Spatial flexibility of distractor suppression in the tactile modality

Abstract

Object sensing and manipulation rely on the somatosensory systems ability to relay relevant information about a skin location encoding tactile information about the object while suppressing irrelevant or distracting inputs on the skin--a process known as distractor suppression. Although tactile selective attention is flexible, capable of being allocated to non-contiguous skin areas on the hand and with spatial resolution limited to within a finger, the spatial properties of distractor suppression in touch remain poorly understood. In particular, studies have not explored the effects of proactively cueing distractor locations in touch, leaving open questions about whether active deployment of distractor suppression operates independently of attentional enhancement. To address this gap in knowledge, in this study, participants performed an amplitude discrimination task on the hand in the presence of distractors that were cued in advance. Our data revealed that validly cueing distractor locations improves discrimination accuracy and reduces reaction times of behaviorally-relevant tactile stimuli. The data also showed that behavior is unaffected when attended stimuli are flanked by distractors within or across fingers, suggesting that distractor suppression mechanisms can be split across different skin locations on the hand. These findings provide novel insights into the spatial allocation and flexibility of distractor suppression mechanisms in touch, and underscore the importance of proactive cueing in shaping these mechanisms.