Paper Co-Authored by Associate Professor Nobuhito Abe Has Been Published in NeuroImage: Clinical
A paper co-authored by Associate Professor Nobuhito Abe et al., entitled “Impaired perception of illusory contours and cortical hypometabolism in patients with Parkinson’s disease,” has been published in NeuroImage: Clinical.
This research examined the hypothesis that hypometabolism of the higher-order visual cortex related to the ventral form-processing stream, which is induced by Parkinson’s disease (PD), is associated with the impaired perception of illusory contours* in PD patients (*illusory contours: illusion of perceived contours in situations where no change in luminance or color occurs along the contour lines).
We assessed and compared the stimulus presentation time necessary to perceive two types of illusory contours formed by Kanizsa figures or aligned line ends between PD patients and controls. Additionally, we also conducted FDG-PET imaging with a voxel-by-voxel, whole-brain analysis to effectively assess the relationship between an impaired perception of illusory contours and decreased cerebral glucose metabolism at rest in PD patients. The results showed that PD patients exhibited significantly longer stimulus durations for the perception of Kanizsa illusory figures compared to healthy controls.
The impaired perception of Kanizsa illusory figures in PD patients was correlated with hypometabolism in the higher-order visual cortical areas, which is located in the ventral form-processing stream, including the posterior inferior temporal gyrus. This study revealed the difficulty in perceiving illusory contours in PD patients and suggest that their visual impairment may be due to dysfunction in the higher-order visual cortex. These neuropsychological findings substantiate previous functional neuroimaging findings and support the view that the higher-order visual cortex is responsible for the human perception of illusory contours.
Ishioka T, Hirayama K, Hosokai Y, Takeda A, Suzuki K, Nishio Y, Sawada Y, Abe N, Mori E (2021) Impaired perception of illusory contours and cortical hypometabolism in patients with Parkinson’s disease
Neuroimage: Clinical 32: 102779