INVESTIGADORES
GARCIA adolfo Martin
congresos y reuniones científicas
Título:
The interplay of linguistic and executive deficits in Parkinson?s disease
Autor/es:
GARCÍA, A. M., BOCANEGRA, Y., PINEDA, D., BURITICÁ, O., VILLEGAS, A., LOPERA, F., GÓMEZ, D., ARIAS, C., CARDONA, J. F., TRUJILLO, N. E IBÁÑEZ, A
Lugar:
San Miguel de Tucumán
Reunión:
Congreso; XV Reunión Nacional y IV Encuentro Internacional de la Asociación Argentina de Ciencias del Comportamiento; 2015
Institución organizadora:
Asociación Argentina de Ciencias del Comportamiento
Resumen:
Introduction: Several studies have recently shown that basal ganglia deterioration leads to distinctive impairments in the domains of syntax, action verbs, and action semantics. In particular, such disruptions have been repeatedly observed in Parkinson?s disease (PD), a neurodegenerative motor disorder associated with basal ganglia dysfunction. However, it remains unclear whether these deficits are language-specific and whether they are equally dissociable from other reported disturbances ?viz., processing of object semantics. Objective: The present study sought to examine whether the above impairments were similarly dependent on (i) executive dysfunction and (ii) mild cognitive impairment. Method: To address these issues, we administered linguistic, semantic, and executive function tasks to two groups of non-demented PD patients, with and without mild cognitive impairment (PD-MCI and PD-nMCI, respectively). We compared these two groups with each other and with matched samples of healthy controls. Action-verb production and syntax were assessed via specific subtests of the Boston Diagnostic Aphasia Examination. Action and object semantics were evaluated through the Kissing and Dancing Test and the Pyramids and Palm Trees Test, respectively. Finally, executive functions were examined with the INECO Frontal Screening battery. Results: Our results showed that PD patients exhibited linguistic and semantic deficits even in the absence of MCI. Relative to their respective controls, both patient groups showed impairments in action-verb production, action semantics, object semantics, syntax, and executive functioning. However, not all linguistic and semantic domains were equally related to executive dysfunction. Regression analyses revealed that whereas EFs predicted disturbances of syntax and object semantics in both PD-nMCI and PD-MCI, they had no impact on action-verb and action-semantic impairments in either group. Critically, patients showed disruptions of action-verb production and action semantics in the absence of MCI and without any executive influence. Discussion: These findings suggest that action-language impairments constitute a sui generis deficit present since early stages of the disease. They further indicate that varied language domains are differentially related to the basal ganglia, contradicting popular approaches to neurolinguistics. Our results have clinical implications. The current model for assessing PD also taps EFs, as these may be disrupted following fronto-striatal damage. We propose that additional linguistic evaluations may hone the efficacy of current assessment tools. More effective diagnosis might be achieved through early detection of linguistic alterations even before other domains are affected, paving the way for timely application of cognitive stimulation programs. Also, this study offers theoretically relevant insights. Crucially, it highlights a critical role of the basal ganglia in processing action-related language and syntax, in agreement with embodied cognition approaches. At the same time, our findings question the descriptive and explanatory adequacy of modular neurolinguistic models, in general, and the declarative/procedural model, in particular. Contrary to this model?s predictions, lexical processing is affected by damage beyond declarative memory circuits, such as basal ganglia structures. Moreover, the finding that syntactic deficits in frontobasal patients are subordinate to executive dysfunction undermines the model?s claim that the basal ganglia subserve grammar-specific skills. [Research partially supported by CONICET, CONICYT/FONDECYT Regular (1130920), COLCIENCIAS (1115-545-31374 and 1115-569-33858), FONCyT-PICT 2012-0412, FONCyT-PICT 2012-1309, and the INECO Foundation.]