Figure 3

Alpha-band power modulations in the sighted group. (A) Topographies of alpha-band activity (10–14 Hz, 400 to 600 ms, marked with black rectangle in (B) with uncrossed (a,b) and crossed hands (d,e) following attended (a,d) and unattended (b,e) stimuli. (c,f,g,h) Difference topographies for attention effects with uncrossed (c) and crossed (f) hands, and for posture effects following attended (g) and unattended (h) stimuli. (i) Topography of the interaction between attention and posture. Data are displayed as if stimuli always occurred on the anatomically right hand, so that the left hemisphere is contralateral to tactile stimulation in a skin-based reference frame, independent of posture. (B) Time-frequency representation of the electrode showing the largest interaction between posture and attention (marked with an asterisk in (A) approximately P3/4 in the 10–10 system) with uncrossed (a,b) and crossed hands (d,e) following attended (a,d) and unattended (b,e) stimuli. Unmasked areas in (c,f,g,h) and (i) indicate significant differences between attention conditions with uncrossed (c) and crossed hands (f), between posture conditions following attended (g) and unattended stimuli (h), and a significant interaction between posture and attention (i) (cluster-based permutation test, p < 0.05). (C) Neural sources of alpha-band activity. Alpha-band activity (12 ± 2 Hz, t = 400 ms) with hands uncrossed (a,b) and crossed (d,e) following attended (a,d) and unattended (b,e) stimuli. Source statistics are shown for the interaction effect between posture and attention (i), for effects of posture following attended (g) an unattended (h) stimuli, and for effects of attention with uncrossed (c) and crossed (f) hands. Significant clusters in (c,f,g,h) and (i) are unmasked. The left (right) hemisphere is contralateral (ipsilateral) to the stimulated hand. The white dashed line denotes the central sulcus. Used with permission from ref.⁴⁷.