Spatiotemporal Tuning of Rapid Interactions between Visual-Motion Analysis and Reaching Movement

Abstract

In addition to the goal-directed preplanned control, which strongly governs reaching movements, another type of control mechanism is suggested by recent findings that arm movements are rapidly entrained by surrounding visual motion. It remains, however, controversial whether this rapid manual response is generated in a goal-oriented manner similarly to preplanned control or is reflexively and directly induced by visual motion. To investigate the sensorimotor process underlying rapid manual responses induced by large-field visual motion, we examined the effects of contrast and spatiotemporal frequency of the visual-motion stimulus. The manual response amplitude increased steeply with image contrast up to 10% and leveled off thereafter. Regardless of the spatial frequency, the response amplitude increased almost proportionally to the logarithm of stimulus speed until the temporal frequency reached 15-20 Hz and then fell off. The maximum response was obtained at the lowest spatial frequency we examined (0.05 cycles/°). These stimulus specificities are surprisingly similar to those of the reflexive ocular-following response induced by visual motion, although there is no direct motor entrainment from the ocular to manual responses. In addition, the spatiotemporal tuning is clearly different from that of perceptual effects caused by visual motion. These comparisons suggest that the rapid manual response is generated by a reflexive sensorimotor mechanism. This mechanism shares a distinctive visual-motion processing stage with the reflexive control for other motor systems yet is distinct from visual-motion perception.

How Motion Signals Are Integrated Across Frequencies: Study on Motion Perception and Ocular Following Responses Using Multiple-Slit Stimuli

“…It has been suggested that visuomotor control systems have spatiotemporal tunings different from those for motion perception (Amano et al 2007;Gomi et al 2006;. Indeed the present study showed directional dissociations between motion perception and OFRs, in particular for the CA-MSV stimuli, which can be ascribed at least partially to preference of the OFR responses to higher speeds.…”

“…The frequency dependence of motion processing has been conventionally measured by contrast threshold, and it has been reported that it has a peak at a moderate spatial frequency (0.5-1 cpd) and moderate temporal frequency (5-10 Hz) (Burr and Ross 1982;Gomi et al 2006;Hutchinson and Ledgeway 2006). As an alternative way to measure contrast threshold, we proposed using a reverse correlation method to estimate the frequency tuning of motion processing above threshold.…”

“…Despite such potential incongruence, the motion system seems to incorporate the motion signals from multiple filters, enabling us to judge the direction of the moving objects and to control our eyes. Although the frequency property of the motion detection process has been investigated mainly by measuring contrast threshold (Burr and Ross 1982;Gomi et al 2006;Hutchinson and Ledgeway 2006), how the visual system integrates motion signals across different frequencies after detection (i.e., supra-threshold motion signals) remains poorly understood. In the present paper, we describe behavioral experiments that address this problem.…”

Implicit Visuomotor Processing for Quick Online Reactions Is Robust against Aging

“…3 A, B, solid curves), on the other hand, the hand trajectories deviated from the control as well. These deviations are also regarded as implicit visuomotor reactions (MFR) (Saijo et al, 2005;Gomi et al, 2006;Gomi, 2008). As shown in Figure 3A, these deviations of trajectories were readjusted in the later phase of reaching so that the reaching went to the center visible target.…”

“…During reaching movement, the hand can quickly adjust to target displacement (Soechting and Lacquaniti, 1983;Brenner and Smeets, 1997;Day and Lyon, 2000) even without perception of target location change (Goodale et al, 1986;Prablanc and Martin, 1992). Another type of quick and automatic reaction has also been observed when a surrounding visual motion is suddenly given during reaching, called the manual following response (MFR) (Brenner and Smeets, 1997;Whitney et al, 2003;Saijo et al, 2005;Gomi et al, 2006;Gomi, 2008). The reaction latencies of these two types of responses are much faster [100 -150 ms vs Ͼ250 ms for discrimination-reaction tasks (Anzola et al, 1977;Heister et al, 1986)], even though participants in the reaction tasks intently concentrated on detecting the stimulus onset.…”