The early reference to the brain is found in Edwin Smith Papyrus
The Edwin Smith Papyrus, an ancient Egyptian medical treatise written in the 17th century BC, contains the earliest recorded reference to the brain.
Edwin Smith Papyrus is believed to be around 3000 BC
Edwin Smith papyrus, (c. 1600 BC), ancient Egyptian medical treatise, believed to be a copy of a work dating from c. 3000 BC.
Although the text contains about brain, the idea of brain's thinking capability was not mentioned in it. And fifth century BC is the time of origin for the idea that brain has the capability of thinking.
In the fifth century BC, Alcmaeon of Croton in Magna Grecia, first considered the brain to be the seat of the mind. Also in the fifth century BC in Athens, the unknown author of On the Sacred Disease, a medical treatise which is part of the Hippocratic Corpus and traditionally attributed to Hippocrates, believed the brain to be the seat of intelligence.
So summarizing all, the idea that human head has the capability of thinking was started from fifth century BC.
Is my inference correct? Or are there any early mentions that thoughts arise from human head before fifth century BC?
Please note that I am not asking for the idea thoughts arise from human brain. It is enough if there is any idea of thoughts arising from human head before the time mentioned above.