Week 2: Chapter 19 - Language Flashcards
What has research shown about language localization in the brain?
Language is distributed across a broad neural network, not localized to a single area.
What did Nina Dronkers’ 2007 study reveal about Broca’s area?
Aphasia in Broca’s patients involved regions beyond Broca’s area, challenging the classic localization model.
What does the Wernicke-Geschwind model propose?
- Wernicke’s area for comprehension
- Info passed via arcuate fasciculus
- Broca’s area for articulation
What areas are part of the core language network?
Inferior frontal gyrus (Broca), superior temporal gyrus (Wernicke), supramarginal gyrus, angular gyrus, medial temporal gyrus, and more.
What deeper structures within the lateral fissure are important for language?
Insula, Heschl’s gyrus, and the superior temporal plane.
What subcortical regions contribute to language?
Thalamus, caudate nucleus, and cerebellum.
What roles does the right hemisphere play in language?
Interpreting prosody, emotional tone, and contextual meaning.
What are the two major language pathways in the brain?
Dorsal and ventral pathways.
What is the function of the dorsal language pathway?
Converts sound to motor representations (speech production, repetition).
What is the function of the ventral pathway?
Converts sound to meaning using top-down semantic processing.
What happens when the ventral pathway is damaged?
Ability to read aloud is preserved, but comprehension is impaired.
What happens when the dorsal pathway is damaged?
Impaired speech/repetition, but comprehension remains intact.
What did Penfield’s cortical stimulation studies reveal?
Mapped speech zones, revealing positive and negative speech effects.
What are examples of positive effects from stimulation?
Involuntary vocalizations (e.g., “Oh”).
What are common negative effects of stimulation?
Speech arrest, slurred speech, anomia, misnaming, number confusion.
What did Ojemann find about Broca’s area stimulation?
Disrupted speech, facial movement, phoneme discrimination, and gesture coordination.
What does TMS allow researchers to do?
Temporarily disrupt or enhance brain activity in healthy individuals (a “virtual lesion”).
What are TMS limitations?
Auditory distraction, discomfort, limited reach to deep brain areas.
What did TMS studies reveal about Broca’s area?
Anterior region → semantic processing
Posterior region → phonological processing
What did reaction time studies show using TMS?
Region-specific delays in semantic vs. phonological tasks confirmed functional subdivisions.
What did Binder et al. (1997) find using fMRI?
Word processing activated widespread areas across temporal, frontal, parietal, and occipital lobes, plus thalamus and cerebellum.
What did Petersen et al. (1988) discover about language tasks?
- Word processing → sensory areas
- Speech → bilateral motor areas, supplementary speech area
- Verb generation → Broca, posterior temporal, cingulate, cerebellum
What does this imaging evidence suggest about language?
Language is supported by a distributed and flexible neural network.
What does the Core Language Network model propose?
Five functional modules, each with specialized nodes for specific language tasks.