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Previous issue date: 2017-10-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / As bases neurais do processamento da emo??o facial na inf?ncia s?o amplamente
desconhecidas. Os fatores ambientais que podem afetar o processamento facial e o
reconhecimento emocional ao longo do curso de desenvolvimento tamb?m s?o pouco
compreendidos. No entanto, acredita-se que as experi?ncias iniciais, particularmente
envolvendo exposi??o repetida a faces emocionais dos cuidadores, influenciem esse curso. O
objetivo deste estudo foi investigar os correlatos neurais do processamento de faces
emocionais em lactentes usando a espectroscopia funcional no infravermelho pr?ximo
(fNIRS), e examinar a poss?vel influ?ncia das experi?ncias emocionais iniciais dos lactentes,
indiretamente medida pela investiga??o de sintomas de ansiedade materna. Foram avaliadas
29 crian?as de 5 meses de idade e suas m?es, recrutadas de uma amostra da comunidade de
Boston, EUA. A ansiedade materna foi avaliada usando o componente tra?o do Invent?rio de
Ansiedade Tra?o-Estado (STAI-T). Os lactentes observaram imagens visuais est?ticas de
faces femininas retratando express?es de alegria e medo, enquanto as respostas
hemodin?micas corticais foram medidas usando fNIRS. As respostas de oxihemoglobina
(oxiHb) e deoxihemoglobina (deoxiHb) nas ?reas frontais, parietais e temporais foram
comparadas entre as faces emocionais, e entre filhos de m?es com n?veis altos e baixos de
sintomas de ansiedade. Os resultados demonstraram efeito principal significativo da emo??o
(p=0,022), evidenciado pelo aumento na concentra??o de oxiHb para faces de alegria em
compara??o a faces de medo. Ademais, observou-se efeito principal significativo da regi?o
(p=0,013), induzido por maior concentra??o de oxiHb nas regi?es corticais temporais em
rela??o ?s regi?es corticais frontais (p=0,031). Al?m disso, houve uma intera??o significativa
entre emo??o, hemisf?rio e ansiedade (p=0,037). As an?lises revelaram que filhos de m?es
com alta ansiedade demonstraram uma resposta hemodin?mica significativamente elevada no
hemisf?rio esquerdo para faces de alegria, em compara??o com faces de medo no hemisf?rio
direito (p=0,040) e esquerdo (p=0,033). Os resultados indicam que lactentes de 5 meses
discriminaram faces de alegria em compara??o com faces de medo, evidenciado pela maior
ativa??o para a primeira. A maior ativa??o nas regi?es temporais em rela??o ?s ?reas frontais
foi discutida em rela??o ? ontog?nese do processamento facial e ?s redes neurais de
reconhecimento emocional. A resposta mais acentuada, comparando faces de alegria e medo
observada nos filhos de m?es com alta ansiedade, pode estar relacionada a altera??es no
ambiente emocional dessas crian?as em compara??o com os filhos de m?es com baixa
ansiedade. Assim, os n?veis de ansiedade materna parecem moderar as respostas cerebrais
hemodin?micas das crian?as ?s faces emocionais. / The neural bases of facial emotion processing in infancy are largely unknown. The
environmental factors that may impact facial processing and emotion recognition along the
developmental course are also not clearly understood. However, early experiences,
particularly involving consistent exposure to familiar caregiver faces, are believed to
influence this course. The aim of this study was to investigate the neural correlates of infants?
emotional face processing using functional near-infrared spectroscopy (fNIRS), and examine
the potential influence of infants? early emotional experiences, indirectly measured by
investigating maternal anxiety symptoms. Participants were 29 typically developing 5-monthold
infants and their mothers, recruited from a community sample from the Boston greater
area, MA, USA. Maternal anxiety was assessed using the trait component of the State-Trait
Anxiety Inventory. Infants observed static visual images of a female model portraying happy
and fearful expressions, while hemodynamic brain responses were measured using fNIRS.
The oxyhemoglobin (oxyHb) and deoxyhemoglobin (deoxyHb) responses over frontal,
parietal and temporal areas were compared for the emotional expressions in infants of
mothers reporting low and high levels of anxiety symptoms. Results revealed a significant
main effect of emotion (p=.022), driven by greater oxyHb concentration responses for happy
compared to fearful faces. There was also a main effect of region (p=.013) induced by a
significantly greater oxyHb concentration in temporal compared to frontal cortical regions
(p=.031). Additionally, a significant three-way interaction between emotion, hemisphere and
anxiety was observed (p=.037). Planned comparisons revealed that infants of high-anxious
mothers showed significantly greater left hemispheric activation of oxyHb to happy faces
when compared with right (p=.040) and left (p=.033) hemispheric activation of oxyHb to
fearful faces. These findings possibly indicate that 5-month-olds can discriminate happy from
fearful faces, evinced by the greater activation for the former. The greater activation in
temporal as compared to frontal areas was discussed in relation to the ontogenesis of face
processing and emotion recognition neural networks. The enhanced response to happy versus
fearful faces observed in infants of high-anxious mothers can be related to the presumed
altered emotional environment experienced by these infants, compared to that of infants of
low-anxious mothers. Therefore, maternal anxiety levels appeared to moderate infants?
hemodynamic brain responses to emotional faces.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/7867 |
| Date | 31 October 2017 |
| Creators | Porto, Juliana Antola |
| Contributors | Nunes, Magda Lahorgue, Nelson, Charles A. |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Medicina e Ci?ncias da Sa?de, PUCRS, Brasil, Escola de Medicina |
| Source Sets | IBICT Brazilian ETDs |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 7620745074616285884, 500, 500, 500, 600, -224747486637135387, -969369452308786627, 2075167498588264571 |
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