During her years in clinical practice and her work with thousands of underprivileged teachers and students in her home country of South Africa and in the USA, she developed her theory (called the Geodesic Information Processing theory) of how we think, build memory, and learn, into tools and processes that have transformed the lives of hundreds of thousands of individuals with Traumatic Brain Injury (TBI), Chronic Traumatic Encephalopathy (CTE), learning disabilities (ADD, ADHD), autism, dementias and mental ill-health issues like anxiety and depression. She has helped hundreds of thousands of students and adults learn how to use their mind to detox and grow their brain to succeed in every area of their lives, including school, university, and the workplace.

Dr. Leaf is the host of the podcast Cleaning Up Your Mental Mess, has published in scientific journals and is the author of 18 bestselling books translated into 24 languages, including Cleaning Up Your Mental Mess, How to Help Your Child Clean Up their Mental Mess, and Think, Learn, Succeed. She teaches at academic, medical and neuroscience conferences, and to various audiences around the world.

Dr. Leaf has conducted clinical trials using the 5-step program she developed while in private practice to further demonstrate the effectiveness of mind-directed techniques to help relieve mental ill-health problems such as anxiety, depression and intrusive thoughts. The primary aim of these trials is to make mental health care more affordable, applicable, and accessible worldwide, and to reduce the stigma around mental health.

She has presented her unique Switch on Your Brain with the 5-Step Learning Process® and the Metacognitive-Map™ learning tool to thousands of students and corporations worldwide. She developed the Geodesic Learning™ theory and the metacognitive-mapping approach (how we think and process information), which has been shown to increase thinking, behavioral and academic performance by 35-75%. This revolutionary theory has contributed to how we understand the science of thought, explaining how thoughts form, how we process information, the power of the non-conscious mind and the relationship between the non-conscious and conscious. The theory proposes that everything you say and do is first a physical thought in the physical brain, a thought which you built with your mind. You think, and then you do, which cycles back to the original thought, changing it, and the thoughts connected to it, in a dynamic interrelationship. 

Dr. Leaf has published a number of articles in academic journals and consumer magazines, and has been widely interviewed in newspapers, on radio and on television shows about her research and theories. 

Her passion is to help people see the power of the mind and teach them how to control their thoughts and emotions, and learn how to think and find their sense of purpose in life.

She frequently lectures to audiences worldwide, linking scientific principles of the brain to spiritual, intellectual and emotional issues in simple and practical ways. She speaks on diverse topics relating to how the mind controls the brain through optimal thinking, and hence improved brain performance. These topics include:

1. Thinking and learning
2. Controlling your thought life through mind management 
3. Managing toxic stress
4. Managing toxic thoughts and trauma through the 5-step Neurocycle process
5. Overcoming mental, emotional, and spiritual challenges 
6. Identifying your unique way of thinking through the UQ profile