Abstract:
Previous research investigating auditory short-term memory using a tone discrimination paradigm found same-dimension similarity to be the primary source of memory disruption [e.g., C. Semal and L. Demany, J. Acoust. Soc. Am. 89, 2404--2410 (1991)]. However, grouping principles (e.g., Gestalt principles) also provide a possible explanation for the observed effects, because increases in same dimension similarity may also increase the likelihood of the standard tone grouping with additional tones. This project investigated the contribution of grouping to interference effects in short term memory for the dimensions of pitch and timbre. A modified ``captor effect'' task was used, with participants discriminating either the pitch or timbre of a standard tone (the sixth tone in an 11-tone sequence) from a comparison tone presented 5 s after the standard. Two variables were orthogonally varied, the same-dimension distance between the standard tone and the captor tones (either close or far), and the grouping structure of the sequence, with structures that either promoted or prevented grouping of the standard tone with the captor tones. Results suggest that grouping contributes to the amount of interference because increases in grouping led to increases in interference.