Reaching to inhibit a prepotent response: a wearable 3-axis accelerometer kinematic analysis

Abstract

The present work explores the distinctive contribution of motor planning and control to human reaching movements. In particular, the movements were triggered by the selection of a prepotent response (Dominant) or, instead, by the inhibition of the prepotent response, that required the selection of an alternative one (Non-dominant). To this aim, we adapted a Go/No-Go task to investigate both the dominant and non-dominant movements of a cohort of 19 adults, utilizing kinematic measures to discriminate between the planning and control components of the two actions. To sample such measures, a low-cost, easy to use, 3-axis wrist worn accelerometer was put to good use to obtain raw acceleration data and to compute and break down its velocity components. The values obtained with such task indicate that with the inhibition of a prepotent response, the selection and execution of the alternative one yields both a longer reaction time and movement duration. Moreover, the peak velocity occurred later in time with respect to the dominant response, revealing that participants tended to indulge more in motor planning rather than in adjusting their movement along the way. Finally, comparing such results to the findings obtained by other means in literature, we discuss the feasibility of an accelerometer-based analysis to disentangle distinctive cognitive mechanisms of human movements.

Reduced motor planning underlying inhibition of prepotent responses in children with ADHD

“…We then computed the percent Time to Peak Velocity (TPV), which is the percentage of MD spent from movement onset to maximum peak velocity. Data calibration and pre-processing of raw acceleration data, as well as computation of TPV values were conducted following the steps reported in our previous work (20). Participants provided 6,576 valid responses.…”

“…They were instructed to place the dominant hand at a specific starting position, monitored by a presence sensor, and completely extend their arm to tap on the response touchscreen. A Go/No-Go paradigm was adapted to assess the inhibition of a prepotent response and tested with neurotypical adults in a previous work (20). Upon comparison of a central stimulus (red/green, upwards/downwards arrow), participants were asked to select, reach, and press one of two response keys (either a red or green circle) placed one on the left and one on the right side of the central stimulus, following specific instructions.…”

“…The present study aims at investigating children’s ability to inhibit prepotent motor responses, through an adapted version of the Go/No-Go paradigm. The task embedded a reaching movement and kinematic measures to surface motor planning characteristics of inhibition (20). Children with ADHD or typical development were recruited.…”

“…Theoretical (e.g., in robotics) reaching trajectories starting and ending at full rest will show a bell-shaped velocity path, with the first half of MD spent accelerating and the second one decelerating, resulting in a 50% TPV (23, 24). The more cognitive load is required in a given task, the more human reaching movements have a greater need for motor planning, thus resulting in increased acceleration phase and TPV (20).…”

“…We have previously found that, to correctly inhibit a prepotent response and select the instructed alternative one, neurotypical adults show longer RT and MD, as well as increased TPV overall dedicating more resources to motor planning than monitoring and control of ongoing movements (20). Assuming that this is the motor strategy that has been established as most effective in adults, a developmental perspective is needed to understand how it specializes during childhood and is potentially subject to deviation in cases of atypical development.…”