The role of visual and acoustic coding in retrieval from very short-term memory

Several studies have implicated acoustic processing in short-term memory despite stimuli being visual. It is commonly assumed that very short-term memory (VSTM) for visual stimuli, in contrast, operates entirely in the modality of input. The present study tested this assumption by investigating whether an acoustic code is used in VSTM. An experiment required subjects to detect whether a critical letter was present or absent in a brief display of 16 letters. Latency and accuracy of detection were not affected by acoustic similarity but were affected by visual similarity between the critical letter and the other letters of the display. Thus, the results support the assumption that retrieval from very short-term memory (visual) does not involve acoustic information.