Akademik Veri Yönetim Sistemi
19. Ulusal Sinirbilim Kongresi, İstanbul, Türkiye, 21 - 23 Kasım 2021, ss.28
Objective: Chimeric faces used for the detection of cerebral lateralization are created by dividing two different faces vertically from the midline and combining them into a single face. Chimeric faces studies have been generally carried out with right-handed subjects, and a left visual field(LVF)/right hemisphere(RH) bias has been found in the participants mostly. The aim of this study is to examine LVF/RH bias in the Chimeric Faces Task by comparing right and left-handed subjects’performance.
Methods: A total of 158 university students (118 right-handers/109 females) with a mean age of 20.77±1.76 years and whose handedness was evaluated according to the Edinburgh Handedness Inventory participated in the study. The original Chimeric Faces Task (Levy et al., 1983) was administered. In this task, photos of nine people with happy and neutral expressions combined by cutting and reversed, which is also used for providing mirror images to create 36 chimeric faces. Participants were asked to decide which face was happier from two chimeric faces, representing a different half-visual field, one half smiling one half neutral on the same page, and then a laterality quotient (LQ) was calculated for each participant. A positive LQ score shows a right visual field(RVF)/left hemisphere(LH) bias while a negative LQ score indicates a LVF/RH bias.
Results:The findings showed that the mean handedness score was +75.25±15.62 for the right-handers and -74.25±17.67 for the left-handers. In terms of LQ scores, a marginally significant difference was found (p=.046) between right-handers (M=-.23±.54) and left-handers (M=.014±.70).
Conclusion: Consistent with the literature, the results indicate that a LVF/RH bias in the Chimeric Faces Task for the righthanders. Although the LQ scores in the left-handers represent a RVF/LH bias, it is observed that left-handers did not show a certain visual-field bias as clearly as right-handers exhibited. It is thought that left-handers use more bilateral processing during the task.
Keywords: chimeric faces, cerebral lateralization, handedness