Neuropsychologia
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Review Meta Analysis
A meta-analytic review of theory of mind difficulties in behavioural-variant frontotemporal dementia.
Theory of mind (ToM) refers broadly to our understanding of others' complex emotions and mental states. Deficits in ToM are widely regarded as one of the key defining features of the behavioural variant of frontotemporal dementia (bvFTD), which is unsurprising given the key role that frontal and temporal neural systems are considered to play in mental state decoding. Here we report the first meta-analysis of this literature, providing a timely summary of the breadth, magnitude and specificity of ToM difficulties in this population. ⋯ BvFTD-related ToM difficulties were also significantly larger than the ToM difficulties seen in people with Alzheimer's disease. However, ToM difficulties in people with bvFTD were of a similar magnitude to the difficulties seen on measures of more basic social cue perception (emotion recognition). These data have important implications for understanding the types of ToM difficulties associated with bvFTD.
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In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. ⋯ A final experiment employed a more specific measure of the global effect typically associated with the rod-and-frame illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p=.078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another.