The world literally fades to grey when we feel depressed, scientists have discovered。
To investigate links between mood disorders and vision, Emanuel Bubl at the University of Freiburg, Germany, and colleagues ran an electrode along one eye in each of 40 people with depression, and 40 people without. The electrodes measured activity in the nerves connecting photoreceptors to the optic nerve, but not the brain。
Participants sat in a dimly lit room and watched a black and white chequered screen which became greyer in six distinct stages, reducing the contrast between each square. Each stage was presented for 10 seconds。
The team found that electrical signals to the optic nerve were lower in people with depression. For example, when viewing the stage containing black and white squares, healthy volunteers had three times the nerve activity of those with depression, indicating that depression diminishes the ability to detect contrast. The more severe a person's depression, the worse their perception of contrast。
Bubl believes that a similar technique could be used to aid diagnosis of clinical depression。
据《新科学家》杂志报道，科学家近日发现，人们抑郁时，眼中的世界确实会变得灰暗无光。
为了研究情绪失调和视觉的关系，德国弗莱堡大学的伊曼纽尔-巴布和同事们利用电极测量感光细胞和视神经连接神经的活动，受试对象中，40个有抑郁情绪，而另外40个没有。
受试者在暗房内观察带有不同颜色方格图样的屏幕，该屏幕在六个不同的颜色背景下逐渐变暗，变暗过程中颜色差异减小。每个背景保留10秒钟。
研究发现，到达抑郁群体视神经的电流信号更弱。例如，在观察布满黑白方块的屏幕时，健康受试者的神经活动强度是有抑郁情绪受试者的3倍，这就意味着抑郁让辨别颜色差异的能力下降了。且一个人的抑郁情况越严重，其差异感知能力就越低。
巴布认为相似技术可用于临床抑郁症的诊断。 |