Introduction To Neuropsychology: History, Methodology, And Assessment
Learning outcomes
Familiarity with the Logic and Rationale for Studying Patients with Brain Lesions
The neuropsychological assessment of individuals is highly dependent on the evaluation of their brain’s pathophysiology. Any anatomic or pathological disruption in the human brain substantially impacts its overall functionality and associated executive/memory performance. For example, the assessment by (Dwan, Ownsworth, Chambers, Walker, & Shum, 2015) revealed the adverse impact of a brain tumor on the overall neuropsychological functioning of individuals. The multi-faceted neuropsychological evaluation of the patients affected with brain tumor assists in identifying their cognitive and memory deterioration and correlating the findings with the extent of tumor invasion. The neuropsychologists utilize the valuable information related to the patient’s tumor structure for assessing the complex memory and cognition deterioration mechanisms/pathways in the context of facilitating the appropriate psychotherapeutic interventions. Furthermore, the assessment of working memory, auditory memory, information processing speed, focused attention, and visuomotor performance of the brain tumor patients assists in evaluating their tumor prognosis and associated clinical outcomes. The assessment by (Warren, et al., 2014) reveals the direct impact of a focal brain injury on the behavioral and cognitive outcomes of the affected individuals. The experimental induction of brain injury in humans is not feasible for the neuropsychologists across the laboratory environment. Therefore, the inclusion of brain injury patients in various neuropsychological studies is highly essential to understand and identify the actual impact of brain trauma on their psychosocial and behavioral outcomes. The neuropsychological assessment of brain networks in trauma cases assists in identifying the impact of brain injury on its structural and functional organization. For example, the neuropsychological evaluation of traumatized patients with lesions in the temporal lobe’s auditory cortex helps in identifying the extent of their hearing and language dysfunction. Indeed, speech and hearing defects experienced by traumatized individuals might exhibit entirely different pathophysiology as compared to the sensory or motor deficits experienced by the patients under the impact of a debilitating disease condition. Therefore, the inclusion of the patients affected with the brain trauma in neuropsychological studies substantially helps in delineating the mechanisms and pathways of their auditory, language, visual, and behavioral inconsistencies. These organization of these studies prove highly challenging under laboratory conditions since the experimental induction of brain trauma scenarios in human population is ethically and legally restricted across the globe.
The rate of neurocognitive impairment in individuals varies reciprocally with the location, size, and histology of their brain lesions (Noll & Fardell, 2015). This substantiates the requirement of histopathological assessment of brain lesions to evaluate their impact on the psychological outcomes of the affected patients. The routine neuropsychological practice focuses on the comparative analysis of the cognitive and behavioral outcomes in individuals affected with different pathological conditions. The scientific community prioritizes the comparative assessment of brain size, brain trauma, brain lesions, and premorbid intellectual functioning of patients for understanding their significant neurocognitive mechanisms and their complex interrelationships. The neuropsychologists utilize PST (premorbid standardized testing) score in similar scenarios to clinically correlate the cognitive outcomes with the pathology of brain lesions, ventricle-to-brain ratio, and total intracranial volume (Kesler, Adams, Blasey, & Bigler, 2003). These evidence-based facts substantiate the requirement of investigating the patients affected with various brain diseases in the context of exploring their brain pathology and their impact on the clinical/neuropsychological outcomes. Clinicians utilize radiological interventions including CT and MRI to study a range of significant brain lesions based on the reported symptoms in the human population (Bigler, 2016). The clinical outcomes obtained from these radiological interventions assist in improving the capacity of various behavioral and cognitive assessment methods in the context of attaining a better insight of the neuropsychological processes that substantially impact the functioning of the central and peripheral nervous systems. The tissue, organ, and systemic level assessment of the human brain assists in analyzing the probable perturbations that adversely impact the neuropsychological functioning of individuals. Therefore, the inclusion of radiological brain studies in neuropsychological research is highly essential to attain an insightful understanding of the brain pathology and its association with various dimensions of cognition and behavior.
Familiarity with the Logic and Rationale for Studying Patients with Brain Lesions
The volume of cerebral cortices of the human brain is related to auditory and language capacity of individuals. Furthermore, the bilateral Heschl’s gyri prove to be the sensory centers that effectively facilitate the processing of acoustic information and auditory stimuli (Andrewes, 2015). The patients affected with auditory hallucinations in schizophrenia exhibit elevated functional connectivity of the left frontoparietal area with the left Heschl’s gyrus (Shinn, Baker, Cohen, & Öngür, 2013). Similarly, they also exhibit limited physiological connectedness of mediodorsal thalamus and right hippocampal formation with the left Heschl’s gyrus. The auditory or multi-modal hallucinations indicate the extent of neuropsychological deterioration of the affected patients (Katzen, et al., 2010). These evidence-based outcomes substantiate the requirement of evaluating the pathophysiology of the Heschl’s gyri lesions to evaluate and identify the risk/extent of cognitive disruption in patients affected with various neuropsychological conditions (including Parkinson’s disease and Schizophrenia). Similarly, the left Sylvian fissure facilitates the development of language and enhancement of information processing potential in individuals (Andrewes, 2015). The findings by (Knaus, Tager-Flusberg, & Foundas, 2012) reveal a substantial correlation between parietal asymmetries and Sylvian fissure in children affected with autism spectrum disorder that impacts their non-verbal interactions and social behavior (Park, et al., 2016). These findings necessitate the radiological investigation of the Sylvian fissure of the autistic patients to delineate or rule out the existence of any lesion in the context of understanding its impact on the behavioral and psychosocial outcomes of the affected children. Therefore, the neuropsychological investigation of autistic patients is highly necessary for exploring their Sylvian fissure pathology and its impact on communication and behavioral deterioration. Indeed, the brain lesion studies significantly improve the insight of researchers in relation to the brain structure and function (Adolphs, 2016). However, the functional MRI approaches and electrophysiological interventions assist in evaluating the psychological processes in a restricted manner. The limited knowledge of the psychological processes in the absence of insightful analysis of the brain function/structure and its impact on cognitive/ behavioral outcomes radically defeats the objective of neuropsychology. The assessment of the clinical valuable brain lesion information is therefore highly necessary to explore and decode various neuropsychological and pathophysiological mechanisms/processes that significantly impact the overall functioning of the dynamic brain networks. The evaluation of the patients with brain lesions not only facilitates the modular analysis of human cognition but also paves the way for a rational utilization of cognitive functioning theories to assess the plasticity and degeneracy mechanisms.
The beneficial information obtained from the subjects of brain impairment and the conceptual/methodological limitation of such studies
The Beneficial Information Obtained from the Subjects of Brain Impairment and the Conceptual/Methodological Limitation of Such Studies
The assessment of patients affected with brain impairment or lesions significantly assist in evaluating their personality changes. Various levels of brain impairment impact the behavior quality, distinctive individual attributes, mental activities/attitudes, physical activity, habitual pattern, individuality, and personal identity of the affected individuals ( Maruish & Moses, 1997, pp. 119-122). These outcomes substantially impact the overall behavior, feelings, and thought processes of patients affected with various types of brain lesions/impairment. The neuropsychologists utilize personality theory to categorically evaluate the behavioral traits of individuals and their environmental factors (Hampson, 2012). However, the assessment of complex pathophysiology of human brain lesions helps in delineating the internal processes that deteriorate the psychosocial outcomes to a considerable extent. These facts signify the potential of brain lesions’ assessment interventions in terms of improving the use of personality theory that would otherwise remain infeasible during the evaluation of healthy individuals. (Kosslyn, 1999) questions the potential of healthy brain’s neural loci’s neuroimaging in terms of assessing a range of significant mental mechanisms. The cognitive reserve theory advocates the need for evaluating the brain reserve of individuals in the context of determining their brain pathology tolerance level. The cognitive aging theory is widely utilized to evaluate several mental health disruptions in patients affected with age-related conditions like dementia and Alzheimer’s disease (Stern, Cognitive reserve in aging and Alzheimer’s disease, 2012). However, these interventions fail to evaluate the detailed pathology of various brain lesions and their significant impact on human behavior and cognition. The assessment of personality factors, cognitively stimulating behaviors, and lifestyle factors in the absence of brain pathology evaluation leads to several knowledge gaps in neuropsychological research. The deterioration of various functional and cognitive tasks’ processing in the human brain reciprocates with the type, location, and severity of respective brain lesions. The brain pathology significantly impacts the neural reserve and neural compensation mechanisms that radically impacts the overall mental health, including behavior and cognition as well as the disease coping capacity of the affected patients (Stern, 2009). These evidence-based outcomes reveal the requirement of brain pathology/lesion assessment to radically enhance the effectiveness, utilization, and outcomes of the cognitive reserve theory in neuropsychological studies for the human population.
Various brain lesion studies assist in evaluating the critical functions, dietary factors, and comorbidity risk of individuals that would otherwise be impossible to identify through the assessment of a healthy brain. For example, the study by indicated a linear relationship pattern between brain lesion volume and calcium-containing diet in elderly patients. Furthermore, the brain lesion volume reciprocates with significant comorbidities including stroke, dementia, cognitive decline, depression, and physical disability. Therefore, the evaluation of brain lesion’s volume assists in identifying the need for reducing the calcium intake level to minimize the risk of adverse neuropsychological outcomes in elderly patients (Payne, McQuoid, Steffens, & Anderson, 2014). The patients affected with prefrontal cortex lesions lose their capacity for utilizing the localized contextual information (Fogelson, Shah, Scabini, & Knight, 2009). Resultantly, they exhibit an inadequate response time based on the induction of visual stimuli prior to the occurrence of the target episode. The neuropsychological assessment of this critical information processing function is never possible through the evaluation of individuals with a healthy brain. These findings again affirm the significance of assessing the brain lesions and associated neuropsychological outcomes in the brain-impaired patients.
Patients affected with traumatic brain injury variably experience mental health issues, cognitive deficits, and activity limitations probably due to the heterogeneity of their background (Rabinowitz & Levin, 2014). This variation in the functional deficits is rarely explained by the structural and functional assessment of the traumatic brain lesions. The scientific community needs to conduct prospective studies on traumatic brain lesions in the context of unraveling these evidence-based knowledge gaps. The researchers need to explore the heterogeneity of brain lesions and their complex relationship with the executive functioning, processing speed, attention span, and memory of the affected patients. They also need to explore the causative mechanisms of posttraumatic amnesia and consciousness reduction in relation to the occurrence of traumatic and non-traumatic brain lesions in individuals of various age groups.
A range of brain lesion assessment interventions continues to explore the impact of brain pathology on critical areas of brain functions. However, despite the technological advancement the novel machine learning interventions fail to precisely identify the true structural/functional locus across the brain lesion and its impact on the significant neuropsychological outcomes. These findings substantiate the need for reassessing the lesion mapping-based defects in human brain function with the core objective of unraveling the lesion data’s multidimensional structure and associated multifactorial functional domains (Mah, Husain, Rees, & Nachdev, 2014). The assessment by reveals the contribution of traumatic brain lesions on the social behavior and emotional perception disruption in the affected individuals. However, the alternative behavioral processes and the affective-state of individuals substantially masks the significant effects of the concerned brain lesions. This finding warrants the multidimensional assessment of brain lesions in relation to the associated behavioral processes for identifying the actual impact on these lesions on the psycho-socio-somatic outcomes of the concerned patients (Saxton, Younan, & Lah, 2013). The double dissociation model in exploring functional relationships between the neural network of a specific brain location and the associated sensorimotor, emotional, cognitive, and behavioral outcomes (Fama & Sullivan, 2014). This model helps in tracking the selective behavior of the human brain in relation to various chronic conditions including alcohol and drugs addiction. However, the double dissociation model fails to correlate the neuropathologic signature of the localized brain pathology with the neuropsychological deterioration in the human population. Resultantly, the assessment of the relationship between human behavior and brain functioning becomes highly challenging in complex clinical scenarios. These findings substantiate the need for developing innovative brain lesion assessment tools and techniques with the core objective of exploring the emotional, behavioral, and neurological inconsistencies related to the lesion magnitude and pathology in the affected patients.
References
Maruish, M. E., & Moses, J. A. (1997). Clinical Neuropsychology: Theoretical Foundations for Practitioners. New Jersey: Lawrence Erlbaum.
Adolphs, R. (2016). Human Lesion Studies in the 21st Century. Neuron, 90(6), 1151-1153. doi:[10.1016/j.neuron.2016.05.014]
Andrewes, D. (2015). Neuropsychology: From Theory to Practice (2nd ed.). USA: Psychology Press.
Bigler, E. D. (2016). Systems Biology, Neuroimaging, Neuropsychology, Neuroconnectivity and Traumatic Brain Injury. Front Syst Neurosci. doi:[10.3389/fnsys.2016.00055]
Dwan, T. M., Ownsworth, T., Chambers, S., Walker, D. G., & Shum, D. H. (2015). Neuropsychological Assessment of Individuals with Brain Tumor: Comparison of Approaches Used in the Classification of Impairment. Front Oncol, 5(56), 1-8. doi:[10.3389/fonc.2015.00056]
Fama, R., & Sullivan , E. V. (2014). Methods of association and dissociation for establishing selective brain-behavior relations. Handb Clin Neurol., 175-181. doi:10.1016/B978-0-444-62619-6.00011-2
Fogelson, N., Shah, M., Scabini, D., & Knight, R. (2009). Prefrontal cortex is critical for contextual processing: evidence from brain lesions. Brain, 132(11), 3002–3010. doi:[10.1093/brain/awp230]
Hampson, S. E. (2012). Personality Processes: Mechanisms by which Personality Traits “Get Outside the Skin”. Annu Rev Psychol., 315-339. doi:[10.1146/annurev-psych-120710-100419]
Katzen, H., Myerson, C., Papapetropoulos, S., Nahab, F., Gallo, B., & Levin, B. (2010). Multi-Modal Hallucinations and Cognitive Function in Parkinson’s Disease. Dement Geriatr Cogn Disord., 30(1), 51-56. doi:[10.1159/000314875]
Kesler, S. R., Adams , H. F., Blasey, C. M., & Bigler , E. D. (2003). Premorbid intellectual functioning, education, and brain size in traumatic brain injury: an investigation of the cognitive reserve hypothesis. Appl Neuropsychol., 10(3), 153-62. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12890641
Knaus, T. A., Tager-Flusberg, H., & Foundas , A. L. (2012). Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder. Behav Neurol., 327-339. doi:[10.3233/BEN-2012-110214]
Kosslyn, S. M. (1999). If neuroimaging is the answer, what is the question? Philos Trans R Soc Lond B Biol Sci, 354((1387)), 1283–1294. doi:[10.1098/rstb.1999.0479]
Mah, Y. H., Husain, M., Rees, G., & Nachdev, P. (2014). Human brain lesion-deficit inference remapped. Brain, 137(9), 2522-2531. doi:[10.1093/brain/awu164]
Noll, K. R., & Fardell, J. E. (2015). Commentary: “Neuropsychological Assessment of Individuals with Brain Tumor: Comparison of Approaches Used in the Classification of Impairment”. Front Oncol., 1-2. doi:[10.3389/fonc.2015.00188]
Park, H. R., Lee, J. M., Moon, H. E., Lee, D. S., Kim, B. N., Kim, J., . . . Paek, S. H. (2016). A Short Review on the Current Understanding of Autism Spectrum Disorders. Exp Neurobiol, 25(1), 1-13. doi: [10.5607/en.2016.25.1.1]
Payne, M. E., McQuoid, D. R., Steffens, D. C., & Anderson, J. J. (2014). Elevated brain lesion volumes in older adults who use calcium supplements: a cross sectional clinical observational study. Br J Nutr., 112(2), 220-227. doi:[10.1017/S0007114514000828]
Rabinowitz, A. R., & Levin, H. S. (2014). Cognitive Sequelae of Traumatic Brain Injury. Psychiatr Clin North Am, 37(1), 1-11. doi:[10.1016/j.psc.2013.11.004]
Saxton, M. E., Younan , S. S., & Lah, S. (2013). Social behaviour following severe traumatic brain injury: contribution of emotion perception deficits. NeuroRehabilitation, 263-271. doi:10.3233/NRE-130954.
Shinn, A. K., Baker, J. T., Cohen, B. M., & Öngür, D. (2013). Functional Connectivity of Left Heschl’s Gyrus in Vulnerability to Auditory Hallucinations in Schizophrenia. Schizophr Res, 143(2-3), 260-268. doi:[10.1016/j.schres.2012.11.037]
Stern, Y. (2009). Cognitive Reserve. Neuropsychologia, 47(10), 2015–2028. doi:[10.1016/j.neuropsychologia.2009.03.004]
Stern, Y. (2012). Cognitive reserve in ageing and Alzheimer’s disease. Lancet Neurol., 11(11), 1006–1012. doi:[10.1016/S1474-4422(12)70191-6]
Warren, D. E., Power, J. D., Bruss, J., Denburg, N. L., Waldron, E. J., Sun, H., . . . Tranel, D. (2014). Network measures predict neuropsychological outcome after brain injury. Proc Natl Acad Sci U S A, 111(39), 14247–14252. doi:[10.1073/pnas.1322173111]