ABSTRACT
Transcranial magnetic stimulation (TMS) is a noninvasive and relatively pain-free technique for cortical stimulation in humans that has been applied with success in the study of motor and sensory physiology [1]. This technique widely has been investigated and developed [6,8,9,11,12,13] during many years in many places of the world. TMS applied over the occipital cortex induces either visual suppression [2] or localized visual perceptions, named phosphenes, depending on coil design, current intensity, pulse polarity, duration, and use of single or repetitive pulses [3,4,5]. However, a method to reliably induce phosphenes is not available and no sampling standards have been yet described for topographic mapping of the human visual cortex by TMS. Here, we present a new method to enhance the analysis of the visual perceptions induced focal TMS.
