Factors of choking under pressure in musicians.

Under pressure, motor actions, such as those required in public speech, surgery, or musical performance, can be compromised, even when these have been well-trained. The latter is often referred to as 'choking' under pressure. Although multifaceted problems mediate such performance failure in anxiogenic situations, such as compromised motor dexterity and cognitive disruption, the fundamental set of abnormalities characterizing choking under pressure and how these abnormalities are related have not been elucidated. Here, we attempted, first, to classify behavioural, psychological, and physiological abnormalities associated with choking under pressure in musicians and, second, to identify their relationship based on datasets derived from a questionnaire with 258 pianist respondents. Explorative factor analysis demonstrated eight functional abnormalities related to the musicians' choking, such as attention to the audience, erroneous motor actions, perceptual confusion, and failure of memory recall, which however did not include exaggerated attention to the performance. This suggests distraction of attention away from skill execution, which may underlie the spoiled performance under pressure. A structural equation analysis further inferred causal relationships among them. For instance, while failure of memory recall was influenced by passive behaviours manifesting under pressure, erroneous motor actions during performance were influenced by feeling rushed and a loss of body control. In addition, some specific personal traits, such as neuroticism, public self-consciousness, and a lack of confidence, were associated with the extent to which pressure brought about these abnormalities. These findings suggest that distinct psycho-behavioural abnormalities and personal traits underlie the detrimental effects of pressure on musical performance.

Regioisomer Differentiation of Ring-Substituted Chloromethcathinones and Bromomethcathinones Using Gas Chromatography/Electron Ionization-Triple Quadrupole Energy-Resolved Mass Spectrometry.

Positional isomers o-, m-, and p-chloromethcathinones (CMCs) and m- and p-bromomethcathinones (BMCs) were effectively differentiated using gas chromatography (GC) and energy-resolved mass spectrometry (ERMS) analyses. GC demonstrated that the free bases of CMC and BMC isomers were simultaneously baseline-separated at a slow column heating rate (5 °C/min) using a conventional low-polar capillary column. ERMS showed that the trifluoroacetyl derivatives of the positional isomers differed in mass spectral abundances of both halophenyl and halobenzoyl cations. Moreover, the logarithmic plots of the abundance ratio of the two cations as a function of the collision energy (CE) exhibited marked differences among the isomers at each CE, following the order of ortho < para < meta for CMCs and para < meta for BMCs. The performed theoretical calculations of dissociation energy agreed well with the ERMS measurements. The GC and ERMS methodologies enabled unambiguous and reliable differentiation of CMC and BMC isomers. The developed approach is expected to significantly contribute to the accurate structural identification of new psychoactive substances in forensic, toxicological, and clinical fields.