PI: Thomas Schenk
Neglect is a mysterious neuropsychological disorder: difficult to understand and difficult to treat. In this project we want to use the concept of active perception to further our understanding of this disorder and to develop a new treatment approach. Patients with unilateral neglect typically ignore information from their left side. For example when copying a picture of a house they will copy all the details on the right but not those from the left. It is particularly puzzling that neglect patients fail to notice that their pictures and percepts are incomplete. We suggest that predictive coding or the Bayesian account of perception can explain this puzzling observation. Moreover, the Bayesian account also offers an explanation for why prismatic-adaptation therapy improves some symptoms in neglect but not others. To explain this last finding we assume that perception can involve the suppression of incongruent sensory data. We propose to use binocular rivalry to detect signs of suppression and, thereby, to test the predictions derived from the Bayesian account of neglect. The second half of our project aims to exploit one specific aspect of active perception to develop a new treatment for neglect patients. When eye-movements into one direction are prevented, attentional allocation to the corresponding part of visual space is abolished. In neglect, attention is focused onto the right side and the left side is ignored. By preventing eye-movements to the right side we can redress this imbalance and thereby reduce neglect symptoms. We want to develop this approach first in healthy participants, apply it to neglect patients and compare it in its efficacy with a classical treatment approach.