This suggests the effects in SA are related to her AHS or CBS. In summary, we provide evidence from a single case study that (1) motor responses made with an alien hand may be hyper-sensitively modulated by affordances, and (2) that there may be disruption of automatic and unconscious inhibition of unwanted actions in the alien hand. Such disruption may go some way to explain the involuntary grasping behaviour shown in some patients

with AHS, even when such grasping actions conflict with their intentions. We would like to thank Jane Fowlie for help with patient testing. This research was supported by The Wellcome Trust and the NIHR CBRC at UCL/UCLH. screening assay “
“In the natural world, what we see is always embedded within a wider context. As such, we never perceive what is in front of our eyes in complete isolation,

but instead an object is perceived as part of a visual scene, and each scene as one of an infinite set of related scenes that somehow form a continuous sense of space and place. A central tenet of perception is that visual input is necessarily limited and ambiguous. The brain overcomes this by making predictions about the likely content of the external world, extrapolating beyond the information that is directly available through the senses (Gregory, 1968, 1980; Friston, 2010). see more This is exemplified by a phenomenon known as ‘boundary extension’ (BE), whereby people reliably remember seeing more of a scene than was present in

the physical input, because they extrapolate beyond the borders of the original stimulus (Intraub and Richardson, 1989). BE occurs across a variety of testing conditions including recognition, free recall, both visually and haptically (Intraub, 2004, 2012). It is apparent in all populations sampled including adults (Intraub and Richardson, 1989; Seamon et al., 2002), children (Seamon et al., 2002; Candel et al., 2004), and even babies (Quinn and Intraub, 2007). Importantly, BE only occurs in response to scenes, and not isolated objects (Intraub et al., 1998; Gottesman Dichloromethane dehalogenase and Intraub, 2002). It is thought to comprise a two-stage process (Fig. 1); the first stage involves the active extrapolation of the scene beyond its physical boundaries, and is constructive in nature. This occurs because when we initially encounter a scene, we are not limited to the direct sensory input entering the retina, but also have access to an automatically constructed and implicitly maintained representation of the scene. This constructed representation extends beyond the borders of the physical scene, and provides a global framework into which it can be rapidly embedded (Intraub, 2012). This process supports our experience of a continuous and coherent world, despite it being amassed from discontinuous sensory input, and is therefore highly adaptive.