General cognitive ability in children with reading comprehension difficulties

Background. Children with specific reading comprehension difficulties read accurately and fluently but are poor at understanding what they read. Aims. This study investigated cognitive ability in children with poor reading comprehension with a view to determining the relationship between general cognitive ability and specific reading comprehension difficulty. Sample. Twenty-five poor comprehenders and 24 control children, matched for chronological age and word reading ability, participated in this study. Methods. General conceptual ability (GCA) was assessed using the British Ability Scales (2^nd edition; BAS-II); good and poor comprehenders' performance on different subscales was compared and related to underlying skills in reading accuracy, reading comprehension and number. Results. There was a general tendency for poor comprehenders to achieve lower scores on verbal tasks than on non-verbal and spatial tasks. Although the poor comprehenders scored significantly below the control children across most subtests, most obtained GCA scores within the normal range. For these children, reading comprehension was significantly below GCA-expected levels. A subset of poor comprehenders with below average GCA showed a clear hyperlexic profile in which comprehension was not unexpectedly poor but rather, reading accuracy was surprisingly good. Conclusions. These findings highlight the heterogeneity of children presenting with poor reading comprehension. Although most poor comprehenders have weaknesses that appear to be restricted to the verbal domain, a minority have more general cognitive impairments.