Prevalence of Powassan Virus Seropositivity Among People with History of Lyme Disease and Non-Lyme Community Controls in the Northeastern United States.

Introduction: Lyme disease (LD) affects ∼476,000 people each year in the United States. Symptoms are variable and include rash and flu-like symptoms. Reasons for the wide variation in disease outcomes are unknown. Powassan virus (POWV) is a tick-borne flavivirus that causes disease ranging from asymptomatic infection to encephalitis, neurologic damage, and death. POWV and LD geographic case distributions overlap, with Ixodes species ticks as the common vectors. Clinical ramifications of coinfection or sequential infection are unknown. Objectives: This study's primary objective was to determine the prevalence of POWV-reactive antibodies in sera samples collected from previously studied cohorts of individuals with self-reported LD history residing in the Northeastern United States. As a secondary objective, we studied clinical differences between people with self-reported LD history and low versus high POWV antibody levels. Methods: We used an enzyme-linked immunosorbent assay (ELISA) to quantify IgG directed at the POWV envelope (E) protein domain III in 538 samples from individuals with self-reported LD history and 16 community controls. The samples were also tested with an ELISA assay to quantify IgG directed at the POWV NS1 protein. Results: The percentage of individuals with LD history and possible evidence of POWV exposure varied depending on the assay utilized. We found no significant difference in clinical symptoms between those with low or high POWV IgG levels in the in-house assay. Congruence of the EDIII and NS1 assays was low with only 12% of those positive in the in-house EDIII ELISA testing positive in the POWV NS1 ELISA. Conclusions: The results highlight the difficulty in flavivirus diagnostic testing, particularly in the retrospective detection of flavivirus exposure. The findings suggest that a prospective study with symptomatic patients using approved clinical testing is necessary to address the incidence and clinical implications of LD and POWV co-infection or sequential infection.

Persistent Symptoms, Lyme Disease, and Prior Trauma.

ABSTRACT: One prior study suggests that traumatic events before Lyme disease play an important role in symptom severity. We examined this hypothesis among 60 individuals with persistent symptoms after Lyme disease using validated measures of trauma history, mental and physical symptoms, and functional status. Analysis of variance with Tukey-Kramer multiple comparisons test revealed that a greater number of traumatic events were significantly associated with greater symptom severity on the scales of mood (stress, depression, and anxiety), cognition, multisystem symptom burden, and functional status (mental and physical), but not on measures of pain and fatigue. The effect sizes-meaningful but not large (0.17-0.29)-were mostly produced by comparison with individuals reporting multiple prior traumatic events, representing half of the posttreatment Lyme disease syndrome (PTLDS) group. In conclusion, although PTLDS may be exacerbated by past trauma, trauma plays a role in only a subgroup of PTLDS. Whether addressing prior trauma can improve outcomes in this subgroup requires study.

A different kind of pain: affective valence of errors and incongruence.

People hiss and swear when they make errors, frown and swear again when they encounter conflicting information. Such error- and conflict-related signs of negative affect are found even when there is no time pressure or external reward and the task itself is very simple. Previous studies, however, provide inconsistent evidence regarding the affective consequences of resolved conflicts, that is, conflicts that resulted in correct responses. We tested whether response accuracy in the Eriksen flanker task will moderate the effect of trial incongruence using affective priming to measure positive and negative affect. We found that responses to incongruent trials elicit positive affect irrespective of their accuracy. Errors, in turn, result in negative affect irrespective of trial congruence. The effects of conflicts and errors do not interact and affect different dimensions of affective priming. Conflicts change the speed of evaluative categorisation while errors are reflected in categorisation accuracy. We discuss the findings in light of the "reward value and prediction" model and the "affect as a feedback for predictions" framework and consider the possible mechanisms behind the divergent effects.

Nintendo Wii Fit-Based Sleepiness Testing is Not Impaired by Contagious Sleepiness.

Sleep deprivation may cause accidents, and it has deteriorating effects on health. A measurement of postural steadiness by a portable and affordable Nintendo Wii Fit balance board can be used to quantify a person's alertness. At work, people are under the influence of their environment-often other people-that may affect their alertness. This work investigates whether sleep deprivation among people is "contagious," as quantified by sway measures. We measured 21 volunteers' postural steadiness while alert and sleep deprived. During the measurements, a screen placed in front of the participants showed a footage of either alert or sleep-deprived faces. We found a significant difference between the day time and night time steadiness, but found no effect resulting from watching footage of sleep-deprived people. This finding shows that a posturographic sleepiness tester quantifies physiological sleep deprivation, and is insensitive to the influence of social factors.

Implicit processing during change blindness revealed with mouse-contingent and gaze-contingent displays.

People often miss salient events that occur right in front of them. This phenomenon, known as change blindness, reveals the limits of visual awareness. Here, we investigate the role of implicit processing in change blindness using an approach that allows partial dissociation of covert and overt attention. Traditional gaze-contingent paradigms adapt the display in real time according to current gaze position. We compare such a paradigm with a newly designed mouse-contingent paradigm where the visual display changes according to the real-time location of a user-controlled mouse cursor, effectively allowing comparison of change detection with mainly overt attention (gaze-contingent display; Experiment 2) and untethered overt and covert attention (mouse-contingent display; Experiment 1). We investigate implicit indices of target detection during change blindness in eye movement and behavioral data, and test whether affective devaluation of unnoticed targets may contribute to change blindness. The results show that unnoticed targets are processed implicitly, but that the processing is shallower than if the target is consciously detected. Additionally, the partial untethering of covert attention with the mouse-contingent display changes the pattern of search and leads to faster detection of the changing target. Finally, although it remains possible that the deployment of covert attention is linked to implicit processing, the results fall short of establishing a direct connection.

Blame everyone: Error-related devaluation in Eriksen flanker task.

Preferences are determined not only by stimuli themselves but also by the way they are processed in the brain. The efficacy of cognitive processing during previous interactions with stimuli is particularly important. When observers make errors in simple tasks such as visual search, recognition, or categorization, they later dislike the stimuli associated with errors. Here we test whether this error-related devaluation exists in Erisken flanker task and whether it depends on the distribution of attention. We found that both attended stimuli (targets) and ignored ones (distractors) are devaluated after errors on compatible trials but not incompatible ones. The extent of devaluation is similar for targets and distractors, indicating that distribution of attention does not significantly influence the attribution of error-related negative affect. We discuss this finding in light of the possible mechanisms of error-related devaluation.