The role of facial emotional expression in 3-month-old recognition of an individual face

crumcasteΤεχνίτη Νοημοσύνη και Ρομποτική

17 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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The role of facial emotional expression in 3
-
month
-
old recognition of an individual face

Background and Aims

In contrast to traditional models on adults’ face processing, recent studies demonstrated that
in adults personal identity recognition and expres
sed emotion recognition mutually interact
(Calder & Young, 2005). Although infants’ ability to recognize an individual face and
infants’ capacity to process facial emotion expressions have been largely investigated, to date
no study addressed in infancy th
e issue of the interaction between these two processes. The
present study was aimed at investigating whether three
-
month
-
old infants’ ability to recognize
an individual face is affected by the positive (happiness) or neutral emotional expression
displayed.

Method

Infants were familiarized with a video of a woman’s face expressing a positive emotion
(happiness group, n=37) or displaying a neutral expression (neutral group, n=36). Within
each group the video was shown for a total fixation time of 20 (n=38) o
r 40s (n=35). After
habituation infants saw two woman faces with a neutral expression: one familiar because
already seen in the familiarization phase and the other one completely new. Each face was
presented twice and alternately. In accordance with the v
isual
-
habituation paradigm, greater
fixation time towards the novel face was interpreted as an index of infant’s recognition of the
familiar face.

Results

A repeated measure Anova on novelty scores in test with Presentation (first, second) as
within
-
subjec
ts factor and Familiarization Period (brief, long) and Emotional expression
(happiness, neutral) as between subjects factor revealed a significant Presentation x Emotional
expression interaction, F(1, 69)= 6.37, p <.05 . During the first test presentation,

infants in the
happiness group recognized the novel face (Novelty preference: Happiness, M= 60.34%,
p
<.01, one
-
sample t
-
test
vs. chance); Neutral, M= 49.2%, ns, one
-
sample t
-
test vs. chance).

In
the second test presentation infant recognized the novel f
ace only in the neutral condition
(Novelty preference: Happiness, M= 53.28% (ns vs. chance); Neutral, M= 56.32% (p<.05 vs
chance).

Conclusions

Overall, results showed
that infants’ face recognition appear enhanced when faces display an
emotional expressio
n, given that the familiar happy face is recognized the first time it is
shown. Differently, the familiar neutral face is recognized only during the second stimulus
presentation.
Consistently with recent studies on adults, obtained evidence suggests the
p
resence of a mutual interaction between face identity and emotion recognition also as early
as at 3 months of age: we found a facilitatory effect of positive facial emotional expression.