Temporal and spatio-temporal attention to tactile stimuli in extinction patients.
The temporal deployment of attention to tactile stimuli delivered to the same or to a symmetrical position of the body was assessed in 6 Right-Brain Damaged (RBD) patients with left tactile extinction and 6 healthy controls. Two different tasks called Temporal (T) and Spatio-Temporal (ST) extinction were used. In the T task single or double electro tactile stimuli were delivered to the same point to the left or, in separate blocks, to the right index finger. Double stimuli were separated by different Stimulus Onset Asynchronies (SOAs). In the ST task, stimuli could be single (left or right) or double (left and right). Double stimuli were delivered to the index finger of both hands simultaneously or sequentially. In both tasks subjects were asked to report the number of the stimuli they perceived. In the ST task, subjects were also requested to report the stimuli location. Results show that in both tasks RBD patients' detection of left sided stimuli was significantly lower than of right sided stimuli detection, mainly at shortest SOAs. Moreover, detection of left sided stimuli was higher when two stimuli were delivered in sequence and in symmetrical body areas and in different sides of the space than when stimuli were delivered in sequence in the same body area. Results suggest that the interaction between spatial and temporal variables enhances the ability of tactile extinction patients to detect left sided stimuli.
Guerrini
Chiara
C
Clinical Neuroscience Centre and Department of Psychology, University of Hull, Hull, England, UK. c.guerrini@hull.ac.uk
Aglioti
Salvatore M
SM
D000368:Aged; D001288:Attention / Q000502:physiology*; D001925:Brain Damage, Chronic / Q000150:complications / Q000503:physiopathology; D004558:Electric Stimulation; D005108:Extinction, Psychological; D005260:Female; D005364:Field Dependence-Independence; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000209:etiology / Q000503:physiopathology*; D010812:Physical Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D013028:Space Perception / Q000502:physiology; D013998:Time Perception / Q000502:physiology*; D014110:Touch / Q000502:physiology*