Landmark based navigation in brain-damaged patients with neglect.
We tested navigational abilities of brain-damaged patients suffering from representational or perceptual neglect asking them to retrieve a location according to salient spatial cues included in a rectangular empty room. Both groups of patients showed difficulties in learning the spatial definition of the target location in relation to two landmarks. However in a delayed attempt performed after several trials the group of patients with perceptual neglect proved able to easily retrieve the target location. In this condition they performed as controls showing a spared ability to navigate according to a stable representation of the room in long-term memory. In contrast the difficulty of patients with representational neglect remained unchanged across experimental conditions. At variance with clinical assessment, in which patients show asymmetrical performances in describing a well-known environment from memory, this latter result depicts a behavioural counterpart of the disorder, namely the inability to orient in a new environment according to an inner representation. Data are further discussed in order to provide a description of the cognitive mechanisms required for space representation for navigation.
Nico
D
D
Dipartimento di Psicologia, Università La Sapienza, Rome, Italy.
Piccardi
L
L
Iaria
G
G
Bianchini
F
F
Zompanti
L
L
Guariglia
C
C
D000328:Adult; D000368:Aged; D001925:Brain Damage, Chronic / Q000503:physiopathology*; D035061:Control Groups; D003463:Cues; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D005556:Form Perception / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology*; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000503:physiopathology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology