Conventional and HD-tDCS May (or May Not) Modulate Overt Attentional Orienting: An Integrated Spatio-Temporal Approach and Methodological Reflections

Transcranial Direct Current Stimulation (tDCS) has been employed to modulate visuo-spatial attentional asymmetries, however, further investigation is needed to characterize tDCS-associated variability in more ecological settings. In the present research, we tested the effects of offline, anodal conventional tDCS (Experiment 1) and HD-tDCS (Experiment 2) delivered over the posterior parietal cortex (PPC) and Frontal Eye Field (FEF) of the right hemisphere in healthy participants. Attentional asymmetries were measured by means of an eye tracking-based, ecological paradigm, that is, a Free Visual Exploration task of naturalistic pictures. Data were analyzed from a spatiotemporal perspective. In Experiment 1, a pre-post linear mixed model (LMM) indicated a leftward attentional shift after PPC tDCS; this effect was not confirmed when the individual baseline performance was considered. In Experiment 2, FEF HD-tDCS was shown to induce a significant leftward shift of gaze position, which emerged after 6 s of picture exploration and lasted for 200 ms. The present results do not allow us to conclude on a clear efficacy of offline conventional tDCS and HD-tDCS in modulating overt visuospatial attention in an ecological setting. Nonetheless, our findings highlight a complex relationship among stimulated area, focality of stimulation, spatiotemporal aspects of deployment of attention, and the role of individual baseline performance in shaping the effects of tDCS.

Effects of High-Definition Transcranial Direct Current Stimulation Over the Left Fusiform Face Area on Face View Discrimination Depend on the Individual Baseline Performance

A basic human visual function is to identify objects from different viewpoints. Typically, the ability to discriminate face views based on in-depth orientation is necessary in daily life. Early neuroimaging studies have identified the involvement of the left fusiform face area (FFA) and the left superior temporal sulcus (STS) in face view discrimination. However, many studies have documented the important role of the right FFA in face processing. Thus, there remains controversy over whether one specific region or all of them are involved in discriminating face views. Thus, this research examined the influence of high-definition transcranial direct current stimulation (HD-tDCS) over the left FFA, left STS or right FFA on face view discrimination in three experiments. In experiment 1, eighteen subjects performed a face view discrimination task before and immediately, 10 min and 20 min after anodal, cathodal and sham HD-tDCS (20 min, 1.5 mA) over the left FFA in three sessions. Compared with sham stimulation, anodal and cathodal stimulation had no effects that were detected at the group level. However, the analyses at the individual level showed that the baseline performance negatively correlated with the degree of change after anodal tDCS, suggesting a dependence of the change amount on the initial performance. Specifically, tDCS decreased performance in the subjects with better baseline performance but increased performance in those with poorer baseline performance. In experiments 2 and 3, the same experimental protocol was used except that the stimulation site was the left STS or right FFA, respectively. Neither anodal nor cathodal tDCS over the left STS or right FFA influenced face view discrimination in group- or individual-level analyses. These results not only indicated the importance of the left FFA in face view discrimination but also demonstrated that individual initial performance should be taken into consideration in future research and practical applications.

SP2.1.5Does the introduction of ward round stickers improve surgical ward rounds?

Aims With surgical teams in the NHS pushed to their limit under unprecedented demands, simple and effective ways for maintaining standards of patient care are necessitated. This quality improvement project aims to implement user-friendly and coherent ward round stickers as an adjunct to surgical ward rounds to deliver standardised care. Methods Baseline performance was measured against The Royal College of Surgeons of Edinburgh Surgical Ward Round Toolkit. Five recorded items were studied including: bloods, venous thromboembolism (VTE) prophylaxis, regular medications, observations, and handover to nursing staff. The surgical team was informed of the audit but not over which dates it would be conducted. In the first cycle, data was collected over a 4 week period. Ward round stickers were then implemented and a second cycle was completed 2 months later over another 4 week period. Results Baseline performance recorded from 74 ward round entries showed checking of bloods, VTE, regular medications, observations and handover ranged from 0% to 65%. After the introduction of ward round stickers, a second cycle was performed from 81 ward round entities. There was significant improvement from baseline with compliance in recording all five items > 85%. Conclusion This quality improvement project showed that the use of stickers as an adjunct to surgical ward round is a simple and effective way of evidencing good practice against recommended standards.

264 Does the Introduction of Ward Round Stickers Improve Surgical Ward Rounds?

Aim With surgical teams in the NHS pushed to their limit under unprecedented demands, simple and effective ways for maintaining standards of patient care are necessitated. This quality improvement project aims to implement user-friendly and coherent ward round stickers as an adjunct to surgical ward rounds to deliver standardised care. Method Baseline performance was measured against The Royal College of Surgeons of Edinburgh Surgical Ward Round Toolkit. Five recorded items were studied including: bloods, venous thromboembolism(VTE) prophylaxis, regular medications, observations, and handover to nursing staff. The surgical team was informed of the audit but not over which dates it would be conducted. In the first cycle, data was collected over a 4-week period. Ward round stickers were then implemented, and a second cycle was completed 2 months later over another 4-week period. Results Baseline performance recorded from 74 ward round entries showed checking of bloods, VTE, regular medications, observations and handover ranged from 0% to 65%. After the introduction of ward round stickers, a second cycle was performed from 81 ward round entities. There was significant improvement from baseline with compliance in recording all five items > 85%. Conclusions This quality improvement project showed that the use of stickers as an adjunct to surgical ward round is a simple and effective way of evidencing good practice against recommended standards.

Task-dependent effects of nicotine treatment on auditory performance in young-adult and elderly human nonsmokers

Electrophysiological studies show that nicotine enhances neural responses to characteristic frequency stimuli. Previous behavioral studies partially corroborate these findings in young adults, showing that nicotine selectively enhances auditory processing in difficult listening conditions. The present work extended previous work to include both young and older adults and assessed the nicotine effect on sound frequency and intensity discrimination. Hypotheses were that nicotine improves auditory performance and that the degree of improvement is inversely proportional to baseline performance. Young (19–23 years old) normal-hearing nonsmokers and elderly (61–80) nonsmokers with normal hearing between 500 and 2000 Hz received nicotine gum (6 mg) or placebo gum in a single-blind, randomized crossover design. Participants performed three experiments (frequency discrimination, frequency modulation identification, and intensity discrimination) before and after treatment. The perceptual differences were analyzed between pre- and post-treatment, as well as between post-treatment nicotine and placebo conditions as a function of pre-treatment baseline performance. Compared to pre-treatment performance, nicotine significantly improved frequency discrimination. Compared to placebo, nicotine significantly improved performance for intensity discrimination, and the improvement was more pronounced in the elderly with lower baseline performance. Nicotine had no effect on frequency modulation identification. Nicotine effects are task-dependent, reflecting possible interplays of subjects, tasks and neural mechanisms.

Running Fast and Standing Slow: a Study on the Effect of Gesture Posing on Time Perception

Everyone has 24 hours in a day, but this does not feel the same for everyone. Time perception can be subjective and is affected by a wide range of factors. Studies have shown that presenting pictures with actions can bias observers’ performance in a duration reproduction task. Instead of watching pictures of actions, this research explored the effect of gesture posing on such a time perception bias. Sixty participants were assigned into either a watching or posing group. Compared with the corresponding baseline performance, participants overestimated time duration when viewing or posing pictures suggesting action. A corresponding underestimation was observed when the pictures or gestures suggested inaction. The role of physical gestures and their potential effect on time perception based on the embodiment account is discussed. Further investigation is also proposed to examine the role of the embodiment effect on subsecond time intervals.

Novel Interpretable Tissue-Specific and Multi-Tissue Transcriptomic Clocks to Infer Aging Mechanisms

Aging is characterized as a progressive decline in fitness that ultimately results in death. We set out to build both tissue-specific and multi-tissue transcriptomic clocks to make global tissue age predictions in individuals from GTEx. Existing work in the field primarily uses epigenetic clocks as predictors of age, but these models have known issues and are significantly less interpretable than their transcriptomic counterparts. Due to their transcriptomic nature, we can use these models to directly infer mechanisms of aging from their features. Linear regression remains the current standard analysis technique, but we improved upon its baseline performance with modern techniques, exploring both XGBoost and MLPs. We also experimented with using deconvolved cell data for predictions, which account for cellular composition and reduce signal distortion from rare cell types. Since it is known that the heterogeneity of cell types in particular tissues can lead to noise in these models, we proposed using deconvolution as a potential remedy for this problem. Our results found that MLPs are not well suited for the task due to a lack of training data, but the use of XGBoost is effective at improving the baseline performance of predictions of existing tissue-specific clocks. These models allowed us to directly compute genes most important to age prediction in our models, and we showed that multiple genes found have been independently identified elsewhere to show evidence of correlation with age. Given the small size of our datasets, we were unable to make conclusive determinations about multi-tissue predictors, but preliminary results suggest that the technique shows promise and is worthy of future investigation. Likewise, given our limited deconvolved cell data, we did not currently observe strong results, but we again note that this is an area in need of further investigation. By improving upon the performance of existing models, we demonstrated that a novel machine learning technique, XGBoost, can be an effective technique to further our understanding of aging mechanisms by extraction of the most relevant genes found in those models. This is significant because the genetic causes of aging are still not fully understood, and research in the field of aging is lacking in comparison to other domains. As the problem of identifying tissues that age at different rates is of specific interest, our tissue-specific models potentially have other applications in this domain, including informing pathologies in tissues that are found to be aging faster, or analyzing how people with similar ages can have vastly different tissue ages.