A book that helps to understand the concept of cognitive freedom is "Prohibition, Religious Freedom and Human Rights: Regulating Traditional Drug Use". 

The book includes the chapter by Charlotte Walsh, titled "Beyond Religious Freedom: Psychedelics and Cognitive Liberty". 



Blueprint for Regulation - After the War on Drugs

"Blueprint for Regulation: after the war on drugs" is a book published by Transform Foundation. 

Review of the book:
"There is a growing recognition around the world that the prohibition of drugs is a counterproductive failure. However, a major barrier to drug law reform has been a widespread fear of the unknown - how could drugs be made safely available after prohibition ends?
For the first time, 'After the War on Drugs: Blueprint for Regulation' answers that question by proposing specific models of regulation for each main type of currently prohibited drug.
We demonstrate that legal regulation is not an unthinkable, politically impossible step in the dark, but a sensible, pragmatic approach to control drug production, supply and use."

The PDF of the book is available here.

The Psychedelic Policy Quagmire

This is a very valuable collection of essays on the public health and policy implications of research on psychedelics. Starting from the premiss that individuals have a constitutional right to change their consciousness by pharmacological means, the contributors discuss a range of issues that arise as society attempts to integrate the uses of psychedelics into an evolving social system. Psychedelic experiences can provide unique insights into the complex relationships between mind and body, especially when studied from multiple perspectives and paradigms. Yet their use in treatment or research is unusually tightly controlled and therefore subject to enormous political challenges and methodological puzzles. This volume gives an excellent overview of the range of issues involved, pointing the way to new possibilities in the area of drug policy." 

Ralph Metzner, Ph.D., Psychotherapist and Professor Emeritus at the California Institute of Integral Studies in San Francisco. 

Journal of Cognitive Liberties

Another way to learn more about cognitive freedom is by reading the Journal of Cognitive Liberties, freely available from the website of the Center for Cognitive Liberty and Ethics