Browsing by Author "Boncompte, Gonzalo"
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- ItemBrain activity complexity has a nonlinear relation to the level of propofol sedation(2021) Boncompte, Gonzalo; Medel, Vicente; Cortinez, Luis, I; Ossandon, TomasBackground: Brain activity complexity is a promising correlate of states of consciousness. Previous studies have shown higher complexity for awake compared with deep anaesthesia states. However, little attention has been paid to complexity in intermediate states of sedation.
- ItemCognitive function mediates the relationship between age and anaesthesia-induced oscillatory-specific alpha power(2023) Boncompte, Gonzalo; Freedman, Isaac; Qu, Jason; Turco, Isabella; Khawaja, Zain Q.; Cortinez, Ignacio; Pedemonte, Juan C.; Akeju, OluwaseunCognitive decline is common among older individuals, and although the underlying brain mechanisms are not entirely understood, researchers have suggested using EEG frontal alpha activity during general anaesthesia as a potential biomarker for cognitive decline. This is because frontal alpha activity associated with GABAergic general anaesthetics has been linked to cognitive function. However, oscillatory-specific alpha power has also been linked with chronological age. We hypothesize that cognitive function mediates the association between chronological age and (oscillatory-specific) alpha power. We analysed data from 380 participants (aged over 60) with baseline screening assessments and intraoperative EEG. We utilized the telephonic Montreal Cognitive Assessment to assess cognitive function. We computed total band power, oscillatory-specific alpha power, and aperiodics to measure anaesthesia-induced alpha activity. To test our mediation hypotheses, we employed structural equation modelling. Pairwise correlations between age, cognitive function and alpha activity were significant. Cognitive function mediated the association between age and classical alpha power [age -> cognitive function -> classical alpha; beta = -0.0168 (95% confidence interval: -0.0313 to -0.00521); P = 0.0016] as well as the association between age and oscillatory-specific alpha power [age -> cognitive function -> oscillatory-specific alpha power; beta = -0.00711 (95% confidence interval: -0.0154 to -0.000842); P = 0.028]. However, cognitive function did not mediate the association between age and aperiodic activity (1/f slope, P = 0.43; offset, P = 0.0996). This study is expected to provide valuable insights for anaesthesiologists, enabling them to make informed inferences about a patient's age and cognitive function from an analysis of anaesthetic-induced EEG signals in the operating room. To ensure generalizability, further studies across different populations are needed.
- ItemIntraoperative electroencephalographic marker of preoperative frailty: a prospective cohort study(2023) Boncompte, Gonzalo; Sun, Haoqi; Elgueta Le-Beuffe, María Francisca; Benavides, Javiera; Carrasco, Marcela; Morales, María I.; Calderón, Natalia; Contreras, Victor; Westover, M. Brandon; Cortínez, Luis I.; Akeju, Oluwaseun; Pedemonte Trewhela, Juan CristóbalFrailty was common in elderly patients undergoing non cardiac surgery. Electroencephalogram alpha-band power does not predict preoperative frailty above patients' age. Frailty predictions by machine learning algorithms, were not improved by the addition of electroencephalogram features. Frailty might be different to the concept of brain vulnerability, accounting for a possible brain-body dissociation.
- ItemLearning emotional dialects: A British population study of cross-cultural communication(2023) Tsikandilakis, Myron; Bali, Persefoni; Lanfranco, Renzo C.; Kausel, Leonie; Yu, Zhaoliang; Boncompte, Gonzalo; Karlis, Alexandros-Konstantinos; Alshammari, Alkadi; Li, Ruiyi; Milbank, Alison; Burdett, Michael; Mevel, Pierre-Alexis; Madan, Christopher; Derrfuss, JanThe aim of the current research was to explore whether we can improve the recognition of cross-cultural freely-expressed emotional faces in British participants. We tested several methods for improving the recognition of freely-expressed emotional faces, such as different methods for presenting other-culture expressions of emotion from individuals from Chile, New Zealand and Singapore in two experimental stages. In the first experimental stage, in phase one, participants were asked to identify the emotion of cross-cultural freely-expressed faces. In the second phase, different cohorts were presented with interactive side-by-side, back-to-back and dynamic morphing of cross-cultural freely-expressed emotional faces, and control conditions. In the final phase, we repeated phase one using novel stimuli. We found that all non-control conditions led to recognition improvements. Morphing was the most effective condition for improving the recognition of cross-cultural emotional faces. In the second experimental stage, we presented morphing to different cohorts including own-to-other and other-to-own freely-expressed cross-cultural emotional faces and neutral-to-emotional and emotional-to-neutral other-culture freely-expressed emotional faces. All conditions led to recognition improvements and the presentation of freely-expressed own-to-other cultural-emotional faces provided the most effective learning. These findings suggest that training can improve the recognition of cross-cultural freely-expressed emotional expressions.
- ItemNeural correlates of conscious motion perception(2018) Boncompte, Gonzalo; Cosmelli, Diego
- ItemSpontaneous Alpha Power Lateralization Predicts Detection Performance in an Un-Cued Signal Detection Task(2016) Boncompte, Gonzalo; Villena González, Mario; Cosmelli, Diego; López Hernández, Vladimir
- ItemThe effect of age on electroencephalogram measures of anesthesia hypnosis: A comparison of BIS, Alpha Power, Lempel-Ziv complexity and permutation entropy during propofol induction(2022) Biggs, Daniela; Boncompte, Gonzalo; Pedemonte, Juan C. C.; Fuentes, Carlos; Cortinez, Luis I. I.BackgroundImproving anesthesia administration for elderly population is of particular importance because they undergo considerably more surgical procedures and are at the most risk of suffering from anesthesia-related complications. Intraoperative brain monitors electroencephalogram (EEG) have proved useful in the general population, however, in elderly subjects this is contentious. Probably because these monitors do not account for the natural differences in EEG signals between young and older patients. In this study we attempted to systematically characterize the age-dependence of different EEG measures of anesthesia hypnosis. MethodsWe recorded EEG from 30 patients with a wide age range (19-99 years old) and analyzed four different proposed indexes of depth of hypnosis before, during and after loss of behavioral response due to slow propofol infusion during anesthetic induction. We analyzed Bispectral Index (BIS), Alpha Power and two entropy-related EEG measures, Lempel-Ziv complexity (LZc), and permutation entropy (PE) using mixed-effect analysis of variances (ANOVAs). We evaluated their possible age biases and their trajectories during propofol induction. ResultsAll measures were dependent on anesthesia stages. BIS, LZc, and PE presented lower values at increasing anesthetic dosage. Inversely, Alpha Power increased with increasing propofol at low doses, however this relation was reversed at greater effect-site propofol concentrations. Significant group differences between elderly patients (>65 years) and young patients were observed for BIS, Alpha Power, and LZc, but not for PE. ConclusionBIS, Alpha Power, and LZc show important age-related biases during slow propofol induction. These should be considered when interpreting and designing EEG monitors for clinical settings. Interestingly, PE did not present significant age differences, which makes it a promising candidate as an age-independent measure of hypnotic depth to be used in future monitor development.
- Item"There Is No (Where a) Face Like Home": Recognition and Appraisal Responses to Masked Facial Dialects of Emotion in Four Different National Cultures(2021) Tsikandilakis, Myron; Yu, Zhaoliang; Kausel, Leonie; Boncompte, Gonzalo; Lanfranco, Renzo C.; Oxner, Matt; Bali, Persefoni; Urale Leong, Poutasi; Qing, Man; Paterakis, George; Caci, Salvatore; Milbank, Alison; Mevel, Pierre-Alexis; Carmel, David; Madan, Christopher; Derrfuss, Jan; Chapman, PeterThe theory of universal emotions suggests that certain emotions such as fear, anger, disgust, sadness, surprise and happiness can be encountered cross-culturally. These emotions are expressed using specific facial movements that enable human communication. More recently, theoretical and empirical models have been used to propose that universal emotions could be expressed via discretely different facial movements in different cultures due to the non-convergent social evolution that takes place in different geographical areas. This has prompted the consideration that own-culture emotional faces have distinct evolutionary important sociobiological value and can be processed automatically, and without conscious awareness. In this paper, we tested this hypothesis using backward masking. We showed, in two different experiments per country of origin, to participants in Britain, Chile, New Zealand and Singapore, backward masked own and other-culture emotional faces. We assessed detection and recognition performance, and self-reports for emotionality and familiarity. We presented thorough cross-cultural experimental evidence that when using Bayesian assessment of non-parametric receiver operating characteristics and hit-versus-miss detection and recognition response analyses, masked faces showing own cultural dialects of emotion were rated higher for emotionality and familiarity compared to other-culture emotional faces and that this effect involved conscious awareness.