Hyperdeactivation of the Default Mode Network in People With Schizophrenia When Focusing Attention in Space.
When studying selective attention in people with schizophrenia (PSZ), a counterintuitive but replicated finding has been that PSZ display larger performance benefits than healthy control subjects (HCS) by cues that predicts the location of a target stimulus relative to non-predictive cues. Possible explanations are that PSZ hyperfocus attention in response to predictive cues, or that an inability to maintain a broad attentional window impairs performance when the cue is non-predictive. Over-recruitment of regions involved in top-down focusing of spatial attention in response to predictive cues would support the former possibility, and an inappropriate recruitment of these regions in response to non-predictive cues the latter. We probed regions of the dorsal attention network while PSZ (N = 20) and HCS (N = 20) performed a visuospatial attention task. A central cue either predicted at which of 4 peripheral locations a target signal would appear, or it gave no information about the target location. As observed previously, PSZ displayed a larger reaction time difference between predictive and non-predictive cue trials than HCS. Activity in frontoparietal and occipital regions was greater for predictive than non-predictive cues. This effect was almost identical between PSZ and HCS. There was no sign of over-recruitment when the cue was predictive, or of inappropriate recruitment when the cue was non-predictive. However, PSZ differed from HCS in their cue-dependent deactivation of the default mode network. Unexpectedly, PSZ displayed significantly greater deactivation than HCS in predictive cue trials, which may reflect a tendency to expend more processing resources when focusing attention in space.
['Hahn|Britta|B|', 'Harvey|Alexander N|AN|', 'Gold|James M|JM|', 'Fischer|Bernard A|BA|', 'Keller|William R|WR|', 'Ross|Thomas J|TJ|', 'Stein|Elliot A|EA|']
D000328:Adult D001288:Attention D002540:Cerebral Cortex D003463:Cues D005260:Female D059907:Functional Neuroimaging D006801:Humans D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D009415:Nerve Net D011597:Psychomotor Performance D012559:Schizophrenia D013028:Space Perception D055815:Young Adult
top-down default network fMRI