Developmental Dyslexia and Aphasia Quiz

Introduction to Behavioral Neuroscience

• Course: PSYC 211
• Lecture: 18 of 24
• Textbook chapter: 13
• Instructor: Jonathan Britt
• Contact information: [email protected]

Speech Comprehension

• Verbal behavior is lateralized in the brain, primarily on the left side.
• Language impairments (comprehension and expression) often result from damage to the left hemisphere.
• The left hemisphere dominates speech in approximately 90% of the population (94% of right-handed individuals and 70% of left-handed individuals).

Prosody: Rhythm, Tone, and Emphasis

• Prosody encompasses the rhythm, emphasis, and tone of speech.
• It is primarily a function of the right hemisphere.
• People use emphasis and pitch changes to clarify meaning and distinguish between different aspects of speech (such as assertions and questions).
• Individuals with left hemisphere damage may still comprehend and extract emotional information from prosody.

Recognition of People's Voices

• People readily recognize familiar voices, even newborns.
• Voice recognition is independent of word comprehension.
• People with damage to the right temporal lobe may have difficulty recognizing voices (phonagnosia).

Unfamiliar Metaphors

• Attempts to understand unfamiliar metaphors mainly activate the right hemisphere.
• The left hemisphere plays a crucial role in comprehending the literal meaning of words.

Aphasia

• Aphasia is a language disturbance impacting understanding, repeating, or producing meaningful speech.
• It isn't a result of sensory or motor deficits or lack of motivation.
• Sufferers must be able identify others' communication attempts and have some awareness of their surroundings.
• Subsequent notes focus on left hemisphere damage, impacting most people.

Middle Cerebral Artery

• Damage to this artery often results in aphasia.
• Symptom severity is highly variable, contingent on the specific location of cell death.

Types of Aphasia

• Various types of aphasia result from specific brain damage localization.
• Sensory aphasia pertains to understanding language.
• Wernicke's aphasia affects both understanding and expressing fluent language.
• Broca's aphasia encompasses difficulty in speech output.
• Non-fluent aphasia generally refers to trouble generating meaningful language.
• Transcortical sensory aphasia involves issues with comprehending language.
• Transcortical motor aphasia features trouble in initiating speech.
• Conduction aphasia mainly hinders repetition of words.
• Anomic aphasia often impacts word retrieval.

Word Comprehension

• Many different factors (sight, hearing, touch, smell, taste, and physical actions) contribute to word comprehension.
• Crucial regions involved include the auditory cortex, Wernicke's area, and the posterior language area.

Word Comprehension (Posterior Language Area)

• The posterior language area is pivotal for language comprehension across different input modalities (heard, spoken, read).
• Damage to the area can lead to transcortical sensory aphasia, causing comprehension issues.
• Repetition of words remains relatively unaffected.

Receptive Fluent Aphasia (Wernicke's Aphasia)

• This condition involves difficulties in understanding spoken language despite fluent speech.

Byron's Road to Recovery

• Byron's wife discussed his recovery from Wernicke's aphasia five years post-stroke.
• Progress is possible, but full recovery is often atypical.
• Current capabilities include comprehension of various texts, including financial documents, and math problem completion.

All Language Perception Areas

• Various language processing areas are connected to posterior and Broca's areas in the brain.
• This connectivity ensures comprehensive interaction between different linguistic processes.

Conduction Aphasia

• Damage to the arcuate fasciculus, a crucial connection between Wernicke's and Broca's areas, results in conduction aphasia.
• This condition mainly affects word repetition ability, while maintaining fluency and comprehension.

Wernicke's Area

• Wernicke's area is an integral portion of the auditory association cortex within the left temporal lobe.
• It is critical in recognizing spoken words.
• Distinguishing between hearing sounds and comprehending them as words is a key function of Wernicke's area.

Pure Word Deafness

• Pure word deafness is a condition resulting from damage in a specific part of Wernicke's area.
• It hinders the comprehension and repetition of spoken words while preserving other auditory capabilities (such as interpreting non-word sounds).

Pure Alexia

• Damage to the visual word-form area (VWFA) can cause pure alexia (or word blindness).
• This disorder impacts the ability to recognize and read written words while typically preserving other language functions.
• Reading comprehension is severely impaired, but other written output stays relatively intact.

Reading

• Reading involves two key processes: whole-word (sight) reading and phonetic reading.
• Sight reading focuses on recognizing entire words, whereas phonetic reading processes individual letter sounds.
• The interaction between these methods can vary depending on the familiarity of the word or stimuli. 

Surface Dyslexia

• Difficulty with unfamiliar or irregular words, although proficient with regular words.

Phonological Dyslexia

• Difficulty with unfamiliar or irregular words, especially non-words.
• This is often contrasted with surface dyslexia, where familiar words are strong but irregular words are difficult.

Selective Disorders of Reading

• Some stroke patients experience selective difficulties in extracting meaning from written words, even when capable of pronouncing them aloud.

Reading (Object Recognition)

• Reliable cues for object recognition (and words) are those that remain stable regardless of angles of view.

Types of Aphasia (Summary)

• A table summarizing the different classifications of aphasia by fluency/comprehension/repetition.

Speech Production (Broca's Area)

• Broca's area, a vital component in the left inferior frontal lobe, is critical for speech production tasks.
• Damage to this region causes Broca's aphasia, which impacts speech production with slowed, non-fluent output, although comprehension remains largely intact.

Agrammatism

• A breakdown in understanding and using grammatical components of language.
• This severely limits the grammatical elements of speech output and, in some cases, comprehension.

Speech Production and Comprehension

• Distinctions between content words (nouns, verbs, etc.) and function words (articles, prepositions and others) are important during aphasia.
• Content words convey meaning, while function words provide grammatical structure.

Anomic Aphasia

• Difficulty naming objects or articulating concepts is a common symptom of diverse aphasia types, especially Broca's.
• Characterized by the ability to understand others and communicate relatively fluently despite difficulty verbally articulating ideas.

Test your knowledge on developmental dyslexia and aphasia with this quiz. Explore key characteristics, brain areas involved, and comprehension levels. Perfect for students studying language disorders or cognitive psychology.