Intra- and Inter-Task Reliability of Spatial Attention Measures in Pseudoneglect

<div><p>Healthy young adults display a leftward asymmetry of spatial attention (“pseudoneglect”) that has been measured with a wide range of different tasks. Yet at present there is a lack of systematic evidence that the tasks commonly used in research today are i) stable measures over time and ii) provide similar measures of spatial bias. Fifty right-handed young adults were tested on five tasks (<i>manual line bisection</i>, <i>landmark</i>, <i>greyscales</i>, <i>gratingscales</i> and <i>lateralised visual detection</i>) on two different days. All five tasks were found to be stable measures of bias over the two testing sessions, indicating that each is a reliable measure in itself. Surprisingly, no strongly significant inter-task correlations were found. However, principal component analysis revealed left-right asymmetries to be subdivided in 4 main components, namely asymmetries in size judgements (<i>manual line bisection</i> and <i>landmark</i>), luminance judgements (<i>greyscales</i>), stimulus detection (<i>lateralised visual detection</i>) and judgements of global/local features (<i>manual line bisection</i> and <i>grating scales</i>). The results align with recent research on hemispatial neglect which conceptualises the condition as multi-component rather than a single pathological deficit of spatial attention. We conclude that spatial biases in judgment of visual stimulus features in healthy adults (e.g., pseudoneglect) is also a multi-component phenomenon that may be captured by variations in task demands which engage task-dependent patterns of activation within the attention network.</p>