Before prism adaptation, the mean choice of the gradient with the dark side on the right as the ‘darker’ was 98% (mean 19.5 out of 20 pairs, with SD = .9). The corresponding percentage after prism adaptation was again 98% (mean = 19.5 out of 20, with SD = .8). Similarly to the results for the chimeric face lateral preference task, prism intervention was thus found to have no impact
whatsoever on lateral preferences in the greyscale gradients task [t(10) = 0, p = 1, n.s.] and this was true for all the individual participating patients, none of whom showed an individually significant impact of prisms in this task; see Fig. 5. Thus, Selleckchem Afatinib for both the chimeric face expression and greyscale gradients lateral preference tasks, all patients showed strong left neglect, manifested as expression or darkness judgements (respectively) being pathologically based on just the right side of the stimuli, unlike the normal tendency for the left side to predominate slightly for both the face task (cf. Levy et al., 1983, Luh et al., 1991, Mattingley et al., 1993 and Mattingley et al., 1994) and the greyscale gradients task (Mattingley et al., 1994, Nicholls Epigenetic inhibitor manufacturer et al., 2004 and Nicholls et al., 2005) in neurologically healthy
subjects. Indeed all of our neglect patients fell well outside the normative range for these particular tasks (see Mattingley et al., 1994), IKBKE with the sole exception of patient AK in the chimeric face expression task (see also Sarri et al., 2006). But the main point for present purposes is that the patients’ performance for both these
lateral preference tasks was completely unaffected by prism adaptation (see Fig. 4 and Fig. 5). Turning to the chimeric/non-chimeric face discrimination task, all six participating patients showed signs of neglect in this task before the prism adaptation procedure, failing to classify 40% or more of the chimeric face tasks presented as such. In particular, patients tended to erroneously classify ‘chimeric’ faces as ‘real’, presumably failing to notice any differences in emotional expression between the left and the right halves of the chimeric face tasks, due to their left neglect. By contrast they were mostly accurate at classifying the non-chimeric, ‘real’ faces as such. Specifically, EY classified correctly only 20% of the chimeric face tasks presented (erroneously classifying 80% of the chimeric face tasks presented as ‘real’), whereas she correctly classified 85% of the ‘real’ faces.