A down-on-his-luck writer alleviates his writer's block with the help of a helmet provided by a mysterious woman.

"He opened the cupboard door. An empty gin bottle tilted forward and crashed to the floor. He ignored it and groped inside the cupboard, his fingers scrabbling air. As he did so, he began to talk to himself. A nasty habit, but one he seemed to have acquired."

Other Worlds (June 1953)
Bogey Men (1963)
Complete Stories of Robert Bloch -- V 1: Final Reckonings (1990)

Comments: Although not the focus of the story, The Thinking Cap contains a number of well-placed jabs at the psychiatry profession.