Developmental, behavioural, and neurological similarities in the processing of different magnitudes (time, number, space) support the existence of a common magnitude processing system (e.g., a theory of magnitude, ATOM). It is, however, unclear whether the recruitment of wider cognitive resources (short-term memory, STM; and executive function) during magnitude processing is similar across magnitude domains or is domain specific. The current study used an individual differences approach to examine the relationship between STM, executive function, and magnitude processing. In two experiments, participants completed number, length, and duration bisection tasks to assess magnitude processing and tasks that have been shown to assess STM span and executive component processes. The results suggest that the recruitment of STM and executive resources differed for the different magnitude domains. Duration perception was associated with access, inhibition, and STM span. Length processing was associated with updating, and number processing was associated with access to semantic memory. For duration and length, greater difficulty in the magnitude judgement task resulted in more relationships to STM and executive function. It is suggested that duration perception may be more demanding of STM and executive resources because it is represented sequentially, unlike length and number which can be represented nonsequentially.
Keywords: Duration; Executive function; Magnitude; Memory; Number.