Flash-lag, attention, and representational momentum

Abstract

When a flashed object is spatially aligned with a moving object, observers tend to indicate that the position of the flashed object lags behind that of the moving object. This phenomenon has been referred to as the flash-lag effect (Nijhawan, 1994). There have been several hypotheses put forth to explain the flash-lag effect: extrapolation, differential neural latencies, temporal integration, and attentional processes. The current set of experiments examined the extrapolation and attentional processes hypotheses and introduced a representational momentum hypothesis, and indicated that extrapolation rather than attentional processes appeared to better explain the flash-lag effect. Experiment 1 varied the gap between the moving objects and the flashed object, if an effect of gap size was found, it would support the attentional processes hypothesis; however, if no difference between gap sizes was found, the extrapolation hypothesis would be supported. Experiment 2 addressed the possible confound that the overall display size interacted with gap size to influence the results in Experiment 1. No effects of gap size were found in either experiment indicating that the attentional processes hypothesis does not appear to fully explain the flash-lag effect.