Frames of reference in hemineglect: a computational approach.

Publisher Summary This chapter discusses the different explanation for the mixture of frames of reference found in hemineglect subjects. The approach is based on interpreting the responses of parietal neurons as basis function of their sensory inputs. The chapter reveals that the basis function decomposition is a computationally efficient way to represent the position of objects in space for the purpose of sensorimotor transformation. Basis function representations also have the property that each cell can encode the location of objects in multiple frames of reference simultaneously allowing them to be involved in the control of multiple behaviors. The chapter discusses the issue of object-centered neglect, which refers to the possibility that patients neglect the left side of object, regardless of the position and orientation of objects in space. Object-centered neglect is illustrated with an experiment, in which patients are asked to detect a gap in the upper part of a triangle embedded within a larger object. It is reported that patients detected the gap more reliably when it was associated with the right side of the object than when it belonged to the left side even when this gap appeared at the same retinal location across conditions.