Transcranial direct current stimulation (tDCS) is a non-invasive technique of brain stimulation that can modulate activity in specific brain cortex regions, and it involves the application of low-intensity (up to 2 mA) constant direct current to the scalp through electrodes in order to modulate excitability of large cortical areas. tDCS may have a role in pain assessment by contributing to efforts in distinguishing between somatic and affective aspects of pain experience. Zaghi and colleagues (2011) found that the motor cortex, when stimulated with tDCS, increases the threshold for both the perception of non-painful and painful stimuli. Although there is a greater need for research examining the mechanism of electrical stimulation in relation to pain treatment, one theory suggests that the changes in thalamic activity may be due the influence of motor cortex stimulation on the decrease in pain sensations.