| Working Memory Capacity correlates with a number of higher-order reasoning tasks, such as Raven's Progressive Matrices and reading comprehension, as well as a number of attention paradigms, such as dichotic listening and the antisaccade task. The purpose of the following study was to examine the role of WMC on low-level sensory tasks that require decisions about non-verbal information, such as difference threshold for tone frequency. In Experiment 1, WMC predicted difference threshold for pitch in a delayed match-to-sample task with a 500 ms intertone interval. Experiment 2 ruled out evidence for differences in sensory acuity between high and low WMC participants, since WMC did not affect difference threshold on a task without a delay. Experiment 3 showed that if the number of standard tone frequencies was increased to discourage the potential for categorical rehearsal of the tones, WMC still affected performance on the delay version. Experiment 4 compared performance on a number of threshold tasks that varied in the duration of the intertone interval (ITI). Since WMC affected performance with ITI's of 20 ms, it does not seem likely that the effect was due to rehearsal maintenance, leaving encoding differences as a remaining possible cause for the relationship between WMC and difference threshold for pitch. Individual differences in WMC may determine the focus of attention during encoding two tones separated by a perceivable time gap. Findings expand already wide array of paradigms associated with WMC to include delayed match-to-sample with non-verbal stimuli. |
