Zero gravity induced by parabolic flight enhances automatic capture and weakens voluntary maintenance of visuospatial attention

Adriana Salatino,Donna R Roberts,Dominika Sulcova,Mark S George,Roberto Gammeri,André Mouraux,Julien Lambert,Anna Berti,Claudio Iacono,Raffaella Ricci,Stefano T Chiadò

doi:10.1038/s41526-021-00159-3

Abstract

Orienting attention in the space around us is a fundamental prerequisite for willed actions. On Earth, at 1 g, orienting attention requires the integration of vestibular signals and vision, although the specific vestibular contribution to voluntary and automatic components of visuospatial attention remains largely unknown. Here, we show that unweighting of the otolith organ in zero gravity during parabolic flight, selectively enhances stimulus-driven capture of automatic visuospatial attention, while weakening voluntary maintenance of covert attention. These findings, besides advancing our comprehension of the basic influence of the vestibular function on voluntary and automatic components of visuospatial attention, may have operational implications for the identification of effective countermeasures to be applied in forthcoming human deep space exploration and habitation, and on Earth, for patients’ rehabilitation.

Highlights

Spatial attention on Earth, i.e. the capacity to allocate our attentional resources to specific regions in the space around us, enhances our ability to select relevant objects and to anticipate expected events, in order to coherently act in our environment
Newman–Keuls post hoc analyses[13] revealed, for the interaction of the exogenous task [F3,12 = 4.688; P = 0.022; partial η2 = 0.540], faster reaction times (RTs) for valid trials in 0 g (0 G) compared to PRE (P = 0.0002), 1 g (1 G) (P = 0.0003), and POST (P = 0.0002)
For the interaction of the endogenous task [F3,12 = 6.809; P = 0.006; partial η2 = 0.630], Newman–Keuls post hoc analyses showed faster RTs for invalid trials in 0 G compared to PRE (P = 0.0008), 1 G (P = 0.033), and POST (P = 0.022), besides, invalid trials were slower in PRE compared to 1 G (P = 0.020) and POST (P = 0.030)

Summary

Introduction

Spatial attention on Earth, i.e. the capacity to allocate our attentional resources to specific regions in the space around us, enhances our ability to select relevant objects and to anticipate expected events, in order to coherently act in our environment. The specific contribution of vestibular signals to automatic and voluntary attention remains largely unknown. Zero gravity represents a unique condition to unweight the otolith organ and test its contribution to visuospatial attention. Studies in microgravity induced by free-fall conditions of parabolic and orbital space flights (see9), suggested that this condition increases the weight of visual information over vestibular signals, enhancing visual processing[10,11]. This in turn might affect attentional processes. The evidence on how microgravity might affect visuospatial attention is scant and controversial[10,11,12] and no data exist on its effects on the two distinct attentional components (automatic vs. voluntary)

Methods

Results

Conclusion