A study examined the effects of sex, handedness, and instructions in the processing of verbal and spatial information presented tachistoscopically. Subjects, 48 volunteers from Illinois Benedictine College, were evenly distributed in terms of sex and handedness, and were further divided into two subgroups based on whether visual field attendance instructions were provided. In each test trial, subjects attended to a geometric figure placed in the middle of the tachistoscopic screen while a four-by-four matrix containing five strategically placed letters was presented in either the left or right visual field for a 100 millisecond duration. Mixed factorial analyses were employed to measure the number of letters and letter positions correctly recalled in each visual field, with sex (male, female), handedness (left, right), and experimental instructions (field attendance, non-attendance) representing the between-subject factors and target material (letters, positions) representing the within-subject factors. Retention analyses showed that dextral males demonstrated a right visual field (RVF) advantage for letters, and that instructions consistently contributed to more effective recall. It would appear that the attentional hypothesis is a more effective explanation of asymmetrical performance than cerebral differences. (A figure of the stimulus matrix used in the tachistoscopic experiment, and a table of the mean number correct letter responses in RVF as a function of sex, handedness, and instructions are included, and 45 references are appended.) (MM)