Improvement of left visuo-spatial hemineglect by left-sided transcutaneous electrical stimulation.
The effects of transcutaneous electrical stimulation on left visuo-spatial hemineglect, assessed by a visuo-motor exploratory task (letter cancellation), were investigated in patients with right hemisphere lesions. In Experiment 1 left neck stimulation temporarily improved the deficit in 13 out of 14 patients (93%), while stimulation of the right neck had no positive effects, worsening exploratory performance in nine patients (64%). Experiment 2 showed that left neck stimulation temporarily improved neglect also when head movements were prevented by a chin-rest. In Experiment 3, stimulation of both the left hand and left neck had comparable positive effects on visuo-spatial hemineglect. These results are interpreted in terms of: (1) non-specific activation of the right hemisphere, contralateral to the stimulation side; (2) specific directional effects of left somatosensory stimulation on the egocentric co-ordinates of extra-personal space, which in neglect patients are distorted towards the side of the brain lesion.
Vallar
G
G
Dipartimento di Psicologia, Università di Roma, La Sapienza, Italy.
Rusconi
M L
ML
Barozzi
S
S
Bernardini
B
B
Ovadia
D
D
Papagno
C
C
Cesarani
A
A
D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology*; D007839:Functional Laterality; D006801:Humans; D008875:Middle Aged; D013028:Space Perception; D013647:Task Performance and Analysis; D004561:Transcutaneous Electric Nerve Stimulation; D014794:Visual Fields; D014796:Visual Perception