The expression of emotion in head-injured and normal children
This thesis reports eight experiments which investigate voluntary emotional expressions in head-injured and normal children and four experiments which investigate spontaneous expressiveness in head-injured and normal children. A novel technique using dynamic video film was used to elicit more truly spontaneous expressions and then surreptitiously video the child's expressive responses to the film clips. In the voluntary condition children posed expressions on verbal request and imitated expressions depicted in photographs. Independent adult raters then viewed still images of the children's' expressions and categorised them for emotion shown and rated intensity of expression. Results indicated that for the spontaneous expressions not all film clips elicited expressions equally as well. The best clips were those that elicited happiness, sadness and disgust and differences in expressiveness were shown to exist between the head-injured and normal children. The acquired head-injury children as a group were significantly less expressive than the controls while differential effects on positive and negative spontaneous expression were found in left and right congenital hemiplegics. In right hemiplegics (left brain damage) the spontaneous expressions of disgust, sadness and happiness were poorer than controls, while in left hemiplegics (right brain damage) only negative spontaneous expressions of disgust and sadness were poorer than controls. These findings add new information to the existing body of knowledge in that they suggest that the left hemisphere is more important than one thought for the expression of negative emotion. The results from the voluntary production conditions indicated that the head-injured children could accurately imitate expressions suggesting that their ability to manipulate facial muscles was intact. However, the acquired head-injury children were found to be poorer than controls at producing expressions on verbal request particularly so in the left brain damage group.