Neuropsychology is a field of study within the neurosciences. Like its parent, neuroscience
, neuropsychology is multi-disciplined, drawing much of its knowledge from other areas including, but not limited to, psychology
. Whilst its subject may be varied, simply put neuropsychology is the study of the relation between behavior and brain function.
The use of the term neuropsychology is a recent development, having only been in use since about 1950. Even in the early days of its existence, the term was used without a formal definition. In fact, in one of its very first appearances in Hebb's The Organization of Behavior: A Neuropsychological Theory, the term was limited to its title and was not even used within the text itself.
Though the use of the term neuropsychology as a recognised divsion of neuroscience is a contemporary designation, the concept behind it -that is, relating behavior with the physical brain- is nothing new and goes back to the early Greeks and Romans. Plato theorised that the rational part of the soul resided within the brain and Galen, as an experienced physician, was aware of behavioral changes resulting from brain damage.
Later, in the 18th century, Gall and Spurzheim suggested that different cortical areas be ascribed different functions. They developed this idea further by stating that the skull will reflect physically the characteristics of the underlying brain. For instance, if one of the cortical functions were particularly well developed that area of the brain would be larger, thus in turn causing the skull to also be affected, resulting in a bump on the skill. If this is true then the inverse would be true of an underdeveloped function, resulting in a depression in the skull. From this hypothesis, phrenology, the study of the relationship between the skull's surface features and a person's faculties, was born. This relationship has since been shown to be inexistent, however, with the advancement of neuropsychology.
Neuropsychology is a growing field and has changed a lot since its humble beginnings with Plato and Hippocrates or as an undefined and unheard of term used by a handful of people less than half a century ago. Part of its growth can be accredited to advances in technology, such as brain imaging devices like PET scan or MRI. Another contribution is the development of psychometrics; the method of measuring and statistically analysing human psychological abilities as a means of learning about the mind. As technology improves even more and our way of approaching neuroscience changes, so too will the field of neuropsychology.