3. Main Causes & Impacts of Brain Damage.docx

CRITICAL READING: CORNELL NOTES Main Causes & Impacts of Brain Damage Name: Date: 29 August 2023 Section: Lecture 3 Period: Questions/Main Ideas/Vocabulary Notes/Answers/Definitions/Examples/Sentences Temporal Lobes Site of: Primary auditory cortex. Association cortex. + Parts o...

CRITICAL READING: CORNELL NOTES Main Causes & Impacts of Brain Damage Name: Date: 29 August 2023 Section: Lecture 3 Period: Questions/Main Ideas/Vocabulary Notes/Answers/Definitions/Examples/Sentences Temporal Lobes Site of: Primary auditory cortex. Association cortex. + Parts of the limbic system. Important and varied functions: Auditory processing. Language. Memory. The lateral sulcus/fissure, also termed sylvian fissure, separates the temporal lobes from the frontal and parietal lobes. Primary Auditory Cortex Located on superior temporal gyrus, adjacent to lateral fissure. Receives auditory information. Auditory input is: Ipsilateral (same side). Contralateral (opposite side). Mostly contralateral input. Organised according to tones – tonotopically organised: Anterior: High frequency. Posterior: Low frequency. Auditory Association Cortex Analyses complex sounds. Left and right differ in function and size (left is larger). Left: Referred to as Wernicke’s area (all right-handed people, most left-handed people): Specialises in processing speech. Comprehending speech. Right: Specialises in analysing non-verbal sounds. Music, other day-to-day sounds. Temporal Lobes & Memory Temporal lobes are important for memory. Forming and storing new memories – declarative/explicit memory. Left: Verbal memory. Right: Non-verbal memory. Important areas located medially – amygdala, hippocampus. Damage to the Primary Auditory Cortex Serious problems are relatively rare because: Located deep in the lateral fissure. Contra and ipsilateral input means bilateral damage needed in order to be very disabling. Problems with basic auditory processing: Detecting sounds. Locating sounds. Discriminating between sounds that are presented quickly. Affect the ability to process speech. Cortical deafness: Cortical – as opposed to sensory/hearing problem/deafness. Rare – usually as a result of large bilateral lesions. Person complains of not being able to hear when someone is speaking. Damage to the Auditory Association Area Different problems, depending on the side. Left-sided damage: Wernicke’s area. Pure word deafness: Problems recognising speech, despite being able to hear, speak, read and write. Problem of recognition. Feel as though they can’t hear when someone is talking. May have no problems hearing other sounds. Wernicke’s aphasia: May also have pure word deafness. Unable to comprehend speech. Have fluent (lots of output), but meaningless speech. Unaware that their speech is incomprehensible. Can’t repeat words or sentences. Right-sided damage: Problems recognising non-verbal sounds. Problems with processing music (amusia). Damage to the Medial Temporal Lobes Left-sided damage: Verbal memory problems. Inability to learn new information. Recall short stories, word lists, etc. Inability to retrieve information from the past. Right-sided damage: Non-verbal memory problems. Affecting geometric designs/stimuli, faces, spatial arrangements. Amnesia. Frontal Lobes Divided into: Motor. Premotor. Prefrontal cortex. Motor cortex: Located on precentral gyrus, anterior to central sulcus. Controls muscles/movement. Projections to neurons in spinal cord, which project to muscles. Highly organised. Contralateral control: Left motor cortex controls muscles on right side of the body. Motor homunculus. Premotor Cortex Located anterior to motor cortex. Selects, sequences, programmes complex movements. Broca’s area (left hemisphere): Premotor cortex. Specialised for movements involved in speech and writing. Prefrontal Cortex Last part of the brain to fully mature. Rich connections with all other areas of the brain. Responsible for very high level functions: ‘executive functions’. Executive functions – impact on everything. Intact executive functions needed to function. Independently responsible for: Working memory/attention. Integrating information. Formulating plans. Executing plans. Monitoring and modifying. Damage to the Motor Cortex Motor functions on opposite side of the body affected, Severe damage: paralysis on one side (hemiplegia). Lesser damage: weakness on one side (hemiparesis). Damage often restricted to one side. Damage to the Premotor Cortex Complex motor sequences. Broca’s area: Broca’s aphasia: Speech production problems. Range from mild slowing of speech to an inability to speak. Writing problems: Agraphia. Damage to the Prefrontal Cortex Wide-reaching/global effects. Impacts on capacity to live independently. Impacts on: How a person approaches a task. Ability to plan. Ability to monitor performance. Initiate activities. Affects divergent thinking: Struggle with problem solving: generating and evaluating solutions, planning. Behavioural regulation: Ability to start, stop and change, as needed (flexibility). Perseveration: repeat a response when no longer appropriate. Don’t adapt to change. Fail to comply with instructions. Working memory: Unable to focus attention or retain information. Impact on longer term retention of information. Doesn’t invoke strategies to assist recall. Poor prospective memory. Deficits in attention: Executive control of attention compromised, affects selective attention. Distractable. Behavioural changes: ‘Depressed’ demeanour. Apathy. Withdrawn. Indifferent. Outgoing demeanour: Immature. Inappropriate. Disinhibited. Agitated. Aggressive. Mixture of above.