Talma Hendler says lack of sleep may make neutral images suddenly provoke an emotional response, reports New Scientist.
To probe the link in more detail, her team conducted a similar experiment in an fMRI scanner, which is used to measure activity in different areas of the brain.
Inside the scanner, volunteers were again shown potentially distracting neutral and emotional images while they tried to complete a task – and again, sleep-deprived people found all images distracting, whereas the non-sleep-deprived were only distracted by emotional images.
Moreover, a region of the brain called the amygdala, which is known to play a part in emotion, fired up in response only to emotional images when the volunteers had had a good night’s sleep. But when they were sleep-deprived, it reacted to neutral images in the same way as emotional ones.