Abstract：An important aspect of human cognition is that performance depends on the strategies that people use in a wide range of cognitive domains. In the field of arithmetic cognition, the performance of strategy utilization was influenced by many factors in which central executive functions (central executive functions, EFs) were involved and played critical roles. In previous studies, researchers tended to focus on the impact of central executive load on the use of arithmetic strategy in children or adults with typically development (TD) of mathematical ability while children with mathematics difficulties (MD) had been out of consideration. Thus, the present study used the choice/no-choice method to investigate the influence of central executive load upon the strategy utilization of children with MD during arithmetic processing which seemed to be meaningful both theoretically and practically.
74 sixth graders consisting of 36 MD and 38 TD were selected in accordance with previous studies strictly. All participants who were asked to finish a two-digit addition computational estimation with rounding-up or rounding-down strategy and a secondary task at the same time. We manipulated a secondary task as varying central executive load by requiring participants to memorize five (high central executive load) or three (low central executive load) digits presented randomly in sequence at the beginning of each trial and rank them with descending order or no digit (no central executive load). Five or three digits were presented randomly in sequence at the beginning of each trial and rank them with descending order.
Results showed that: (1) In terms of the strategy executive, the accuracy of MD was significantly lower than that of TD under all the three central executive loaded conditions and the reaction time of MD was significantly longer than that of TD only under the no and low central executive loaded conditions. With the increasing of central executive load, the MD had distinct manifestation relative to that of TD on strategy executive; (2) In the case of strategy selection, the accuracy of MD was significantly lower than that of TD and the reaction time of MD was significantly longer than that of TD under three central executive loaded conditions. Compared with TD, the strategy selection of MD was more heavily influenced by the levels of central executive load. Likewise, the performance of MD was influenced by growing central executive load other than that of TD on strategy selection; (3) For the adaptivity of strategy choice, the higher the levels of central executive load was, the worse the adaptivity of strategy choice of participants became, and the adaptivity of strategy choice of MD was significantly worse than that of TD under all three central executive loaded conditions. These findings of current study have important theoretical and practical significance for the profound understanding of the potential mechanism of MD with worse strategy utilization.
In conclusion, the strategy utilization of MD is worse than that of TD during arithmetic processing. Though strategy utilization of both the MD and TD is getting worse as a function of the levels of central executive load, MD are more heavily influenced by central executive load. The adaptivity of strategy choice of two groups is affected negatively by the strength of central executive load while the adaptivity of strategy choice of MD is worse than that of TD. What’s more, the present study is contributing to exploring how the central executive load influences the process of strategy utilization clearly. Combining with electrical technology as well as functional magnetic resonance imaging technology (fMRI), future research should further explore the changes of individuals’ electrical components or brain regions activated under different levels of central executive load.