Investigating the effect of cognitive load on working memory tasks in children with arithmetical difficulties

Abstract

In this study of working memory spans, children with low arithmetical ability were compared to an age-matched control group with normal arithmetical ability in their performance on dual-task procedures. Literacy skills were controlled for in both groups. Centred on the time-based resource-sharing model of Barrouillet et al (2004), working memory tasks require attention, with decay of memory traces occurring as soon as attention is switched away from memory items. Cognitive load of the processing task was manipulated by task complexity and pace and is defined by Barrouillet et al (2004) as ‘ the function of the time during which a cognitive task captures attention in such a way that the refreshing of decaying memory traces are impeded’. It was hypothesised that as the cognitive load increased memory span would decrease in both groups but that the decrease would be greater in children with poor arithmetical skills. The difference in memory spans was significant between the groups (F(1,23) = 6.78 ; p < 0.05). The main effect of task was found to be non significant in both experimental and control groups and pace was found to have a significant effect in the control group only (F (1, 11) = 0.006; p <0.05) showing differences in working memory between children with normal arithmetical ability and those with poor arithmetical ability. 4 2. Introduction The acquisition of mathematical skills in young children has been given an increasing amount of attention in recent years, in particular examining the role of working memory as an explanatory device accounting for individual differences in ability. (Barrouillet and Camos, 2001; Logie and Gilhooly, 1998; Miyake and Shah, 1999; Adams and Hitch, 1997). Often children who display specific learning difficulties have working memory deficits that cause limitations in their performance on a variety of tasks such as the reading span developed by Daneman and Carpenter (1980) and the counting span by Case (1985). Children with poor arithmetical abilities, commonly referred to as a mathematic disabled group (MD), have consistently produced results highlighting their deficits in working memory related to poor flexibility when dealing with numerical information (Baddeley and Hitch 1974; Passolunghi and Siegel,2001); slow and inaccurate problem solving( Hitch and McAuley, 1991; Seigel and Ryan 1989; Swanson 1993, Passolunghi and Siegel, 2001) and poor working memory capacity associated with the maintenance of irrelevant information and inefficient storage systems (Passolunghi and Seigel, 2001; 2004). 2.1 Working memory Hitch (1974) was one of the first researchers to investigate the role of working memory in mental arithmetic, which he proposed referred to the temporary storage and processing over a range of cognitive tasks. Together, Baddeley and Hitch (1974) proposed the