Variaciones de las vocalizaciones del bebé y del habla materna en función de la depresión posparto: Modulaciones según edad y sexo infantil / Variations of Babies Vocalizations and Maternal Speech Depending on Postpartum Depression: Modulations According to Infant's Age and Sex

RESUMEN

Resumen El presente trabajo indaga sobre la influencia de la depresión posparto (DPP) materna en las características prosódicas del Habla Dirigida al Bebé (HDB) y las emisiones preverbales infantiles en diversos contextos de interacción madre-hijo/a. Participaron 40 madres y sus bebés entre 3 y 6 meses de edad. Las madres fueron evaluadas con la Escala de DPP de Edimburgo (Cox, Holden y Sagoysky, 1987) y las díadas madre-hijo fueron filmadas en sesiones de juego no estructurado; 27 madres no presentaron indicadores de DPP y 13, sí. Las madres con DPP emitieron menor cantidad de vocalizaciones que las del grupo control y presentaron menor intensidad media y máxima al hablarle a sus bebés de 5-6 meses y esto fue particularmente observable en bebés varones (p < .07). Además, estas madres usaron menos curvas descendentes al dirigirse a bebés más pequeños (3-4 meses) y curvas ascendentes y descendentes al dirigirse a sus hijos varones (p < .01). En los bebés -tanto en los de 5-6 meses como en varones- (con madres con DPP se observó menor producción de emisiones preverbales, aunque sin ser significativa. La DPP materna impactó en los bebés más pequeños observándose una disminución de la frecuencia fundamental (p < .01) y de las intensidades media y máxima, pero solo en bebés varones (p < .05). También se halló una ausencia de curvas con forma de U en los varones e hijos de madres con DPP (p < .05). Aparentemente, la DPP afecta el HDB materno, el que varía a nivel acústico y prosódico en función de la edad del bebé afectando las emisiones preverbales, siendo mayor el impacto en los varones.

ABSTRACT

Abstract The present work aims to study the influence of postpartum depression (PPD) on the acoustic and melodic characteristics present in the vocal interaction between the mother and her baby. We analyze acoustic qualities of the mother's voice when she is talking to her baby (Infant-Directed Speech) such as fundamental frequency (F0 maximum, medium and minimum values) and intensity (maximum, medium and minimum values). The changes of F0 during a vocalization (intonation contours such as rising, falling, bell-shape, U-shape and sinusoidal and flat contours) were also examined. The same prosodic parameters were investigated in regard to prelinguistic vocalizations. The mothers were healthy, primiparous and native speakers of argentinian spanish. The babies were 3 to 6 month old, and those with congenital diseases or diseases that could affect the assessment of the variables under consideration were excluded. We evaluated 40 dyads of mother and child who attend the University Hospital of Maternity and Neonatology of Córdoba, Argentina. The presence of indicators for PPD was examined through the Edinburgh postpartum depression Scale (Cox, Holden & Sagoysky, 1987). The mother-infant interactions were filmed in unstructured play sessions. The categorization of different contexts in which those interactions occur were taken into account for the acoustic and melodic analysis. The types of interactional contexts were distinguished according the classification made in Papousek, Papousek & Symmes (1991). The results showed that 27 mothers did not present indicators of PPD and 13 did. Acoustically, the infant-directed speech of mothers who exhibit the presence of postpartum depression indicators featured lower values of medium and maximum intensity (p < .07, in both measures) in babies between 5 and 6 months old, and in male babies in particular (F0 medium p < .04 and F0 maximum p < .03). According to the melodic characteristics of IDS, less use of falling contours (p < .01) was found in mothers with PPD when addressing smaller babies -3 and 4 month old- and the same happened with the rising (p < .02) and falling (p < .01) contours when their children were males. In preverbal vocalizations, children whose mothers had indicators of postpartum psychopathology showed a lower number of emissions at a later age (p < .1) and in males (p < .1). Also, lower values of F0 were found in smaller babies (F0 minimum p < .01 and F0 medium p < .002). Male infants of mothers with PPD also presented a decrease in intensity (medium p < .05 and maximum p < .03). Finally, at the melodic analysis, the rising contours were not used at all for the oldest babies (p < .01) nor the U-shaped contours in males (p < .02). In conclusion, the findings of the present study not only confirm -through physiological measures- the effect of the interaction of mothers with their babies as a function of the presence of signs of postpartum depression, already from the first months of childhood life, but also that these alterations are modulated by the age and the gender of the infant. It is essential, therefore, to continue investigating whether these difficulties related to the primary bond that each mom and her child share are perpetuated over time. It is also necessary to adopt a gender perspective of maternal and child relationships and the importance of therapeutic approach and intervention of the dyad as early as the first months after birth. At the same time, the exhaustive and immediate diagnosis of PPD cases is a matter of primary healthcare and the multidisciplinary intervention is urgent from the beginning in order to ensure maternal-infant metal health and harmonic social, cognitive and emotional development in children.