Introduction to Neuropsychology

Introduction to Neuropsychology

• Focuses on the structure and function of the brain, mind, and mental processes.
• Investigates behavioral and functional correlates of brain-damaged patients and neurologically healthy subjects across development, adulthood, and aging.
• Employs models to identify processing units ("modules") and how they interact to enable complex cognitive processes like memory, attention, and language.

Neuropsychology Disciplines

• Experimental Neuropsychology: Investigates the (neuro)functional organization of the mind's neural correlates in relation to cognitive (dys)functions. It studies how brain-related disruptions impact psychological processes.
• Clinical Neuropsychology: Diagnoses and rehabilitates brain dysfunctions (e.g., traumatic brain injury, stroke, dementia) through assessments, treatment plans, and consultations. Aims to improve daily living skills and cognitive functions.

Causes of Neuropsychological Disorders

• Vascular pathologies: Ischemic pathologies (e.g., thrombosis, embolism, TIA) and hemorrhagic pathologies (e.g., hematomas).
• Degenerative pathologies: Alzheimer's disease, focal onset dementias, Parkinson's disease, Huntington's chorea, subcortical degenerative diseases, metal accumulation diseases, and progressive ataxias.
• Language and learning disorders: primary language disorders and specific learning disabilities.
• Autism Spectrum Disorders and other Complex Disabilities: Autism spectrum disorders, psychomotor delay, and isolated and syndromic intellectual disabilities.

The Central Nervous System

• The CNS comprises the brain and spinal cord.
• The peripheral nervous system (PNS) encompasses everything else (including skeletal and autonomic nervous systems)

Nerve Cells (Neurons)

• Neurons are the basic unit of the nervous system.
• They transmit information electrically via synapses to other neurons and muscles.
• The human brain has approximately 86 billion neurons.

Brain Structure and Function

• The brain's structure includes grey matter (neuronal cell bodies) and white matter (nerve fibers).
• White matter allows efficient communication between grey matter regions.
• The brain is divided into specialized regions with specific functions, and areas are interconnected via complex networks.
• The Cerebrospinal Fluid (CSF) plays a crucial role in nutrient transport, waste removal, and protection.
• The brain's blood supply is crucial for function, with cerebral arteries supplying oxygenated blood and veins draining deoxygenated blood.

Different Brain Regions

• The Cerebrum is divided into lobes (frontal, temporal, parietal, occipital, insula), each with specialized areas.
• The brain stem and cerebellum play essential roles in basic life functions and movement.

Brain Development and Maturation

• Development involves neurogenesis, cell migration, cell differentiation, synaptogenesis, cell death and pruning, and myelogenesis.
• Brain maturation is a complex process that involves both structural and functional changes over time.
• Sex differences affect the structure of the brain.

Neuropsychological Assessment and Techniques

• Neuropsychological assessment: Involves evaluating an individual's cognitive functions to understand brain-behavior relationships, impairments, diagnose conditions, and plan interventions.
• Techniques: Electroencephalography (EEG), magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI), positron emission tomography (PET), transcranial magnetic stimulation (TMS), and diffusion tensor imaging (DTI).
• Neurogenesis: The creation of new neurons from neural stem cells.
• Cell migration: The movement of cells to their appropriate locations in the brain.
• Cell differentiation: The process by which cells become specialized into different types of neurons.
• Synaptogenesis: The formation of synapses between neurons, allowing them to communicate.
• Pruning: The elimination of excess neurons and synapses to refine neural circuits.
• Myelogenesis: The formation of myelin sheaths around neurons, increasing communication speed.
• Brain maturation: A progressive refinement of neural organization over time.
• Different parts of the brain mature at different rates.
• Techniques: Neuroimaging techniques, like MRI and PET scans, are used for creating detailed images of brain structure and function. Non-invasive techniques such as EEG and MEG help measure changes in electrical activity from the scalp. Transcranial magnetic stimulation (TMS) assesses the causal relationship between the brain and behavior by temporarily disrupting function.

Brain Injury and Clinical Cases

• Case studies like those of Phineas Gage and Henry Gustav Molaison exemplify the importance of brain localization for different functions, and how damages can have significant consequences.

Limits of Anatomo-Clinical Correlations

• Different types of brain lesions can vary in complexity and distribution, making it challenging to pinpoint specific causes of cognitive deficits.

Cognitive Neuroscience Techniques

• Neuroimaging techniques: Measure brain activity using different methods, including MRI, PET, and EEG.
• Brain stimulation techniques: Temporarily affect brain activity, allowing researchers to infer causality.
• Lesion studies: Analyze how brain damage influences behavior to infer the function of affected regions.

In Vivo Brain Recording

• Invasive techniques that directly record neuronal activity (e.g. electrophysiology, fMRI).

Neuropsychological Treatment

• Cognitive rehabilitation techniques aim to enhance brain plasticity to facilitate recovery from cognitive impairment.

Summary of Clinical Neuropsychology

• Aims: Diagnose conditions, assess patient’s cognitive profile, and plan appropriate treatment.
• Assessment: Include interviews, standardized tests, and a variety of neuropsychological instruments.
• Treatment: Includes therapeutic interventions and/or recommendations for rehabilitation and support.