Person: Gajardo-Vidal, Andrea
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Gajardo-Vidal
First Name
Andrea
Name
3 results
ĀæQuĆ© estĆ”s buscando?
Search Results
Now showing 1 - 3 of 3
Publication Enhanced left superior parietal activation during successful speech production in patients with left dorsal striatal damage and error-prone neurotypical participants(2023) Geva, Sharon; Schneider, Letitia M.; Khan, Shamima; Lorca-Puls, Diego L.; gajardo vidal; Gajardo-Vidal, Andrea; PLORAS team; Hope, Thomas M. H.; Green, David W.; Price, Cathy J.Functional imaging studies of neurotypical adults report activation in the left putamen during speech production. The current study asked how stroke survivors with left putamen damage are able to produce correct spoken responses during a range of speech production tasks. Using functional magnetic resonance imaging, activation during correct speech production responses was assessed in 5 stroke patients with circumscribed left dorsal striatal lesions, 66 stroke patient controls who did not have focal left dorsal striatal lesions, and 54 neurotypical adults. As a group, patients with left dorsal striatal damage (our patients of interest) showed higher activation than neurotypical controls in the left superior parietal cortex during successful speech production. This effect was not specific to patients with left dorsal striatal lesions as we observed enhanced activation in the same region in some patient controls and also in more error-prone neurotypical participants. Our results strongly suggest that enhanced left superior parietal activation supports speech production in diverse challenging circumstances, including those caused by stroke damage. They add to a growing body of literature indicating how upregulation within undamaged parts of the neural systems already recruited by neurotypical adults contributes to recovery after stroke.Publication Degeneracy in the neurological model of auditory speech repetition(2023) Sajid, Noor; Gajardo-Vidal, Andrea; Ekert, Justyna O.; Lorca-Puls, Diego L.; Hope , Thomas M. H.; Green, David W.; Friston, Karl J.; Price, Cathy J.Both classic and contemporary models of auditory word repetition involve at least four left hemisphere regions: primary auditory cortex for processing sounds; pSTS (within Wernickeās area) for processing auditory images of speech; pOp (within Brocaās area) for processing motor images of speech; and primary motor cortex for overt speech articulation. Previous functional-MRI (fMRI) studies confirm that auditory repetition activates these regions, in addition to many others. Crucially, however, contemporary models do not specify how regions interact and drive each other during auditory repetition. Here, we used dynamic causal modelling, to test the functional interplay among the four core brain regions during single auditory word and pseudoword repetition. Our analysis is grounded in the principle of degeneracyāi.e., many-to-one structure-function relationshipsāwhere multiple neural pathways can execute the same function. Contrary to expectation, we found that, for both word and pseudoword repetition, (i) the effective connectivity between pSTS and pOp was predominantly bidirectional and inhibitory; (ii) activity in the motor cortex could be driven by either pSTS or pOp; and (iii) the latter varied both within and between individuals. These results suggest that different neural pathways can support auditory speech repetition. This degeneracy may explain resilience to functional loss after brain damage.Publication Degeneracy in the neurological model of auditory speech repetition(2023) Sajid, Noor; Gajardo-Vidal, Andrea; Ekert, Justyna O.; Lorca-Puls, Diego L.; Hope, Thomas M. H.; Green, David W.; Friston, Karl J.; Price, Cathy J.Both classic and contemporary models of auditory word repetition involve at least four left hemisphere regions: primary auditory cortex for processing sounds; pSTS (within Wernicke's area) for processing auditory images of speech; pOp (within Broca's area) for processing motor images of speech; and primary motor cortex for overt speech articulation. Previous functional-MRI (fMRI) studies confirm that auditory repetition activates these regions, in addition to many others. Crucially, however, contemporary models do not specify how regions interact and drive each other during auditory repetition. Here, we used dynamic causal modelling, to test the functional interplay among the four core brain regions during single auditory word and pseudoword repetition. Our analysis is grounded in the principle of degeneracy-i.e., many-to-one structure-function relationships-where multiple neural pathways can execute the same function. Contrary to expectation, we found that, for both word and pseudoword repetition, (i) the effective connectivity between pSTS and pOp was predominantly bidirectional and inhibitory; (ii) activity in the motor cortex could be driven by either pSTS or pOp; and (iii) the latter varied both within and between individuals. These results suggest that different neural pathways can support auditory speech repetition. This degeneracy may explain resilience to functional loss after brain damage.