Enhancing the comprehension of visual metaphors in individuals with intellectual disability with or without down syndrome

This study is the first to investigate the effectiveness of deep and shallow intervention programs
in the acquisition of visual metaphor comprehension in individuals with non-specific intellectual
disability (NSID; aged 15–59, N=53) or Down syndrome (DS; aged 15–52, N=50). The deep
intervention program was based on dynamic assessment model for enhancing analogical
thinking. The shallow intervention program involves memorizing a metaphorical relationship
between pairs of pictures. Visual metaphor comprehension was measured by the construction of a
metaphorical connection between pairs of pictures. The results indicated that both etiology
groups exhibited poor understanding of visual metaphors before the intervention. A significant
improvement was observed in both interventions and both etiology groups, with greater improvement
among individuals who underwent the deep processing. Moreover, the latter procedure
led to greater generalization ability. The results also indicated that vocabulary contributed
significantly to understanding unstudied metaphors and that participants with poorer linguistic
abilities exhibited greater improvement in their metaphorical thinking. Thus, individuals with ID
with or without DS are able to recruit the higher-order cognitive abilities required for visual
metaphor comprehension.