Changes in pupil diameter are correlated with the occurrence of pareidolias in patients with dementia with Lewy bodies

Yumi Suzuki, Kazumi Hirayama, Tatsuo Shimomura, Makoto Uchiyama, Hiromi Fujii, Etsuro Mori, Yoshiyuki Nishio, Osamu Iizuka, Ryusuke Inoue, Mika Otsuki, Shinya Sakai

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Pareidolias are visual illusions of meaningful objects, such as faces and animals, that arise from ambiguous forms embedded in visual scenes. Pareidolias and visual hallucinations have been suggested to have a common underlying neural mechanism in patients with dementia with Lewy bodies (DLB). The aim of the present study was to find an externally observable physiological indicator of pareidolias. Using a pareidolia test developed by Uchiyama and colleagues, we evoked pareidolias in patients with DLB and recorded the resultant changes in the diameters of their pupil. The time frequencies of changes in pupil diameters preceding pareidolic utterances and correct utterances by the patients, as well as correct utterances by healthy control participants, were analyzed by a fast Fourier transform program. The power at time frequencies of 0-0.46 Hz was found to be greatest preceding pareidolic utterances in patients with DLB, followed by that preceding correct utterances in control participants, followed by that preceding correct utterances in patients with DLB. When the changes in power preceding the utterance were greater than the median value of correct utterances by the control group, the frequency of pareidolic utterances was significantly greater than that of correct utterances and when the changes were the same as or lower than the median value, the frequency of correct utterances was significantly greater than that of pareidolic utterances. Greater changes in power preceding the utterance at time frequencies of 0-0.46 Hz may thus be an externally observable physiological indicator of the occurrence of pareidolias.

Original languageEnglish
Pages (from-to)187-192
Number of pages6
JournalNeuroReport
Volume28
Issue number4
DOIs
Publication statusPublished - 2017

Keywords

  • dementia with Lewy bodies
  • fast fourier transform
  • hallucination
  • pareidolias
  • pupil diameter

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Changes in pupil diameter are correlated with the occurrence of pareidolias in patients with dementia with Lewy bodies'. Together they form a unique fingerprint.

Cite this