Role of the Brain in Mental Processes and Behaviour + Brain Injury and Brain Plasticity

This is based on the VCE units 1&2 of Psychology 2025

Association Area

An area surrounding both sensory and motor areas that deals with more complex functions that require integration of inputs of information from different areas

Blood-brain barrier

A network of blood vessels and tissue that is made up of closely spaced cells, that helps keep harmful substances from reaching the brain.

Brain

An organ that controls mental processes and behaviour.

Brain ablation

The destruction or removal of part of the brain. It is done intentionally and damage caused is irreversible. Followed by an assessment of subsequent change in behaviour and mental functioning.

Brain lesioning

Disrupting or damaging the normal structure or function of the brain, a lesion can be caused by ablation. Some lesions are temporary, for example, injection of a drug into the brain area. When lesions are done intentionally, they are followed by an assessment of subsequent change in behaviour and mental functioning.

Brain versus heart debate

The issue of whether the brain or the heart was the source of human thoughts, feelings and behaviour, comes from ancient Egypt.

Broca’s area

Located in left frontal lobe, an association area that has a crucial role in the production of articulate speech.

Cerebellum

Located at the base of the brain, it coordinates fine muscle movements, regulates posture and balance, organises and adjusts muscle activity to help ensure movement is smooth and precise. Contains 80% of the brains neurons.

Cerebral cortex

The outer layer of the cerebrum that covers the brain, it’s involved in higher order mental abilities, such as perception, learning, memory, language, thinking and problem-solving.

Cerebral hemisphere

One of the two brain areas running from front to back of the brain, known as the left and right hemisphere.

Cerebrum

The largest part of the brain, split into 2 hemispheres and contains 4 lobes. Initiates and coordinates movement and regulates temperature

Cerebrospinal fluid

A watery like liquid that circulates between membranes to provide cushion against knocks to the head.

Computerised tomography (CT)

A structural neuroimaging technique that uses x-rays of the brain to observe.

Contralateral function

The left side of the brain controls the right side of the body and vice versa.

Corpus callosum

A thick band of nerve tissue that connects the left and right hemispheres, and there is no communication between the two hemispheres when the corpus callosum is cut.

Forebrain

Above the midbrain and extending across the top of the brain. Has complex cognitive processes, such as thinking, learning, memory, perception, and various aspects of emotion and personality.

Frontal lobe

The largest lobe, located in the upper, forwards half. It contains the prefrontal cortex, the premotor cortex, the primary motor cortex and Broca’s area.

Functional Magnetic Resonance Imaging - fMRI

A neuroimaging technique that detects and records brain activity by measuring oxygen consumption across the brain, without exposing participants to radioactive tracers. It is a functional technique, and it can be done to 2 people simultaneously.

Functional Neuroimaging

Techniques that provide views of some aspect of brain function, by showing images of the brain at work. They also provide information about brain structure.

Grey Matter

The darker areas of the brain, which are largely composed of nerve cell bodies and their local connections to each other. Outer cerebral cortex is made up entirely of grey matter.

Hemispheric specialisation

The dominance or particular control of each hemisphere over particular functions, however both are often involved.

Hindbrain

Base of the brain, a collection of structures including the medulla, pons and cerebellum. Controls or influences various motor functions, and vital autonomic responses.

Hypothalamus

In the forebrain, it maintains homeostasis. It regulates the release of hormones, influences behaviours associated with basic biological needs, and is a part of the limbic system, so it is also involved in emotions.

Magnetic Resonance Imaging (MRI)

Structural neuroimaging technique, that vibrates brains neurons to generate a computer image. Clearer and more detailed than CT scans.

Medulla

In the hindbrain, the lowest part of the brain. Controls vital bodily function, such as swallowing, breathing heart rate etc. Some parts are involved in some sensations.

Meninges

3 transparent skin-like membranes that help protect the brain.

Midbrain

Central part of the brain. A collection of structures involved with movement, processing of visual, auditory and tactile information, sensory and arousal. Contains the reticular formation.

Mind-body problem

Questions whether our mind and body are distinct, separate entities or whether they are the same.

Mind-brain problem

Questions about the relationship between brain activity and conscious experience. That is, the relationship between what our brain does and our awareness of our own existence and our internal and external environments

Neocortex

Largest and most recently evolved part of the cerebral cortex. Involved in complex, higher order mental abilities.

Neuroimaging

A selection of techniques that capture pictures of the brain, observing either brain structure or function.

Occipital lobe

Rearmost area of each cerebral hemisphere. Almost exclusively devoted to sense of vision. Each hemisphere receives and processes half the visual information. The left half of each eye looks at the right visual field, and is sent to the left occipital lobe. This is the same with the right half of each eye. Contains the primary visual cortex.

Parietal lobe

Behind the frontal lobe, upper back half of the brain. Receives and processes somatosensory information, including touch, temperature, muscle movement and body position. Contains association areas involved in attention, spacial reasoning, and taste perception. Contains the primary somatosensory cortex.

Phrenology

Describes the study of the relationship between the skull’s surface features and a person’s personality and behavioural characteristics. Proposed by Franz Gall.

Pons

Just above the medulla, in the hindbrain. Involved in sleeping, dreaming, and arousal from sleep, as well as helping control breathing and coordination of some muscle movements. Also relays messages throughout the brain.

Positron Emission Tomography (PET)

Produces colour images showing structure, activity and function. Used to record the level of activity while the participant engages in some kind of mental activity.

Primary auditory cortex

In the temporal lobe. Receives and processes sounds from both ears so that we can perceive and identify different types of sounds.

Primary motor cortex

Rear of frontal lobe. Initiates and controls voluntary movements through its control of skeletal muscles. Contralateral organisation.

Primary somatosensory cortex

Front of each parietal lobe, receives and processes sensory information from the skin and body parts. Homunculus represents how the body would look in relation to the amount of cortex it takes up. Contralateral organisation.

Primary visual cortex

Back of each occipital lobe. The major destination of visual information from the two eyes. Neurons in the primary visual cortex are specialised to respond to different features of visual information. Some neurons respond to specific features like shape or colour, while other neurons respond to two or more features like shape and colour.

Reticular formation

Part of the midbrain. Help screen incoming information so as not to overload the brain, alerts higher brain areas to important information, and regulates arousal and muscle tone.

Split-Brain Surgery

Involves cutting the main band of nerve tissue connecting the two hemispheres, usually as a treatment for severe epilepsy. This tissue is called the corpus calossum

Structural neuroimaging

Refers to techniques that produce scans showing brain structure and anatomy.

Temporal lobe

Lower central area above and around the top of the ear. Involved with auditory perception, memory, aspects of visual perception and our emotional response to sensory information and memories.

Thalamus

Part of the forebrain. Filters information from almost all over receptor sites that detect sensory information, except the nose. It then passes it on to relevant brain areas for further processing.

Wernickes area

In the left temporal lobe. Involved in the comprehension of speech and interpreting the sounds of human speech. Also involved in the production of meaningful and coherent speech.

White Matter

The light areas of the brain, primarily made up of nerve fibres that connect distant brain areas to one another. A fatty coating produces the white appearance. White matter is found beneath the cortex.

Why would brain ablation/lesioning be done?

To treat a debilitating brain-related disorder for people who don’t respond to or can’t have other treatments.

Left hemisphere functions

Receive and process sensations from the right side of the body. Control voluntary movements on the right side of the body. Verbal tasks. Analysis. Logical reasoning.

Right hemisphere functions

Receive and process sensations from the right side of the body. Control voluntary movements on the right side of the body. Non-verbal tasks. Processing of the whole, rather than the bits. Spatial and visual thinking. Creativity. Fantasy. Appreciation of art and music. Recognising emotions.

Why get a CT scan?

To diagnose a disease, and brain trauma and injury.

Why get an fMRI?

To examine which parts of the brain are handling critical functions and to evaluate the effects of strokes or other diseases

Why get an MRI?

To investigate or diagnose conditions that affect soft tissue such as tumours or brain disorders.

Why get a PET?

To evaluate organs and/or tissues for the presence of disease or other conditions.

What brain parts are in the forebrain?

Hypothalamus, thalamus and cerebrum.

What brain parts are in the midbrain?

Reticular formation

What brain parts are in the hindbrain?

Medulla, pons and cerebellum.

What are the functions of the frontal lobe

Voluntary movement, expressive language, capacity to plan, organise, initiate, self-monitor and control one's responses

What are the functions of the prefrontal cortex?

Reasoning, planning, problem solving, decision making, symbolic thinking, attention, regulation of emotions, expression of emotional reactions, self awareness and aspects of personality.

What are the functions of the parietal lobe

Processing sensory information, attention, and spatial reasoning.

What are the functions of the occipital lobe

Processes visual information, almost exclusively devoted to sense of vision.

What are the functions of the temporal lobe

Auditory perception, memory, ability to identify objects and recognise faces, and our emotional responses to sensory information.

Strengths of CT

Enables observation and identifies brain abnormalities

Strengths of MRI

Can be produced in full colour. More sensitive than CT and can reveal small changes in brain anatomy.

Strengths of PET

It reveals brain activity during mental processes and behaviour

Strengths of fMRI

No radioactive traces. Can take numerous images of the brain and rapid succession.

Limitations of CT

Only shows brain structure and emits radiation. Relies on x-ray technology.

Limitations of PET

Radioactive traces. Less detailed than MRI

Limitations of MRI

Cannot reveal brain function

Limitations of fMRI

Large machine and expensive.

What is homunculus

A misshapen person who represents the body parts in terms of the relative size of the area each body part occupies along the primary somatosensory cortex.

What happens when Broca’s area is damaged?

Broca’s aphasia. considerable difficulty producing speech. Reading and writing are also impaired. Speech comprehension is relatively good, but there is considerable difficulty understanding complex speech and lengthy verbal instructions

What happens when cerebellum is damaged?

Damage to the cerebellum may affect the individual’s coordination and balance.

What happens when wernicke’s area is damaged?

Wernicke’s aphasia. Considerable difficulty understanding spoken or written language and speaking in a meaningful way. Cannot make sense of the words. Little or no conscious awareness or understanding of their condition. 

Split-brain experiments?

Neuroplasticity?

The ability of the brain and other parts of the nervous system to change in response to experience. This includes the brain’s capacity to recover from or compensate for loss of function through injury, the brain as a whole doesn’t change it’s shape.

Experience-expectant plasticity

Brain change in response to environmental experience that is ordinarily expected. Occurs largely during development and all members of the relevant species usually have the particular experience.

What happens when experience-expectant plasticity fails to occur in the sensitive period?

Brain development may not occur as it should.

Experience-dependent plasticity 

Brain change that modifies some part its neuronal structure that is already present. It depends on exposure to various environmental experiences that are unique to each individual and may occur at any time during the life span. No sensitive or critical period, so it is not time dependent.

Generation of new networks

When networks that have been disrupted by injury may change by forming new connections. The brain’s plasticity enables it to take over or shift functions from damaged to undamaged areas. In order for this to happen neurons need to be stimulated through repetitive activity. 

Example of Generation of new networks

An undamaged neuron that has lost a connection with an active neuron may seek a new active neuron and connect with it.

Reassignment of function

Through neuroplasticity, functions that were performed by certain areas of the brain can sometimes be reassigned to other undamaged areas of the brain to compensate for changing input from the environment. 

Example of reassignment of function

An extraordinary amount of stimulation of one finger can result in that finger ‘taking over’ a part of the somatosensory cortex that usually represents other adjacent fingers. 

Neurogenesis

The production or birth of new neurons, which is a lifelong process.

Where does neurogenesis occur?

The hippocampus, new neurons migrate from their place of origin to other brain areas.

Brain injury

Any type of brain damage or disorder that impairs or interferes with the normal functioning of the brain, either temporarily or permanently.

Acquired brain injury

Damage or disorders that occur after birth.

What is not considered to be a brain injury?

Any brain damage or disorder due to a developmental condition.

Sudden onset

When a brain injury occurs abruptly, often at a single point in time.

Insidious onset

When a brain injury gradually develops over a period of time in an imperceptible way, showing few signs and symptoms.

Traumatic brain injury

A type of acquired brain injury that occurs when an external force causes damage to the brain.

Causes of traumatic brain injury

A blow to the head, by the head being forced to move rapidly forward or backward, or when an object pierces the skull and enters brain tissue.

How may a traumatic brain injury be required?

In a single traumatic event, such as a ‘king hit’ or ‘coward punch’ to the head, or from repeated blows over time.

Phineas Gage case study

It was 1848, and he was 25. He was packing sand onto an explosive with a metal pole, when it went off and the pole went through his frontal lobe. He later died in 1859.

Phineas Gage biological changes due to brain injury?

Movement disorders, dizziness and balance problems, eyesight, hearing problems, loss of taste and smell, headaches, impaired speech, fatigue and sleep problems, and hormonal imbalances.

Phineas Gage psychological changes due to brain injury?

Memory problems, difficulty problem-solving, poor concentration, reduced ability to organise and plan, lack of initiative and motivation, lack of insight and awareness, poor judgment, loss of self-esteem, personality changes, distress, anxiety, panic attacks, slowed responses, and impulsive behaviour.

Phineas Gage social changes due to brain injury?

social isolation, altered personal relationships, disrupted family relationships, changes to living arrangements, social role changes, different vocational capabilities, different educational opportunities, financial hardship, legal restrictions, and social stigma

Aphasia

A language disorder that results from an acquired brain injury to an area responsible for language production or processing. Aphasia in itself does not affect intelligence, nor is it a mental health disorder. The disorder may change over time through speech and language therapy contributing to neuroplasticity.

Fluent aphasia

Speech is easily produced and flows freely, but the sentences don’t make sense, and the person often has difficulties understanding what is heard or read.

Non-fluent aphasia

Difficulties in speaking clearly, often in short sentences with words omitted. Speech is effortful and includes only key words necessary for communication, but no difficulties understanding what is heard or read.