I found this interesting article in my local newspaper: There is really a switch inside us! US researchers find an on-off switch in the brain that controls the fear response, and say the discovery may help people with anxiety disorders. Researchers in the United States have identified an “on-off” switch in the brain that controls the emotional response to fear, adding that it might some day be used to help patients with anxiety disorders. The team at the Columbia University Medical Centre that made the discovery had used a simple attention test and a type of real-time brain scan called functional magnetic resonance imaging, which can catch the brain in action. It showed that an area in the rostral cingulated, or rACC region of the brain, was involved in turning on or off the fear response in the amygdala. This is the almond-shaped brain center that processes the emotional responses to fear, the team said last week. “People are exposed to an ever-increasing amount of stimuli in our everyday lives, so we realized that the brain must employ a processing mechanism to priorities and refine responses-we don’t run away from every loud sound or unexpected sight,” said Dr Joy Hirsch, who led the study published in the journal, Neuron. The team used a test called the Stroop test to try to activate whatever region must be involved. It measures mental flexibility by forcing people to choose between a word’s meaning and its colour. For instance, someone may be asked to read a list of words such as “red”, “yellow”, or “green”. However, the word “red” might be written in blue ink or “yellow” in pink ink. People usually respond more quickly if the color and word match. Dr Hirsch’s team adapted this test, using photographs of fearful and happy faces, with “fear” or “happy” written across the images. The researchers gave the test to 19 healthy volunteers and ran the brain scan at the same time. The rostral cingulated seemed to light up just before the amygdala was activated the team reported. The amygdala activated at first if “fear” was written across a happy face, followed by the rostral cingulated, as the image of the smiling face registered. After that, the amygdala would calm down, it said. But the amygdala stayed activated for longer, and the rostral cingulated stayed unlit longer, if a fearful face also carried the “fear” label. Dr Hirsch said it is important to have a circuit to control the fear response.