Right hemisphere brain damage impairs strategy updating
We conclude that RBD leads to impaired updating of mental models to exploit environmental changes.
Our behavior is predicated on mental models of the environment that must be updated to accommodate incoming information.
The term “updating” has been used previously to refer to a range of functions.
As evident from the discussion above, for a broad range of behaviors (e.g., directing saccades, motor imagery, time perception, and decisions), it is critical to be able to update mental models of the environment with respect to goal states.
Furthermore, we wanted to assess whether updating impairments were separable from the neglect syndrome, a common consequence of right-hemisphere injury with component deficits that could also be characterized as impaired updating of mental models. Patients with right-parietal lesions fail to acquire the second target when the first target is in ipsilesional space and the second appears contralesionally, consistent with a failure to update spatial representations based on the intended actions (Duhamel, Goldberg, et al. In patients with parietal lesions, imagined movements do not conform to Fitts' law such that there is no relationship between the duration of the imagined movements and the factors that would normally modulate actual movements (e.g., target size and distance; Sirigu et al. When the computer exploited the biased play of the monkeys to maximize win rate, the monkeys quickly learned to alter their play indicative of an ability to update current decisions based on the changes to the incoming information.
The most common task used to explore spatial updating is the double-step saccade task. While this work does not speak directly to the neural bases of the ability to update play strategy, the work discussed above, exploring the role of parietal regions such as area LIP in coding expected gain and intention to act, suggests that this is a good candidate region for such a process.