Emotions

Emotions
Can anyone tell me what emotions are?
Discussion: Do you think it is important to be able to recognize other people’s
emotions? Why? Suppose that you could no longer recognize people’s facial
expressions of emotions. What consequences would that loss hae for you?
I. General Overview
An emotional response consists of three types of components: behavioral,
autonomic, an hormonal !controlle by the amy"ala#.
1. The behavioral component consists of muscular movements that are
appropriate to the situation that elicits them.
2. Autonomic responses facilitate the behaviors and provide quick
mobilization of energy for vigorous movement.
3. Hormonal responses reinforce the autonomic responses. The hormones
secreted by the adrenal medulla— epinephrine and norepinephrine—
further increase blood flow to the muscles and cause nutrients stored in
the muscles to be converted into glucose. n addition! the adrenal corte"
secretes steroid hormones! which also help to make glucose available to
the muscles.
$EA%
The amygdala plays a special role in physiological and behavioral reactions to
ob#ects and situations that have biological significance! such as those
that warn of pain or other unpleasant consequences or signify the
presence of food! water! salt! potential mates or rivals! or infants in need
of care.
$e need concern ourselves with #ust three ma#or regions% the lateral nucleus, the
basal nucleus, and the central nucleus.
The lateral nucleus !&A# receives information from all regions of the neocorte"!
including the ventromedial prefrontal corte"! the thalamus! and the
hippocampal formation. The lateral nucleus sends information to the
basal nucleus !'# and to other parts of the brain! including the ventral
striatum &a brain region involved in the effects of reinforcing stimuli on
learning' and the dorsomedial nucleus of the thalamus! whose pro#ection
region is the prefrontal corte". The () and * nuclei send information to
the ventromedial prefrontal corte" and the central nucleus !CE#, which
pro#ects to regions of the hypothalamus! midbrain! pons! and medulla
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that are responsible for the e"pression of the various components of
emotional responses.
The central nucleus of the amy"ala is the single most important part of the brain
for the e"pression of emotional responses provoked by aversive
stimuli.
)nimals%
After the central nucleus has been estroye, animals no lon"er show si"ns
of fear when confronte with stimuli that have been paire with
aversive events. (hey also act more tamely when hanle by
humans, their bloo levels of stress hormones are lower, an they
are less li)ely to evelop ulcers or other forms of stress*inuce
illnesses &+oover! ,urison! and -ellestad! 1..2/ 0avis! 1..2/ (e0ou"!
1..2'.
+ormal mon)eys show si"ns of fear when they see a sna)e, but those with
amy"ala lesions o not &)maral! 2113'. n contrast! when the central
amy"ala is stimulate by means of electricity or by an in,ection of
an e-citatory amino aci, the animal shows physiolo"ical an
behavioral si"ns of fear an a"itation &0avis! 1..2'! and lon"*term
stimulation of the central nucleus produces stress*inuce illnesses
such as gastric ulcers &2enke! 1.32'.
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2umans%
 $hite! 1.41/ 2algren et al.!1.53/ 6loor et al.! 1.32% stimulation of parts of the
brain &the hypothalamus' produced autonomic responses that are often
associated with fear and an"iety but only when the amygdala was stimulated
did people also report that they actually felt afraid.
 *echara et al. &1..7' and (a*ar et al. &1..7'% people with lesions of the
amygdala showed impaired acquisition of a conditioned emotional response.
 6osselin et al. &2117'% patients with damage to the amygdala showed no
trouble with musical perception but were unable to recognize scary music.
A+GE%, AGG%E..IO+, A+D I/01&.E CO+(%O&
)ggressive behavior% threat behaviors, which consist of postures or gestures that
warn the adversary to leave or it will become the target of an attack.
The threatened animal might show efensive behaviors—threat behaviors or an
actual attack against the animal that is threatening it—or it might show
submissive behaviors—behaviors that indicate that it accepts defeat
and will not challenge the other animal.
0reation is the attack of a member of one species on a member of another!
usually because the latter serves as food for the former.
*ut what actually triggers aggression in humans8
$hat are the factors to be considered8
a' 2ereity: 9iding studied a group of same:se" twins at the ages of 5 years and
. years and found a higher correlation between monozygotic twins than
dizygotic twins on measures of antisocial behavior and levels of callous!
unemotional behavior.
b' .erotonin: (idberg et al.! 1.34! 1.37/ 9irkkunen et al.!1.3. : a depressed
rate of serotonin release &indicated by low levels of 7:2)) in the +;<' is
associated with aggression and other forms of antisocial behavior &including
assault! arson! murder! and child beating'.
c# 3entromeial 0refrontal Corte- :
i. *echara &2111' =
patients with bilateral lesions of the vm0$C% severe impairments in personal
and social decision-making.
i. patients with vm0$C lesions% defects both in emotional response and
emotion regulation &emotional responsivity diminished, reduced social
emotions such as compassion, shame and guilt'.
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ii. patients with focal lesions in the vm><+% personality changes such as
lack of empathy, irresponsibility, and poor decision making.
II. Communication of Emotions
 $acial E-pression of Emotions: Innate %esponses
Charles Darwin (1872/1965) suggested that human expressions of emotion hae eoled
from similar expressions in other animals! "e said that emotional expressions are innate#
unlearned responses $onsisting of a $omplex set of moements# prin$ipall% of the fa$ial
mus$les!
&esear$h '% ()man and his $olleagues (()man and *riesen# 1971+ ()man# 198,) tends to
$onfirm Darwin-s h%pothesis that fa$ial expression of emotion uses an innate# spe$ies.t%pi$al
repertoire of moements of fa$ial mus$les (Darwin# 1872/1965)! *or example# ()man and
*riesen (1971) studied the a'ilit% of mem'ers of an isolated tri'e in /ew 0uinea to
re$ogni1e fa$ial expressions of emotion produ$ed '% 2esterners!
 +eural 'asis of the Communication of Emotions: %eco"nition
&A(E%A&I(4
$e recognize other people?s feelings by means of vision and audition—
seeing their facial e"pressions and hearing their tone of voice and choice of
words. ,any studies have found that the ri"ht hemisphere plays a more
important role than the left hemisphere in comprehension of emotion.
;everal functional:imaging studies have confirmed these results. <or e"ample!
6eorge et al. &1..@' had sub#ects listen to some sentences and identify their
emotional content. n one condition the sub#ects listened to the meaning of the
words and said whether they described a situation in which someone would be
happy! sad! angry! or neutral. n another condition the sub#ects #udged the
emotional state from the tone of the voice. The investigators found that
comprehension of emotion from wor meanin" increase the activity of the
prefrontal corte- bilaterally, the left more than the ri"ht. Comprehension of
emotion from tone of voice increase the activity of only the ri"ht prefrontal
corte-.
♦ %ole of (he Amy"ala An 0refrontal Corte-
Lesions of the amygdala impair people’s ability to recognize facial expressions of
emotion, especially expressions of fear!
3% ta)ing out all low spatial fre4uen$% information from the fa$es# %ou end up with
the pi$tures in the middle $olumn 'elow! 5hese fa$es would 'e dete$ted easil% '% the
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paro$ellular pathwa%# 'ut not '% the magno$ellular or the retinote$tal pathwa%s!
Conersel%# the low spatial fre4uen$% fa$es in the right $olumn $ontain less information than
the normal fa$es in the left $olumn 6 and this is entirel% the paro$ellular pathwa%-s loss!
5he magno$ellular and retinote$tal pathwa%s are presuma'l% $oded in su$h $oarse resolution
that the% $annot dis$riminate 'etween the fa$es in the left and right $olumns!
7uilleumier et al (2,,8) used f9&: to inestigate the neural responses to the three
t%pes of fa$es (normal# high spatial fre4uen$%# low spatial fre4uen$%)# whi$h were either
neutral or fearful! 5he parti$ipants were as)ed to ;udge the gender of the fa$es# 'ut this was
mainl% to )eep their attention on the fa$es# whi$h were presented in random order! 5he
resear$her h%pothesised that areas in the entral isual $ortex (ie the fusiform fa$e area)
would 'e sensitie to the high spatial fre4uen$% fa$es# while the am%gdala would 'e
sensitie to the low spatial fre4uen$% fa$es!
5his latter h%pothesis is 'ased on the idea that there is a )ind of short$ut in the 'rain to
ena'le potentiall% dangerous stimuli su$h as fearful fa$es to get to the am%gdala as 4ui$)l%
as possi'le# where the fear response is produ$ed that then guides the response (fight/flee et$)!
7uilleumier et al (2,,8) found ample support for 'oth h%potheses 6 a$ross neutral and
fearful expressions# the fusiform fa$e area responded more strongl% to the high spatial
fre4uen$% fa$es than the low spatial fre4uen$% fa$es# while the opposite was true of the
am%gdala!
5o further the eiden$e for low spatial fre4uen$% $oding in the am%gdala# 7uilleumier
et al (2,,8) also showed that the am%gdala onl% responded to fearful fa$es (as $ompared to
neutral fa$es) when the fa$es were presented at low spatial fre4uen$%! /o signifi$ant
differen$e appeared for the high spatial fre4uen$% $omparison 'etween fearful and neutral
fa$es! 3etter %et# the same a$tiation patterns appeared for a part of the thalamus
$orresponding to the pulinar and the superior $olli$ulus# whi$h# as %ou ma% re$all# was
h%pothesised to 'e part of the retinote$tal pathwa% that ena'les the am%gdala response! 5he
figure 'elow gies the mean a$tiit% a$ross the $onditions for the am%gdala (d)# and the
pulinar.$olli$ulus area (e)!
III. $eelin"s of Emotions
5.5. (he 6ames*&an"e (heory
2illiam <ames (18=26191,)# an >meri$an ps%$hologist# and Carl ?ange (188=619,,)#
a Danish ph%siologist# independentl% suggested similar explanations for emotion# whi$h
most people refer to $olle$tiel% as the James-Lange theory ( <ames# 188=+ ?ange# 1887)!
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Basically, the theory states that emotion-producing situations elicit an
appropriate set of physiological responses, such as trembling, sweating, and increased
heart rate. The situations also elicit behaiors, such as clenching of the fists or fighting.
The brain receies sensory feedbac! from the muscles and from the organs that
produce these responses, and it is this feedbac! that constitutes our feeling of emotion.
<ames said that our own emotional feelings are 'ased on what we find ourseles doing and
on the sensor% feed'a$) we re$eie from the a$tiit% of our mus$les and internal organs! *or
example# when we find ourseles trem'ling and feel 4ueas%# we experien$e fear! 2here
feelings of emotions are $on$erned# we are selfo'serers! 5hus# the two aspe$ts of emotions
reported in the first two se$tions of this $hapter gie rise to the third@ feelings!
<ames-s theor% is diffi$ult to erif% experimentall% 'e$ause it attempts to explain
feelings of emotion# not the $auses of emotional responses# and feelings are priate eents!
Aome ane$dotal eiden$e supports the theor%! *or example# Aweet (1966) reported the $ase
of a man in whom some s%mpatheti$ neres were seered on one side of the 'od% to treat a
$ardioas$ular disorder! 5he manB a musi$ loerBreported that the shiering sensation he
felt while listening to musi$ now o$$urred onl% on the unoperated side of his 'od%! "e still
en;o%ed listening to musi$# 'ut the surger% had altered his emotional rea$tion!
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