Intrinsic Alertness Research Articles

General low alertness in people with obstructive sleep apnea.

In patients with obstructive sleep apnea (OSA), a previous study using a Go/No-Go task reported an average attention deficit. However, the temporal dynamics of such a deficit are unknown. Here, we investigated whether attention deficits in different subdomains increased as the test progressed. We also investigated the effect of target frequency and speed of stimulus presentation on performance. Twenty-seven untreated people with OSA and 27 age- and sex-matched controls underwent a 15-minute Go/No-Go task, divided into 6 blocks. Each block was subdivided into 3 different interstimulus intervals (1, 2, and 4 seconds). Three blocks had a low and three had a high target probability (20% and 80%, respectively). Reaction time (alertness), variability of reaction time (sustained attention), commission errors (response inhibition), and omission errors (focused attention) were measured. Alertness was lower in the group with OSA compared with controls, as evidenced by a significantly higher average reaction time. This effect was seen from the start of the task and continued until the end but did not increase in test progression. The temporal pattern of intrinsic alertness deficits in patients with OSA was found to be independent of target frequency or interstimulus interval. The primary attention problem in OSA is on the alertness subdomain irrespective of the number of required responses or speed of stimulus presentation. The present results support the notion that OSA is distinct from other neurological and psychiatric conditions, such as depression or chronic pain. The results also suggest significant concerns regarding daily life activities (eg, driving). de Souza Bezerra ML, van Duinkerken E, Simões E, Schmidt SL. General low alertness in people with obstructive sleep apnea. J Clin Sleep Med. 2024;20(5):689-698.

Impaired interhemispheric synchrony and effective connectivity in right temporal lobe epilepsy.

The brain functional network plays a crucial role in cognitive impairment in temporal lobe epilepsy (TLE). Based on voxel-mirrored homotopic connectivity (VMHC), this study explored how directed functional connectivity changes and is associated with impaired cognition in right TLE (rTLE). Twenty-seven patients with rTLE and twenty-seven healthy controls were included to perform VMHC and Granger causality analysis (GCA). Correlation analysis was performed based on GCA and cognitive function. Bilateral middle frontal gyrus (MFG), middle temporal gyrus, dorsolateral superior frontal gyrus (SFGdor), and supramarginal gyrus (SMG) exhibited decreased VMHC values in the rTLE group. Brain regions with altered VMHC had abnormal directed functional connectivity with multiple brain regions, mainly belonging to the default mode network, sensorimotor network, and visual network. Besides, the Montreal Cognitive Assessment (MoCA) score was positively correlated with the connectivity from the left SFGdor to the right cerebellum crus2 and was negatively correlated with the connectivity from the left SMG to the right supplementary motor area (SMA) before correction. Before correction, both phasic and intrinsic alertness reaction time were positively correlated with the connectivity from the left MFG to the left precentral gyrus (PreCG), connectivity from the left SMG to the right PreCG, and the connectivity from the left SMG to the right SMA. The executive control effect reaction time was positively correlated with the connectivity from the left MFG to the left calcarine fissure surrounding cortex before correction. The disordered functional network tended to be correlated with cognition impairment in rTLE.

Structural neural correlates of mental fatigue and reward-induced improvement in performance

Neuroimaging studies investigating the association between mental fatigue (henceforth fatigue) and brain physiology have identified many brain regions that may underly the cognitive changes induced by fatigue. These studies focused on the functional changes and functional connectivity of the brain relating to fatigue. The structural correlates of fatigue, however, have received little attention. To fill this gap, this study explored the associations of fatigue with cortical thickness of frontal and parietal regions. In addition, we aimed to explore the associations between reward-induced improvement in performance and neuroanatomical markers in fatigued individuals. Thirty-nine healthy volunteers performed the psychomotor vigilance task for 15 min (i.e., 3 time-on-task blocks of 5 min) out of scanner; followed by an additional rewarded block of the task lasting 5 min. Baseline high-resolution T1-weigthed MR images were obtained. Reaction time increased with time-on-task but got faster again in the rewarded block. Participants’ subjective fatigue increased during task performance. In addition, we found that higher increase in subjective mental fatigue was associated with the cortical thickness of the following areas: bilateral precuneus, right precentral gyrus; right pars triangularis and left superior frontal gyrus. Our results suggest that individual differences in subjective mental fatigue may be explained by differences in the degree of cortical thickness of areas that are associated with motor processes, executive functions, intrinsic alertness and are parts of the default mode network.

Neurofeedback in patients with frontal brain lesions: A randomized, controlled double-blind trial.

BackgroundFrontal brain dysfunction is a major challenge in neurorehabilitation. Neurofeedback (NF), as an EEG-based brain training method, is currently applied in a wide spectrum of mental health conditions, including traumatic brain injury.ObjectiveThis study aimed to explore the capacity of Infra-Low Frequency Neurofeedback (ILF-NF) to promote the recovery of brain function in patients with frontal brain injury.Materials and methodsTwenty patients hospitalized at a neurorehabilitation clinic in Switzerland with recently acquired, frontal and optionally other brain lesions were randomized to either receive NF or sham-NF. Cognitive improvement was assessed using the Frontal Assessment Battery (FAB) and the Test of Attentional Performance (TAP) tasks regarding intrinsic alertness, phasic alertness and impulse control.ResultsWith respect to cognitive improvements, there was no significant difference between the two groups after 20 sessions of either NF or sham-NF. However, in a subgroup of patients with predominantly frontal brain lesions, the improvements measured by the FAB and intrinsic alertness were significantly higher in the NF-group.ConclusionThis is the first double-blind controlled study using NF in recovery from brain injury, and thus also the first such study of ILF NF. Although the result of the subgroup has limited significance because of the small number of participants, it accentuates the trend seen in the whole group regarding the FAB and intrinsic alertness (p = 0.068, p = 0.079, respectively). We therefore conclude that NF could be a promising candidate promoting the recoveryfrom frontal brain lesions. Further studies with larger numbers of patients and less lesion heterogeneity are needed to verify the usefulness of NF in the neurorehabilitation of patients with frontal brain injury (NCT02957695 ClinicalTrials.gov).

Attention profile of physically recovered COVID-19 inpatients on the day of discharge

Few studies have reported specific attention deficits in post-COVID-19 patients. Attention consists of different subdomains. Disruptions to specific attention subdomains might impair a wide range of everyday tasks, including road safety. As there are millions of COVID-19 patients with different socio-economic backgrounds, screening of attentional performance less dependent on education is needed. Here, we verified if physically recovered COVID-19 inpatients showed specific attention decrements at discharge. The Continuous Visual Attention Test (CVAT) is a Go/No-go task which is independent of participants’ schooling. It detects visuomotor reaction time (RT = intrinsic alertness), variability of reaction time (VRT = sustained attention), omission (focused-attention), and commission errors (response-inhibition). Thirty physically functional COVID-19 inpatients at discharge and 30 non-infected controls underwent the CVAT. A MANCOVA was performed to examine differences between controls and patients, followed by post-hoc ANCOVAs. Then, we identified the percentile score for each patient within the distribution of the CVAT performance of 211 subjects mentally capable of driving (reference group). COVID-19 patients at discharge showed greater RT and VRT, and more omission errors than controls. Twenty-two patients (73%) had performance below the 5th percentile of the reference group in one or more subdomains. As slow visuomotor RT, deficits in focusing and difficulties in keeping visual attention are associated with traffic accidents, we concluded that most COVID-19 patients at discharge had deficits that may increase the risk of road injuries. As these deficits will probably affect other daily activities, a routine assessment with the CVAT could provide useful information on whom to send to post-COVID centers.

Cognitive dysfunction associated with COVID-19: A comprehensive neuropsychological study

ObjectiveRecent evidence suggests that patients suffering post-acute COVID syndrome frequently report cognitive complaints, but their characteristics and pathophysiology are unknown. This study aims to determine the characteristics of cognitive dysfunction in patients reporting cognitive complaints after COVID-19 and to evaluate the correlation between cognitive function and anxiety, depression, sleep, and olfactory function. MethodsCross-sectional study involving 50 patients with COVID-19 reporting cognitive complaints 9.12 ± 3.46 months after the acute infection. Patients were evaluated with a comprehensive neuropsychological protocol, and scales of fatigue, depression, anxiety, sleep and an olfactory test. Normative data and an age- and education matched healthy control group were used for comparison. ResultsCOVID-19 patients showed a diminished performance on several tests evaluating attention and executive function, with alterations in processing speed, divided attention, selective attention, visual vigilance, intrinsic alertness, working memory, and inhibition; episodic memory; and visuospatial processing. Cognitive performance was correlated with olfactory dysfunction, and sleep quality and anxiety to a lesser extent, but not depression. ConclusionsPatients with COVID-19 reporting cognitive symptoms showed a reduced cognitive performance, especially in the attention-concentration and executive functioning, episodic memory, and visuospatial processing domains. Future studies are necessary to disentangle the specific mechanisms associated with COVID-19 cognitive dysfunction.

A study of brain functional network and alertness changes in temporal lobe epilepsy with and without focal to bilateral tonic\u2013clonic seizures

BackgroundTemporal lobe epilepsy (TLE) is commonly refractory. Epilepsy surgery is an effective treatment strategy for refractory epilepsy, but patients with a history of focal to bilateral tonic-clonic seizures (FBTCS) have poor outcomes. Previous network studies on epilepsy have found that TLE and idiopathic generalized epilepsy with generalized tonic-clonic seizures (IGE-GTCS) showed altered global and nodal topological properties. Alertness deficits also were found in TLE. However, FBTCS is a common type of seizure in TLE, and the implications for alertness as well as the topological rearrangements associated with this seizure type are not well understood.MethodsWe obtained rs-fMRI data and collected the neuropsychological assessment data from 21 TLE patients with FBTCS (TLE- FBTCS), 18 TLE patients without FBTCS (TLE-non- FBTCS) and 22 controls, and constructed their respective functional brain networks. The topological properties were analyzed using the graph theoretical approach and correlations between altered topological properties and alertness were analyzed.ResultsWe found that TLE-FBTCS patients showed more serious impairment in alertness effect, intrinsic alertness and phasic alertness than the patients with TLE-non-FBTCS. They also showed significantly higher small-worldness, normalized clustering coefficient (γ) and a trend of higher global network efficiency (gE) compared to TLE-non-FBTCS patients. The gE showed a significant negative correlation with intrinsic alertness for TLE-non-FBTCS patients.ConclusionOur findings show different impairments in brain network information integration, segregation and alertness between the patients with TLE-FBTCS and TLE-non-FBTCS, demonstrating that impairments of the brain network may underlie the disruptions in alertness functions.

Baseline levels of alertness influence tES effects along different age-related directions

Normal aging is usually accompanied by several structural and functional physiological changes of the brain, which are closely related to alterations of cognitive functions (e.g., visual short-term memory). As the average age of the population increases, it has become crucial to identify cognitive-behavioural interventions to maintain a healthy level of cognitive performance. Among a variety of approaches, the targeting of specific intrinsic alertness mechanisms has shown a solid rationale and beneficial effects in both healthy and pathological ageing. In a similar vein, the use of non-invasive transcranial electrical stimulation (tES) represents another promising approach to induce an alerting state that can produce advantages in the information processing in the brain and therefore behaviour. Here, we investigated whether time-locked bursts of tES (i.e., transcranial random noise stimulation) were effective in inducing behavioural and physiological changes, consistently with an alertness increase, in both young and older healthy adults. Namely, we expected to find a beneficial alerting effect on visual short-term memory performance as a function of stimulus perceptual salience and tES. The initial results showed that the performance of younger adults was not affected by tES, while older adults scored lower correct responses for high-salience stimuli during real tES with respect to sham stimulation. However, after including a baseline measure of subjective level of alertness in the analyses, a tES-induced memory improvement did emerge in the less alerted younger adults, while only the more alerted older adults were subject to the worsening effect by tES. We discuss these results in consideration of the evidence on critical age-related differences as well as the interaction between neurostimulation and baseline alerting mechanisms.

P.217 Adolescent methamphetamine use is associated with impairments in memory retrieval and intrinsic alertness

P.217 Adolescent methamphetamine use is associated with impairments in memory retrieval and intrinsic alertness

Intrinsic Alertness Is Impaired in Patients with Nigrostriatal Degeneration: A Prospective Study with Reference to [123I]FP-CIT SPECT and [18F]FDG PET.

Variations in alertness and attention are common in Lewy body diseases (LBD) and among the core features of dementia with Lewy bodies (DLB). Dopamine transporter SPECT is an accurate biomarker of nigrostriatal degeneration (NSD) in LBD. The present study investigated performance on a computerized alertness test as a potential measure of attention in patients with NSD compared to patients without NSD. Thirty-six patients with cognitive impairment plus at least one core feature of DLB referred for [123I]FP-CIT SPECT imaging were prospectively recruited. Performance in a computerized test of intrinsic alertness was compared between patients with and those without NSD as assessed by [123I]FP-CIT SPECT. Reaction times to auditory stimuli (adjusted for age, sex, and education) were significantly longer in patients with NSD compared to those with a normal [123I]FP-CIT SPECT scan (p < 0.05). Statistical analyses revealed no significant differences comparing reaction times to visual stimuli or dispersion of reaction times between groups. Exploratory analysis in a subgroup of patients with available [18F]FDG PET revealed that longer reaction times were associated with decreased glucose metabolism in the prefrontal cortex (statistical parametric mapping, adjusted for age and sex; p < 0.005, cluster extent > 50 voxels). Computerized assessment of auditory reaction times is able to detect alertness deficits in patients with NSD and might help to measure alertness deficits in patients with LBD and NSD. Future studies in larger samples are needed to evaluate the diagnostic utility of computerized alertness assessment for the differential diagnosis of LBD.

Resting EEG in alpha band predicts individual differences in visual size perception

Human visual size perception results from an interaction of external sensory information and internal state. The cognitive mechanisms involved in the processing of context-dependent visual size perception have been found to be innate in nature to some extent, suggesting that visual size perception might correlate with human intrinsic brain activity. Here we recorded human resting alpha activity (8–12 Hz), which is an inverse indicator of sustained alertness. Moreover, we measured an object’s perceived size in a two-alternative forced-choice manner and the Ebbinghaus illusion magnitude which is a classic illustration of context-dependent visual size perception. The results showed that alpha activity along the ventral visual pathway, including left V1, right LOC and bilateral inferior temporal gyrus, negatively correlated with an object’s perceived size. Moreover, alpha activity in the left superior temporal gyrus positively correlated with size discrimination threshold and size illusion magnitude. The findings provide clear evidence that human visual size perception scales as a function of intrinsic alertness, with higher alertness linking to larger perceived size of objects and better performance in size discrimination and size illusion tasks, and suggest that individual variation in resting-state brain activity provides a neural explanation for individual variation in cognitive performance of normal participants.

Alterations Functional Connectivity in Temporal Lobe Epilepsy and Their Relationships With Cognitive Function: A Longitudinal Resting-State fMRI Study.

Background: Cognitive impairments in temporal lobe epilepsy (TLE) patients has been described as a chronically progressive feature of the disease. However, how severe recurrent seizures modify neuronal circuits in the human brain and subsequently degrade cognitive function, remains largely unknown. Here, we aimed to investigate longitudinal alterations by functional magnetic resonance imaging (fMRI) in TLE patients and to assess how those alterations are related to cognitive function performance.Methods: Sixteen TLE patients and 20 normal controls (NCs) were recruited for a study to observe longitudinal alterations in resting-state functional connectivity (FC) and to estimate alertness, orientation, and executive function both at baseline and at a follow-up time ~3 years later.Results: TLE patients, compared with NCs, showed impaired executive function, intrinsic alertness, and phasic alertness and exhibited lengthened reaction time (RT) in the spatial cue and center cue conditions at baseline. The orienting function of TLE patients was declined at follow-up compared to the baseline. Cross-sectional analysis demonstrated that TLE patients displayed significantly greater positive correlation than NCs between the right dorsolateral prefrontal cortex (DLPFC) and the right inferior parietal lobule (IPL) and right superior frontal gyrus (SFG). Furthermore, among TLE patients, the longitudinal study revealed a decrease in correlation between the right DLPFC and the right SFG compared to the baseline. In addition, there was a significant negative correlation between the longitudinal change in FC and the change in orienting function in TLE subjects.Conclusions: Abnormal connectivity between the DLPFC and the SFG suggests the potential of longitudinal resting-state fMRI to delineate regions relevant to cognitive dysfunction for disease progression.

Individual differences in lapses of sustained attention: Ocolumetric indicators of intrinsic alertness.

Two experiments examined individual differences in lapses of sustained attention. Participants performed variants of the psychomotor vigilance task while pupillary responses and fixations were recorded. Examining pupillary responses during the interstimulus interval in both experiments suggested that individuals particularly susceptible to lapses of attention (indexed by the slowest response times) demonstrated a decreased pupillary response during the interstimulus interval, whereas individuals less susceptible to lapses of attention demonstrated an increased pupillary response during the interstimulus interval. These results suggest that variation in lapses of attention are partially attributable to individual differences in the ability to voluntarily control the intensity of attention (intrinsic alertness) and fully engage preparatory processes on a moment-by-moment basis. Furthermore, across both experiments additional individual differences factors covaried with lapses of attention, including attention control, working memory capacity, susceptibility to off-task thinking, task-specific motivation, and fixation stability. These results provide evidence for the notion that individual differences in lapses of attention are multifaceted and that variation in intrinsic alertness and other factors are important contributors to this variation. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Entrepreneurial alertness: a systematic literature review

Recently, cognitive perspectives have garnered increasing attention in entrepreneurship alertness research. But the broader psychological basis of the alertness, which differentiates intrinsic and phasic aspects of alertness, has somehow been neglected, even though some entrepreneurship scholars have described alertness as the main cognitive capability of entrepreneurs in recognizing entrepreneurial opportunities. In this systematic review, the literature of entrepreneurial alertness has been critically examined. We categorize the previous works into five broad research themes: the alertness construct itself, its cognitive foundations, its operational measurement, the theoretical antecedents of alertness, and its consequences. We then identify two gaps where future research should direct greater efforts. First, past attention to the cognitive foundations of alertness has largely focused on its phasic aspects without exploration of the role of intrinsic alertness. The recent separate theorizing of opportunity creation/discovery has only begun to explore the potential of intrinsic alertness in opportunity spotting. Secondly, a lack of attention to establishing a clear definition of the alertness construct has hampered development of valid and robust measurement instruments, which may have confounded past efforts to empirically confirm the role of alertness in a range of theoretical models.

Working memory capacity and sustained attention: A cognitive-energetic perspective.

A cognitive-energetic account of individual differences in working memory capacity (WMC) and sustained attention performance is proposed suggesting that variation in the voluntary control of the intensity of attention (intrinsic alertness) is critical for the relation between WMC and attention control. Four experiments examining individual differences were conducted to test this account. The results suggested that WMC was consistently related to the slowest reaction times in conditions where the interstimulus interval (ISI) was varied or was fixed at a long interval. Variation in WMC was not related to performance when the ISI was fixed at a short interval which is thought to decrease demands on intrinsic alertness. The current results are consistent with the hypothesis that normal variation in WMC and sustained attention performance are partially the result of individual differences in intrinsic alertness whereby low WMC individuals are less able to consistently control the intensity of attention than high WMC individuals. Other possible reasons for the relation between WMC and sustained attention performance such as differences in goal activation, speed of goal activation, goal maintenance during a trial, or sustaining goal maintenance across the duration of the task were associated with weaker and inconsistent evidence. Collectively we suggest that the current cognitive-energetic account can be used to understand individual differences in WMC and attention control and their relations with other cognitive abilities. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Resting-state brain entropy in right temporal lobe epilepsy and its relationship with alertness.

BackgroundTo date, no functional MRI (fMRI) studies have focused on brain entropy in right temporal lobe epilepsy (rTLE) patients. Here, we characterized brain entropy (BEN) alterations in patients with rTLE using resting‐state functional MRI(rs‐fMRI) and explored the relationship between BEN and alertness.MethodThirty‐one rTLE patients and 33 controls underwent MRI scanning to investigate differences in BEN and resting‐state functional connectivity (rs‐FC) in regions of interest (ROIs) between patients and controls. Correlation analyses were performed to examine relationships between the BEN of each ROI and alertness reaction times (RTs) in rTLE patients.ResultsCompared with controls, the BEN of rTLE patients was significantly increased in the right middle temporal gyrus, inferior temporal gyrus, and other regions of the left hemisphere and significantly decreased in the right middle frontal gyrus and left supplementary motor area (p < .05). The rs‐FCs between the ROIs (at p < .01, with the left superior parietal lobule and right precentral gyrus defined as ROI1 and ROI2, respectively) and the whole brain showed an increasing trend in rTLE patients. In addition, the BEN of ROI2 was associated with the intrinsic alertness and phasic alertness RTs of patients with rTLE.ConclusionsOur findings suggest that BEN is altered in patients with rTLE and that decreased BEN in the right precentral gyrus is positively related to intrinsic and phasic alertness; the abnormal FC in the brain regions with altered entropy suggests a reconstruction of brain functional connectivity. These findings suggest that BEN mapping may provide a useful tool for probing brain mechanisms related to TLE.

Pupillary Correlates of Fluctuations in Sustained Attention.

The current study examined pupillary correlates of fluctuations and lapses of sustained attention. Participants performed a sustained attention task with either a varied ISI or a fixed ISI (fixed at 2 or 8 sec) while pupil responses were continuously recorded. The results indicated that performance was worse when the ISI was varied or fixed at 8 sec compared with when the ISI was fixed at 2 sec, suggesting that varied or long ISI conditions require greater intrinsic alertness compared with constant short ISIs. In terms of pupillary responses, the results demonstrated that slow responses (indicative of lapses) were associated with greater variability in tonic pupil diameter, smaller dilation responses during the ISI, and subsequently smaller dilation responses to stimulus onset. These results suggest that lapses of attention are associated with lower intrinsic alertness, resulting in a lowered intensity of attention to task-relevant stimuli. Following a lapse of attention, performance, tonic pupil diameter, and phasic pupillary responses, all increased, suggesting that attention was reoriented to the task. These results are consistent with the notion that pupillary responses track fluctuations in sustained attention.

Targeting alertness to improve cognition in older adults: A preliminary report of benefits in executive function and skill acquisition

Efficient self-regulation of alertness declines with age exacerbating normal declines in performance across multiple cognitive domains, including learning and skill acquisition. Previous cognitive intervention studies have shown that it is possible to enhance alertness in patients with acquired brain injury and marked attention impairments, and that this benefit generalizes to improvements in more global cognitive functions. In the current preliminary studies, we sought to test whether this approach, that targets both tonic (over a period of minutes) and phasic (moment-to-moment) alertness, can improve key executive functioning declines in older adults, and enhance the rate of skill acquisition. The results of both Experiments 1 and 2 demonstrate that, compared to active control (AC) training, alertness training significantly enhanced performance in several validated executive function measures. In Experiment 2, alertness training significantly improved skill acquisition compared to AC training in a well-characterized speed of processing (SOP) task, with the largest benefits shown in the most challenging SOP blocks. The results of the current study suggest that targeting intrinsic alertness through cognitive training provides a novel approach to improve executive functions in older adults and may be a useful adjunct treatment to enhance benefits gained in other clinically validated treatments.

Three Points about Current German Anthropology

Comment on World Anthropology with an Accent: the Discipline in Germany since the 1970s, by Bierschenk, Thomas, Krings, Matthias, and Carola Lenz

No stress after 24-hour on-call shifts?

Irregular sleep patterns can adversely affect physiological functions and have been associated with increased physiological and psychological stress. Nocturnal work of physicians during 24-hour on-call shifts (OCS) disrupts the sleep/wake cycle. Chronic exposure to distress has been shown to affect cardiovascular homeostasis and to impair performance in neurocognitive and simulated clinical tasks. In a prospective cohort study, biochemical and physiological stress parameters were assessed in 11 female and 9 male physicians (median age: 32 years, range 26-42 years) before a normal working day and after a 24-hour OCS in internal medicine. In addition, various tests of attentional performance (TAP) were conducted. The levels of thyroid stimulating hormone (TSH) were significantly higher after a 24- hour OCS, while there were no significant changes in cortisol, epinephrine, and norepinephrine levels. Heart rate variability and skin resistance increased following an OCS, although the differences were not statistically significant. Intrinsic alertness was comparable, while phasic alertness was significantly improved following a 24-hour OCS. Focused attention tended to be better following a night shift. There was no correlation with age or medical working experience; however, men experienced more stress than women. Following a 24-hour OCS, (i) TSH may be an early and sensitive biochemical predictor of stress; (ii) other classical biochemical stress parameters do not depict the psychological stress perceived by physicians; (iii) there may be a mismatch between experienced and objective stress levels; (iv) neurocognitive functions are not impaired, while performance may even be improved; and (v) men might be more sensitive to distress.