Tachistoscope

EMG (electromyography)

EKG/ECG (electrocardiography)

EOG (electro-opthalmography)

EEG (electroencephalography)

ERP (event related potential)

X-ray

CT (computer tomography)

PET (positron emission tomography)

MRI (magnetic resonance imaging)

fMRI (functional magnetic resonance imaging)

MEG (magnetoencephalography)