Central Nervous System Test Questions – Flashcards

The central nervous system comprises the brain and spinal cord. The spinal cord connects the brain and the peripheral nervous system.

The peripheral nervous system includes all parts of the nervous system that lie outside the brain and the spinal cord. It links the central nervous system and all other parts of the body, carrying messages to and from the central nervous system.

The cerebral cortex is involved with information-processing activities such as perception, language, learning, memory, thinking and problem solving. It is also involved with the planning and control of voluntary bodily movements. It is recognisable as the convoluted outer layer or covering of two cerebral hemispheres of the brain

The two halves of the cerebral cortex are called cerebral hemispheres. Two almost-symmetrical brain structures that appear to be separated by a deep groove called the longitudinal fissure. Connected at several points by strands of nerve tissue, those most important of these is the corpus callosum. Have both common and specialised functions.

A band of nerve tissue that connects the left and right cerebral hemispheres and serves as the main communication pathway between them. Acts as a bridge for neural messages between the two cerebral hemispheres allowing for information to be exchanged between hemispheres when performing functions.

Receive and process information from sensory receptors in the body that detect and respond to a specific type of sensory information. Sensory receptors convert the raw sensory information into neural impulses and transmit it to sensory areas in the brain via neural pathways where it is processed.

Receives and process information about voluntary bodily movements. The primary cortex controls our movements by sending neural messages to various parts of the body to make them move in a required way.

Receive and combine information from more specialised areas such as sensory and motor areas and areas that store memories, allowing us to undertake more complex cognitive processes such as perceiving, thinking, learning, remembering and reasoning.

Primary cortex has a specific sensory or motor function whereas association areas do not have any specialised sensory or motor function.

Occupies the upper forward half of each cerebral hemisphere right behind the forehead. Involved with voluntary movements, attention, personality, control of emotions and expression of emotional behaviour. Association areas enable us to perform complex mental functions such as decision making and abstract thinking.

The primary motor cortex is specifically involved in controlling voluntary bodily movements through its control of skeletal muscles. It is a strip of neural tissue located at the rear of each frontal lobe. A different area along the primary motor cortex is involved with movement of each specific body part. The amount of cortex devoted to a particular body part corresponds to the complexity or fineness of its movements.

Located in the forward section of each lobe Receive and combine information from elsewhere in the lobe and other lobes to enable us to perform complex mental functions such as decision making and abstract thinking.

Broca's area has a crucial role in the production of articulate speech; that is speech that is clear and fluent. In particular Broca's area is involved with coordinating movements of the muscles required for speech and supplying this information to the appropriate motor cortex areas. Linked to and interacts with areas of the cerebral cortex involved with the meaning of words and structure of sentences as well as specific grammatical parts of speech such as adjectives, prepositions and conjunctions.

The parietal lobe is located behind the frontal lobe and occupies the upper back half of the brain but not the rearmost area The parietal lobe receives and processes sensory information from the body and skin senses and other areas in the brain Other functions include attention and spatial reasoning (such as understanding how far something is from something else), usually occurring in the right hemisphere of the brain

The primary somatosensory cortex receives and processes information from the skin and body, enabling us to perceive bodily sensations. This sensory information includes touch, pressure and temperature from sensory receptors in the skin and information about muscle movement and the position of limbs from sensory receptors in the muscles, tendons and joints. The amount of cortex devoted to a particular body part corresponds to the sensitivity and amount of use of the body part.

A visual representation of the amount of cortical area devoted to each body part in the primary somatosensory cortex or primary motor cortex.

Receive and combine information from within the lobe and other areas of the brain. e.g to enable us to sense the position of our body in space association areas integrate the information about the body's positions and movements with information about vision transmitted from the primary visual cortex.

Located in the lower central area of the brain above and around the top of each ear Primarily involved in auditory perception. Also plays an important role in memory, aspects of visual perception such as our ability to identify objects and faces and our emotional responses to sensory information and memories.

The primary auditory cortex in each temporal lobe receives and processes sounds from both ears Has specialised areas that receive and process different features of sound and therefore play vital roles in identification of sounds. Verbal sounds are mainly processed in the left hemisphere. Non-verbal sounds are mainly processed in the right hemisphere

Located towards the middle of the temporal lobe in an area called the medial temporal lobe Play crucial roles in memory formation. The hippocampus forms long term memories and the amygdala links emotions to memory.

Specific association areas in the temporal lobes have different types of long term memory such as: Semnatic memories: Receiving, processing and storing memories of facts Procedural memories: how to do things Personal experiences: Episodic memories Also involved in object identification and facial recognition.

Specific cortical area towards the rear of the temporal lobe of the left hemisphere only. Connected to Broca's area by a bundle of nerves Involved in speech production but has a crucial role in the comprehension of speech; more specifically in interpreting the sounds of human speech When a word is heard, the primary auditory cortex of the left temporal lobe processes the auditory sensation but you cannot understand the world until the information has been processed by Wernicke's area. Also vital for locating appropriate words from memory to express intended meanings when we speak and write.

Located at the rearmost area of the cerebral hemisphere at the back of the head The occipital lobe is almost exclusively devoted to the sense of vision. Damage to the occipital lobe can produce blindness even if the eyes and their neural connections to the brain are normal.

Located at the base of each occipital lobe. The major destination of visual information from the two eyes. Information comes to the primary visual cortex from visual receptors (photoreceptors) located on the retina at the back of each eye Neurons in the primary visual cortex and surrounding secondary visual areas are specialised to respond to different features of visual information

Interact with the primary visual cortex in each lobe to select, organise and integrate visual information. Also interact with association areas in other lobes to integrate visual information with other information such as memory, language and sounds. Enables information to be interpreted in an organised and meaningful way.

The idea that one hemisphere has specialised functions or exerts greater control over a particular function is often described as hemispheric specialisation Despite this both hemispheres are usually involved in nearly all functions and act together in a coordinating and interactive way.

• Receives and processes sensations from the right side of the body • Controls voluntary movements of the right side of the body • Specialises in verbal functions involving the use or recognition of words such as in reading, writing, speaking and understanding speech all of which are important in the use of our language • Specialises in analytical functions that essential involve breaking a task down into its key parts and approaching it in a sequential step-by-step way. o Using logical reasoning to interpret and apply a formula to solve a math problem o Critically evaluate an experimental design o Developing an argument for a debate o Devising a plan o Organise sufficient time to complete the homework for all different subjects

• Receives and processes sensations from the left side of the body • Controls voluntary movement of the left side of the body • Specialises in non-verbal functions that do not depend on language skills. • Its non-verbal functions include: o Spatial and visual thinking such as completing a jigsaw puzzle, reading a map or visualising the location of objects or places o Recognising faces, patterns and tunes o Appreciating music and artworks o Creative thinking o Daydreaming • More involved in recognising emotions from facial cues and in non-verbal emotional expression

The spinal cord is the cable-like column of nerve fibres that extends from the base of the brain to the lower back. It is encased in a series of bones called vertebrae that extend further than the actual cord.

1. Receive sensory information from the body via the peripheral nervous system and send these messages to the brain. 2. Receive information from the brain and send it to relevant parts of the body via the peripheral nervous system to control muscles, glands and internal organs.

Transmission of information along the spinal cord to and from the brain occurs through interconnected neurons that form neural pathways. The spinal cord contains: o Ascending neural pathways for somatosensory information which comes in from various parts of the body through the spinal nerves and travels up to the brain o Descending neural pathways for motor information which leaves the brain and travels down the spinal cord to exit via the spinal nerves to its destination in the muscles, organs and glands.

Spinal reflex responses are involuntary and occur automatically in response to certain stimuli. They are called reflex arcs because the response to an incoming stimulus is automatically 'reflected back' from the spinal cord without any initial input from the brain. Fr example, the reflex response when an individual pulls their hand away from a painful stimulus occurs within the spinal cord without any involvement from the brain. This immediate response enables a faster reaction time. Consequently the spinal reflex serves as an adaptive response that protects us from harm and enhances our survival.

Neuropsychologists commonly define aphasia more specifically to refer to a language disorder apparent in speech comprehension or production, writing or reading caused by injury to brain areas specialised for these functions

o Fluent aphasias: Speech is fluent but there are difficulties in either auditory verbal comprehension or in the repetition of words, phrases or sentences spoken by others. o Non-fluent aphasias: there are difficulties in articulating but auditory verbal comprehension is relatively good o Pure aphasias: there are specific impairments in reading, writing or the recognition of words

In Broca's aphasia a person has difficulty speaking, although they continue to understand speech. Speech consists of very short sentences, typically three or four words and these words are mainly verbs and nouns.

• Damage to Broca's area often produces speech that is very deliberate, consisting of view words with a very simple grammatical structure. • Grammatical parts of the speech such as conjunctions and suffixes are omitted. o 'went house visit cousin' • Speech comprehension can be impaired by damage to Broca's area. Someone with Broca's aphasia can become easily confused when the usual order of words is changed especially if the meaning cannot be inferred from individual word meanings alone. • Most people with Broca's aphasia are usually aware of their own language difficulties and have a relatively clear understanding of their condition.

Wernicke's Aphasia is a type of aphasia whereby a person has considerable difficulty comprehending speech and speaking in a meaningful way.

A person with Wernicke's aphasia will often have fluent and grammatically correct speech, but what is said is nonsense. Their speech often has the correct rhythm and general sound of normal speech but the content is odd, conveys little information and is nonsense. People with Wernicke's aphasia have little or no conscious awareness or understanding of their condition. Thye talk nonsense without realising it and lack awareness that other people cannot understand what is being said.

Research has repeatedly confirmed the link between speech comprehension and production problems associated with Wernicke's aphasia and damage to Wernicke's area. It has been found that the right hemisphere also has a role in language. Some people with major destruction to the left hemisphere are capable of swearing and using other emotionally charged words or singing and producing well learnt phrases. In some cases these individuals can sing sentences they are unable to say and thereby make use of the right hemispheres musical function.

Spatial neglect is an attentional disorder whereby individuals fail to notice anything either on their left or right side. They tend to behave as if one side of their world does not exist. Most commonly observed in stroke or accident victims who have fairly extensive damage to the rear area of the parietal lobe of the right hemisphere. Consequently these patients mostly neglect the left side of the world.

The side of the world opposite to the damaged hemisphere tends to be neglected rather than the same side. When tested some patients acknowledge the presence of a stimulus on the neglected side and mistakenly report its presence as if it appeared on the non-neglected side. Although spatial neglect is mostly experienced with visual sense, it may occur for other senses such as hearing or touch. The most common and consistently occurring feature of spatial neglect disorder is an apparent lack of awareness of the presence of an anything on their left side. Half their world is missing and they cannot attend to anything on their left side or locate anything on their left side. Demonstrates the importance of the right parietal lobe and right hemisphere in attention and in consciousness awareness of objects both internally and externally.

• Split brain surgery involves surgically cutting the corpus callosum thereby disconnecting one hemisphere of the brain from the other. The effect is that the two hemispheres do not directly receive information from each other. • Used to treat severe and debilitating epilepsy that is not responsive to any other treatment. The procedure was eventually refined and proved to be successful, resulting in significant relief for some patients and leaving others virtually seizure free with minimal side effects on their everyday behaviour.

o Sperry's aim was to pinpoint the effects of hemispheric disconnection and thereby to address the question of how the hemispheres work in the normal brain o Under controlled laboratory conditions Sperry used a tachistoscope to test the abilities of split brain patients and compare their responses with those of participants with no hemispheric disconnection. • Sperry's research not only provided research evidence that indicated specialised functions of the different hemispheres but his research also determined the role of the corpus callosum in enabling the exchange of information between the two hemispheres of the brain.

Device which enables different visual stimuli to be sent to different hemispheres

• Sperry also argued that consciousness was the combined result of both hemispheres in the intact brain.

o One reason is that the two hemispheres are involved in many tasks. Although one hemisphere may specialise in a task, this does not necessarily mean that the task is exclusively performed in that hemisphere and the other hemisphere does not make any contribution. o Another reason is that not all nerve fibres connecting the two hemispheres are cut during split brain surgery. Lower areas remain intact and some motor and sensory information can be exchanged by the hemispheres via these nerve fibres. o Eye movements as well as the fact that each eye projects to both hemispheres assist in establishing the unity of the visual world. This avoids much of the conflict that would result from having the two hemispheres view different halves of the visual feed. o Information from the touch sense provides a means by which each hemisphere is made aware of stimulation from both sides of the body

Each hemisphere learns to communicate with the other by observing and responding to the mental processes and behaviour the other produces.

• Split-brain studies have been based on patients with serious medical conditions. • The factors that produced the epilepsy in the first place and the epilepsy itself may have produced changes in the patient's brain, making their brain fundamentally different from those of people without epilepsy.