Statistical and perceptual updating: correlated impairments in right brain injury

It has been hypothesized that many of the cognitive impairments commonly seen after right brain damage (RBD) can be characterized as a failure to build or update mental models. We (Danckert et al. in Neglect as a disorder of representational updating. NOVA Open Access, New York, 2012a; Cereb Cortex 22:2745-2760, 2012b) were the first to directly assess the association between RBD and updating and found that RBD patients were unable to exploit a strongly biased play strategy in their opponent in the children's game rock, paper, scissors. Given that this game required many other cognitive capacities (i.e., working memory, sustained attention, reward processing), RBD patients could have failed this task for various reasons other than a failure to update. To assess the generality of updating deficits after RBD, we had RBD, left brain-damaged (LBD) patients and healthy controls (HCs) describe line drawings that evolved gradually from one figure (e.g., rabbit) to another (e.g., duck) in addition to the RPS updating task. RBD patients took significantly longer to alter their perceptual report from the initial object to the final object than did LBD patients and HCs. Although both patient groups performed poorly on the RPS task, only the RBD patients showed a significant correlation between the two, very different, updating tasks. We suggest these data indicate a general deficiency in the ability to update mental representations following RBD.