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Abstract:
Abstract: We used fMRI to investigate the fronto-temporal
disconnection hypothesis in schizophrenia. Eight DSM IV R
schizophrenic subjects and 10 closely matched control subjects were
studied with fMRI. During scanning subjects performed the Hayling
sentence completion task. The last word of each visually presented
sentence was omitted and the subjects had to add the missing word.
In pilot studies we confirmed that this task activated an extensive
left lateralised fronto-temporal brain system. Based on a random
effects analysis of the main effect of sentence completion versus
rest, we defined regions of interest, centred around the most
significant voxels. In a second step we calculated correlation
coefficients between left temporal cortex (x=-54, y=-42, z=3) and
left dorsolateral prefrontal cortex (x=-39, y=12, z=24). Comparing
the correlation coefficients between these regions of controls and
schizophrenics revealed a significantly lower functional
connectivity in the schizophrenic group. More importantly, we found
a negative correlation of hallucinations and fronto-temporal
functional connectivity within the schizophrenic group, pointing at
a direct link between psychopathology and measures of functional
connectivity.
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