In this study, we aimed to characterize the effect of anodal and cathodal direct current stimulation (tDCS) on contrast sensitivity inside the central 10 degrees of the visual field in healthy subjects. Distinct eccentricities were investigated separately, since at the cortical level, more central regions of the visual field are represented closer to the occipital pole, i.e. closer to the polarizing electrodes, than are the more peripheral regions. Using a double-blind and sham-controlled within-subject design, we measured the effect of stimulation and potential learning effect separately across testing days. Anodal stimulation of the visual cortex compared to sham stimulation yielded a significant increase in contrast sensitivity within 8° of the visual field. A significant increase in contrast sensitivity between the conditions "pre" and "post" anodal stimulation was only obtained for the central positions at eccentricities smaller than 2°. Cathodal stimulation of the visual cortex did not affect contrast sensitivity at either eccentricity. Perceptual learning across testing days was only observed for threshold perimetry before stimulation. Measuring contrast sensitivity changes after tDCS with a standard clinical tool such as threshold perimetry may provide an interesting perspective in assessing therapeutic effects of tDCS in ophthalmological or neurological defects (e.g. with foveal sparing vs. foveal splitting).

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Negative childhood family environments have been associated with stress-related physical and psychological health consequences across the lifespan. The present study examined the relation between adverse relationships in the family of origin and physiological stress response, as measured by salivary cortisol, in emerging adulthood. Seventy-six university students (age range = 18-22) selected from intact married families-of-origin characterized by either negative (n = 39) or positive (n = 37) relationship quality engaged in a challenging role play task. Results from multilevel models indicated that those from negative families exhibited significantly lower salivary cortisol across the task than those from positive families. This relation did not change in strength or direction after controlling for experiences with abuse or recent anxiety or depressive symptoms. These findings suggest the significance of early family relationships on the long-term activity of the HPA axis. Keywords childhood family cortisol stressA considerable body of research supports an association between high-risk childhood family characteristics and negative physical and mental health outcomes throughout the life span. Family discord has been associated with the development of internalizing and externalizing symptoms in children and depression, anxiety, and poorer self-image in adolescents as well as adults (Burns & Dunlop, 2002;Kot & Shoemaker, 1999;Margolin et al., 2001). In addition, several studies have shown that individuals raised in high-risk family environments are at increased life-time risk for a wide range of behavioral and physical health related outcomes, including sleep disturbances, obesity, alcoholism, smoking initiation and prevalence, sexual disorders, somatic symptoms, chronic pain disorders, asthma, autoimmune disorders, chronic obstructive pulmonary disease, chronic bronchitis and emphysema, high blood pressure, and heart disease (Anda et al., 2006(Anda et al., , 2008Dong et al., 2004;Dube et al., 2002;Felitti et al., 1998;Lundberg, 1993;Margolin et al., 2001;Mechanic & Hansell, 1989;Repetti, Taylor, & Seeman, 2002;Weidner, et al., 1992).It has been theorized that the physical and mental health consequences of exposure to familyof-origin adversity are co-morbid outcomes of common underlying biological processes, including dysregulation of the hypothalamic-pituitary-adrenal (HPA) stress system (Luecken Corresponding Author: Linda J. Luecken, Ph.D. Department of Psychology, Arizona State University, Tempe, AZ 85287, Phone: (480) Fax: (480) 965-8544, E-mail: Luecken@asu.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all l...