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1.
BMC Infect Dis ; 22(1): 787, 2022 Oct 13.
Article in English | MEDLINE | ID: mdl-36229777

ABSTRACT

We assess the causal impact of social distancing on the spread of SARS-CoV-2 in the U.S. using the quasi-natural experimental setting created by the spontaneous relaxation of social distancing behavior brought on by the protests that erupted across the nation following George Floyd's tragic death on May 25, 2020. Using a difference-in-difference specification and a balanced sample covering the [- 30, 30] day event window centered on the onset of protests, we document an increase of 1.34 cases per day, per 100,000 population, in the SARS-CoV-2 incidence rate in protest counties, relative to their propensity score matching non-protest counterparts. This represents a 26.8% increase in the incidence rate relative to the week preceding the protests. We find that the treatment effect only manifests itself after the onset of the protests and our placebo tests rule out the possibility that our findings are attributable to chance. Our research informs policy makers and provides insights regarding the usefulness of social distancing as an intervention to minimize the spread of SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Incidence , Physical Distancing
2.
Can J Anaesth ; 67(11): 1497-1506, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32767054

ABSTRACT

PURPOSE: Function describes an individual's ability to perform everyday activities. In the context of cardiac surgery, functional changes quantify the effect of surgery on one's day-to-day life. Decreases in regional cerebral oxygen saturation (rScO2) measured using near-infrared spectroscopy (NIRS) has been associated with postoperative cognitive decline but its relationship with function has not been studied. We sought to determine the feasibility of conducting a large observational study examining the relationship between decreases in rScO2 during cardiac surgery and postoperative functional decline. METHODS: We undertook a single-centre, pilot sub-study of the NeuroVISION-Cardiac Surgery pilot study, which included adults undergoing isolated coronary artery bypass grafting on cardiopulmonary bypass; all patients enrolled in NeuroVISION-Cardiac Surgery were included. Function was evaluated at baseline, 30 days, and three months using the Standardized Assessment of Global activities in the Elderly (SAGE) scale. Blinded NIRS monitors were affixed for the duration of surgery. Our feasibility outcomes were to recruit one patient per week, obtain complete NIRS data in ≥ 90%, obtain SAGE at all time-points in ≥ 90%, and determine the time required for NIRS data to be transcribed into case report forms. RESULTS: 49/50 patients enrolled in NeuroVISION-Cardiac Surgery were recruited over 48 weeks (1.02 patients/week). Of the 49 included patients, 49 (100%) had complete NIRS data and 44 (90%) had complete SAGE data. The time required for NIRS data collection was a mean (standard deviation) of 5.5 (1.8) min per patient. CONCLUSION: This pilot study shows the feasibility of conducting a large observational study examining the relationship between decreases in cerebral saturation during cardiac surgery and postoperative functional decline. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT04241289); registered 27 January 2020.


RéSUMé: OBJECTIF : La capacité fonctionnelle constitue la capacité d'une personne à accomplir des activités quotidiennes. Dans le contexte d'une chirurgie cardiaque, les changements fonctionnels permettent de quantifier l'effet de la chirurgie sur le quotidien des individus. Les baisses de la saturation en oxygène cérébral régional (rScO2) mesurées à l'aide de la spectroscopie proche infrarouge (NIRS) ont été associées à un déclin cognitif postopératoire, mais leur relation par rapport à la capacité fonctionnelle n'a pas été étudiée. Nous avons tenté de déterminer s'il était possible de réaliser une vaste étude observationnelle examinant la relation entre les baisses de rScO2 pendant une chirurgie cardiaque et le déclin fonctionnel postopératoire. MéTHODE : Nous avons entrepris une sous-étude pilote monocentrique de l'étude pilote NeuroVISION-Cardiac Surgery, qui incluait des adultes subissant une chirurgie de pontage aortocoronarien sous circulation extracorporelle; tous les patients recrutés dans l'étude NeuroVISION-Cardiac Surgery ont été inclus dans ce volet. La capacité fonctionnelle a été évaluée avant l'opération, puis à 30 jours et trois mois à l'aide de l'échelle SAGE (Standardized Assessment of Global activities in the Elderly, soit Évaluation standardisée de la fonction globale chez la personne âgée). Des moniteurs de NIRS étaient installés pour toute la durée de la chirurgie sans que les valeurs ne soient connues de l'équipe traitante. Nos critères de faisabilité consistaient à recruter un patient par semaine, obtenir des données de NIRS complètes pour ≥ 90 % des patients, obtenir des données de SAGE pour tous les points dans le temps pour ≥ 90 % des patients, et déterminer le temps nécessaire à retranscrire les données de NIRS dans les formulaires d'étude de cas. RéSULTATS : Au total, 49/50 patients recrutés dans l'étude NeuroVISION-Cardiac Surgery ont été recrutés sur une période de 48 semaines (1,02 patients/semaine). Parmi les 49 patients inclus, les données de NIRS ont été obtenues pour 49 (100 %) patients et les données de SAGE pour 44 (90 %) patients. Le temps nécessaire à la collecte de données de NIRS était en moyenne (écart type) de 5,5 (1,8) min par patient. CONCLUSION : L'étude pilote a démontré la faisabilité d'une vaste étude observationnelle examinant la relation entre les baisses de la saturation cérébrale pendant la chirurgie cardiaque et le déclin fonctionnel postopératoire. ENREGISTREMENT DE L'éTUDE : www.clinicaltrials.gov (NCT04241289); enregistrée le 27 janvier 2020.


Subject(s)
Cardiac Surgical Procedures , Monitoring, Intraoperative , Adult , Aged , Feasibility Studies , Humans , Oximetry , Oxygen , Pilot Projects
3.
Curr Biol ; 30(10): 1821-1833.e8, 2020 05 18.
Article in English | MEDLINE | ID: mdl-32243859

ABSTRACT

The ability to anticipate and flexibly plan for the future is critical for achieving goal-directed outcomes. Extant data suggest that neural and cognitive stress mechanisms may disrupt memory retrieval and restrict prospective planning, with deleterious impacts on behavior. Here, we examined whether and how acute psychological stress influences goal-directed navigational planning and efficient, flexible behavior. Our methods combined fMRI, neuroendocrinology, and machine learning with a virtual navigation planning task. Human participants were trained to navigate familiar paths in virtual environments and then (concurrent with fMRI) performed a planning and navigation task that could be most efficiently solved by taking novel shortcut paths. Strikingly, relative to non-stressed control participants, participants who performed the planning task under experimentally induced acute psychological stress demonstrated (1) disrupted neural activity critical for mnemonic retrieval and mental simulation and (2) reduced traversal of shortcuts and greater reliance on familiar paths. These neural and behavioral changes under psychological stress were tied to evidence for disrupted neural replay of memory for future locations in the spatial environment, providing mechanistic insight into why and how stress can alter planning and foster inefficient behavior.


Subject(s)
Hippocampus/physiology , Prefrontal Cortex/physiology , Spatial Navigation/physiology , Adolescent , Adult , Humans , Hydrocortisone/chemistry , Hydrocortisone/metabolism , Magnetic Resonance Imaging , Male , Saliva/chemistry , Young Adult
4.
Cogn Process ; 21(2): 287-302, 2020 May.
Article in English | MEDLINE | ID: mdl-31974762

ABSTRACT

Finding one's way to a destination is a common, everyday task that often relies on spatial information provided by humans and/or automatic devices. However, the information can be inaccurate. How we decide which route to take will depend on our thoughts about the available route information, including who or what provided it, and how these sources may be associated with differential accuracy and fallibility. In three experiments (previously reported in Brunyé et al. (Q J Exper Psychol 68(3):585-607, 2015)), we found that when route directions conflicted with the perceived environment, people trusted the landmark information other humans provided, but relied on the turn direction information from an automatic device. But what guides these behavioral results? Here we present a systematic linguistic analysis of retrospective reports that sheds some light on how information about the direction source affects cognitive focus. A focus on direction sources in the instruction triggered a cognitive focus on the direction source throughout. Participants who systematically switched strategies focused more on features of the scenario than those who did not. Non-switching strategies were associated with a higher focus on the participants' own reasoning processes, in particular when relying on turn information. These results highlight how cognitive focus is guided by scenario factors and individual preferences, triggering inferences that influence decisions.


Subject(s)
Decision Making , Spatial Navigation , Adult , Cognition , Female , Humans , Problem Solving , Retrospective Studies , Uncertainty
5.
JTCVS Open ; 4: 1-11, 2020 Dec.
Article in English | MEDLINE | ID: mdl-36004290

ABSTRACT

Objectives: Covert stroke is a complication of coronary artery bypass graft surgery that is increasingly recognized as a serious problem. In noncardiac surgery settings, covert stroke is associated with the development of delirium, long-term cognitive decline, and future clinical stroke. Therefore, we sought to determine the feasibility of conducting a large, prospective cohort study of the influence of covert stroke on neurocognitive outcomes in patients undergoing coronary artery bypass graft surgery. Methods: NeuroVISION Cardiac pilot was a prospective cohort study enrolling patients aged ≥21 years undergoing isolated coronary artery bypass graft surgery to receive diffusion-weighted magnetic resonance imaging of the brain after surgery to identify patients with covert stroke. Patients were screened for postoperative delirium in-hospital and were administered questionnaires of cognitive and global function (once before and twice after surgery). Regional cerebral oxygen saturation was recorded during surgery using near-infrared spectroscopy. Results: Between March 27, 2017, and February 11, 2018, 50 of 66 patients enrolled (76%) completed the brain magnetic resonance imaging (1 patient per week). Among the 49 patients included in the analysis, 19 (39%; 95% confidence interval, 26%-53%) experienced perioperative covert stroke and 3 (6%) had a clinical stroke within 30 days of surgery. Postoperative delirium occurred in 5 (26%) patients with covert stroke and in 3 (10%) patients who did not experience covert stroke. Conclusions: The NeuroVISION Cardiac pilot study established the feasibility of conducting a large, prospective cohort study of the determinants and consequences of covert stroke in patients undergoing coronary artery bypass graft surgery.

6.
eNeuro ; 6(5)2019.
Article in English | MEDLINE | ID: mdl-31451605

ABSTRACT

How do we recall vivid details from our past based only on sparse cues? Research suggests that the phenomenological reinstatement of past experiences is accompanied by neural reinstatement of the original percept. This process critically depends on the medial temporal lobe (MTL). Within the MTL, perirhinal cortex (PRC) and parahippocampal cortex (PHC) are thought to support encoding and recall of objects and scenes, respectively, with the hippocampus (HC) serving as a content-independent hub. If the fidelity of recall indeed arises from neural reinstatement of perceptual activity, then successful recall should preferentially draw upon those neural populations within content-sensitive MTL cortex that are tuned to the same content during perception. We tested this hypothesis by having eighteen human participants undergo functional MRI (fMRI) while they encoded and recalled objects and scenes paired with words. Critically, recall was cued with the words only. While HC distinguished successful from unsuccessful recall of both objects and scenes, PRC and PHC were preferentially engaged during successful versus unsuccessful object and scene recall, respectively. Importantly, within PRC and PHC, this content-sensitive recall was predicted by content tuning during perception: Across PRC voxels, we observed a positive relationship between object tuning during perception and successful object recall, while across PHC voxels, we observed a positive relationship between scene tuning during perception and successful scene recall. Our results thus highlight content-based roles of MTL cortical regions for episodic memory and reveal a direct mapping between content-specific tuning during perception and successful recall.


Subject(s)
Magnetic Resonance Imaging/methods , Mental Recall/physiology , Perirhinal Cortex/diagnostic imaging , Perirhinal Cortex/physiology , Photic Stimulation/methods , Adolescent , Adult , Female , Humans , Male , Random Allocation , Temporal Lobe/diagnostic imaging , Temporal Lobe/physiology , Young Adult
7.
Cereb Cortex ; 29(7): 2947-2964, 2019 07 05.
Article in English | MEDLINE | ID: mdl-30060134

ABSTRACT

Despite decades of science investigating the neural underpinnings of episodic memory retrieval, a critical question remains: how does stress influence remembering and the neural mechanisms of recollection in humans? Here, we used functional magnetic resonance imaging and multivariate pattern analyses to examine the effects of acute stress during retrieval. We report that stress reduced the probability of recollecting the details of past experience, and that this impairment was driven, in part, by a disruption of the relationship between hippocampal activation, cortical reinstatement, and memory performance. Moreover, even memories expressed with high confidence were less accurate under stress, and this stress-induced decline in accuracy was explained by reduced posterior hippocampal engagement despite similar levels of category-level cortical reinstatement. Finally, stress degraded the relationship between the engagement of frontoparietal control networks and retrieval decision uncertainty. Collectively, these findings demonstrate the widespread consequences of acute stress on the neural systems of remembering.


Subject(s)
Cerebral Cortex/physiopathology , Hippocampus/physiopathology , Mental Recall/physiology , Stress, Psychological/physiopathology , Adolescent , Adult , Humans , Magnetic Resonance Imaging , Male , Young Adult
8.
Physiol Rep ; 6(14): e13799, 2018 07.
Article in English | MEDLINE | ID: mdl-30009507

ABSTRACT

Obese individuals exhibit a diminished muscle protein synthesis response to nutrient stimulation when compared with their lean counterparts. However, the effect of obesity on exercise-stimulated muscle protein synthesis remains unknown. Nine lean (23.5 ± 0.6 kg/m2 ) and 8 obese (33.6 ± 1.2 kg/m2 ) physically active young adults participated in a study that determined muscle protein synthesis and intracellular signaling at rest and following an acute bout of resistance exercise. Mixed muscle protein synthesis was determined by combining stable isotope tracer ([13 C6 ]phenylalanine) infusion with serial biopsies of the vastus lateralis. A unilateral leg resistance exercise model was adopted so that resting and postexercise measurements of muscle protein synthesis could be obtained simultaneously. Obesity was associated with higher basal levels of serum insulin (P < 0.05), plasma triacylglycerol (P < 0.01), plasma cholesterol (P < 0.01), and plasma CRP (P < 0.01), as well as increased insulin resistance determined by HOMA-IR (P < 0.05). However, resting and postexercise rates of muscle protein synthesis were not significantly different between lean and obese participants (P = 0.644). Furthermore, resistance exercise stimulated muscle protein synthesis (~50% increase) in both groups (P < 0.001), with no difference between lean and obese (P = 0.809). Temporal increases in the phosphorylation of intracellular signaling proteins (AKT/4EBP1/p70S6K) were observed within the exercised leg (P < 0.05), with no differences between lean and obese. These findings suggest a normal anabolic response to muscle loading in obese young adults.


Subject(s)
Muscle, Skeletal/metabolism , Obesity/metabolism , Protein Biosynthesis , Resistance Training , Adult , Case-Control Studies , Cholesterol/blood , Female , Humans , Insulin/blood , Male , Muscle, Skeletal/physiology , Triglycerides/blood
9.
J Sex Med ; 15(3): 346-360, 2018 03.
Article in English | MEDLINE | ID: mdl-29502982

ABSTRACT

BACKGROUND: Digital intravaginal palpation remains the favored method for clinical assessment of pelvic floor muscle (PFM) function in women; however, there is growing interest in using transperineal ultrasound imaging (TPUSI). TPUSI does not involve vaginal penetration, making it particularly relevant for PFM assessment in women with genito-pelvic pain and penetration disorders. AIMS: To study the relations between measures of PFM morphology and function assessed using 3-dimensional (3D) TPUSI and PFM assessment through intravaginal palpation. METHODS: 77 nulliparous premenopausal women with (n = 38) and without (n = 39) PVD participated. 3D TPUSI was used to measure levator hiatal dimensions at rest, at maximal voluntary contraction (MVC) of the PFMs, and at maximal Valsalva maneuver (MVM). Intravaginal palpation was used to assess PFM strength, PFM tone, PFM relaxation after contraction, and vaginal flexibility; each was scored using an ordinal grading scale. Ultrasound and palpation outcomes were compared using Spearman correlation coefficients and Kruskal-Wallis 1-way analyses of variance by rank. OUTCOMES: Outcomes included ultrasound measures of the levator hiatal area, anteroposterior diameter, and left-right transverse diameter at rest, at MVC, and at MVM; raw and relative changes in hiatal dimensions between rest and MVC and between rest and MVM; and palpation measures of PFM strength, tone, and relaxation after contraction, and vaginal flexibility. RESULTS: Weak to fair correlations were found between ultrasound and palpation measures. A smaller levator hiatus at rest was associated with greater PFM tone, less PFM relaxation, and less vaginal flexibility. Greater levator hiatal constriction and shortening of the hiatal anteroposterior diameter at MVC were associated with greater palpated PFM strength. Greater hiatal distention at MVM was associated with lower PFM tone and greater relaxation. CLINICAL TRANSLATION: 3D TPUSI and intravaginal palpation provide related but distinct information about PFM function in young women with and without PVD with high functioning PFMs. STRENGTHS AND LIMITATIONS: This was the first study to compare PFM assessment using 3D TPUSI and intravaginal palpation in nulliparous premenopausal women. A main strength of the study was the inclusion of women with PVD and asymptomatic controls, which provided a wide range in outcomes because differences in PFM morphology and function exist between women with and without PVD. The lack of inclusion of older women and women with weaker and/or hypotonic PFMs limits the generalizability of the findings. CONCLUSION: Although TPUSI has several advantages, including painless application, it is not recommended as a replacement for digital palpation in the clinical assessment of PFM function. Thibault-Gagnon S, Goldfinger C, Pukall C, et al. Relationships Between 3-Dimensional Transperineal Ultrasound Imaging and Digital Intravaginal Palpation Assessments of the Pelvic Floor Muscles in Women With and Without Provoked Vestibulodynia. J Sex Med 2018;15:346-360.


Subject(s)
Pelvic Floor/diagnostic imaging , Ultrasonography/methods , Valsalva Maneuver/physiology , Vulvodynia/diagnostic imaging , Adolescent , Adult , Female , Humans , Imaging, Three-Dimensional/methods , Muscle Contraction/physiology , Muscle Tonus , Palpation , Pelvic Floor/physiopathology , Pelvic Floor Disorders/diagnostic imaging , Pelvic Floor Disorders/physiopathology , Vagina/physiopathology , Vulvodynia/physiopathology , Young Adult
10.
J Electromyogr Kinesiol ; 38: 126-135, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29245113

ABSTRACT

AIMS: The purpose of this study was to investigate the relationship between pelvic floor muscle (PFM) electromyographic (EMG) activation and urogenital landmark motion measured using 2D transperineal ultrasound (US) imaging. METHODS: Eight healthy, nulliparous women performed maximum voluntary PFM contractions while EMG and transperineal US images were acquired simultaneously. Changes in the levator plate length (LPL), bladder neck (BN) position and urethral position were determined by visual inspection. The relative timing of EMG onset and the onset of landmark motion, and the correlation coefficients between EMG activation and landmark motion were computed. Comparisons between the correlation coefficients and onset latencies of each landmark motion were made using one-way analysis of variance models. RESULTS: Despite generally good reliability metrics for the onset of EMG and the onset of landmark motion, the relative timing of EMG onset and the onset of landmark motion demonstrated no systematic patterns of activation onset. That said, the overall motion of the different urogenital landmarks throughout the MVC task was highly correlated with the PFM EMG data; correlation coefficients were generally good (>0.90) and highly significant (p < .001). The correlation between PFM EMG and LPL motion was significantly better than the correlation between PFM EMG and motion of the other landmarks. The relevance of one outlier is discussed. CONCLUSIONS: The motion of all urogenital landmarks seen on US imaging is highly correlated with PFM EMG activation during maximum voluntary PFM contractions and may therefore be of value in the context of biofeedback training to infer that PFM activation has occurred. The motion of the BN, however, may require more cautious interpretation than the reduction of LPL. The timing of the onset of urogenital landmark motion on transperineal US imaging does not precede nor follow the timing of PFM activation, while the high variance of relative onset timing makes the onset of landmark motion of questionable value when training or evaluating co-ordination or motor control.


Subject(s)
Muscle Contraction , Pelvic Floor/physiology , Urogenital System/physiology , Adult , Female , Humans , Pelvic Floor/diagnostic imaging , Ultrasonography , Urogenital System/diagnostic imaging
11.
J Sex Med ; 13(6): 963-71, 2016 06.
Article in English | MEDLINE | ID: mdl-27215690

ABSTRACT

OBJECTIVE: Pelvic morphology has been suggested to reflect increased tone and reduced strength of the pelvic floor muscles (PFMs) in women with provoked vestibulodynia (PVD) compared to healthy controls. We aimed to determine whether there are differences in pelvic morphology in the resting state, on maximum voluntary contraction (MVC), or on maximum effort Valsalva maneuver (MVM) between women with and without PVD. METHODS: While imaged using ultrasound, 38 women with PVD and 39 controls relaxed their PFMs, performed 3 MVCs and performed 3 MVMs. Levator plate length (LPL), levator plate angle (LPA), and anorectal angle (ARA) were determined at rest, at MVC and at MVM. The displacement of the bladder neck (BN) on MVC and on MVM was also determined. Two-way ANCOVAs were used to evaluate the main effects of group and task, the interaction between group and task, and the effect of resting morphology on LPL, LPA, and ARA. A 2-way repeated-measures ANOVA was used to determine whether the groups differed in terms of BN displacement during the tasks. RESULTS: Women with PVD had smaller LPLs and LPAs than controls across all tasks. The significant group differences in LPL and LPA at MVC and MVM were no longer significant once the resting values were included as covariates in the models. Bladder neck displacement differed between the groups at MVM but not at MVC. CONCLUSION: Women with PVD display shorter LPL sand smaller LPAs than controls but their behavior does not differ when MVC and MVMs are performed. Our results do not support the hypothesis that women with PVD demonstrate abnormalities in PFM contractility on MVC or compliance on MVM.


Subject(s)
Muscle Contraction/physiology , Pelvic Floor , Valsalva Maneuver/physiology , Vulvodynia/physiopathology , Adult , Female , Humans , Rest , Ultrasonography , Young Adult
12.
J Sex Med ; 13(1): 88-94, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26755091

ABSTRACT

INTRODUCTION: Non-medical and non-surgical treatments for provoked vestibulodynia target psychological, sexual, and pelvic floor muscle factors that maintain the condition. AIM: The goal of the study was to compare the effects of cognitive-behavioral therapy (CBT) and physical therapy (PT) on pain and psychosexual outcomes in women with provoked vestibulodynia. METHODS: In a clinical trial, 20 women with provoked vestibulodynia were randomly assigned to receive CBT or comprehensive PT. Participants were assessed before treatment, after treatment, and at 6-month follow-up by gynecologic examination, structured interviews, and standardized questionnaires measuring pain, psychological, and sexual variables. MAIN OUTCOME MEASURES: Outcome measurements were based on an adaptation of the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations. The primary outcome was change in intercourse pain intensity. Secondary outcomes included pain during the cotton swab test, pain with various sexual and non-sexual activities, and sexual functioning and negative pain cognitions. RESULTS: The two treatment groups demonstrated significant decreases in vulvar pain during sexual intercourse, with 70% and 80% of participants in the CBT and PT groups demonstrating a moderate clinically important decrease in pain (≥30%) after treatment. Participants in the two groups also had significant improvements in pain during the gynecologic examination, the percentage of painful intercourse attempts, the percentage of activities resulting in pain, and the ability to continue intercourse without stopping because of pain. Psychological outcomes, including pain catastrophizing and perceived control over pain, also showed improvement in the two groups. Significant improvements in sexual functioning were observed only in participants who completed CBT. Few between-group differences were identified other than the PT group showing earlier improvements in some outcomes. Nearly all improvements were maintained at the 6-month follow-up. CONCLUSION: The results of the study suggest that CBT and PT can lead to clinically meaningful improvements in pain and areas of psychosexual functioning.


Subject(s)
Cognitive Behavioral Therapy , Coitus/psychology , Vulvodynia/therapy , Adult , Female , Follow-Up Studies , Humans , Middle Aged , Pain Measurement , Pelvic Pain , Physical Therapy Modalities , Pilot Projects , Surveys and Questionnaires , Treatment Outcome , Vulvodynia/etiology , Vulvodynia/physiopathology , Vulvodynia/psychology , Young Adult
13.
Ann N Y Acad Sci ; 1369(1): 55-75, 2016 04.
Article in English | MEDLINE | ID: mdl-26799371

ABSTRACT

Episodic retrieval allows people to access memories from the past to guide current thoughts and decisions. In many real-world situations, retrieval occurs under conditions of acute stress, either elicited by the retrieval task or driven by other, unrelated concerns. Memory under such conditions may be hindered, as acute stress initiates a cascade of neuromodulatory changes that can impair episodic retrieval. Here, we review emerging evidence showing that dissociable stress systems interact over time, influencing neural function. In addition to the adverse effects of stress on hippocampal-dependent retrieval, we consider how stress biases attention and prefrontal cortical function, which could further affect controlled retrieval processes. Finally, we consider recent data indicating that stress at retrieval increases activity in a network of brain regions that enable reflexive, rapid responding to upcoming threats, while transiently taking offline regions supporting flexible, goal-directed thinking. Given the ubiquity of episodic memory retrieval in everyday life, it is critical to understand the theoretical and applied implications of acute stress. The present review highlights the progress that has been made, along with important open questions.


Subject(s)
Attention/physiology , Memory, Episodic , Mental Recall/physiology , Prefrontal Cortex/physiopathology , Stress, Psychological/psychology , Temporal Lobe/physiopathology , Humans , Nerve Net/physiopathology , Reaction Time/physiology
14.
J Sex Med ; 13(2): 243-52, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26805942

ABSTRACT

INTRODUCTION: Pelvic floor muscle (PFM) involvement is suspected in the pathophysiology of provoked vestibulodynia (PVD); however, the underlying mechanisms are unclear. PFM morphology can be inferred from the biometry of the levator hiatus determined through dynamic ultrasound imaging. AIMS: The aim of this study was to determine the nature of PFM involvement in women with PVD via an evaluation of the biometry of the levator hiatus at rest, upon maximal voluntary contraction (MVC) of the PFMs, and upon maximal Valsalva maneuver (MVM). METHODS: Thirty-eight women with PVD and 39 asymptomatic controls were imaged using 3D transperineal ultrasound. Levator hiatal dimensions (area; left-right [LR] and anteroposterior [AP] diameters) were measured at rest, on MVC, and on MVM. Differences in hiatal dimensions and in relative changes in dimensions from rest to MVC and from rest to MVM were compared between groups using separate 1-way analyses of variance for each measure and task. Analysis of covariance models were used to investigate the impact of levator hiatal dimensions at rest on the relative changes in the levator hiatal dimensions during MVC and MVM. MAIN OUTCOME MEASURES: Levator hiatal area, LR, and AP diameters, at rest, on MVC, and on MVM were the main outcome measures. Relative changes in hiatal dimensions were assessed as the percent change in hiatal area, LR diameter, and AP diameter. RESULTS: In comparison with controls, women with PVD had smaller hiatal areas at rest, on MVC, and on MVM, concurrent with smaller LR diameters on MVM. Women with PVD had a significantly smaller change in hiatal area on MVM than controls, but no differences were evident on MVC. In both groups, smaller levator hiatal dimensions at rest were associated with smaller relative decreases in dimensions on MVC and larger relative increases in dimensions on MVM. CONCLUSION: In comparison to controls, women with PVD appear to have narrower levator hiatus' and less capacity to distend their hiatus on Valsalva. The state of the PFMs at rest appears to significantly influence biometric changes in the PFMs during contraction and Valsalva.


Subject(s)
Biometry , High-Energy Shock Waves/therapeutic use , Pelvic Floor/physiopathology , Vulvodynia/physiopathology , Adult , Canada , Female , Humans , Imaging, Three-Dimensional/methods , Muscle Contraction , Pelvic Floor/diagnostic imaging , Pelvic Floor/pathology , Rest , Ultrasonography , Valsalva Maneuver , Vulvodynia/diagnostic imaging , Vulvodynia/pathology
15.
Future Sci OA ; 1(4): FSO55, 2015 Nov.
Article in English | MEDLINE | ID: mdl-28031910

ABSTRACT

AIM: Testosterone undecanoate (TU) is metabolized by nonspecific esterases in blood to testosterone (T). Typical clinical practice has been to analyze testosterone in human serum. The degradation of TU to testosterone was evaluated in conditions typically used in clinical studies. METHODS & RESULTS: Freshly collected whole blood was fortified with TU at known concentration. Serum was prepared and T concentration was determined by LC-MS/MS. It was observed that TU degrades extensively to T in human blood under conditions typical of harvesting serum causing overestimation of T concentration of up to 243%. These results were confirmed in a clinical study in which serum and plasma samples were compared. CONCLUSION: It was demonstrated that T must be analyzed in enzyme-inhibited plasma when TU is the administered medication.

16.
Q J Exp Psychol (Hove) ; 68(3): 585-607, 2015.
Article in English | MEDLINE | ID: mdl-25285995

ABSTRACT

Previous research on route directions largely considers the case when a knowledgeable route-giver conveys accurate information. In the real world, however, route information is sometimes inaccurate, and directions can lead navigators astray. We explored how participants respond to route directions containing ambiguities between landmarks and turn directions, forcing reliance on one or the other. In three experiments, participants read route directions (e.g., To get to the metro station, take a right at the pharmacy) and then selected from destinations on a map. Critically, in half of the trials the landmark (pharmacy) and turn (right) directions were conflicting, such that the participant had to make a decision under conditions of uncertainty; under these conditions, we measured whether participants preferentially relied upon landmark- versus direction-based strategies. Across the three experiments, participants were either provided no information regarding the source of directions (Experiment 1), or told that the source of directions was a GPS device (Experiment 2), or a human (Experiment 3). Without information regarding the source of directions, participants generally relied on landmarks or turn information under conditions of ambiguity; in contrast, with a GPS source participants relied primarily on turn information, and with a human source on landmark information. Results were robust across gender and individual differences in spatial preference. We discuss these results within the context of spatial decision-making theory and consider implications for the design and development of landmark-inclusive navigation systems.


Subject(s)
Decision Making/physiology , Orientation/physiology , Space Perception/physiology , Spatial Navigation/physiology , Uncertainty , Adaptation, Psychological , Adolescent , Female , Humans , Individuality , Male , Reaction Time , Reproducibility of Results , Surveys and Questionnaires , Time Factors , User-Computer Interface , Young Adult
17.
J Sex Med ; 12(11): 2178-89, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26745618

ABSTRACT

AIM: Pelvic floor muscle (PFM) dysfunctions, especially elevated tone or tension, are suggested to play an important role in the pathophysiology of provoked vestibulodynia (PVD). However, the involvement of the PFMs remains misunderstood as the assessment of muscle tone is complex and requires a thorough understanding of muscle physiology in relation to the characteristics and limitations of current PFM assessment tools. The aim of this review was to describe the structures and mechanisms involved in muscle tone in normally innervated muscle, and to discuss and relate these concepts to the PFM findings in women with PVD. METHODS: A narrative overview of the literature retrieved from searches of electronic databases and hand searches. RESULTS: Muscle tone in a normally innervated muscle comprises both active (contractile) and passive (viscoelastic) components. Current methods for evaluating PFM tone such as digital palpation, ultrasound imaging, pressure perineometry, dynamometry, and electromyography may evaluate different components. Research findings suggestive of PFM hypertonicity in women with PVD include elevated general PFM tone, changes in viscoelastic properties, and at least in some women, abnormal increases in electrogenic activity. CONCLUSION: There is a growing body of evidence to support the involvement of PFM hypertonicity in the pathophysiology of PVD. Limitations of the instruments as well as their properties should be considered when evaluating PFM tone in order to obtain better insight into which component of PFM tone is assessed. Future research is required for further investigating the underlying mechanisms of PFM hypertonicity, and studying the specific effects of physiotherapeutic interventions on PFM tone in women with PVD.


Subject(s)
Pelvic Floor Disorders/pathology , Pelvic Floor/pathology , Vulvodynia/pathology , Electromyography , Female , Humans , Muscle Contraction/physiology , Muscle Strength , Palpation , Pelvic Floor/physiopathology , Pelvic Floor Disorders/physiopathology , Pressure , Quality of Life , Vulvodynia/physiopathology , Vulvodynia/therapy
18.
Neuroreport ; 25(16): 1320-5, 2014 Nov 12.
Article in English | MEDLINE | ID: mdl-25275640

ABSTRACT

Both acute and chronic exercise is consistently associated with a number of benefits to physical and mental health, including cardiovascular function, body weight, mood, and cognition. Near-infrared spectroscopy is an ideal method to measure changes in oxygenated and deoxygenated hemoglobin (O2Hb and dHb) levels in the prefrontal cortex (PFC) during exercise, to better understand the locus of such changes in affective and cognitive processes. The present study tracked time-dependent changes in O2Hb and dHb levels in the PFC as a function of parametrically manipulated target exercise intensity. Near-infrared spectroscopy was conducted as regular exercisers completed a 30-min bout of exercise with one of three target intensities: 52% (low condition), 68% (moderate condition), or 84% (high condition) of age-adjusted maximum heart rate. Heart rate data confirmed that the participants reached their goal intensities immediately, after 10 min, or after 20 min, respectively. Data showed that O2Hb and dHb levels in the PFC increased as a function of both exercise load and duration. An 84%>68%>52% difference was evident after 18 min of cycling for O2Hb and after 23 min of cycling for dHb. The present results add to the growing body of literature showing that at submaximal levels, increasing exercise intensities reliably promote prefrontal cerebral oxygenation.


Subject(s)
Exercise/physiology , Oxygen Consumption , Prefrontal Cortex/blood supply , Prefrontal Cortex/metabolism , Adolescent , Adult , Brain Mapping , Female , Heart Rate , Humans , Male , Physical Exertion , Spectroscopy, Near-Infrared , Young Adult
19.
Int Urogynecol J ; 25(10): 1389-98, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24853113

ABSTRACT

INTRODUCTION AND HYPOTHESIS: The levator ani is thought to play an important role in sexual function; however, to date little literature has been published on the impact of delivery-related levator trauma on female sexual function. We hypothesised that delivery-related levator trauma has a negative impact on women's reports of pelvic floor and sexual function postpartum. METHODS: In 294 primigravid women with a singleton pregnancy, four-dimensional (4D) translabial ultrasound imaging was used to assess delivery-related levator avulsion and levator hiatal over-distension, and postpartum pelvic floor and sexual function was assessed by an in-house validated questionnaire. Associations between questionnaire responses and levator avulsion and hiatal over-distension were investigated using standard linear modelling methods. RESULTS: Levator avulsion was diagnosed in 14% of women (42 out of 292; 25 unilateral, 17 bilateral) and was found to be significantly associated with lower scores for the pelvic floor integrity and function domain of the questionnaire (P < 0.0005). Avulsion was associated with lower scores for this domain (no avulsion = 2.78, unilateral avulsion = 2.61, bilateral avulsion = 2.29). This association remained significant after controlling for potential confounders (p = 0.013). Avulsion was not associated with any of the other domains of sexual function and levator hiatal over-distension was not associated with scores for any of the questionnaire domains. CONCLUSIONS: The effect of levator avulsion on pelvic floor and sexual function an average of 5.2 months after childbirth seems to be limited to a perception of increased vaginal and pelvic floor muscle laxity, and reduced pelvic floor muscle efficiency. The impact of levator hiatal over-distension on postpartum pelvic floor and sexual function appears to be negligible.


Subject(s)
Delivery, Obstetric/adverse effects , Pelvic Floor/diagnostic imaging , Pelvic Floor/injuries , Pelvic Organ Prolapse/epidemiology , Puerperal Disorders/epidemiology , Sexual Dysfunction, Physiological/epidemiology , Adolescent , Adult , Anal Canal/injuries , Female , Follow-Up Studies , Gravidity , Humans , Middle Aged , Pelvic Floor/physiopathology , Pelvic Organ Prolapse/diagnostic imaging , Pregnancy , Puerperal Disorders/diagnosis , Sexual Dysfunction, Physiological/diagnosis , Surveys and Questionnaires , Time Factors , Ultrasonography
20.
Cogn Sci ; 38(2): 275-302, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23855500

ABSTRACT

Learning a novel environment involves integrating first-person perceptual and motoric experiences with developing knowledge about the overall structure of the surroundings. The present experiments provide insights into the parallel development of these egocentric and allocentric memories by intentionally conflicting body- and world-centered frames of reference during learning, and measuring outcomes via online and offline measures. Results of two experiments demonstrate faster learning and increased memory flexibility following route perspective reading (Experiment 1) and virtual navigation (Experiment 2) when participants begin exploring the environment on a northward (vs. any other direction) allocentric heading. We suggest that learning advantages due to aligning body-centered (left/right/forward/back) with world-centered (NSEW) reference frames are indicative of three features of spatial memory development and representation. First, memories for egocentric and allocentric information develop in parallel during novel environment learning. Second, cognitive maps have a preferred orientation relative to world-centered coordinates. Finally, this preferred orientation corresponds to traditional orientation of physical maps (i.e., north is upward), suggesting strong associations between daily perceptual and motor experiences and the manner in which we preferentially represent spatial knowledge.


Subject(s)
Learning/physiology , Memory/physiology , Orientation/physiology , Space Perception/physiology , Adult , Female , Humans , Male , Students/psychology , Young Adult
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