Date of Degree
PhD (Doctor of Philosophy)
Steven J. Luck
This dissertation evaluated whether Visual Working Memory (VWM) is a distinct memory system or if it is an activated state of Visual Long Term Memory (VLTM). These two positions suggest different roles for VLTM representations in the performance of VWM. If VWM representations are an activated state of VLTM representations, it seems plausible that strong VLTM representations should facilitate VWM performance. However, if the two representations are actually distinct, it seems less likely that a facilitation interaction between VLTM and VWM representations should be observed.
Five experiments were conducted in which participants learned a set of trained stimuli over two days of training. Participant performance with the trained stimuli was compared to performance with novel stimuli on a subsequent VWM change detection task to determine the plausibility of VLTM-VWM interactions.
The first and second experiments revealed a LTM facilitation effect that could not be explained by priming, but the third experiment suggested that this facilitation effect was mediated by non-visual representations. The fourth and fifth experiments parceled out the contributions of non-visual memory representations, and failed to demonstrate any evidence of VLTM-VWM performance interactions.
These results, in conjunction with other examples from the literature, all converged on the conclusion that VLTM-VWM facilitation interactions are relatively implausible. As such, it was concluded that VWM and VLTM representations are discreet.
Copyright 2008 Adam Trent Niese