Memory for serial order: A network model of the phonological loop and its timing

A connectionist model of human short-term memory is presented that extends the "phonological loop" (A. D. Baddeley, 1986) to encompass serial order an d learning. Psychological and neuropsychological data motivate separate lay ers of lexical, timing, and input and output phonemic information. Connecti on weights between layers show Hebbian learning and decay over short and lo ng time scales. At recall, the timing signal is rerun, phonemic information feeds back from output to input, and lexical nodes compete to be selected. The selected node then receives decaying inhibition. The model provides an explanatory mechanism for the phonological loop and for the effects of ser ial position, presentation modality, lexicality, grouping, and Hebb repetit ion. It makes new psychological and neuropsychological predictions and is a starting point for understanding the role of the phonological loop in voca bulary acquisition and for interpreting data from functional neuroimaging.