Fig. 9.

Small bias in fixation toward the cued locations does not account for the observed topographic organization obtained with attention mapping. A: histogram of the correlation between the measured eye positions and the cued locations for blocks of trials in which subjects moved their eyes to the cued locations. Each event in the histogram corresponds to eye position data from a single scan (about 5 min), derived from 6 scanning sessions (2 for subject MAS and 4 for subject DJH) during which eye movements were recorded. B: histogram of correlation coefficients from covert attention trials. Correlation coefficients are small but significantly greater than zero. C: maps derived during covert attention from scans with low (<0.122 in panel B) correlation coefficients (subject MAS, left hemisphere, same format as Fig. 2). D: maps derived again during covert attention but from scans with high (>0.122 in panel B) correlation coefficients. Maps in C and D are virtually identical, indicating that eye movements were very unlikely to substantially contribute to the observed topographic pattern of activity. Scale bar, 1 cm.