Gyan mudra Mudra of knowledge

Method:
Touch the tip of the thumb to the tip of the index finger, with the
other three fingers stretched out.
Specialty:
As it is a mudra of knowledge, it enhances the knowledge. The
tip of thumb has centers of pituitary and endocrine glands.
When we press these centers by index finger the two glands
work actively.
Time duration:
There is no particular time duration for this mudra. You can
practice by sitting, standing or lying on bed whenever and
wherever you have time.
Benefits:
Increases memory power and sharpens the brain
Enhances concentration and prevents Insomnia
If we practice it regularly, it will cure all psychological disorders
like Mental, Hysteria, Anger and Depression