Purchase this article with an account.
Taryn Bingley, Matthew Heath; Digit magnitude does not influence the spatial parameters of goal-directed reaching movements. Journal of Vision 2010;10(7):1061. doi: 10.1167/10.7.1061.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Movement times are advantaged when numerical magnitude is used to prompt the initiation of a goal-directed reaching response. In particular, movement times in left and right visual space are reported to be faster when respectively paired with smaller (i.e., 1, 2) and larger (i.e., 8, 9) digits (Fisher 2003: Vis Cogn). In other words, the well-documented spatial numerical association of response codes (the so-called SNARC effect) can be extended to the movement domain. The present study sought to determine whether the SNARC effect differentially influences not only the temporal properties of a reaching response, but also the spatial properties of the unfolding trajectory. To accomplish this objective, participants completed left and right space reaches following movement cuing via numerical stimuli (i.e., 1, 2, 8, or 9). Importantly, placeholders were used to denote the amplitude of the reaching response and were either continuously visible to participants (Experiment 1) or occluded prior to movement onset (Experiment 2). Results for Experiments 1 and 2 elicited a SNARC effect for reaction time; that is, smaller and larger digits produced faster response latencies when used to cue left and right space reaches, respectively. In terms of movement time, Experiment 1 yielded a reversed SNARC effect: reaches were completed faster to larger and smaller digits in left and right space, respectively. For Experiment 2, movement times were not influenced by digit magnitude and the direction of the reaching response. Further, spatial analysis of movement trajectories (Experiments 1 and 2) did not yield reliable interactions between digit magnitude and reaching direction. In general, our results support the assertion that numerical magnitude influences the planning of a response, but does not reliably influence the temporal or spatial parameters of the unfolding reaching trajectory.
This PDF is available to Subscribers Only