Article

Retinotopic memory is more precise than spatiotopic memory

McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 01/2012; 109(5):1796-801. DOI: 10.1073/pnas.1113168109
Source: PubMed

ABSTRACT

Successful visually guided behavior requires information about spatiotopic (i.e., world-centered) locations, but how accurately is this information actually derived from initial retinotopic (i.e., eye-centered) visual input? We conducted a spatial working memory task in which subjects remembered a cued location in spatiotopic or retinotopic coordinates while making guided eye movements during the memory delay. Surprisingly, after a saccade, subjects were significantly more accurate and precise at reporting retinotopic locations than spatiotopic locations. This difference grew with each eye movement, such that spatiotopic memory continued to deteriorate, whereas retinotopic memory did not accumulate error. The loss in spatiotopic fidelity is therefore not a generic consequence of eye movements, but a direct result of converting visual information from native retinotopic coordinates. Thus, despite our conscious experience of an effortlessly stable spatiotopic world and our lifetime of practice with spatiotopic tasks, memory is actually more reliable in raw retinotopic coordinates than in ecologically relevant spatiotopic coordinates.

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    • "An alternative view of our experiments is that the paradigm actually investigates memory rather than attention, because it involves the active maintenance of a location of interest across a saccade. There is an interesting overlap between attention and memory (Awh & Jonides, 2001), and several previous studies have used a spatial memory task to manipulate attention across saccades (Golomb et al., 2008;Golomb & Kanwisher, 2012;Golomb, Pulido, et al., 2010). However, because we did not ask participants to identify where the cue was, but only to identify a subsequent probe that may or may not appear at the same location of the cue, we have used a standard definition in the field and presented the cued performance as a measure of attention rather than memory. "
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