The effects of processing speed and memory span on working memory

This study examined the processing speed and memory span of young adults and older people using tasks based on the Wechsler Adult Intelligence Scale-III (WAIS-III, <citationReference rid="c26" id="cr26-2">Wechsler, 1997</citationReference>). By comparing the data obtained from these tasks, we examined the effects of processing speed and memory span on working memory (WM). In addition, this study examined how presentation modality and the subject's age are related to WM. Multiple regression analysis of the effect of memory span for each presentation modality used processing time as a factor to predict the WM span of various age groups. The result was two equations for predicting WM span. According to these equations, WM is negatively correlated with "age group" and "processing time," and positively correlated with "memory span." Memory span and processing speed were found to have similar impacts on WM, regardless of the presentation modality. However, our results suggested that visual WM and auditory WM are different functions, and that auditory WM is more strongly affected by memory span than visual WM.