SUMMARYA mechanistic understanding of goal-directed behavior in vertebrates is hindered by the relative inaccessibility and size of their nervous systems. Here, we have studied the kinematics of prey capture behavior in a highly accessible vertebrate model organism, the transparent larval zebrafish (Danio rerio), to assess whether they use visual cues to systematically adjust their movements. We found that zebrafish larvae scale the speed and magnitude of turning movements according to the azimuth of one of their standard prey, paramecia. They also bias the direction of subsequent swimming movements based on prey azimuth and select forward or backward movements based on the prey's direction of travel. Once within striking distance, larvae generate either ram or suction capture behaviors depending on their distance from the prey. From our experimental estimations of ocular receptive fields, we ascertained that the ultimate decision to consume prey is likely a function of the progressive vergence of the eyes that places the target in a proximal binocular 'capture zone'. By repeating these experiments in the dark, we demonstrate that paramecia are only consumed if they contact the anterior extremities of larvae, which triggers ocular vergence and tail movements similar to close proximity captures in lit conditions. These observations confirm the importance of vision in the graded movements we observe leading up to capture of more distant prey in the light, and implicate somatosensation in captures in the absence of light. We discuss the implications of these findings for future work on the neural control of visually guided behavior in zebrafish. Supplementary material available online at

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The relationships between event-related potential (ERP) measures and neuropsychological measures were investigated in a group of 39 male alcoholics and 22 age-matched male controls. Late component ERP measures such as N1, Nd, and P3 components and neuropsychological measures of perceptual-motor function, semantic and figural memory and verbal abstracting functions were included in a correlational analysis. No significant correlations between N1 amplitude or latency and neuropsychological tests were obtained. However, visual Nd amplitude correlated significantly with perceptual-motor tests and figural memory scores in the alcoholics. Significant correlations were found in alcoholics for visual P3 amplitude at PZ and delayed figural memory scores and two of the perceptual-motor tests. No significant correlations were obtained among the controls. These data indicate that significant relationships exist between some neuropsychological and ERP measures but that these relationships are restricted to measures of perceptual-motor functioning and to delayed figural memory.