Fig. 1.

Experimental paradigm. Visual Analog Mood Scores (VAMS) and measures of excitability were performed before (left) and after (right) environmental light exposure (EL, top) and light deprivation (LD, bottom) sessions in patients with migraine (MP) and in control subjects (CS). In the EL session, subjects were exposed to ambient light. In the LD session, goggles were kept in place for 30 min and until measurements of excitability were finished. After finding the hot spot to register motor-evoked potentials (MEP) in the right abductor pollicis brevis muscle, motor threshold (MT), short-interval intracortical inhibition (SICI), MEP amplitudes at intensities of 0.9, 1.1, and 1.3 MT, and amplitudes of supraxamaximal M responses (M) were evaluated before and after EL or LD. In both sessions, subjects were instructed to remain at rest with eyes open