Purchase this article with an account.
Sara C. Mednick, Sean P. A. Drummond, Arvin C. Arman, Geoffrey M. Boynton; The neural correlates of perceptual learning and deterioration: a role for attention?. Journal of Vision 2005;5(8):1053. doi: 10.1167/5.8.1053.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We have previously shown that repeated, within-day testing on a perceptual task produces performance deterioration. But, an inter-test sleep episode (e.g. daytime nap) leads to performance improvement. Both phenomena demonstrate specificity to retinotopic position and to stimulus features (Mednick et al. 2003, Mednick et al submitted).
In the present study, we investigated the neural correlates of sleep-dependent, perceptual learning and deterioration, and the particular role attention plays in these performance changes. We compared changes in fMRI BOLD response in retinotopically defined visual areas (V1, V2, V3, V4) to changes in performance on a texture discrimination task (Karni & Sagi, 1991). Performance was measured as the threshold inter-stimulus-interval (ISI) between the target and masking stimulus. Subjects (n=20) trained outside the scanner for one hour on the task twice in one day (9AM & 5PM). An fMRI session immediately followed each test session in which subjects performed the task inside the scanner. In the scanner, the task alternated every 20 seconds between performing the texture discrimination in the trained and the untrained hemifield. Stimulus-driven and attention-driven brain responses were measured separately. Half the subjects took a 1.5-hour, polysomnographically-recorded nap in between test sessions (1–3PM).
Our behavioral results replicate previous findings of nap-dependent performance improvement compared to deteriorated performance in non-nappers. The fMRI BOLD response showed an increase in response across the visual areas in the second session in nappers compared with non-nappers. Further, fMRI responses in early visual areas were reversed between the groups. These results demonstrate the neural correlates of performance changes due to task training and sleep. Reversals in BOLD response found between nappers and non-nappers may reflect changes in the ability of top-down mechanisms to suppress the masking stimulus.
This PDF is available to Subscribers Only