediately*ager*birth*
• Data*show*that*exposure*to*androgens*early*in*life*decreases*
the*amount*of*exposure*that*is*necessary*to*ac$vate*
aggressive*behaviour*later*in*life*(vom*Saal,*1983)*
• Androgens*s$mulate*male*sexual*behaviour*by*interac$ng*
with*androgen*receptors*in*neurons*located*in*the*medial*
preop$c*area*(MPA)*
• Implan$ng*testosterone*in*the*MPA*reinstates*intermale*
aggression*in*castrated*male*rats*(Bean*&*Conner,*1978)
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