Increased temporal binding during voluntary motor task under local anesthesia

Abstract

Temporal binding refers to a systemic bias in the perceived time interval between two related events, most frequently voluntary motor actions and a subsequent sensory effect. An inevitable component of most instrumental motor actions is tactile feedback. Yet, the role of tactile feedback within this phenomenon remains largely unexplored. Here, we used local anesthesia of the index finger to temporarily inhibit incoming sensory input from the finger itself, while participants performed an interval-estimation task in which they estimated the delay between a voluntary motor action (button press) and a second sensory event (click sound). Results were compared to a control condition with intact sensation. While clear binding was present in both conditions, the effect was significantly enhanced when tactile feedback was temporarily removed via local anesthesia. The results are discussed in light of current debates surrounding the underlying mechanisms and function of this temporal bias.

Figure 1

Setup and trial structure. Upon pressing the button, an instant mechanical “click” (action) with audible and tactile detent was emitted and then followed by a delayed auditory “click” sound (effect) either 100, 300, 500, or 700 ms after the action. Participants then estimated the interval between their own action and the effect in milliseconds.

Figure 2

Mean estimated intervals per delay for the anesthesia (blue) and intact (orange) condition. Error bars indicate the standard deviation of the mean.