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1.
Acta Psychol (Amst) ; 244: 104195, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38412710

RESUMEN

This study adopts a cross-linguistic perspective and investigates how musical expertise affects the perception of duration and pitch in language. Native speakers of Chinese (N = 44) and Estonian (N = 46), each group subdivided into musicians and non-musicians, participated in a mismatch negativity (MMN) experiment where they passively listened to both Chinese and Estonian stimuli, followed by a behavioral experiment where they attentively discriminated the stimuli in the non-native language (i.e., Chinese to Estonian participants and Estonian to Chinese participants). In both experiments, stimuli of duration change, pitch change, and duration plus pitch change were discriminated. We found higher behavioral sensitivity among Chinese musicians than non-musicians in perceiving the duration change in Estonian and higher behavioral sensitivity among Estonian musicians than non-musicians in perceiving all types of changes in Chinese, but no corresponding effect was found in the MMN results, which suggests a more salient effect of musical expertise on foreign language processing when attention is required. Secondly, Chinese musicians did not outperform non-musicians in attentively discriminating the pitch-related stimuli in Estonian, suggesting that musical expertise can be overridden by tonal language experience when perceiving foreign linguistic pitch, especially when an attentive discrimination task is administered. Thirdly, we found larger MMN among Chinese and Estonian musicians than their non-musician counterparts in perceiving the largest deviant (i.e., duration plus pitch) in their native language. Taken together, our results demonstrate a positive effect of musical expertise on language processing.


Asunto(s)
Música , Percepción de la Altura Tonal , Humanos , Electroencefalografía/métodos , Lenguaje , Lingüística , Estimulación Acústica/métodos
2.
Neurosci Biobehav Rev ; 153: 105366, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37633625

RESUMEN

Event-related potentials (ERPs), specifically the Mismatch Response (MMR), holds promise for investigating auditory maturation in children. It has the potential to predict language development and distinguish between language-impaired and typically developing groups. However, summarizing the MMR's developmental trajectory in typically developing children remains challenging despite numerous studies. This pioneering meta-analysis outlines changes in MMR amplitude among typically developing children, while offering methodological best-practices. Our search identified 51 articles for methodology analysis and 21 for meta-analysis, involving 0-8-year-old participants from 2000 to 2022. Risk of Bias assessment and methodology analysis revealed shortcomings in control condition usage and reporting of study confounders. The meta-analysis results were inconsistent, indicating large effect sizes in some conditions and no effect sizes in others. Subgroup analysis revealed the main effects of age and brain region, as well as an interaction of age and time-window of the MMR. Future research requires a specific protocol, larger samples, and replication studies to deepen the understanding of the auditory discrimination maturation process in children.

4.
Cogn Emot ; 37(5): 959-972, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37338015

RESUMEN

Affective aspects of a stimulus can be processed rapidly and before cognitive attribution, acting much earlier for verbal stimuli than previously considered. Aimed for specific mechanisms, event-related brain potentials (ERPs), expressed in facial expressions or word meaning and evoked by six basic emotions - anger, disgust, fear, happy, sad, and surprise - relative to emotionally neutral stimuli were analysed in a sample of 116 participants. Brain responses in the occipital and left temporal regions elicited by the sadness in facial expressions or words were indistinguishable from responses evoked by neutral faces or words. Confirming previous findings, facial fear elicited an early and strong posterior negativity. Instead of expected parietal positivity, both the happy faces and words produced significantly more negative responses compared to neutral. Surprise in facial expressions and words elicited a strong early response in the left temporal cortex, which could be a signature of appraisal. The results of this study are consistent with the view that both types of affective stimuli, facial emotions and word meaning, set off rapid processing and responses occur very early in the processing stage.


Asunto(s)
Electroencefalografía , Emociones , Humanos , Electroencefalografía/métodos , Emociones/fisiología , Potenciales Evocados/fisiología , Encéfalo/fisiología , Felicidad , Expresión Facial
5.
Brain Behav ; 13(8): e3106, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37278143

RESUMEN

OBJECTIVES: The Estonian National Mental Health Study (EMHS) was conducted in 2021-2022 to provide population-wide data on mental health in the context of COVID-19 pandemic. The main objective of this paper is to describe the rationale, design, and methods of the EMHS and to evaluate the survey response. METHODS: Regionally representative stratified random sample of 20,000 persons aged 15 years and older was drawn from the Estonian Population Register for the study. Persons aged 18 years and older at the time of the sampling were enrolled into three survey waves where they were invited to complete an online or postal questionnaire about mental well-being and disorders, and behavioral, cognitive, and other risk factors. Persons younger than 18 years of age were invited to fill an anonymous online questionnaire starting from wave 2. To complement and validate survey data, data on socio-demographic, health-related, and environmental variables were collected from six national administrative databases and registries. Additionally, a subsample was enrolled into a validation study using ecological momentary assessment. RESULTS: In total, 5636 adults participated in the survey wave 1, 3751 in wave 2, and 4744 in wave 3. Adjusted response rates were 30.6%, 21.1%, and 27.6%, respectively. Women and older age groups were more likely to respond. Throughout the three survey waves, a considerable share of adult respondents screened positive for depression (27.6%, 25.1%, and 25.6% in waves 1, 2, and 3, respectively). Women and young adults aged 18 to 29 years had the highest prevalence of depression symptoms. CONCLUSIONS: The registry-linked longitudinal EMHS dataset comprises a rich and trustworthy data source to allow in-depth analysis of mental health outcomes and their correlates among the Estonian population. The study serves as an evidence base for planning mental health policies and prevention measures for possible future crises.


Asunto(s)
COVID-19 , Salud Mental , Adulto Joven , Humanos , Femenino , Anciano , Adolescente , COVID-19/epidemiología , Pandemias , Estonia/epidemiología , Estudios Longitudinales , Sistema de Registros
6.
R Soc Open Sci ; 10(2): 191375, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36756055

RESUMEN

The low reproducibility rate in social sciences has produced hesitation among researchers in accepting published findings at their face value. Despite the advent of initiatives to increase transparency in research reporting, the field is still lacking tools to verify the credibility of research reports. In the present paper, we describe methodologies that let researchers craft highly credible research and allow their peers to verify this credibility. We demonstrate the application of these methods in a multi-laboratory replication of Bem's Experiment 1 (Bem 2011 J. Pers. Soc. Psychol. 100, 407-425. (doi:10.1037/a0021524)) on extrasensory perception (ESP), which was co-designed by a consensus panel including both proponents and opponents of Bem's original hypothesis. In the study we applied direct data deposition in combination with born-open data and real-time research reports to extend transparency to protocol delivery and data collection. We also used piloting, checklists, laboratory logs and video-documented trial sessions to ascertain as-intended protocol delivery, and external research auditors to monitor research integrity. We found 49.89% successful guesses, while Bem reported 53.07% success rate, with the chance level being 50%. Thus, Bem's findings were not replicated in our study. In the paper, we discuss the implementation, feasibility and perceived usefulness of the credibility-enhancing methodologies used throughout the project.

8.
Appetite ; 168: 105758, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34655665

RESUMEN

Momentary positive and negative emotions have shown to affect eating behaviour. In this study, we used experience sampling method (ESM) to assess how momentary positive affect (PA) and negative affect (NA) relate to overeating (OE) and binge eating (BE) episodes among men and women compared to no OE/BE episodes. We additionally looked at how situational and social context moderate these relationships. For this purpose, 87 women and 94 men participated in the study where they were instructed to rate their levels of various positive and negative emotions, situational whereabouts, and the presence of OE/BE 7 times a day for 3 consecutive days. We found that men and women greatly differed in how momentary PA and NA relate to OE and BE. In women, NA was highest before BE, followed by OE compared to no OE/BE. Further, an interaction between the type of an eating episode and situational context demonstrated that this relationship was significant when at home, but not away from home. No differences in the momentary NA between the types of eating episodes were found in men. In men, PA was significantly higher before OE compared to BE and no OE/BE. Additionally, an interaction between the type of eating episode and situational context showed that this relationship was significant when at home, but not when away from home. Our results further confirm the role of negative affect in overeating and binge eating in women, whereas also suggesting that the role of positive affect in eating behaviour is warranted more research, particularly in men.


Asunto(s)
Trastorno por Atracón , Bulimia , Afecto , Evaluación Ecológica Momentánea , Conducta Alimentaria , Femenino , Humanos , Hiperfagia , Masculino
10.
Front Hum Neurosci ; 15: 612617, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33994973

RESUMEN

Similar to visual perception, auditory perception also has a clearly described "pop-out" effect, where an element with some extra feature is easier to detect among elements without an extra feature. This phenomenon is better known as auditory perceptual asymmetry. We investigated such asymmetry between shorter or longer duration, and level or falling of pitch of linguistic stimuli that carry a meaning in one language (Estonian), but not in another (Russian). For the mismatch negativity (MMN) experiment, we created four different types of stimuli by modifying the duration of the first vowel [ɑ] (170, 290 ms) and pitch contour (level vs. falling pitch) of the stimuli words ('SATA,' 'SAKI'). The stimuli were synthesized from Estonian words ('SATA,' 'SAKI') and follow the Estonian language three-way quantity system, which incorporates tonal features (falling pitch contour) together with temporal patterns. This made the meaning of the word dependent on the combination of both features and allows us to compare the relative contribution of duration and pitch contour in discrimination of language stimuli in the brain via MMN generation. The participants of the experiment were 12 Russian native speakers with little or no experience in Estonian and living in Estonia short-term, and 12 Estonian native speakers (age 18-27 years). We found that participants' perception of the linguistic stimuli differed not only according to the physical features but also according to their native language, confirming that the meaning of the word interferes with the early automatic processing of phonological features. The GAMM and ANOVA analysis of the reversed design results showed that the deviant with longer duration among shorter standards elicited a MMN response with greater amplitude than the short deviant among long standards, while changes in pitch contour (falling vs. level pitch) produced neither strong MMN nor asymmetry. Thus, we demonstrate the effect of language background on asymmetric perception of linguistic stimuli that aligns with those of previous studies (Jaramillo et al., 2000), and contributes to the growing body of knowledge supporting auditory perceptual asymmetry.

11.
Conscious Cogn ; 93: 103150, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34051391

RESUMEN

The present study investigates how the brain automatically discriminates emotional schematic faces, as indicated by the mismatch responses, and how reliable these brain responses are. Thirty-three healthy volunteers participated in the vMMN EEG experiment with four experimental sets differing from each other by the type of standard (object with scrambled face features) and the type of deviants (Angry, Happy and Neutral schematic faces) presented. Conscious subjective evaluations of valence, arousal and attention catching of the same stimuli showed clear differentiation of emotional expressions. Deviant faces elicited rather similar vMMN at frontal and occipital sites. Bayesian analyses suggest that vMMN does not differ between angry and happy faces. Neutral faces, however, did not yield statistically significant vMMN at occipital leads. Pearson's correlation and intra-class correlation analyses showed that the brain's reactions to the stimuli were highly stable within individuals across the experimental sets, whereas the mismatch responses were much more variable.


Asunto(s)
Electroencefalografía , Expresión Facial , Teorema de Bayes , Encéfalo , Emociones , Humanos
12.
Behav Brain Res ; 407: 113255, 2021 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-33745984

RESUMEN

The exact mechanism how serotonergic and dopaminergic systems relate to one another in working memory (WM) updating is unknown. Platelet monoamine oxidase (MAO) has been used as a marker for central serotonergic capacity, and catechol-O-methyltransferase (COMT) as a marker for central dopaminergic capacity. This study aimed to describe the interaction of platelet MAO activity and COMT Val158Met genotype in visual working memory updating: the ability to replace old information with new within hundreds of milliseconds. Previous studies suggest that platelet MAO activity and COMT Val158Met genotype could have an interaction effect on working memory. However, there are no studies that have directly examined the interaction of these biomarkers in WM updating. We used a 2-back updating task with facial expressions and defined updating efficiency as response times for correct responses. 455 subjects from a population representative sample were included. Mixed models were used for data analysis with an aim to study the interaction of COMT Val158Met genotype (Val/Val, Val/Met and Met/Met) and the level of MAO activity (high vs low). Education, IQ, sex, simple reaction times, and overall updating accuracy were included as covariates. We found that the effect of COMT Val158Met on updating efficiency depends on the level of platelet MAO activity. Low MAO in contrast to high MAO was associated with an increase in updating efficiency in Val/Met but a decrease in Met/Met. The results are discussed in the context of serotonin and dopamine functions in brain regions related to WM. The findings support the view that serotonin modulates dopaminergic activation in updating and contribute to understanding the role of serotonin in PFC, top-down inhibitory signals, and its interactions with dopamine in WM processes.


Asunto(s)
Plaquetas/metabolismo , Catecol O-Metiltransferasa/genética , Función Ejecutiva/fisiología , Reconocimiento Facial/fisiología , Memoria a Corto Plazo/fisiología , Monoaminooxidasa/metabolismo , Adulto , Femenino , Humanos , Estudios Longitudinales , Masculino , Adulto Joven
13.
Acta Psychol (Amst) ; 209: 103117, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32603911

RESUMEN

Individual differences in updating emotional facial expressions in working memory are not fully understood. Here we focused on the effects of high trait anxiety and high depressiveness in men and women on updating schematic emotional facial expressions (sad, angry, scheming, happy, neutral). A population representative sample of young adults was divided into four emotional disposition groups based on STAI-T and MADRS cut-offs: high anxiety (HA, n = 41), high depressiveness (HD, n = 31), high depressiveness & high anxiety (HAHD, n = 65) and control (CT, n = 155). Participants completed a 2-back task with schematic emotional faces, and valence/arousal ratings and verbal recognition tasks. A novel approach was used to separate encoding from retrieval. We found an interaction of emotional dispositions and emotional faces in updating accuracy. HD group made more errors than HA when encoding happy schematic faces. Other differences between emotional dispositions on updating measures were found but they were not specific to any emotional facial expression. Our findings suggest that there is a minor happy disadvantage in HD in contrast to HA which can be seen in lower accuracy for visual encoding of happy faces, but not in retrieval accuracy, the speed of updating, nor perception of emotional content in happy faces. These findings help to explain differences and similarities between high trait anxiety and high depressiveness in working memory and processing of facial expressions. The results are discussed in relation to prevalent theories of information processing in anxiety and depression.


Asunto(s)
Ansiedad , Emociones , Expresión Facial , Memoria a Corto Plazo , Trastornos de Ansiedad , Femenino , Humanos , Masculino , Adulto Joven
14.
J Psychoactive Drugs ; 52(3): 255-263, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32299306

RESUMEN

The study aims to describe ayahuasca users in Estonia and compare their mental health and quality of life to those of nonusers. Ceremonial practices, motivation for ayahuasca use, use-related experiences, and subjective consequences of use are described. We conducted a cross-sectional case-controlled study of thirty ayahuasca users and thirty nonusers matched by gender, age, and education. The participants completed questionnaires, standardized psychometric tests, and neuropsychiatric interviews. Ayahuasca use in Estonia occurred mainly in (neo)shamanic group ceremonies. The main motives for ayahuasca use were spiritual development, self-knowledge, and spiritual experiences. The users reported mostly positive subjective consequences of ayahuasca use for their health and life. However, some difficult experiences and adverse effects were reported. No abuse of ayahuasca or addiction to it was found. Screening test indicators of depression and anxiety were lower in the ayahuasca-using group. No deterioration of the mental health of ayahuasca users in comparison to nonusers was found. The participants perceive their use of ayahuasca as a spiritual practice with mostly favorable outcomes for their health and life. They also perceive ayahuasca use in Estonia as a reasonably safe and self-limiting form of spiritual practice.


Asunto(s)
Banisteriopsis , Conducta Ceremonial , Salud Mental , Calidad de Vida , Adulto , Anciano , Estudios de Casos y Controles , Estudios Transversales , Estonia , Femenino , Alucinógenos , Humanos , Masculino , Persona de Mediana Edad , Psicometría , Autoimagen , Chamanismo , Encuestas y Cuestionarios , Tiempo
15.
Front Psychol ; 10: 883, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31133914

RESUMEN

Food reward is an important concept for research in eating behaviors. Many food reward tasks have been developed and are in active use. However, little is known how much these tasks overlap. Here, we sought to compare three promising food reward tasks: (1) the Leeds Food Preference Questionnaire (LFPQ; a procedure combining explicit ratings of wanting and liking and an implicit wanting task based on forced choice), (2) a hand grip force task, and (3) an emotional attentional blink (EAB) task. Specifically, we assessed whether the tasks are sensitive to changes in hunger, correlate with each other, and correlate with trait binge eating and snack food calorie intake. Thirty-nine women aged 25.51 ± 5.99 years, with a BMI of 22.51 ± 3.58 kg/m2 completed the three tasks twice: after a 6-h fast and following a breakfast meal. In the fasted condition, participants were also given ad libitum access to snack foods to assess calorie intake. Prior to the two laboratory sessions, participants completed a trait binge eating questionnaire. Results revealed that the LFPQ's explicit wanting and explicit liking subscales, as well as grip force reflected higher food reward scores in the fasted condition. The three metrics also correlated positively with each other. Explicit wanting and liking correlated with snack food intake, while grip force did not. None of the tasks were related to trait binge eating. Reaction times in the forced choice procedure did not reflect changes in hunger, but the task was nevertheless able to differentiate between foods varying in taste and fat content. The EAB was not sensitive to the hunger manipulation; neither did the task correlate with binge eating or energy intake. Collectively, our findings suggest that the explicit wanting and liking scales and the grip force task measure the same construct, whereas EAB results may be obscured by a variety of potential confounding factors. Future research could include additional food reward tasks in comparisons, measure covariates that may moderate the variables' associations, and compare hunger-dependent changes in food reward in different subgroups.

16.
Appetite ; 133: 324-336, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30508611

RESUMEN

Automatic detection of important and unexpected stimuli in the visual environment is crucial for survival. We sought to explore whether visual food stimuli are detected already in the pre-attentive stimulus processing phase, and whether hunger enhances such automatic detection. To attain these goals, we adapted an electroencephalography paradigm - visual mismatch negativity (vMMN). vMMN is a useful paradigm to study the processing of salient emotional stimuli which has not yet been applied in the context of eating behaviours. In our study, 18 right-handed women (25.2 ±â€¯7.4 years) underwent two experimental sessions: hunger and fed conditions. Participants had to focus on a 2-back working memory task in the center of the computer screen, while stimuli depicting high fat savoury (HFSA) and high fat sweet (HFSW) foods were presented as deviants in a stream of neutral standard stimuli in the four corners of the screen. Automatic detection of foods was observed within 80-360 ms after stimulus onset, although some foods were better detected than the others. In HFSA, hunger enhanced the processing of all deviant stimuli in the early (100-160 ms) and mid-latency (160-220 ms) time windows. As the modulating effect of hunger was not food-specific, hunger may enhance automatic detection of changes in the visual environment, regardless of the type of input. Nevertheless, hamburger in HFSA was better detected than other stimuli, indicated by larger peak amplitudes, which supports the food-specificity of hunger modulation. In HFSW, the modulating effect of hunger was not observed, possibly due to suboptimally chosen stimuli within this block. In conclusion, we believe that after careful stimulus selection vMMN has a great potential to be a reliable measure of early food-cue processing.


Asunto(s)
Hambre , Percepción Visual , Adulto , Electroencefalografía , Femenino , Alimentos , Humanos , Saciedad , Adulto Joven
17.
Front Hum Neurosci ; 12: 186, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29780315

RESUMEN

It is not known to what extent the automatic encoding and change detection of peripherally presented facial emotion is altered in dysphoria. The negative bias in automatic face processing in particular has rarely been studied. We used magnetoencephalography (MEG) to record automatic brain responses to happy and sad faces in dysphoric (Beck's Depression Inventory ≥ 13) and control participants. Stimuli were presented in a passive oddball condition, which allowed potential negative bias in dysphoria at different stages of face processing (M100, M170, and M300) and alterations of change detection (visual mismatch negativity, vMMN) to be investigated. The magnetic counterpart of the vMMN was elicited at all stages of face processing, indexing automatic deviance detection in facial emotions. The M170 amplitude was modulated by emotion, response amplitudes being larger for sad faces than happy faces. Group differences were found for the M300, and they were indexed by two different interaction effects. At the left occipital region of interest, the dysphoric group had larger amplitudes for sad than happy deviant faces, reflecting negative bias in deviance detection, which was not found in the control group. On the other hand, the dysphoric group showed no vMMN to changes in facial emotions, while the vMMN was observed in the control group at the right occipital region of interest. Our results indicate that there is a negative bias in automatic visual deviance detection, but also a general change detection deficit in dysphoria.

18.
Emotion ; 18(8): 1174-1188, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29504799

RESUMEN

Affective states are known to distort time perception, but it remains unclear why and how they do so. To test whether appraisal processes involved in affect may play a role in temporal distortions, we investigated bisection behavior during experimental events with varying appraisal values along three dimensions: goal relevance (high vs. low), goal type (approach vs. avoid), and goal congruence (conducive vs. obstructive). Forty female participants performed an incentive-compatible gambling task attempting to accumulate wins and avoid losses of small amounts of chocolate. On each trial, a prechoice stimulus first announced whether a win, a loss, or no change was available. Participants then made a choice that ostensibly determined the outcome of the trial, which was communicated by a postchoice stimulus. Participants also made temporal bisection decisions indicating whether the presentation durations of pre- and postchoice stimuli (which varied between 200, 320, 440, 560, 680, and 800 ms) were closer to a previously learned short (200 ms) or long (800 ms) standard. We analyzed appraisal effects on psychometric bisection point, response speed, and drift diffusion parameter variance using custom regression contrasts. Subjective durations were found to be lengthened by high goal relevance, conducive goal congruence, and approach goal type. Analysis of diffusion parameters suggested that these results reflected appraisal-related shifts in duration perception rather than in subsequent decision-making. These findings encourage further research into the possibility that temporal distortions are among the cognitive changes triggered by appraisal processes during affective states. (PsycINFO Database Record (c) 2018 APA, all rights reserved).


Asunto(s)
Conducta de Elección/fisiología , Emociones/fisiología , Percepción del Tiempo/fisiología , Adulto , Femenino , Humanos , Masculino , Adulto Joven
19.
Appl Physiol Nutr Metab ; 43(1): 63-70, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28873320

RESUMEN

The adaptogen Rhodiola rosea (RR) may mitigate stress responses and have beneficial effects on endurance capacity (EC) and mental performance. Heat acclimation (HA) improves EC in the heat, but the potential impact of RR on the HA process is unknown. Therefore, our intent was to determine if RR has a positive impact on HA. Twenty male subjects (age, 22.5 ± 3.0 years) completed 2 EC tests involving walking (6 km·h-1) until volitional exhaustion in a climate chamber (air temperature, 42 °C; relative humidity, 18%) before (H1) and after (H2) an 8-day HA period. One group (SHR; n = 10) ingested standardised extract SHR-5 of RR (a single daily dose of 432 mg), while a second group (PLC; n = 10) administered a placebo prior to each HA session. Efficacy of HA was evaluated on the basis of changes that occurred from H1 to H2 in the time to exhaustion (TTE), exercise heart rate (HR), core and skin temperatures (Tc, Tsk), stress hormones, ratings of perceived exertion (RPE) and fatigue (RPF), and thermal sensation (TS). HA significantly increased TTE (133.1 ± 44.1 min in H1; 233.4 ± 59.8 min in H2; p < 0.0001) and decreased (p < 0.0001) HR, Tc, Tsk, stress hormones as well as RPE, RPF, and TS. However, the magnitude of all these changes was similar (p > 0.05) in the SHR and PLC groups. These results suggest that the use of RR during HA has no beneficial performance, physiological, or perceptual effects in young healthy males.


Asunto(s)
Aclimatación , Respuesta al Choque Térmico/efectos de los fármacos , Calor , Resistencia Física/efectos de los fármacos , Extractos Vegetales/uso terapéutico , Rhodiola , Adulto , Regulación de la Temperatura Corporal/efectos de los fármacos , Método Doble Ciego , Estonia , Prueba de Esfuerzo , Voluntarios Sanos , Frecuencia Cardíaca , Humanos , Masculino , Procesos Mentales/efectos de los fármacos , Fatiga Muscular/efectos de los fármacos , Fitoterapia , Extractos Vegetales/aislamiento & purificación , Plantas Medicinales , Rhodiola/química , Temperatura Cutánea/efectos de los fármacos , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
20.
Appl Physiol Nutr Metab ; 42(1): 68-76, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28002684

RESUMEN

Acute caffeine ingestion is considered effective in improving endurance capacity and psychological state. However, current knowledge is based on the findings of studies that have been conducted on male subjects mainly in temperate environmental conditions, but some physiological and psychological effects of caffeine differ between the sexes. The purpose of this study was to compare the physical performance and psychological effects of caffeine in young women and men exercising in the heat. Thirteen male and 10 female students completed 2 constant-load walks (60% of thermoneutral peak oxygen consumption on a treadmill until volitional exhaustion) in a hot-dry environment (air temperature, 42 °C; relative humidity, 20%) after caffeine (6 mg·kg-1) and placebo (wheat flour) ingestion in a double-blind, randomly assigned, crossover manner. Caffeine, compared with placebo, induced greater increases (p < 0.05) in heart rate (HR) and blood lactate concentrations in both males and females but had no impact on rectal or skin temperatures or on walking time to exhaustion in subjects of either gender. Caffeine decreased (p < 0.05) ratings of perceived exertion and fatigue in males, but not in females. In females, but not in males, a stronger belief that they had been administered caffeine was associated with a shorter time to exhaustion. In conclusion, acute caffeine ingestion increases HR and blood lactate levels during exercise in the heat, but it has no impact on thermoregulation or endurance capacity in either gender. Under exercise-heat stress, caffeine reduces ratings of perceived exertion and fatigue in males but not in females.


Asunto(s)
Cafeína/uso terapéutico , Suplementos Dietéticos , Ejercicio Físico , Fatiga/prevención & control , Fatiga Mental/prevención & control , Sustancias para Mejorar el Rendimiento/uso terapéutico , Resistencia Física , Adulto , Rendimiento Atlético , Estudios Cruzados , Método Doble Ciego , Ejercicio Físico/psicología , Prueba de Esfuerzo , Tolerancia al Ejercicio , Fatiga/sangre , Fatiga/etiología , Femenino , Agotamiento por Calor/sangre , Agotamiento por Calor/etiología , Agotamiento por Calor/prevención & control , Calor/efectos adversos , Humanos , Ácido Láctico/sangre , Masculino , Fatiga Mental/sangre , Fatiga Mental/etiología , Caracteres Sexuales , Caminata , Adulto Joven
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