Impaired perception of illusory contours and cortical hypometabolism in patients with Parkinson's disease

Toshiyuki Ishioka, Kazumi Hirayama, Yoshiyuki Hosokai, Atsushi Takeda, Kyoko Suzuki, Yoshiyuki Nishio, Yoichi Sawada, Nobuhito Abe, Etsuro Mori

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Neuroimaging evidence suggests that areas of the higher-order visual cortex, including the lateral occipital complex (LOC), are engaged in the perception of illusory contours; however, these findings remain unsubstantiated by human lesion data. Therefore, we assessed the presentation time necessary to perceive two types of illusory contours formed by Kanizsa figures or aligned line ends in patients with Parkinson's disease (PD). Additionally, we used 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to measure regional cerebral glucose metabolism in PD patients. Although there were no significant differences in the stimulus durations required for perception of illusory contours formed by aligned line ends between PD patients and controls, PD patients required significantly longer stimulus durations for the perception of Kanizsa illusory figures. Difficulty in perceiving Kanizsa illusory figures was correlated with hypometabolism in the higher-order visual cortical areas, including the posterior inferior temporal gyrus. These findings indicate an association between dysfunction in the posterior inferior temporal gyrus, a region corresponding to a portion of the LOC, and impaired perception of Kanizsa illusory figures in PD patients.

Original languageEnglish
Article number102779
JournalNeuroImage: Clinical
Publication statusPublished - 2021 Jan


  • Illusory contours
  • Lateral occipital complex
  • Parkinson's disease
  • Perception


Dive into the research topics of 'Impaired perception of illusory contours and cortical hypometabolism in patients with Parkinson's disease'. Together they form a unique fingerprint.

Cite this