Music training is neuroprotective for verbal cognition in focal epilepsy

Focal epilepsy is a unilateral brain network disorder, providing an ideal neuropathological model with which to study the effects of focal neural disruption on a range of cognitive processes. While language and memory functions have been extensively investigated in focal epilepsy, music cognition has received less attention, particularly in patients with music training or expertise. This represents a critical gap in the literature. A better understanding of the effects of epilepsy on music cognition may provide greater insight into the mechanisms behind disease- and training-related neuroplasticity, which may have implications for clinical practice. In this cross-sectional study, we comprehensively profiled music and non-music cognition in 107 participants; musicians with focal epilepsy (n = 35), non-musicians with focal epilepsy (n = 39), and healthy control musicians and non-musicians (n = 33). Parametric group comparisons revealed a specific impairment in verbal cognition in non-musicians with epilepsy but not musicians with epilepsy, compared to healthy musicians and non-musicians (P = 0.029). This suggests a possible neuroprotective effect of music training against the cognitive sequelae of focal epilepsy, and implicates potential training-related cognitive transfer that may be underpinned by enhancement of auditory processes primarily supported by temporo-frontal networks. Furthermore, our results showed that musicians with an earlier age of onset of music training performed better on a composite score of melodic learning and memory compared to non-musicians (P = 0.037), while late-onset musicians did not differ from non-musicians. For most composite scores of music cognition, although no significant group differences were observed, a similar trend was apparent. We discuss these key findings in the context of a proposed model of three interacting dimensions (disease status, music expertise, and cognitive domain), and their implications for clinical practice, music education, and music neuroscience research.

Case report: Is verbal cognitive performance in bilingual neuropsychiatric patients test-language dependent?

Bilingualism (BL) is increasing around the world. Although BL has been shown to have a broad impact-both positive and negative-on language and cognitive functioning, cognitive models and standards are mainly based on monolinguals. If we take cognitive performance of monolinguals as a standard, then the performance of bilinguals might not be accurately estimated. The assessment of cognitive functions is an important part of both the diagnostic process and further treatment in neurological and neuropsychiatric patients. In order to identify the presence or absence of cognitive deficit in bilingual patients, it will be important to determine the positive and/or negative impact of BL properties on measured cognitive performance. However, research of the impact of BL on cognitive performance in neuropsychiatric patients is limited. This article aims to compare the influence of the language (dominant-L1, second-L2) used for assessment of verbal cognitive performance in two cases of bilingual neuropsychiatric patients (English/Czech). Despite the fact that the two cases have different diagnoses, similarities in working memory and verbal learning profiles for L1 and L2 were present in both patients. We expected L1 to have higher performance in all measures when compared with L2. This assumption was partially confirmed. As expected, verbal working memory performance was better when assessed in L1. In contrast, verbal learning showed the same or better performance in L2 when compared with L1. Verbal fluency and immediate recall results were comparable in both languages. In conclusion, the language of administration partially influenced verbal performance of bilingual patients. Whether the language itself influenced low performance in a given language or it was a result of a deficit requires further research. According to our results, we suggest that an assessment in both languages needs to be a component of reasonable cognitive assessment of bilingual patients.

Verbal memory functioning in adolescents and young adults with Costello syndrome: evidence for relative preservation in recognition memory

Costello syndrome (CS) is a rare genetic disorder caused by germline mutations in the HRAS proto-oncogene which belongs to the family of syndromes called rasopathies. HRAS plays a key role in synaptic long-term potentiation (LTP) and memory formation. Prior research has found impaired recall memory in CS despite enhancement in LTP that would predict memory preservation. Based on findings in other rasopathies, we hypothesized that the memory deficit in CS would be specific to recall, and that recognition memory would show relative preservation. Memory was tested using word-list learning and story memory tasks with both recall and recognition trials, a design that allowed us to examine these processes separately. Participants were 11 adolescents and young adults with molecularly confirmed CS, all of whom fell in the mild to moderate range of intellectual disability. Results indicated a clear dissociation between verbal recall, which was impaired (M = 69 ± 14), and recognition memory, which was relatively intact (M = 86 ± 14). Story recognition was highly correlated with listening comprehension (r = 0.986), which also fell in the low-average range (M = 80 ± 12.9). Performance on other measures of linguistic ability and academic skills was impaired. The findings suggest relatively preserved recognition memory that also provides some support for verbal comprehension. This is the first report of relatively normal performance in a cognitive domain in CS. Further research is needed to better understand the mechanisms by which altered RAS-MAPK signaling affects neuronal plasticity and memory processes in the brain.