Neuropsychology: Brain Function and Behavior

Neuropsychology Overview

• Neuropsychology studies the relationship between brain function and behavior.
• It explores the influence of brain functions, structures, and processes on cognitive, emotional, and behavioral outcomes.
• Neuropsychologists use tools and techniques to assess cognitive deficits, emotional disturbances, and behavioral problems resulting from brain injuries, diseases, or developmental disorders.
• They develop and implement treatment plans to improve cognitive and emotional functioning and quality of life.
• It has applications in clinical psychology, education, forensic psychology, and sports psychology.

Main Brain Components

• The brain has three main parts: the cerebrum, brainstem, and cerebellum.
• The cerebrum is the biggest part, divided into two hemispheres.

The Human Cortex

• The human cortex is a thin layer of gray matter covering the brain's surface.
• It is responsible for higher brain functions like consciousness, thought, perception, and memory.
• It divides into four main lobes: frontal, parietal, temporal, and occipital.

Cerebral Cortex

• It is the outer gray matter part that covers the cerebrum
• It Consists of about half of the brain's weight
• The right hemisphere controls the left side of the body, and the left hemisphere controls the right side of the body.
• The corpus callosum, a C-shaped structure of white matter and nerve pathways, is used to communicate between the two hemispheres.

Cerebrum

• It is located at the front of the brain
• It comprises gray (cerebral cortex) and white matter at its center
• It is the largest part of the brain
• It initiates and coordinates movement and regulates temperature
• It enables speech, judgment, thinking, problem-solving, emotions, and learning
• It is also involved in vision, hearing, touch, and other senses

Brainstem

• The brainstem connects the cerebrum with the spinal cord
• The brainstem has the midbrain, the pons, and the medulla.

Cerebellum

• The cerebellum is a fist-sized portion of the brain located at the back of the head, below the temporal and occipital lobes and above the brainstem.
• The function is to coordinate voluntary muscle movements and to maintain posture, balance, and equilibrium
• It consists of two hemispheres, like the cerebral cortex.

Meninges

• Meninges surround the brain and the spinal cord and provide three layers of protective covering
• Dura mater is the thick outermost layer with two layers, provides a tough protective barrier.
• Arachnoid mater is the thin, weblike layer of connective tissue, forms a protective layer and helps to cushion the central nervous system.
• Pia mater is the thin membrane hugs the surface of the brain, provides a delicate and highly vascularized protective layer.

Brain Structures and Function

• Frontal lobe handles motor function, problem-solving, memory, language, judgment, decision-making, planning, social behavior, and personality development.
• Parietal lobe is responsible for processing sensory information like touch, temperature, and pain, spatial perception, and visual information related to object positioning.
• Temporal lobe is responsible for processing auditory information (language, music, etc.), memory formation and storage, and emotional processing.
• Occipital lobe is responsible for processing visual information (color, shape, motion), visual perception, recognition of visual stimuli, and eye movement coordination.
• The hypothalamus regulates body temperature, sleep patterns, hunger, and thirst and plays a role in memory and emotion.
• The amygdala regulates emotion and memory and is associated with reward, stress, and the "fight or flight" response.
• The hippocampus supports memory, learning, navigation, and perception of space
• The pineal gland responds to light and dark and secretes melatonin, which regulates circadian rhythms.
• Ventricles and cerebrospinal fluid (CSF) manufacture cerebrospinal fluid, cushions the spinal cord and brain, washes out waste, and delivers nutrients.

Blood Supply

• The vertebral and carotid arteries supply the brain with oxygen and blood.
• The external carotid arteries are located on the sides of the neck
• The internal carotid arteries branch into the skull and help blood circulate in the front part of the brain.
• The vertebral arteries follow the spinal column into the skull and form the basilar artery at the brainstem, which supplies blood to the rear portions of the brain.
• The circle of Willis is a loop of blood vessels near the bottom of the brain that connects major arteries, circulates blood from the front of the brain to the back, and allows the arterial systems to communicate.

Cranial Nerves

• There are 12 cranial nerves inside the cranium.
• The first two originate in the cerebrum, and the other 10 come from the brainstem (midbrain, pons, and medulla).

The Trigeminal Nerve

• It is the 5th cranial nerve
• It is the largest cranial nerve
• It has both a sensory and motor function.

Main Functions of the Frontal Lobe

• Personality
• Decision-making
• Movement

Traumatic vs Non-Traumatic Brain Injuries

• Traumatic brain injuries (TBI) are caused by an external force the the head, such as a blow or jolt
• Non-traumatic brain injuries are caused by internal factors such as disease

Cognitive Deficit

• A deficit refers to a decline or impairment in one or more cognitive domains, such as attention, memory, language, executive function, or visuospatial skills.

Neuropsychological Assessment (NA)

• This assessment diagnoses cognitive deficits and identify the cognitive strengths and weaknesses of an individual.
• NA is useful when making differential diagnoses between different disorders that may present with similar symptoms.
• NA can be used as a prognostic tool to predict outcomes in patients with neurological or psychiatric disorders.
• NA can be used to monitor treatment response and to assess the efficacy of interventions.

Cognition

• Standardized neuropsychological tests are used to assess each cognitive domain.
• A comprehensive battery of tests can provide a more detailed and accurate assessment of cognitive functioning.
• Important to tailor the assessment to the specific needs and abilities of each patient.
• Comprehensive cognitive assessment can provide important diagnostic and treatment information for a range of neuropsychiatric disorders.
• Cognitive domains are areas of cognitive function that can be assessed with standardized neuropsychological tests.
• Key domains of cognition include: attention, memory, language, visual-spatial skills, and executive functioning.

Neuropsychologists Roles

• Neuropsychological assessment.
• Neuropsychological rehabilitation.

Cognitive Rehabilitation

• Cognitive rehabilitation is a process of assessment and intervention to improve a person's cognitive functioning and overall quality of life.
• It is used to treat individuals who have experienced some form of cognitive impairment due to neurological injury or disease.
• It involves a comprehensive evaluation of the individual's cognitive functioning, followed by developing a tailored treatment plan that focuses on improving specific cognitive abilities.
• The treatment may involve a range of techniques, including cognitive exercises, compensatory strategies, and environmental modifications.
• It is provided by a team of professionals, including neuropsychologists, occupational therapists, speech therapists, and rehabilitation counselors.
• The ultimate goal is to help individuals achieve their functioning and independence, while minimizing the impact of deficits in their daily life activities.

Cognitive Rehabilitation Techniques

• Kelly and O'Sullivan discuss several strategies and techniques for cognitive rehabilitation, including:
  • Errorless learning: gradually reducing the amount of support provided to the patient as they learn a new task or skill.
  • Strategy training: This approach involves teaching the patient specific strategies for completing tasks.

Example Case Study

• An elderly woman has TBI from fall, undergone a comprehensive assessment and treatment plan by a multidisciplinary team.
• The initial assessment identified a range of cognitive, physical, and psychological impairments
• The treatment plan involved a combination of rehabilitation techniques (physiotherapy, occupational therapy, and speech therapy).
• Assessment provided insight into the patient's cognitive functioning, which guided the development of a tailored rehabilitation program.

Example Case Study for Stefan (16-year-old boy)

• This 16-year-old male suffered a severe traumatic brain injury and facial fractures in a motor vehicle accident
• Attention training: The short span of attention and inability to divide attention can be improved with attention training exercises
• Memory training: Stefan can benefit from memory training to improve his new learning and recall skills.
• Cognitive restructuring: Techniques can be used to help him organize and plan his thoughts.
• Rest breaks: Rapid fatigue is a common problem, Stefan can be encouraged to take regular breaks between activities to avoid mental exhaustion.
• Assistive technology: Adaptive tools, such as memory aids and computer software, can help Stefan in organizing his daily activities and notes
• Psychoeducation and counseling: The patient and family can benefit from psychoeducation and counseling.

Health Psychology

• Health psychology is the study of how psychological factors relate to physical health and well-being.
• This encompasses how biological, social, and psychological factors influence our health choices.
• It applies to the development of physical conditions, recovery from illness, and coping with long-lasting health issues.
• A health psychologist evaluates and treats chronic stress, addictions, eating disorders, chronic pain, etc.
• A health psychologist focused on psychoeducation and cognitive-behavioral methods.

Stress

• Stress can be beneficial in certain situations, but chronic stress can negatively affect the brain, including its size, structure, and functionality.
• Cortisol can cause the prefrontal cortex to shrink, leading to a decrease in concentration, decision-making, and social interaction abilities.
• Chronic stress can make it harder to learn and remember things, and can lead to more serious mental health problems, such as depression and Alzheimer's disease.
• The hypothalamus pituitary adrenal axis (HPA axis) is activated when the brain detects stress, leading to the release of cortisol, which can cause damage to the brain over long periods of time.
• Chronic stress can increase neural activity and connections in the amygdala, the brain's fear center, and decrease electrical signals in the hippocampus.
• Epigenetic changes, caused by maternal nurturing or negligence, can affect how individuals respond to stress later in life.
• Exercise and meditation are powerful tools to decrease stress and increase the size of the hippocampus, improving memory and brain function.