Information processing in long delay memory-guided saccades: further insights from TMS.
The performance of memory-guided saccades with two different delays (3 s and 30 s of memorisation) was studied in eight subjects. Single pulse transcranial magnetic stimulation (TMS) was applied simultaneously over the left and right dorsolateral prefrontal cortex (DLPFC) 1 s after target presentation. In both delays, stimulation significantly increased the percentage of error in amplitude of memory-guided saccades. Furthermore, the interfering effect of TMS was significantly higher in the short delay compared to that of the long delay paradigm. The results are discussed in the context of a mixed model of spatial working memory control including two components: First, serial information processing with a predominant role of the DLPFC during the early period of memorisation and, second, parallel information processing, which is independent from the DLPFC, operating during longer delays.
Perception and Eye Movement Laboratory, Department of Neurology, University Hospital, University of Bern, Freiburgstrasse 10, 3010 Bern, Switzerland.
Thomas
T
Nyffeler
Charles
C
Pierrot-Deseilligny
Tobias
T
Pflugshaupt
Roman
R
von Wartburg
Christian W
CW
Hess
René M
RM
Müri
D000328:Adult; D004558:Electric Stimulation; D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D008280:Magnetics; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*