Análise do desempenho e do esforço cognitivo gerado na performance de quatro excertos com demandas técnicas distintas no contrabaixo

Abstract

Given the intricate nature of the movements responsible for performance on the acoustical double bass, this study aimed to investigate the level of performance and mental workload generated in the execution of four musical excerpts with different technical demands on this instrument. The excerpts covered represent the following conditions: (1) pressure of the bow on the string in fortissimo; (2) string crossing; (3) quick alternation between arco and pizzicato; (4) location of target notes. Each excerpt was performed by the same subject using two different techniques, one of which was preferred and the other non-preferred. Excerpts 1, 2 and 3 were performed: (a) using the French bow; (b) using the German bow. The fourth excerpt was performed: (a) using visual references to control pitch; (b) no visual references. From the audio performance record, performance measures were extracted with the aid of Sonic Visualiser Software. Mental workload indices were obtained from electroencephalographic measurements (EEG). The results found partially confirm the hypotheses of the study. The performance with the preferred technique obtained better motor performance in the excerpts referring to bow pressure on the string, string crossing and quick alternation between bow and pizzicato. The subjects who prefer handling the French bow model performed better in the excerpts referring to the crossing of strings and the quick alternation between bow and pizzicato. In cognitive measures, the preferred technique resulted in a lower rate of Engagement in the quick alternation between arco and pizzicato. A lower Workload index was also found in the pressure of the bow on the string. The performance of the excerpt referring to the pressure of the bow on the string showed a lower Δ Workload among the subjects who have the German bow handling as their preferred technique and a lower Δ Engagement among the subjects who prefer the French bow handling. In general, the results indicated different indices of performance and mental workload generated during performance with the German and French bow models. Analyzes involving the use of visual references to control pitch did not show significant results. These findings are discussed in terms of the movement characteristics of each technique and the cognitive processing involved during performance.