Premium
Volitional saccades and attentional mechanisms in schizophrenia patients and healthy control subjects
Author(s) -
Reuter Benedikt,
Möllers David,
Bender Julia,
Schwehn Asysa,
Ziemek Juliane,
Gallinat Jürgen,
Kathmann Norbert
Publication year - 2011
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.2011.01213.x
Subject(s) - saccade , psychology , fixation (population genetics) , audiology , neuroscience , cognitive psychology , eye movement , medicine , population , environmental health
Schizophrenia (SZ) patients showed increased volitional saccade latencies, suggesting deficient volitional initiation of action. Yet increased volitional saccade latencies may also result from deficits in attention shifts. To dissociate attention shifting and saccade initiation, we asked 25 SZ patients and 25 healthy subjects to make saccades toward newly appearing (onset) targets and toward the loci of disappearing (offset) targets. Similar onsets and offsets were also used as attention cues in a Posner‐type manual task. As expected, onsets and offsets had similar effects on attention. In contrast, saccade latencies were considerably longer with offset compared to onset targets, reflecting additional time for volitional saccade initiation. Unexpectedly, SZ patients had normal saccade latencies. Presumably, the expected deficit was compensated by decreased fixation‐related neural activity, which was induced by the disappearance of fixation stimuli.