The neglect syndrome is a frequent consequence of right parietal-frontal cortical-subcortical brain damage (Gaffan 8: Hornak 1997; Leibovitch et al. 1998; Mort et al. 2003; Doricchi 8: Tomaiuolo 2003) causing unawareness ofthe left side of space (both personal and extrapersonal), objects and mental images (Bartolomeo 8: Chokron 2002). This syndrome can affect different spatial reference frames simultaneously or separately. Most frequently, neglect patients have problems in processing objects placed to the left of the head-body midline, but not for those placed to the right of the body midline (ie, egocentric or body-centred neglect: Walker 1995, 1996). More rarely some patients are able to detect all of the objects around them but systematically neglect the left side of the same objects. This form of neglect is now commonly called "object-based "neglect. As Olson described (2003), object-based form of neglect can affect two different frames of reference: a) an "object aligned" frame such that the left side of objects with canonical horizontal orientation (ie, letters and words) or with gravitationally defined left and right sides is neglected regardless of canonical (ie,"B"), or mirror-reversed presentation ("£ 1"), and regardless of changes in object position due to rotations on the frontal parallel plane (Driver, et al. 1994; Driver 8: Halligan 1991; Behrmann 8: Moscovich 1994; Tipper 8: Behrmann 1996); b) an "object cen-tred" frame, such that the left side of objects without canonical left-right orientation is neglected independently of their lateral egocentric spatial position as, for example, typically observed in patients' copies of multi-item line drawings (Gainotti ...
Simulating object-centred neglect with head-centred coding of space based on non-linear gaze-dependent units
Silvetti Massimo;
2006
Abstract
The neglect syndrome is a frequent consequence of right parietal-frontal cortical-subcortical brain damage (Gaffan 8: Hornak 1997; Leibovitch et al. 1998; Mort et al. 2003; Doricchi 8: Tomaiuolo 2003) causing unawareness ofthe left side of space (both personal and extrapersonal), objects and mental images (Bartolomeo 8: Chokron 2002). This syndrome can affect different spatial reference frames simultaneously or separately. Most frequently, neglect patients have problems in processing objects placed to the left of the head-body midline, but not for those placed to the right of the body midline (ie, egocentric or body-centred neglect: Walker 1995, 1996). More rarely some patients are able to detect all of the objects around them but systematically neglect the left side of the same objects. This form of neglect is now commonly called "object-based "neglect. As Olson described (2003), object-based form of neglect can affect two different frames of reference: a) an "object aligned" frame such that the left side of objects with canonical horizontal orientation (ie, letters and words) or with gravitationally defined left and right sides is neglected regardless of canonical (ie,"B"), or mirror-reversed presentation ("£ 1"), and regardless of changes in object position due to rotations on the frontal parallel plane (Driver, et al. 1994; Driver 8: Halligan 1991; Behrmann 8: Moscovich 1994; Tipper 8: Behrmann 1996); b) an "object cen-tred" frame, such that the left side of objects without canonical left-right orientation is neglected independently of their lateral egocentric spatial position as, for example, typically observed in patients' copies of multi-item line drawings (Gainotti ...I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.