Prism adaptation does not alter object-based attention in healthy participants

Abstract

Hemispatial neglect (‘neglect’) is a disabling condition that can follow damage to the right side of the brain, in which patients show difficulty in responding to or orienting towards objects and events that occur on the left side of space. Symptoms of neglect can manifest in both space- and object-based frames of reference. Although patients can show a combination of these two forms of neglect, they are considered separable and have distinct neurological bases. In recent years considerable evidence has emerged to demonstrate that spatial symptoms of neglect can be reduced by an intervention called prism adaptation. Patients point towards objects viewed through prismatic lenses that shift the visual image to the right. Approximately five minutes of repeated pointing results in a leftward recalibration of pointing and improved performance on standard clinical tests for neglect. The understanding of prism adaptation has also been advanced through studies of healthy participants, in whom adaptation to leftward prismatic shifts results in temporary neglect-like performance. Here we examined the effect of prism adaptation on the performance of healthy participants who completed a computerised test of space- and object-based attention. Participants underwent adaptation to leftward- or rightward-shifting prisms, or performed neutral pointing according to a between-groups design. Significant pointing after-effects were found for both prism groups, indicating successful adaptation. In addition, the results of the computerised test revealed larger reaction-time costs associated with shifts of attention between two objects compared to shifts of attention within the same object, replicating previous work. However there were no differences in the performance of the three groups, indicating that prism adaptation did not influence space- or object-based attention for this task. When combined with existing literature, the results are consistent with the proposal that prism adaptation may only perturb cognitive functions for which normal baseline performance is already biased.

Pushing attention to one side: Force field adaptation alters neural correlates of orienting and disengagement of spatial attention

“…Prism adaptation can be effective in reducing these reaction time differences in patients (Nijboer, McIntosh, Nys, Dijkerman, & Milner, ; Schindler et al., ; Striemer & Danckert, ). By contrast, most previous studies have found that prism adaptation does not modify reaction times in a direction‐specific way in healthy young adults (Bracco, Veniero, Oliveri, & Thut, ; Bultitude, List, & Davies, ; Bultitude, Van der Stigchel, & Nijboer, ; Martín‐Arévalo et al., ; Nijboer, Vree, Dijkerman, & Van der Stigchel, ; Schindler et al., ). The only exception is a study by Striemer, Sablatnig, and Danckert (), which found asymmetric reaction time benefits for a subset of participants who had a large initial cuing effect at baseline, and for trials with short cue‐to‐target intervals only.…”

“…In agreement with recent findings on this task after motor adaptation to prismatic distortion (Martín‐Arévalo et al., ), force field adaptation did not induce significant direction‐specific changes in behavioural response times, nor significant changes in response time differences between invalid and valid trials. The effects of prism adaptation on response times in healthy young participants are variable (Bracco et al., ; Bultitude, List, et al., ; Bultitude, Van der Stigchel, et al., ; Martín‐Arévalo et al., ; Nijboer et al., ; Schindler et al., ; Striemer et al., ), despite robust effects in patients with attention deficits (Schindler et al., ; Striemer & Danckert, ), suggesting that response time may lack the sensitivity to capture small attentional changes in the healthy brain. By contrast, the relative amplitude of EEG responses to visual stimuli provides a window into the allocation of neural resources to orient spatial attention to visual stimuli before and after sensorimotor adaptation (Martín‐Arévalo et al., ).…”

Meta-analysis of the visuospatial aftereffects of prism adaptation, with two novel experiments

“…This paper is concerned with two specific visuospatial tasks, but the effects of prisms have been explored across a wide range of attentional (e.g. Bultitude, List, & Aimola Davies, 2013;Bultitude & Woods, 2010;Morris et al, 2004), representational (Loftus et al, 2008;Nicholls & Loftus, 2007), non-visual (e.g. Girardi, McIntosh, Michel, Vallar, & Rossetti, 2004;Michel, Rossetti, Rode, & Tilikete, 2003), and other tasks (see Michel, 2016, for a review).…”

Beyond the Sensorimotor Plasticity: Cognitive Expansion of Prism Adaptation in Healthy Individuals

“…However, adaptation failed to influence performance in the composite face task that is supposed to evaluate the automatic global-level processing of faces ( Bultitude et al, 2013a ). Negative results were also observed on spatial attention in space-based or object-based attention ( Bultitude et al, 2013b ), in a temporal order judgment task ( Berberovic et al, 2004 ), in saccade latencies or antisaccade errors ( Nijboer et al, 2010 ) and in visual search ( Morris et al, 2004 ; Saevarsson et al, 2009 ). Even if a lack of sensitivity cannot be excluded for several tasks, these negative results could be explained by the absence of pseudoneglect behavior in baseline performance.…”