Aspects of early social smiling by infants with Down's syndrome

Abstract

Smiling by five Down's syndrome and seven nonhandicapped infants was recorded longitudinally during face-to-face interactions with their mothers over the first 6 months of the infants' lives. Two conditions, 'mobile' (mothers were asked to talk to the baby as naturally as possible) and 'immobile' (silent and maintain an impassive face), were contrasted. Between-group comparisons confirmed previous findings of significantly delayed emergence and less frequent smiling by the infants with Down's syndrome. Their smiles were also found to be shorter, and less discriminative between the two face-to-face conditions. The non-handicapped infants showed significantly more cry/distress vocalizations in the immobile than in the mobile condition, while the reverse was found for the Down's syndrome infants. A close temporal association between smiling and eye contact with mothers was found for both groups of infants. In a free interaction condition, mothers of the Down's syndrome babies showed a stronger tendency to use kinaesthetic and tactile stimulation than mothers of the non-handicapped infants.

The behavioural phenotype of Angelman syndrome

“…However, studies that have investigated the smiling behaviour of children with Down syndrome have found that they follow the same developmental pattern as in typically developing infants, but that there is a delayed emergence of smiling and a shorter duration of smiling during face to face interactions with their mothers than infants who did not have intellectual disabilities (Carvajal & Iglesias, 1997;Berger and Cunningham, 1986). …”

Cognitive and social factors in the development of infants with Down syndrome

“…This suggests that the infants in each group have similar emotional reactions to the unresponsive behaviour of the mother. Berger and Cunningham (1986) also reported that infants with Down syndrome showed reduced smiling during face-to-face interactions. Similar fi ndings were reported by Legerstee and Bowman (1989) and by Crown, Feldstein, Jasnow, Beebe and Jaffe (1992).…”

Comportamiento expresivo que antecede a la sonrisa social: Comparación entre lactantes normales y afectados por el síndrome de Down

“…Por otra parte, además de dicha semejanza morfológica, hay que subrayar que se encontró también una similaridad en la secuencia temporal en que se desarrollaron estos movimientos expresivos, puesto que el orden y la duración de las acciones que acabamos de mencionar fue idéntico en ambos grupos; así, en un primer momento aparecieron los movimientos de aproximación de las cejas y, posteriormente, éstas se relajaban coincidiendo con el inicio de la sonrisa, iniciándose siempre la secuencia con la fijación visual en la cara de la madre (véase Berger y Cunningham, 1986). En resumen, estos resultados ponen de manifiesto que la sonrisa constituye un patrón organizado de conducta facial similar en los niños normales y en los afectados por el síndrome de Down, debiendo señalarse que tales res-puestas tuvieron lugar en ambos grupos de sujetos en las mismas condiciones estimulares, esto es, durante la interacción cara a cara con su madre mientras se mantenía un contacto ocular permanente.…”

“…Una de dichas diferencias se encontró en la secuencia y duración media de las sonrisas, parámetros que, coincidiendo con otros autores (Berger y Cunningham, 1986;Emde y cols., 1978;Rothbart y Hanson, 1983), resultaron con valores más bajos en los niños con sín-drome de Down que en los niños normales. Estos resultados pueden recibir al menos dos interpretaciones distintas, que se señalan a continuación.…”