Chewing gum benefits sustained attention in the absence of task degradation.

OBJECTIVES: The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. METHODS: In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness were taken before and after the SART. RESULTS: Chewing gum was associated with improved attentional task performance. This finding was not contingent upon a general decrease in attentional performance and was apparent at all stages of the task. Subjective measures of alertness, contentedness, and calmness were higher following the chewing of gum. Changes in sustained attention co-varied with subjective alertness. DISCUSSION: The effects of chewing gum on attention and alertness are consistent with past literature and were not contingent on declines in attention. Additionally, we found evidence that gum-induced changes in self-rated alertness and attention are related. We found no support for the proposition that chewing gum can impair attention due to the division of resources

Why are we not flooded by involuntary thoughts about the past and future? Testing the cognitive inhibition dependency hypothesis

© The Author(s) 2018In everyday life, involuntary thoughts about future plans and events occur as often as involuntary thoughts about the past. However, compared to involuntary autobiographical memories (IAMs), such episodic involuntary future thoughts (IFTs) have become a focus of study only recently. The aim of the present investigation was to examine why we are not constantly flooded by IFTs and IAMs given that they are often triggered by incidental cues while performing undemanding activities. One possibility is that activated thoughts are suppressed by the inhibitory control mechanism, and therefore depleting inhibitory control should enhance the frequency of both IFTs and IAMs. We report an experiment with a between-subjects design, in which participants in the depleted inhibition condition performed a 60-min high-conflict Stroop task before completing a laboratory vigilance task measuring the frequency of IFTs and IAMs. Participants in the intact inhibition condition performed a version of the Stroop task that did not deplete inhibitory control. To control for physical and mental fatigue resulting from performing the 60-min Stroop tasks in experimental conditions, participants in the control condition completed only the vigilance task. Contrary to predictions, the number of IFTs and IAMs reported during the vigilance task, using the probe-caught method, did not differ across conditions. However, manipulation checks showed that participants’ inhibitory resources were reduced in the depleted inhibition condition, and participants were more tired in the experimental than in the control conditions. These initial findings suggest that neither inhibitory control nor physical and mental fatigue affect the frequency of IFTs and IAMs.Peer reviewedFinal Published versio

Alterations in cognitive performance during passive hyperthermia are task dependent

The objectives of this study were to (1) assess the effect of passive heating upon attention and memory task performance, and (2) evaluate the effectiveness of the application of cold packs to the head on preserving these functions. Using a counterbalance design 16 subjects underwent three trials: a control (CON, 20°C, 40% rH), hot (HOT, 50°C, 50% rH) and hot with the head kept cool (HHC). In each condition, three attention tests and two memory tests were performed. Mean core, forehead and tympanic temperatures were all significantly higher (p< 0.05) during HOT (38.6° ±0.1°, 39.6° ±0.2° and 38.8°±0.1°C, respectively) and HHC (38°±0.2, 37.7°±0.3° and 37.7°C, respectively) than in CON (37.1°±0.6°, 33.3° ±0.2° and 35.9°±0.3°C, respectively). Results indicate that there was impairment in working memory with heat exposure (p < 0.05) without alteration in attentional processes. The regular application of cold packs only prevented the detrimental effect of hyperthermia on short-term memory. Our results show that impairments in cognitive function with passive hyperthermia and the beneficial effect of head cooling are task dependent and suggests that exposure to a hot environment is a competing variable to the cognitive processes

Can Ambient Scent Enhance the Nightlife Experience?

Ever since smoking was prohibited in restaurants, bars, and clubs, undesirable smells that were previously masked by cigarette smoke became noticeable. This opens up opportunities to improve the dance club environment by introducing pleasant ambient scents that mask the unwanted odors and to allow competing clubs to differentiate themselves. A field study was conducted at three dance clubs using a 3 × 3 Latin square design with pre- and post-measurements of no-scent control conditions. The three scents tested were orange, seawater, and peppermint. These scents were shown to enhance dancing activity and to improve the evaluation of the evening, the evaluation of the music, and the mood of the visitors over no added scent. However, no significant differences were found between the three scents

Menthol::A Fresh Ergogenic Aid for Athletic Performance

The application of menthol has recently been researched as a performance-enhancing aid for various aspects of athletic performance including endurance, speed, strength and joint range of motion. A range of application methods has been used including a mouth rinse, ingestion of a beverage containing menthol or external application to the skin or clothing via a gel or spray. The majority of research has focussed on the use of menthol to impart a cooling sensation on athletes performing endurance exercise in the heat. In this situation, menthol appears to have the greatest beneficial effect on performance when applied internally. In contrast, the majority of investigations into the external application of menthol demonstrated no performance benefit. While studies are limited in number, menthol has not yet proven to be beneficial for speed or strength, and only effective at increasing joint range of motion following exercise that induced delayed-onset muscle soreness. Internal application of menthol may provoke such performance-enhancing effects via mechanisms related to its thermal, ventilatory, analgesic and arousing properties. Future research should focus on well-trained subjects and investigate the addition of menthol to nutritional sports products

The Relationship between Regular Sports Participation and Vigilance in Male and Female Adolescents

The present study investigated the relationship between regular sport participation (soccer) and vigilance performance. Two groups of male and female adolescents differentiated in terms of their sport participation (athletes, n = 39, and non-athletes, n = 36) took part in the study. In one session, participants performed the Leger Multi-stage fitness test to estimate their aerobic fitness level. In the other session, participants completed the Psychomotor Vigilance Task (PVT) to evaluate their vigilance performance. Perceived arousal prior to the task and motivation toward the task were also measured in the PVT session. The results revealed that athletes had better cardiovascular fitness and showed better performance in the PVT. However, correlation analyses did not show any significant relationship between cardiovascular fitness and performance in the PVT. Athletes showed larger scores in motivation and perceived arousal measures with respect to non-athletes, although, once again, these variables were not correlated with PVT performance. Gender differences were observed only in the Leger test, with males showing greater fitness level than females. The major outcome of this research points to a positive relationship between regular sport participation and vigilance during adolescence. This relationship did not seem to be influenced by gender, perceived arousal, motivation toward the task or cardiovascular fitness. We discuss our results in terms of the different hypotheses put forward in the literature to explain the relationship between physical activity and cognitive functioning.This research was supported by a Spanish Ministerio de Educación y Cultura (https://sede. educacion.gob.es) predoctoral grant (FPU13-05605) to the first author, and project research grants: Junta de Andalucia Proyecto de Excelencia SEJ-6414 (http://www.juntadeandalucia.es) and Ministerio de Economía y Competitividad PSI2013-46385 (http://www.mineco.gob.es) to DS and FH

The potential biomarkers in predicting pathologic response of breast cancer to three different chemotherapy regimens: a case control study

<p>Abstract</p> <p>Background</p> <p>Preoperative chemotherapy (PCT) has become the standard of care in locally advanced breast cancer. The identification of patient-specific tumor characteristics that can improve the ability to predict response to therapy would help optimize treatment, improve treatment outcomes, and avoid unnecessary exposure to potential toxicities. This study is to determine whether selected biomarkers could predict pathologic response (PR) of breast tumors to three different PCT regimens, and to identify a subset of patients who would benefit from a given type of treatment.</p> <p>Methods</p> <p>118 patients with primary breast tumor were identified and three PCT regimens including DEC (docetaxel+epirubicin+cyclophosphamide), VFC (vinorelbine/vincristine+5-fluorouracil+cyclophosphamide) and EFC (epirubicin+5-fluorouracil+cyclophosphamide) were investigated. Expression of steroid receptors, HER2, P-gp, MRP, GST-pi and Topo-II was evaluated by immunohistochemical scoring on tumor tissues obtained before and after PCT. The PR of breast carcinoma was graded according to Sataloff's classification. Chi square test, logistic regression and Cochran-Mantel-Haenszel assay were performed to determine the association between biomarkers and PR, as well as the effectiveness of each regimen on induction of PR.</p> <p>Results</p> <p>There was a clear-cut correlation between the expression of ER and decreased PR to PCT in all three different regimens (<it>p </it>< 0.05). HER2 expression is significantly associated with increased PR in DEC regimen (<it>p </it>< 0.05), but not predictive for PR in EFC and VFC groups. No significant correlation was found between biomarkers PgR, Topo-II, P-gp, MRP or GST-pi and PR to any tested PCT regimen. After adjusted by a stratification variable of ER or HER2, DEC regimen was more effective in inducing PR in comparison with VFC and EFC regimens.</p> <p>Conclusion</p> <p>ER is an independent predictive factor for PR to PCT regimens including DEC, VFC and EFC in primary breast tumors, while HER2 is only predictive for DEC regimen. Expression of PgR, Topo-II, P-gp, MRP and GST-pi are not predictive for PR to any PCT regimens investigated. Results obtained in this clinical study may be helpful for the selection of appropriate treatments for breast cancer patients.</p

Developing an objective indicator of fatigue: An alternative mobile version of the Psychomotor Vigilance Task (m-PVT)

Approximately 20% of the working population report symptoms of feeling fatigued at work. The aim of the study was to investigate whether an alternative mobile version of the ‘gold standard’ Psychomotor Vigilance Task (PVT) could be used to provide an objective indicator of fatigue in staff working in applied safety critical settings such as train driving, hospital staffs, emergency services, law enforcements, etc., using different mobile devices. 26 participants mean age 20 years completed a 25-min reaction time study using an alternative mobile version of the Psychomotor Vigilance Task (m-PVT) that was implemented on either an Apple iPhone 6s Plus or a Samsung Galaxy Tab 4. Participants attended two sessions: a morning and an afternoon session held on two consecutive days counterbalanced. It was found that the iPhone 6s Plus generated both mean speed responses (1/RTs) and mean reaction times (RTs) that were comparable to those observed in the literature while the Galaxy Tab 4 generated significantly lower 1/RTs and slower RTs than those found with the iPhone 6s Plus. Furthermore, it was also found that the iPhone 6s Plus was sensitive enough to detect lower mean speed of responses (1/RTs) and significantly slower mean reaction times (RTs) after 10-min on the m-PVT. In contrast, it was also found that the Galaxy Tab 4 generated mean number of lapses that were significant after 5-min on the m-PVT. These findings seem to indicate that the m-PVT could be used to provide an objective indicator of fatigue in staff working in applied safety critical settings such as train driving, hospital staffs, emergency services, law enforcements, etc

Dopaminergic Polymorphisms Associated with Time-on-Task Declines and Fatigue in the Psychomotor Vigilance Test

Prolonged demands on the attention system can cause a decay in performance over time known as the time-on-task effect. The inter-subject differences in the rate of this decline are large, and recent efforts have been made to understand the biological bases of these individual differences. In this study, we investigate the genetic correlates of the time-on-task effect, as well as its accompanying changes in subjective fatigue and mood. N = 332 subjects performed a 20-minute test of sustained attention (the Psychomotor Vigilance Test) and rated their subjective states before and after the test. We observed substantial time-on-task effects on average, and large inter-individual differences in the rate of these declines. The 10-repeat allele of the variable number of tandem repeats marker (VNTR) in the dopamine transporter gene and the Met allele of the catechol-o-methyl transferase (COMT) Val158Met polymorphism were associated with greater vulnerability to time-on-task. Separately, the exon III DRD4 48 bp VNTR of the dopamine receptor gene DRD4 was associated with subjective decreases in energy. No polymorphisms were associated with task-induced changes in mood. We posit that the dopamine transporter and COMT genes exert their effects by increasing dopaminergic tone, which may induce long-term changes in the prefrontal cortex, an important mediator of sustained attention. Thus, these alleles may affect performance particularly when sustained dopamine release is necessary