Neuropsychological evidence of visual storage in short-term memory tasks

Auditory and visual presentation of verbal material were compared in a single patient having an auditory verbal S.T.M. deficit. A Peterson short-term forgetting experiment and an immediate memory span task are reported. Striking differences in performance related to modality of input were obtained. Auditory short-term forgetting was more rapid, whereas with visual presentation short-term decay functions were relatively normal. With visual presentation there was no evidence of acoustic confusion errors but there was some evidence of visual confusion errors. The findings are interpreted in terms of a separate post-perceptual visual S.T.M. system.