An important aspect in safety–critical domains is Situational Awareness (SA) where operators consolidate data into an understanding of the situation that needs to be updated dynamically as the ...situation changes over time. Among existing measures of SA, only physiological measures can assess the cognitive processes associated with SA in real-time. Some studies showed promise in detecting cognitive states associated with SA in complex tasks using brain signals (e.g. electroencephalogram/EEG). In this paper, an analytical methodology is proposed to identify EEG signatures associated with SA on various regions of the brain. A new data set from 32 participants completing the SA test in the PEBL is collected using a 32-channel dry-EEG headset. The proposed method is tested on the new data set and a correlation is identified between the frequency bands of β (12-30Hz) and γ (30-45Hz) and SA. Also, activation of neurons in the left and right hemisphere of the parietal and temporal lobe is observed. These regions are responsible for the visuo-spatial ability and memory and reasoning tasks. Among the presented results, the highest achieved accuracy on test data is 67%.
Objective: The Psychology Experiment Building Language (PEBL) Test Battery is a recent computerized software for the assessment of cognitive functioning in clinical and healthy populations. However, ...its applicability for the assessment of old adults and the role of level of familiarity with technology on performance have not been tested. Method: To verify if PEBL Test Battery is sensitive to aging cognitive decline, we assessed young and older adults’ performance on the neuropsychological tests relative to the following domains: verbal and visuospatial short-term memory, selective attention, inhibition to interference, planning and problem-solving, set-shifting, and cognitive flexibility. The difference between the two groups was studied taking into account the self-reported level of familiarity with technology, measured through the Attitudes Toward Computers Questionnaire. Results: Old participants showed a lower level of cognitive performance compared with the younger group, in line with the traditional literature about cognitive function decline in aging. However, this difference was not related to the level of familiarity with technology. Conclusion: Our descriptive study seemed to support the applicability of PEBL Test Battery for testing old adults’ cognitive functioning. However, some criticisms and future improvements about this computerized battery were discussed for its applicability in clinical, rehabilitative and research contexts.
To observe the effects of a fast-acute ascent to high altitude on brain cognitive function and transcranial doppler parameters in order to understand the physiological countermeasures of hypoxia.
17 ...high-altitude-naïve male subjects (mean age was 26.3 ± 8.1 years) participated in the study. We measured Critical Flicker Fusion Frequency (CFFF), blood oxygen saturation, Psychology Experiment Building (PEBL) including three tests (Modified Math Processing Task, Perceptual Vigilance Task, and Time Estimation Task), as well as Cerebral Blood Flow index (CBFi), mean cerebral artery Systolic and diastolic velocities, Cerebral Pulsatility index (CPi), and heart Rate. All were measured at sea level, at least 1 h after arrival at the hypobaric hypoxia equivalent of 3842 m and 1 h after return to sea level.
Under acute exposure to hypobaric hypoxic conditions, significant decrease in CFFF 42.1 ± 1 vs. 43.5 ± 1.7 Hz at sea level (asl),
< 0.01, CBFi (611 ± 51 vs. 665 ± 71 asl,
< 0.01) and blood oxygen saturation (83 ± 4% vs. 98 ± 1% asl,
< 0.001) as compared to pre-ascent values were observed. Physiological countermeasures to hypoxia could be involved as there was no significant change in neuropsychometric tests, Systolic and Diastolic velocities and CPi. A significant increase in Heart Rate (81 ± 15 bpm vs. 66 ± 15 bpm asl,
< 0.001) was observed. All parameters returned to their basal values 1 h after regaining sea level.
Hypoxia results in a decrease in CFFF, CBFi and oxygen saturation and in an increase in heart rate. As it decreased, Cerebral Blood Flow index does not seem to be the physiological measurement of choice to hypoxia explaining the maintenance of cognitive performance after acute exposure to hypobaric hypoxia and requires further investigation. Cerebral oxygen delivery and extraction could be one of the underlying mechanisms.
To confirm and extend previous findings on the relationships between executive functioning (EF) and insomnia, as well as the available evidence on the associations between personality traits and ...insomnia, 30 consecutively-admitted insomnia participants and 30 community dwelling adult participants matched on age, gender and educational level, were administered a battery of EF measures and the Personality Inventory for DSM-5 (PID-5). Insomnia participants underwent two full-night polysomnographic (PSG) recording, followed by a morning assessment of subjective sleep parameters. A misperception index (MI) was computed in order to identify participants characterized by objective insomnia and non-objective insomnia. The EF performance associations between insomnia and poor performance on selected executive functions was confirmed. However, the objective insomnia and non-objective insomnia sub-groups show significant differences on specific EF indices, as well as on dysfunctional personality dimensions.
Plasmodium falciparum intraerythrocytic development is a complex process. Development proceeds rapidly from the trophozoite phase of nutrient acquisition and growth through to the synthetic and ...reproductive schizont phase, which ends with production of new invasive merozoites. During this process, the malaria parasite must express a series of different gene products, depending on its metabolic and synthetic needs. We are particularly interested in the development of the merozoite's organelles in the apical complex, which form during the later schizont stages. We have used quantitative real-time RT-PCR fluorogenic 5' nuclease assays (TaqMan registered ) for the first time on malaria parasites for analysis of erythrocytic stage-specific gene expression. We analyzed transcripts of the P.falciparum eba-175 and other erythrocyte binding-like (eb l) family genes in temperature-synchronized parasites and found ebl genes have tightly controlled, stage-specific transcription. As expected, eba-175 transcripts were abundant only at the end of schizont development in a pattern most common among ebl, including baebl, pebl and jesebl. The maebl transcript pattern was unique, peaking at mid-late trophozoite stage, but absent in late-stage schizonts. ebl-1 demonstrated another pattern of expression, which peaked during mid-schizont stage and then significantly diminished in late-stage schizonts. Our analysis demonstrates that using real-time RT-PCR fluorogenic 5' nuclease assays is a sensitive, quantitative method for analysis of Plasmodium transcripts.
As a broader effort to build a holistic biopsychosocial health metric, reaction time data obtained from participants undertaking neurocognitive tests; have been examined using Exploratory Data ...Analysis (EDA) for assessing its distribution. Many of the known existing methods assume, that the reaction time data follows a Gaussian distribution and thus commonly use statistical measures such as Analysis of Variance (ANOVA) for analysis. However, it is not mandatory for the reaction time data, to necessarily follow Gaussian distribution and in many instances, it can be better modeled by other representations such as Gamma distribution. Unlike Gaussian distribution which is defined using mean and variance, the Gamma distribution is defined using shape and scale parameters which also considers higher order moments of data such as skewness and kurtosis. Generalized Linear Models (GLM), based on the family exponential distributions such as Gamma distribution, which have been used to model reaction time in other domains, have not been fully explored for modeling reaction time data in psychology domain. While limited use of Gamma distribution have been reported 5, 17, 21, for analyzing response times, their application has been somewhat ad-hoc rather than systematic. For this proposed research, we use a real life biopsychosocial dataset, generated from the 'digital health' intervention programs conducted by the Faculty of Health, Federation University, Australia. The two digital intervention programs were the 'Mindfulness' program and 'Physical Activity' program. The neurocognitive tests were carried out as part of the 'Mindfulness' program. In this paper, we investigate the participants' reaction time distributions in neurocognitive tests such as the Psychology Experiment Building Language (PEBL) Go/No-Go test 19, which is a subset of the larger biopsychosocial data set. PEBL is an open source software system for designing and running psychological experiments. Analysis of participants' reaction time in the PEBL Go/No-Go test, shows that the reaction time data are more compatible with a Gamma distribution and clearly demonstrate that these can be better modeled by Gamma distribution.
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