284 Cognitive Deficits due to Insufficient Sleep are Mitigated Following Strenuous Physical Exertion in Firefighters

Introduction Insufficient sleep impairs cognitive function which results in costly errors. Firefighter shifts regularly exceed 24-hrs with little to no sleep. Nevertheless, firefighters must maintain and flexibly shift attention in high-pressure scenarios. Firefighters also engage in strenuous physical exertion during fire suppression activities. However, it is unclear whether physical exertion acts as another stressor, exasperating cognitive deficits due to insufficient sleep, or whether physical exertion enhances arousal to reduce cognitive deficits. Moreover, the effects of physical exertion may depend on the type of cognitive process and extent of sleep loss. We examined the effect of physical exertion on vigilant attention and task-switching in firefighters who underwent sleep-deprivation or sleep-disruption. Methods Participants were 17 healthy young adult males who participated in a within-subjects crossover design with three experimental lab visits: sleep-deprivation, sleep-disruption (woken 3 times for 60-min each), and normal sleep. The next day, participants completed a 50-min treadmill exercise task in a heated room in firefighter protective clothing. Participants completed a vigilant attention task (Psychomotor Vigilance Task, PVT) and a task-switching task five to nine times each visit. The five timepoints of interest–before and after the sleep manipulation night, before and after the treadmill exercise task, and recovery (approximately 180-min following exercise)–were examined using linear mixed effects models. Results We analyzed lapses (reaction times [RT]>500ms) on the PVT and switch-trial RT and accuracy on the task-switching task for sleep-deprivation and sleep-disruption conditions relative to normal sleep. Sleep-disruption, p=.001, and sleep-deprivation, p<.001, increased lapses. Sleep-disruption increased switch-trial RT, p=.01, and sleep-deprivation reduced switch-trial accuracy, p=.01. Only switch-trial accuracy improved immediately after the treadmill exercise task and only for the sleep-deprivation condition, p=.01. During recovery, lapses lessened for the sleep-deprivation condition, p=.049, and switch-trial accuracy improved for both sleep-deprivation, p=.01, and sleep-disruption conditions, p=.049. Conclusion Physical exertion reduced task-switching and attentional deficits caused by insufficient sleep, with more benefits observed during recovery. We found no evidence for performance decrements due to physical exertion. Physical exertion may interact with the extent of sleep loss–primarily benefitting performance under conditions of total sleep-deprivation. Support (if any) DSF Charitable Foundation and University of Pittsburgh Clinical and Translational Science Institute UL1TR001857.

Attentional Flexibility Predicts A-Not-B Task Performance in 14-Month-Old-Infants: A Head-Mounted Eye Tracking Study

Early individual differences in executive functions (EFs) are predictive of a range of developmental outcomes. However, despite the importance of EFs, little is known about the processes underlying these early individual differences. Therefore, we investigated the association between 14-month-old infants’ attention on a reaching version of the A-not-B task and task success. We hypothesized that both strategic focused attention (measured as percentage looking time towards the correct location during delay) and attentional flexibility (measured as number of looks per second to available stimuli during delay) would relate positively to task performance. Infants performed the A-not-B task wearing a head-mounted eye tracker (N = 24). Results were trial-dependent and partially supported the hypotheses: (1) infants who were better able to flexibly shift attention between available stimuli on the first pre-switch trial showed better task performance overall; and (2) strategic focused attention to the hiding location during the first switch trial was positively related to performance on that particular trial only (trend-level effect). Thus, the study shows preliminary evidence that particularly attentional flexibility is a key factor underlying EF performance in young children. Advantages and challenges of working with head-mounted eye tracking in infants are discussed.

Effect of benzalkonium chloride-preserved latanoprost and benzalkonium chloride-free latanoprost on intraocular pressure in patients of primary open angle glaucoma

Background: To evaluate the change in mean IOP with BKC-preserved latanoprost versus BKC-free latanoprost in patients of primary open angle glaucoma (POAG).Methods: This was an open-label, randomized, interventional, switch trial. Thirty patients of primary open angle glaucoma (POAG) who were already on benzalkonium chloride (BKC)-preserved latanoprost for a minimum of three months were recruited. Their intraocular pressure (IOP) was recorded at the baseline. Then, they were switched over to benzalkonium chloride (BKC)-free latanoprost for another three months. Their intraocular pressure (IOP) was recorded at both 6 and 12 weeks of follow-up.Results: IOP decreased from 15.57±0.85mm Hg at baseline to 15.40±0.89mm Hg at 6 weeks to 15.30±0.70mm Hg at 12 weeks. p value was found to be 0.209 and 0.115 at 6 and 12 weeks respectively. No statistically significant change was observed between mean IOP at both 6 and 12 weeks as compared to the baseline.Conclusions: BKC-free medications have equal IOP lowering effect as BKC-preserved medications in glaucoma patients.