Transcranial magnetic stimulation reveals high test-retest reliability for phosphenes but not for suppression of visual perception.

OBJECTIVE

To investigate test-retest reliability of visual cortical excitatory and inhibitory phenomena.

METHODS

Transcranial magnetic stimulation (TMS) was applied over occipital cortex twice in 22 healthy young adults with at least a one-month interval between both measurements. The test-retest reliability of the phosphenes and TMS-induced suppression of visual perception was assessed using correlation and calculation of the repeatability coefficient.

RESULTS

Both analyses revealed a high reliability for phosphenes but not for the suppression of visual perception.

CONCLUSIONS

It seems likely that the phosphenes may be better used than the TMS-induced suppression of visual perception in experiments which need repeated measurements (e.g., longitudinal studies or studies with pharmacological and non-pharmacological interventions).

SIGNIFICANCE

The study demonstrates a rather limited value of the TMS-induced suppression of visual perception for studies with repeated measurements.