BRIEF REPORT Reduced Perceptual Asymmetries in Depressed Females Matia Okubo Ó Springer Science+Business Media, LLC 2010 Abstract The present study used the grayscales task to investigate a possible association between depression and free-viewing perceptual asymmetries. Three hundred and eight undergraduates (males = 154; females = 154) per- formed the grayscales task and demonstrated an overall leftward bias. This leftward bias was negatively associated with depressive symptoms in female participants, but not in male participants. These results suggest that for females, depression is associated with deficits in spatial attention mechanisms that normally are localized predominantly in the right hemisphere, deficits which serve to reduce the leftward attentional bias that is typically observed in the grayscales task. Keywords Depression  Pseudoneglect  Spatial attention  Laterality Introduction It has been demonstrated that various right hemisphere (RH) functions are impaired in depressed patients (for a review, see Rotenberg 2004). For example, depressed individuals show deficits in RH-related cognitive tasks, such as the chimeric face task (Heller et al. 1995; Keller et al. 2000), dot localization (Henriques and Davidson 1997; Miller et al. 1995), and simple detection of a target presented to the left-visual field (Liotti et al. 1988). Heller et al.’s (1995, 2003) valence-arousal model can explain these deficits, and is based on functional differences between the anterior and posterior regions of the brain. According to the valence-arousal model, emotional arousal is dependent on the right posterior region, with negative emotional valence specifically activating the right frontal region. According to this model, depression is associated with hypoactivation in the right posterior region, in com- bination with overactivation of the right frontal region. It is noteworthy that depressed individuals show deficits across various types of RH-related tasks. Some of these tasks have an emotional component (Heller et al. 1995; Keller et al. 2000) whereas others do not (Henriques and Davidson 1997; Miller et al. 1995; Liotti et al. 1988). Task requirements differ radically across the various studies to date. The task-nonspecific nature of the relationship between depression and RH functioning suggests that depressed people may show deficits across various RH- related functions, including spatial attention. Patients with spatial hemineglect dramatically demon- strate the role of the RH in spatial attention processing. Symptoms of hemineglect typically arise following lesions to the parietal regions of the RH, which result in inattention to the left hemispace. That is, such patients exhibit per- ceptual asymmetries in the form of a strong bias toward the right. This rightward bias has been extensively investi- gated, and it is widely accepted that these symptoms stem from an attentional rather than an elemental sensorimotor impairment (Heilman et al. 2000). Perceptual asymmetries have also been examined in non-clinical populations. Neurologically normal individu- als generally appear to overestimate features on the left side (for reviews, see Jewell and McCourt 2000; Luh 1995). For example, in the line bisection task participants usually bisect horizontal lines to the left of the true center. This phenomenon is referred to as pseudoneglect, given M. Okubo (&) Department of Psychology, Senshu University, 2-1-1 Higashimita, Tama-ku, Kawasaki-shi, Kanagawa 2148580, Japan e-mail: mokubo@psy.senshu-u.ac.jp 123 Cogn Ther Res DOI 10.1007/s10608-010-9323-1