RESUMO
Above and beyond the critical contributions of left perisylvian regions to language, the neural networks supporting pragmatic aspects of verbal communication in native and non-native languages (L1s and L2, respectively) have often been ascribed to the right hemisphere (RH). However, several reports have shown that left-hemisphere activity associated with pragmatic domains (e.g., prosody, indirect speech, figurative language) is comparable to or even greater than that observed in the RH, challenging the proposed putative role of the latter for relevant domains. Against this background, we report on an adult bilingual patient showing preservation of pragmatic verbal skills in both languages (L1: Spanish, L2: English) despite bilateral damage mainly focused on the RH. After two strokes, the patient sustained lesions in several regions previously implicated in pragmatic functions (vast portions of the right fronto-insulo-temporal cortices, the bilateral amygdalae and insular cortices, and the left putamen). Yet, comparison of linguistic and pragmatic skills with matched controls revealed spared performance on multiple relevant tasks in both her L1 and L2. Despite mild difficulties in some aspects of L2 prosody, she showed no deficits in comprehending metaphors and idioms, or understanding indirect speech acts in either language. Basic verbal skills were also preserved in both languages, including verbal auditory discrimination, repetition of words and pseudo-words, cognate processing, grammaticality judgments, equivalent recognition, and word and sentence translation. Taken together, the evidence shows that multiple functions of verbal communication can be widely spared despite extensive damage to the RH, and that claims for a putative relation between pragmatics and the RH may have been overemphasized in the monolingual and bilingual literature. We further discuss the case in light of previous reports of pragmatic and linguistic deficits following brain lesions and address its relation to cognitive compensation in bilingual patients.
RESUMO
La Afasia Progresiva Primaria (APP) es una patología neurodegenerativa que se presenta con afectación insidiosa y progresiva del lenguaje. Los criterios diagnósticos actuales diferencian tres subtipos de APP, cada una con perfiles neurolingüísticos específicos. Diversas investigaciones han propuesto que un síntoma característico de la APP variante semántica (APP-vs) es un mayor compromiso en el procesamiento de conceptos concretos que de abstractos (Efecto de Concretud Inverso - ECI). Para explicar este ECI se han propuesto diferentes explicaciones: (a). el patrón de compromiso neural, (b). el nivel educativo de los pacientes, (c). el estadio de la enfermedad. El objetivo del presente trabajo es estudiar en forma longitudinal la progresión en el procesamiento de conceptos concretos y abstractos en un paciente diagnosticado con APP-vs. Para ello se utilizó una tarea de juicios de sinonimia donde se debe identificar si dos palabras son sinónimos o no. La tarea cuenta con pares de conceptos concretos y abstractos. Se evaluó al paciente en tres momentos (2014, 2015 y 2016). Se observó un mejor desempeño de conceptos abstractos en la primera evaluación. El ECI desaparece en la segunda evaluación. El patrón se revierte en la tercera. Estos resultados apoyan la propuesta de que el ECI observado en pacientes con APP-vs es un síntoma de los estadios iniciales de la enfermedad. Este ECI se relacionaría con la afectación temprana de las porciones del Lóbulo Temporal Anterior que procesan rasgos visuales, que serían más relevantes para los conceptos concretos.
Primary Progressive Aphasia (PPA) is a neurodegenerative disease which appears with progressive and insidious affectation of language. Current diagnostic criteria establish three different subtypes of PPA, each showing specific neurolinguistic profiles. Several researches have proposed a Reverse Concreteness Effect (RCE) as a main symptom for the Semantic Variant of PPA (sv-PPA), that is, a better performance with abstract than concrete concepts. Different explanations for this effect include: (a). pattern of neural degeneration, (b). patients' educational level, (c). moment of disease progression. The aim of this work is to study the progression of concrete and abstract concepts processing in a patient diagnosed with sv-PPA. We used a synonyms judgement task where the subject has to indicate if two words are synonyms or not. The task include both concrete and abstract concepts. The patient was evaluated in three different moments (2014, 2015 and 2016). A better performance with abstract concepts was observed during the first evaluation. The RCE disappeared during the second assessment. The third time showed a reversed pattern. Our results support those proposing that the RCE can only be found at initial stages of vs-PPA. The RCE appears to be related to the early degeneration of some portions in the Anterior Temporal Lobe which process visual features. These would be much more relevant for processing concrete concepts.