Interhemispheric relations in attention evidenced by the lateralized attention network test (LANT)
Attention has been convincingly demonstrated to involve anatomically and functionally distinct networks that subserve confl ict resolution, spatial orienting and alerting. On the one hand, partially independent symmetric attention networks can be postulated within the two brain hemispheres (Zaidel 1995). On the other hand, large body of data, mostly clinical, suggests asymmetric control of attention (Heilman and Van Den Abell 1980). Not much is known at present on the nature of interhemispheric relations in attention. To address this issue, the Lateralized Attention Network Test (LANT) was designed. The introductory study of Greene et al. (2007) has suggested some hemispheric independence and similarity but no clear asymmetry. To gain better insight we conducted three consequent experiments recruiting 170 participants. We supplemented the original LANT procedure with modifi cations that allowed comparisons between goal-directed and stimulusdriven control of attention. The results show that interhemispheric relations within the attentional networks do depend on whether the “endogenous” or the “exogenous” control dominates in the task.