Unit 1 AOS 2 SAC

Neuroplasticity

the ability of neural networks in the brain to change as a result of experience. These changes can be in both structure and function.

Synaptogenesis

The process of forming new synapses. As the brain develops, neurons grow more dendrites and axon terminals, which allows them to for more synapses (connections) with other neurons.

Long-Term Potentiation

The relatively permanent strengthening of synaptic connections as a result of repeated activation.

‘Neurons that fire together, wire together’

Long-Term Depression

The relatively permanent weakening of synaptic connections as a result of repeated low level activation.

‘Neurons not in sync, do not link’

Synaptic Pruning

The elimination of unused synapses. The removal of unused or weak synaptic connections, making neural networks more efficient.

Experience-Independent Plasticity

a type of plasticity that involves brain changes that occur regardless of experience

Experience-Expectant Plasticity

A type of plasticity that involves brain development triggered by specific environmental cues that the brain expects to encounter at certain times

Experience-Dependent Plasticity

A type of plasticity that involves the unique and personal brain changes that take place when different situations occur

Rerouting

When healthy nearby neurons create alternative neural pathways when existing connections are lost through injury

Sprouting

When existing neurons form new axon terminals and dendrites to allow new connections to be made

Mental Stimulation - Maintaining and Maximizing Brain Functioning

Involves any activity that activates or enriches the mind. activities should be age-appropriate and be suited to the individual and what they enjoy

Benefits of Mental Stimulation

• formation of new dendritic branches and synapses

• increased functioning of the chemicals that aid in the maintenance, growth and synaptic plasticity of neurons

• increased formation and survival of new neurons in certain brain regions

• reduced age-related atrophy in the brain structures involved in memory

Diet - Maintaining and Maximizing Brain Functioning

•Another modifiable lifestyle factor to help maintain good          brain functioning is diet, including the total intake,            frequency and content of food consumed.

Benefits of Diet

• enhancing synaptic transmission and cognitive function

• preventing age-related decline in CNS functioning and neurodegenerative diseases, such as dementia

• increasing the formation and survival of new neurons in certain brain regions

• increasing the functioning of the chemicals that aid in the maintenance, growth and synaptic plasticity of neurons

Physical Activity - Maintaining and Maximizing Brain Functioning

•Regular physical activity is another modifiable behaviour that has been found to have benefits for the brain.

•Physical activity should be suited to a persons age and physical ability.

Benefits of Exercise

• increased density of neuron dendrites

• reduced age-related decline in the cortical tissue of the frontal, temporal and parietal lobes

• increased volume of the brain structures involved in memory

• increased functioning of the chemicals that aid in the maintenance, growth and synaptic plasticity of neurons

• increased formation and survival of new neurons in certain brain regions

• protection against cognitive decline and neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease

• improved neuroplasticity in people with mental disorders, including mood disorders, post-traumatic stress disorder and schizophrenia

Hindbrain

Mainly responsible for survival functions, movement and coordination. It includes the cerebellum, medulla oblongata and pons

Cerebellum

Involved in a range of bodily functions, such as coordinating voluntary movements, balance, posture and movements associated with speech and vision. Some involvement in learning and memory.

Damage can cause poor balance and coordination

Medulla Oblongata

Controls vital autonomic functions including breathing, heart rate, blood pressure, swallowing, vomiting, sneezing and coughing. Occur automatically and is essential for survival.

Damage can be fatal.

Continuation of spinal cord

Pons

Involved in sleep, dreaming, arousal from sleep, facial expressions and learning. Helps coordinate breathing.

Acts as bridge between cerebral cortex and cerebellum

Located above medulla oblongata and below midbrain.

Midbrain

Connects upper and lower brain regions. Plays a vital role in visual and auditory processing, motor control, pain inhibition and reward-based learning.

Substantia Nigra

Contains many dopamine-producing neurons. Dopamine is important for movement and coordination.

Damage to this area is linked to Parkinson’s Disease

Reticular Formation

A network of neurons involved in arousal, consciousness and motor control.

Reticular Activating System (RAS) - part of the reticular formation that promotes alertness, attention and wakefulness. It filters out unnecessary information so important information can be focused on.

Responsible for alertness, attention, consciousness and motor control

Forebrain

is the largest brain region. It coordinates learning memory, thinking, perception and many bodily functions

Hypothalamus

Regulates the release of hormones that play a role in maintaining homeostasis by regulating body temperature, hunger, thirst and sleep. It links the nervous and endocrine systems and it part of the limbic system.

Damage can lead to issues with controlling body temperature, problems sleeping, feeling hungry after eating

Thalamus

Acts as the brains sensory station. Most sensory information (except smell) passes through the thalamus before reaching the cerebral cortex.

Helps regulate attention and arousal.

Cerebrum

The largest part of the forebrain. It controls conscious voluntary movement and processes sensory information. The outer layer is the cerebral cortex.

Coordinates higher mental processes such as learning, thinking, memory, perception and homeostasis

Cerebral Cortex

• Thin outer layer of the cerebrum (~50% of brain weight)

• Divided into 2 hemispheres

• Shows localisation of function (specific areas have specific roles)

• Connected to subcortical regions; involved in sensation, movement, language, thinking, and emotion

• Sensory areas: process sensory information

• Motor areas: initiate voluntary movement

• Association areas: integrate information for language, creativity, and decision-making

Frontal Lobe

• Located at the front of both cerebral hemispheres

• Contains the prefrontal cortex, premotor cortex, and primary motor cortex

• Prefrontal cortex: controls higher-order thinking, including reasoning, planning, problem-solving, decision-making, and symbolic thinking

• Also regulates emotions, self-awareness, personality, and appropriate behaviour

• Known as the brain's "executive" centre because it coordinates thinking, feelings, and behaviour

Primary Motor Cortex

• Located at the back of the frontal lobe

• Controls voluntary movement through skeletal muscles

• Each hemisphere controls movement on the opposite side of the body

• Different areas control specific body parts; more complex movements use more cortex

Parietal Lobe

Located behind frontal lobe but does not extend all the way to back of brain.

This lobe comprises areas involved in spatial awareness, spatial reasoning, attention and receiving and processing somatosensory information.

Processes sensory information such as touch, pressure and pain

Primary Somatosensory Cortex

Receives and processes sensory information from a range of body areas, including arms, feet, legs, lips, tongue and genitals.

Areas more sensitive are devoted more space in the primary somatosensory cortex i.e., fingers allocated more space than the knee.

Occipital Lobe

Located at the rear of each cerebral hemisphere.

Primarily involved in vision.

Primary Visual Cortex

• Receives and processes visual information from the eyes

• Each occipital lobe processes information from the opposite visual field

• Neurons are specialised to detect:

  • Line orientation

  • Edges and shapes

  • Motion

  • Colour

Temporal Lobe

• Located below the frontal and parietal lobes, above the ears

• Receives and processes auditory (sound) information

• Involved in memory and emotional responses to sensory information

• Helps with visual perception, including recognising faces and identifying objects

Primary Auditory Cortex

assists in identifying and responding to sound, with different parts responding to different sounds i.e., high or low pitch.

Broca’s Area

• Located in the left hemisphere, next to the primary motor cortex

• Responsible for speech production

• Coordinates the muscle movements needed for clear, fluent speech

• Communicates with other language areas to help produce meaningful speech

Wernicke’s Area

Wernicke’s area is located in the left temporal lobe.

Plays a critical role in understanding the sounds involved in speech.

Role in speech production and has connections to Broca’s area in the frontal lobe.

Acquired Brain Injury

is the result of damage to the brain that occurs after birth, at any time during life.

Biological Impact of an ABI

• impaired sensory functioning

• muscle weakness

• poor balance

• tremors

• arthritis

• headaches

• fatigue

• seizures

• chronic pain

• slurred or slowed speech

• bladder problems

Psychological Impact of an ABI

• memory loss

• slowed thinking

• confusion

• poor attention and concentration

• inflexible thinking

• poor judgement

• lack of motivation

• anxiety

• depression

• emotional instability

Social Impact of an ABI

• impaired social behaviour

• socially inappropriate behaviour

• aggressive verbal or physical behaviour

• difficulty relating to others

• loss of confidence and self-esteem

• isolation

Traumatic Brain Injury

an injury that occurs when there is a sudden, physical trauma to the brain from an external force

Aphasia

Aphasia is an acquired language disorder resulting from damage to the language -processing centers of the brain

Concussion

a mild form of traumatic brain injury, resulting from external force to the head or body that causes the brain to bounce inside the skull.

Stroke

an acquired brain injury involving an interruption to the blood supply in the brain or bleeding in the brain, resulting in deterioration of brain tissue.

Broca’s Aphasia

An acquired language disorder characterised by difficult producing fluent speech.

Normal speech comprehension is usually good but have trouble understanding complex sentences.

Speech is laboured and hesitant, typically consisting of short sentences (3-4 words) using nouns and words only.

Severity of ABI

Hemispheric Specialisation

Each hemisphere has some specialised functions that are not possessed or controlled to a lesser extent, by the other – this is called hemispheric specialisation, however both hemispheres play at least some role in all functions and act in a coordinated manner.

Wernicke’s Aphasia

An acquired language disorder characterised by difficulty comprehending speech and producing meaningful sentences.

People speak fluently, but what they say is unintelligible. Speech has correct rhythm but content is odd, conveys little information and sounds jumbled.

People with Wernicke’s have little or no conscious awareness of their condition. Talk nonsensically without realizing.