TY - JOUR
T1 - Beyond bias
T2 - A registered examination of the validity of using line bisection to measure non-lateralised attention
AU - Mitchell, Alexandra G.
AU - Ahmad Khan, Aimal
AU - Stocks, Helen
AU - McIntosh, Robert D.
N1 - Publisher Copyright:
© Experimental Psychology Society 2024.
PY - 2025/4
Y1 - 2025/4
N2 - Line bisection is a task widely used to assess lateral asymmetries of attention, in which participants are asked to mark the midpoint of a horizontal line. The directional bisection error (DBE) from the objective midpoint of the line is the traditional measure of performance. However, an alternative method of studying the bisection behaviour, the endpoint weightings method, has been proposed. This method produces two measures of performance: endpoint weightings bias (EWB) and endpoint weightings sum (EWS). While EWB measures attentional asymmetry, it has been suggested that EWS quantifies the total (non-lateralised) attention allocated to the task. If EWS provides a valid index of non-lateralised attention, then changes in tonic and phasic arousal should systematically affect EWS. In this article, we formally tested this prediction, using time on task to manipulate tonic arousal and unpredictable auditory tones, presented simultaneously with line stimuli, to manipulate phasic arousal. Our registered analyses revealed that neither of our manipulations for tonic or phasic arousal significantly influenced EWS. Therefore, the null hypotheses cannot be rejected. An exploratory analysis of all trials and conditions revealed a significant reduction in EWS with time spent on task. However, the lack of any significant effect of the alerting tone on EWS suggests that EWS may not be a valid measure of generalised attention to the task.
AB - Line bisection is a task widely used to assess lateral asymmetries of attention, in which participants are asked to mark the midpoint of a horizontal line. The directional bisection error (DBE) from the objective midpoint of the line is the traditional measure of performance. However, an alternative method of studying the bisection behaviour, the endpoint weightings method, has been proposed. This method produces two measures of performance: endpoint weightings bias (EWB) and endpoint weightings sum (EWS). While EWB measures attentional asymmetry, it has been suggested that EWS quantifies the total (non-lateralised) attention allocated to the task. If EWS provides a valid index of non-lateralised attention, then changes in tonic and phasic arousal should systematically affect EWS. In this article, we formally tested this prediction, using time on task to manipulate tonic arousal and unpredictable auditory tones, presented simultaneously with line stimuli, to manipulate phasic arousal. Our registered analyses revealed that neither of our manipulations for tonic or phasic arousal significantly influenced EWS. Therefore, the null hypotheses cannot be rejected. An exploratory analysis of all trials and conditions revealed a significant reduction in EWS with time spent on task. However, the lack of any significant effect of the alerting tone on EWS suggests that EWS may not be a valid measure of generalised attention to the task.
KW - Attention
KW - line bisection
KW - non-lateralised attention
KW - pseudoneglect
UR - http://www.scopus.com/inward/record.url?scp=105001064579&partnerID=8YFLogxK
U2 - 10.1177/17470218241254761
DO - 10.1177/17470218241254761
M3 - Journal article
C2 - 38706127
SN - 1747-0218
VL - 78
SP - 647
EP - 659
JO - Quarterly journal of experimental psychology
JF - Quarterly journal of experimental psychology
IS - 4
ER -