Modality and domain specific components in auditory and visual working memory tasks.

In the tripartite model of working memory (WM) it is postulated that a unique part system-the visuo-spatial sketchpad (VSSP)-processes non-verbal content. Due to behavioral and neurophysiological findings, the VSSP was later subdivided into visual object and visual spatial processing, the former representing objects' appearance and the latter spatial information. This distinction is well supported. However, a challenge to this model is the question how spatial information from non-visual sensory modalities, for example the auditory one, is processed. Only a few studies so far have directly compared visual and auditory spatial WM. They suggest that the distinction of two processing domains--one for object and one for spatial information--also holds true for auditory WM, but that only a part of the processes is modality specific. We propose that processing in the object domain (the item's appearance) is modality specific, while spatial WM as well as object-location binding relies on modality general processes.