Final Exam Flashcards
Where is language localized
Language is lateralized: for the vast majority of the people, language is almost entirely localized int he left hemisphere.
What is the role of the right hemisphere in language?
Relates more to how people use language, instead of what do words mean. The Prosody of speech: rhythm, tone or emphasis. Emotional state of the speaker. Recognizing people’s voices. Understanding metaphors.
What happens to language when the right hemisphere is damaged?
People get literal in their interpretation of language.
Phonagnosia
A disorder where people have great difficulty recognizing familiar voices. Result of damage to right hemisphere.
Posterior Language Area
It is near the junction of the temporal, occipital, and parietal lobes. It is a hub where the perception of a word is linked up to the concept it represents. It is critical for language comprehension.
Wernicke’s Area
Could also be called: posterior aphasia, sensory aphasia, receptive aphasia, or fluent aphasia. Location in the superior gyrus of the left hemisphere (region of the auditory association cortex). Involved in the analysis of speech sounds and in recognition of spoken words. Important for comprehending words and producing meaningful speech.
Broca’s Area
Could also be referred to as anterior aphasia, motor aphasia, expressive aphasia, or non-fluent aphasia. Location in the frontal lobe. Involved in speech production.
Disorders of language: Aphasia
Important for studying the neural basis of language in humans. Aphasia is the disturbance in understanding, repeating or producing meaningful speech, caused by brain damage. Difficulty patients experience cannot be due to sensory or motor deficits or lack of motivation. Not all language disturbances are aphasias.
2 broad categories of aphasia depending on the location of the brain damage:
- Damage to the frontal lobe:
anterior aphasia, motor aphasia, non-fluent aphasia, Broca’s aphasia, expressive aphasia (difficulty producing language). - Damage to the sensory association cortex: posterior aphasia, sensory aphasia, fluent aphasia, Wernicke’s aphasia, receptive aphasia (difficulty comprehending language).
Transcortical Sensory Aphasia
Caused by damage to the posterior language area. Patients fail to comprehend the meaning of words and they are unable to express their thoughts in meaningful speech. They are able to perceive and recognize words as well as speak fluently. They can repeat words back to you, read, and write without understanding. Suggests that there might be a direct connection between Wernicke’s area (recognizing words) and Broca’s area (speech production) that bypasses the posterior language area.
Conduction Aphasia
Caused by damage to and around the connections between Wernicke’s and Broca’s area known as the arcuate fasiculus. Patients are unable to repeat the words they hear. They have meaningful, fluid speech as well as intact speech comprehension. Especially impaired at repeating nonsense words or novel sounds. Disrupts short term working memory.
Pure Word Deafness
Caused by damage to Wernicke’s area or disruption of auditory input to this region. Patients are unable to recognize the words they hear. In addition, they are unable to comprehend or repeat spoken words. They speak intelligently at first but over time their speech becomes a bit awkward. They are able to hear, read lips, read and write and interpret non-speech sounds (door bell).
Wernicke’s Aphasia
Caused by damage to both Wernicke’s area and the posterior language area. Patients have features of both transcortical aphasia and pure word deafness. Patients have poor language comprehension. What they say is meaningless and filled with function words (a, the, in). Patients have natural and fluent speech, with intact prosody.
Brocca’s Aphasia
Caused by damage to Broca’s area. Patients are unable to express themselves. The speed is slow, laborious, and confluent. They understand language. They are well-aware of their deficits - makes them frustrated.
3 Distinct Issues of Broca’s Aphasia
- Articulation Problems: Patients have issues with engaging in the coordinated movements necessary to make appropriate speech sounds (moving lips, tongue, jaw). A related problem is sequencing the sounds properly (saying LIKSTIP instead of LIPSTICK).
- Agrammatism: Difficulty using and understanding grammar. Grammar is important to understand when the action is happening or who is doing it.
- Anomia: Patients have a hard time coming up with the appropriate word. They think about the word, but it remains at the tip of their tongue. They describe things in a roundabout way (circumlocution).
Facial Paresis: Volitional vs Emotion
Volitional: Difficulty moving facial muscles on command. Able to move muscles in response to emotion. Damage to primary motor cortex.
Emotional: Able to move facial muscles on command. Difficulty moving muscles in response to emotion. Damage to thalamus / insular cortex.
How are emotions measured? (Behavioural, Autonomic, Hormonal)
Behavioural: Movements, Facial expression, Body language.
Autonomic: Signalling through PNS, Fight or flight response.
Hormonal: Signalling through bloodstream, e.g., endorphins linked with relaxation and lower stress.
Common Sense Theory
Perceive emotional event / stimulus –> Emotion occurs –> Physiological response
James-Lange Theory
Perceive emotional event / stimulus –> Physiological response –> Emotion occurs
Limbic System
Group of brain structures involved in feeling, perceiving, and regulating emotion. Central nucleus of the amygdala: important for inducing fear, important for recognizing emotions in others. People with bilateral amygdala damage can still feel fear, it’s just much harder to find things that will induce this.
Ventromedial Prefrontal Cortex (vmPFC)
Important for regulation of emotion: inhibition of emotion expression, fear extinction learning depends on vmPFC. Damage to vmPFC: impulsive (sometimes violently), outwardly emotional, childlike. Serotonin inhibits emotional outbursts: riskier behaviour in rhesus monkeys with low serotonin.
Strokes
Sudden interruption of blood supply to the brain.
Cause: Atherosclerosis. Plaque buildup in arteries. Often form an internal carotid artery. Risk factors: Age, high blood pressure, high cholesterol. Decreases blood flow. Increases blood pressure.
Ischemic Stroke
Blocked artery: blocks blood flow in artery in brain. Thrombus: Clot forms within blood vessel. Embolus: Clot breaks away from origin & occludes artery.
Hemorrhagic Stroke
Ruptured artery: bleeding around the brain (i.e., hemorrhage). High blood pressure: pressure in artery builds up, causes wall of blood vessel to rupture.