The Fidelity of Visual and Auditory Memory Michele Gloede & Melissa Gregg, Ph.D. Introduction Recent studies show that recognition memory for various types of sounds is inferior to memory for pictures of visual objects (e.g., Cohen, Horowitz, & Wolfe, 2009; Gloede, Paulauskas, & Gregg, in press). Although previous research has established a large difference between auditory and visual memory, it is not yet clear why such disparity exists. In the present study, we sought to provide clarity on the inequality between auditory and visual memory by examining the nature of auditory and visual memory representations as well as the time course of information loss in the two memory systems. We examined the nature of memory representations by measuring the fidelity of auditory and visual memory. This measure allowed us to determine whether memory in one modality is more global, gist-based, while memory in the other modality is more specific and detailed. We examined the time course of information loss by measuring capacity and duration in auditory and visual memory over the course of three days. Conclusions The results of Experiment 1 indicate that auditory memory representations are coarse, gist-based representations, rather than richly detailed recollections of an event. Visual memory representations, however, are more fine-tuned, specific, and detailed The results of Experiment 2 suggests a potential trade-off between visual and auditory memory: visual memory seems to have a larger capacity, while auditory memory is more enduring. Collectively, the results indicate that the reported difference in auditory and visual memory is in part due to visual memory being a larger capacity memory system with more precise memory representations. Visual memory does not appear to be completely superior, however, as auditory memory is more enduring. Visual and auditory memory seem to be inherently different memory systems with immanently different neural circuitry specialized for information retention. ° Experiment 1 Stimuli: 96 pictures and 96 sounds of common environmental objects Procedure: Study Phase 64 pictures/sounds presented for 5000 msec Auditory - Hear Visual - See Test phase: 32 old sounds/pictures,32 new sounds/pictures and 32 new within-category (NW) sounds/pictures. Auditory/Old - Hear Visual/Old - See Auditory/New -Hear Visual/New - See Auditory/NW – Hear Visual/NW – See Task: Old or New? Results: Experiment 2 Stimuli: 64 pictures and 64 sounds of common environmental objects Procedure: Day 1 Study phase: Each picture/sound presented for 5000 msec Test phase: 32 old sounds/pictures presented along with 32 new sounds/pictures. Task: Old or New? Day 2 - - - - - - - - - - - - - - - - - - - - - - Day 3 Test phase: 32 old sounds/pictures presented and 32 new sounds/pictures. Task: Old or New? Results: Visual memory performance was significantly better than auditory memory performance on Day 1 and on Day 3. However, there was substantially more visual than auditory memory loss over the course of 3 days. This trend contributed to an interaction between Test Day (day 1 vs. day 3) and Memory Type (auditory vs. visual), F (1,18) = 25.57, p <.05. O or N °° ° Research Questions Are there fundamental differences in the fidelity of auditory and visual memory representations? Is the pattern of information loss over time similar for visual and auditory memory? References Cohen, M.A., Horowitz, T.S., & Wolfe, J.M. (2009). Auditory recognition memory is inferior to visual recognition memory. PNAS, 106, 6008-6010. Gloede, M.E., Paulauskas, E., & Gregg, M.K. (in press). Experience and information loss in auditory and visual memory. QJEP. Visual memory was significantly better than auditory memory, F (1,19) = 53.95, p < .05. Performance on the visual memory tasks indicated that visual memory has more precise memory representations, F (2, 38) = 3.27, p < .05. There were no differences among the trial types during the visual memory test, but performance on the auditory test was more accurate on New and Old trials than on New Within-Category trials, p < .05.