Cross-modal information transfer and the effect of concurrent task-load.

Abstract

Our everyday lives offer plenty of situations where complex processing of information takes place, in which information needs to transfer across modalities to achieve a behavioral goal. The study examined the differential effects on object detection by a visual, verbal or an auditory cue held in Working Memory (WM), and the role of concurrent cognitive task-load on the final detection of that cue. Three experiments, all using same stimuli set but in different modalities, subjects held in memory a representation of a novel cue for a speeded detection in a search display at the end of each trial. The cue stimulus could be an image (visual), the name (verbal) or the sound (auditory) of a common animal or object. A mental arithmetic task was interleaved between the cue presentation and the cue detection. The results showed that information held in WM, either in verbal or auditory form, can efficiently transfer across modalities to complete a visual detection task for a representation of the initial WM-cue. The speed of detection was not affected by the cross-modal transfer of cue information but there was some detrimental effect on detection that could distinctively be attributed to the cognitive task-load. Together, these findings may provide some evidence for the role of Episodic Buffer component of WM (Baddeley, 2000) in integrating multimodal information originated from different sources, hence supporting the notion of the supramodal nature of WM. The results have been discussed in light of Baddeley's (1974, 2000) and Cowan's (1988, 1999) theoretical WM frameworks.