Toque de mãe: efeito da identidade associada ao toque na resposta neural ao toque afetivo em bebês de 6 meses

• Ano de defesa: 2020
• Autor(a) principal: Wirth, Katja de Matos
• Orientador(a): Osório, Ana Alexandra Caldas
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Presbiteriana Mackenzie
• Palavras-chave em Português: desenvolvimento; primeira infância; toque afetivo; neurodesenvolvimento
• Área do conhecimento CNPq: CNPQ::CIENCIAS HUMANAS::PSICOLOGIA::PSICOLOGIA FISIOLOGICA
• Link de acesso: https://dspace.mackenzie.br/handle/10899/28579

Since birth, touch is essential to explore the surrounding physical environment, but also to establish social relationships, acquiring an affective meaning in this context. Touch is often assessed in two dimensions: sensory-discriminatory (texture, pressure etc.), typically mediated by myelinated Aβ fibers; and a motivational-social dimension, related to the context and affective meaning of that touch, mediated by myelinated C-tactile fibers. More specifically, in the case of affective touch, previous research with adults have shown that the identity of the person who applies the touch and the type of emotional connection with that person influence its processing. Preliminary evidence with 9-month-old infants provides support to this idea by showing a heart rate deceleration when touch was performed (apparently) by the mother, compared to an unfamiliar woman. However, until now, it remains to be investigated the effect the identity of the person who touches may have on the neural processing of affective touch in infants. In addition, from 6 months onwards, infants begin to show a preference for proximity and contact with their primary caregivers - typically their mother. Therefore, the aim of this study was to compare the pattern of brain activation in 6-month-old infants in response to affective touch, when the source of the touch is perceived to be the mother versus when the source of the touch is perceived to be a non-familiar female. We analyzed possible differences in cortical activation in the somatosensory areas and temporal region of the brain (bilaterally). The sample consisted of eight 6-month-old infants, full-term and without developmental problems. The neural processing of affective touch was evaluated by using functional near-infrared spectroscopy (fNIRS), which measures changes in the concentration of oxygenated and deoxygenated hemoglobin in brain tissue. The results showed an activation in the somatosensory and temporal region when the infant believed being touched by the mother, but no significant activation emerged when the infant believed being touched by a nonfamiliar female. These results suggest a potentially selective recruitment of these brain areas (temporal and somatosensory) at the age of 6 months, depending on the identity of the person performing the touch.