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Abstract:
The cerebral correlates of observed action slips were
investigated using movies during whole-brain fMRI (12
participants). Four conditions were presented in randomized order.
In the correct action (C) condition, participants observed hands
successfully fulfilling an action. In the qualitative slip of
action (Q) condition, the hands made insufficient movements. In the
substitutional slip of action (S) condition, the hands selected the
wrong object. In the object manipulation (O), the hands took one
object and "thoughtlessly" moved it. The participants classified
the movies pressing one of three optional buttons. Pure motor and
perceptual effects were substracted out by the baseline condition
O. Relative to the baseline, all conditions showed bilateral
activations of the ventrolateral Premotor Cortex (vPMC), the
Frontal Eye Field (FEF), and the mesial left Superior Frontal Gyrus
(SFG). However, activations of the vPMC and the anterior
Intraparietal Sulcus (aIPS, "grasping area") were modulated
significantly by different conditions. The Q condition elicited
less activation than the C condition in both areas in the right
hemisphere. In contrast, the S condition showed a higher activation
in the left vPMC, the lowest of all conditions in the right vPMC;
activations of the aIPS were missing. In summary, brain activations
differed significantly both between (1) observing actions vs.
meaningless movements and (2) different types of action
slips.
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