Humans are distinguished from other species by a massive brain that enables us to imagine a future and influence it by what we do in the present. By using experience, knowledge and insight, our ancestors recognized they could anticipate dangers and opportunities and take steps to exploit advantages and avoid hazards.- David Suzuki
The human brain is a fascinating and mysterious organ that monitor and regulates our bodily functions, thoughts, behaviour and emotions. It receives and interprets information about the environment, stores it in an easily accessible form, maintains our posture, and governs our actions. It facilitates in solving problems ranging from the purely practical to the highly abstract, communicate with other people through language, to feel and express different emotions like happiness, fear, surprise, sadness, anger disgust etc. The brain is not only capable of performing such a wide range of tasks, but it can also perform some or all of them at once. One of the most difficult and intriguing questions in modern science is how to accomplish this. Nevertheless, over the past decade or so, extremely significant advancements have been achieved in the fields of neuroscience, neurology, and neuropsychology, and there is growing optimism among neuroscientists that a true understanding is starting to take shape.
The systematic, objective, and scientific field of neuropsychology which studies brain and behaviour relationship examines the brain and seeks to link variations in individual behaviour to changes that takes place. The goal of neuropsychology is to understand how the structure and neural networks of the brain produce and regulate a variety of behaviours and mental functions, including as emotions, personality, reasoning, learning and memory, problem-solving, and consciousness.
Neuropsychology examines both healthy and injured brain systems in an effort to learn more about the connections between the brain and behaviour. The clinical neuropsychologist can determine whether an abnormal behaviour is more likely the result of an emotional or learnt process or of a biological brain impairment by using neuropsychological tests. Additionally, they created the localization of functions theory, which states that each type of behaviour is controlled by a different, particular brain area.
Language is localised and lateralized to the left side, meaning it is located on one side of the brain. The discovery gave rise to the lateralization of function principle, which states that one brain hemisphere can carry out tasks that are not shared by the other.
The assumption that brain activities are localised was contested in the 19th century by the work of French physiologist Pierre Flourence and later by the German physiologist Fredrich L. Goltz. Small portions of the cortex were removed in order to produce animal models of human clinical problems, with the expectation that the animals would lose particular functions.
Florence discovered that instead, the animals over time recovered from their early limitations to the point where they now appear to function normally. As a result, a pigeon that was originally unable to fly or eat eventually regained both skills. Despite being compromised, the regained abilities strongly suggested that the cortex may be replaced by other areas of the brain.
These early studies laid the groundwork for neuropsychology, which emphasises functional recovery and the promotion of recovery through rehabilitation even in the most severe cases of brain damage. Neuropsychologists understand that, despite the possibility that not all functions may fully return following injury, the brain's plasticity can be used to make considerable functional gains.
Lesion localization was a primary objective of neuropsychology prior to the development of neuroimaging. The focus of neuropsychology today is on differential diagnosis when lesions might not be visible or when there are no obvious biomarkers for the illness. For instance, since different dementias are typically diagnosed based on patterns of obvious cognitive losses and behavioural problems, neuropsychologists aid in the early diagnosis of these conditions. The diagnosis of non-neurological illnesses like depression or somatoform disorders, which can impair cognitive performance, is also aided by neuropsychological testing.
Clinical neuropsychology and experimental neuropsychology are the two primary subfields of neuropsychology. Clinical neuropsychology treats patients with brain lesions. These lesions could be the result of tumours or diseases, brain trauma or physical injury, or other biochemical abnormalities, possibly brought on by toxic substances. They could also be the outcome of additional lesions. By using specialised testing techniques, the clinical neuropsychologist assesses abnormalities in IQ, personality, and sensory-motor abilities and relates them to specific brain regions that have been impacted. Clinical neuropsychologists use these measurements not only in the practical clinical task of assisting in the diagnosis of brain lesions and the rehabilitation of brain injured individuals, but also in the scientific exploration of the relationship between the brain and behaviour.
Experimental neuropsychologists, in contrast, work with healthy individuals who have undamaged brains. This is the most recent branch of neuropsychology to emerge, and it has expanded quickly thanks to the development of numerous tools that may be used in the lab to examine higher brain functioning.
In order to draw conclusions regarding brain organisation, subjects are typically forced to execute activities while their accuracy or response time is being recorded. The development of imaging methods and medical research has made it possible for neuroscientists to investigate the many functions of the brain in depth.
The structural and functional aspects of the brain can be studied in detail using a variety of cutting-edge imaging techniques, including computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), electroencephalography, and electromyography (EMG).
Electroencephalogram - a recent development in the field of neuropsychological rehabilitation is neurofeedback training (EEG-NFT). The therapeutic method of neurofeedback training (NFT) provides the patient with real-time feedback on the electrical activity, or "brainwaves," within their brains. By putting electrodes on the scalp, this is measured. A video display with sound or a multimedia display with bars, graphs, video games, and movies are the common forms of feedback. To make it possible for conscious regulation of brainwave activity, neurofeedback training was developed.
A positive "reward" response is supplied to the patient whose brain activity changes in the way the therapist wants it to, and if it regresses, either a negative feedback or no feedback is given (depending on the protocol). Rewards might be as basic as a tone change or as sophisticated as a certain character action in a video game.
Numerous empirical studies have demonstrated that neurofeedback training can modify the electrical activity in the brain, which in turn alters the problematic presenting symptoms. We have a treasure of mysteries that could shed light on how the brain functions, and there is still much new to be discovered.
Authors
Author 1: Dr Jamuna Rajeswaran
Professor & Head Clinical Neuropsychology & Cognitive Neuroscience,
Faculty In-charge Advanced Functional neuroimaging at Centre for Cognitive Neurosciences.
Department of Clinical Psychology, NIMHANS, Bangalore-560029
Author 2: Akhil. R
Clinical Psychologist
Fellow in Clinical Neuropsychology, NIMHANS, Bengaluru