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No correlation between moving phosphene and motor thresholds: a transcranial magnetic stimulation study.
- Source :
-
Neuroreport [Neuroreport] 2004 Feb 09; Vol. 15 (2), pp. 297-302. - Publication Year :
- 2004
-
Abstract
- The aim of this study was to investigate the temporal stability of moving phosphenes and to assess whether moving phosphene thresholds (PTs) correlate with motor thresholds (MTs). Small moving sensations, so-called moving phosphenes, are perceived when V5, an area important for visual motion analysis, is stimulated by transcranial magnetic stimulation (TMS). However, it is still a matter of debate if V5 phosphenes are stable sensations across measurements and if they are a reasonable index of the cortical excitability of V5. Currently, MT is more commonly used as an index of global cortical excitability. However, previous studies have indicated that stationary PTs are suitable alternatives when the primary visual cortex is stimulated by TMS. Using paired-pulse TMS, stationary and moving PTs and applying single pulse TMS, MTs were measured in 11 subjects. PTs were retested in nine subjects 5-7 days later. Stationary and moving PTs were stable within subjects across the two sessions and showed a high inter-correlation. Conversely, PTs and MTs did not correlate. Our results are in agreement with previous studies showing that excitatory measurements of one specific cortex cannot be generalized to the excitability of the whole cortex. Thus, we propose specific measures for cortices of interest: PT for visual experiments and MT for motor experiments.
- Subjects :
- Adult
Electric Stimulation
Electromagnetic Fields
Evoked Potentials, Motor physiology
Evoked Potentials, Visual physiology
Female
Humans
Male
Photic Stimulation
Statistics as Topic
Transcranial Magnetic Stimulation
Motion Perception physiology
Motor Cortex physiology
Phosphenes physiology
Sensory Thresholds physiology
Visual Cortex physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0959-4965
- Volume :
- 15
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Neuroreport
- Publication Type :
- Academic Journal
- Accession number :
- 15076756
- Full Text :
- https://doi.org/10.1097/00001756-200402090-00017