Neuropsychology
He found that while their brains were cold to the touch and that such contact did not trigger any movements, the heart was warm and active, accelerating and slowing dependent on mood.
[8][9] Such beliefs were upheld by many for years to come, persisting through the Middle Ages and the Renaissance period until they began to falter in the 17th century due to further research.
However, by switching the attention of the medical community to the brain, his theory led to more scientific discovery of the organ responsible for our behaviors.
For years to come, scientists were inspired to explore the functions of the body and to find concrete explanations for both normal and abnormal behaviors.
Scientific discovery led them to believe that there were natural and organically occurring reasons to explain various functions of the body, and it could all be traced back to the brain.
Descartes focused much of his anatomical experimentation on the brain, paying special attention to the pineal gland – which he argued was the actual "seat of the soul."
However controversial they were and remain today, the fresh and well-thought-out perspective Descartes presented has had long-lasting effects on the various disciplines of medicine, psychology, and much more, especially in putting an emphasis on separating the mind from the body in order to explain observable behaviors.
[16] This theory was like many circulating at the time, as many scientists were taking into account physical features of the face and body, head size, anatomical structure, and levels of intelligence; only Gall looked primarily at the brain.
He was once sent a cast of René Descartes' skull, and through his method of phrenology claimed the subject must have had a limited capacity for reasoning and higher cognition.
Towards the late 19th century, the belief that the size of ones skull could determine their level of intelligence was discarded as science and medicine moved forward.
There are many arguable debates as to who deserves the most credit for such discoveries,[18] and often, people remain unmentioned, but Paul Broca is perhaps one of the most famous and well known contributors to neuropsychology – often referred to as "the father" of the discipline.
Inspired by the advances being made in the area of localized function within the brain, Paul Broca committed much of his study to the phenomena of how speech is understood and produced.
Broca was essentially the first to fully break away from the ideas of phrenology and delve deeper into a more scientific and psychological view of the brain.
[20] In 1873, Wernicke observed a patient presenting with poor language comprehension despite maintaining intact speech and hearing following a severe stroke.
[21] Individuals with damage to this area present with fluent but receptive aphasia characterized by the inability to comprehend or express written or spoken language while maintaining intact speech and auditory processes.
[22] Along with Paul Broca, Wernicke's contributions greatly expanded the present knowledge of language development and localization of left hemispheric function.
He called this mass action and he believed that it was a general rule that governed how brain tissue would respond, independent of the type of learning.
But we know now that mass action was a misinterpretation of his empirical results, because in order to run a maze the rats required multiple cortical areas.
Cutting into small individual parts alone will not impair the rats' brains much, but taking large sections removes multiple cortical areas at one time, affecting various functions such as sight, motor coordination, and memory, making the animal unable to run a maze properly.
The majority of work involves studying healthy humans in a laboratory setting, although a minority of researchers may conduct animal experiments.
[26] They also can offer an opinion as to whether a person is demonstrating difficulties due to brain pathology or as a consequence of an emotional or another (potentially) reversible cause or both.
For example, a test might show that both patients X and Y are unable to name items that they have been previously exposed to within the past 20 minutes (indicating possible dementia).
Yet another approach investigates how the pattern of errors produced by brain-damaged individuals can constrain our understanding of mental representations and processes without reference to the underlying neural structure.
A more recent but related approach is cognitive neuropsychiatry which seeks to understand the normal function of mind and brain by studying psychiatric or mental illness.
In particular, the growth of methodologies to employ cognitive testing within established functional magnetic resonance imaging (fMRI) techniques to study brain-behavior relations is having a notable influence on neuropsychological research.
When interpreting neuropsychological testing it is important that the diagnosis is empirically informed in order to determine if the cognitive deficits presented are legitimate.
Successful malingering and symptom exaggeration can result in substantial benefits for the individual including but not limited to significant financial compensation, injury litigation, disability claims, and criminal sentencing.
Due to the nature of these potential benefits, it is imperative that malingering is identified in neuropsychological tests in order to avoid making an invalid diagnosis.
