title: Influence of target size and eccentricity on binocular summation of reaction time in kinetic perimetry.
abstract: To assess how target size and eccentricity affect binocular summation (BS) of reaction time (RT) at suprathreshold level, we measured RT using targets of 0.108° and 0.216° at four eccentricities (0°, 5°, 15°, 25°) in six normal volunteers. The difference between the monocular/binocular RT differentials for both sizes significantly increased in the periphery (P<0.05). The smaller target required significantly longer monocular RT at 25° (P<0.01) and generated greater neural summation than the larger target (P<0.01). This suggests that when monocular function has reached its limit in visual processing in the periphery, BS increases, facilitates visual processing, and shortens binocular RT.
authors.affiliation: Department of Ophthalmology, Kinki University Faculty of Medicine, Osaka, Japan. wakayama@ganka.med.kindai.ac.jp
authors.forename: Akemi
authors.initials: A
authors.lastname: Wakayama
authors.forename: Chota
authors.initials: C
authors.lastname: Matsumoto
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Ohmure
authors.forename: Masahiko
authors.initials: M
authors.lastname: Inase
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Shimomura
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology*; D015349:Vision, Monocular; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult