In a light irradiation device 20 for improving cognitive symptom and depression symptom according to the present invention, photostimulation is given to a retina by continuous flashing of a light source 21 of frequency of 1 to 10 Hz, Homer 1a is made to continuously express by the photostimulation, and BK-type potassium channel in pyramidal cell of cerebral cortex is activated. It is possible to exert an effect equivalent to a depression symptom improving effect obtained by an electroconvusion stimulation device, an effect equivalent to a depression symptom improving effect and an effect equivalent to a cognitive symptom improving effect obtained by a transcranial magnetic stimulation device. It is possible to utilize these devices also in home environment as compared with an electroconvusion stimulation device and a transcranial magnetic stimulation device which are limited to treatment in clinical institutions as opposed to home environment.
LIGHT IRRADIATION DEVICE FOR IMPROVING COGNITIVE SYMPTOM AND DEPRESSION SYMPTOM, ROOM HAVING THE LIGHT IRRADIATION DEVICE, AND LIGHTING DEVICE FOR IMPROVING COGNITIVE SYMPTOM AND DEPRESSION SYMPTOM