A participant in an EEG study has a number of electrodes placed around the head, which allows the researcher to study the activity of the person’s brain. The patterns of electrical activity vary depending on the participant’s current state (e.g., whether he or she is sleeping or awake) and on the tasks the person is engaging in.
University of Arizona researchers have found in a recent study that ultrasound waves applied to specific areas of the brain appear able to alter patients' moods. The discovery has led the scientists to conduct further investigations with the hope that this technique could one day be used to treat conditions such as depression and anxiety.
Jianhui, a 5-year-old monkey, controls a mechanical arm via brain signals in a laboratory of Zhejiang University in Hangzhou, on February 23, 2012. A tiny sensor implanted in Jianhui's brain allows the monkey to control the mechanical arm, reaching and grabbing food and drinks, scientists with east China's Zhejiang University announced. (Reuters/China Daily)