Are working memory measures free of socio-economic and cultural influence?

This research investigated the hypothesis that working memory skills are independent of environmental factors such as socio-economic status (SES) or cultural background. Twenty Brazilian children aged 6 and 7 years from low SES families were evaluated on measures of working memory (verbal short-term memory and verbal complex span, taken form the AWMA: Automated Working Memory Assessment) and of vocabulary (expressive and receptive). They were compared with typically developing Brazilian children from the same region but from families of higher SES and to a population of Portuguese- speaking, immigrant children growing up in Luxembourg/EU. Children were matched on age, sex, and nonverbal ability. The three groups differed significantly on the vocabulary measures but not on the verbal short-term memory tests. Further the groups differed on one of the two complex span measures – counting recall - but performed equally well on backwards digit recall. The results indicate that tests of verbal short-term memory and also backwards digit recall provide measures of cognitive abilities that are not biased by the quality of the child’s socio-economical or cultural background. As these measures are also highly sensitive to language ability, they may provide useful methods for diagnosing language disorder that are independent of environmental opportunity.