Respiratory influences on pupil size dynamics and visual recognition memory

Breathing, a fundamental rhythm of life, has traditionally been associated with the exchange of oxygen and carbon dioxide. However, recent research in both animal models and humans has unveiled additional roles of respiration in modulating cortical neuronal activity, influencing sensory, motor, emotional, and cognitive processes. This dissertation aims to explore the impact of respiration on pupil size dynamics and visual recognition memory in humans. In Study I, we synthesized the research conducted on respiratory influences on pupil size dynamics in humans by conducting a systematic literature review. We discovered that the evidence for respiratory influences on pupil size dynamics in humans is less solid and extensive than previously believed. After more than 50 years of research, only 12 studies have directly investigated this topic. Not only was the underlying evidence for an effect of breathing phase, depth, and rate on pupil size dynamics weak, but the influence of breathing route (oral or nasal breathing) had not been investigated at all. In Study II, we conducted an experimental study to answer the outstanding questions identified in Study I. We collected pupil size data from participants during periods of rest while they breathed through their nose and mouth, on separate occasions. We demonstrated small but significant effects of breathing phase on pupil size and a spurious correlation and phase synchronization between the breathing and the pupil signal that is largely driven by breathing rate. After accounting for this spurious correlation and phase synchronization, we show that a small but significant interaction between the breathing and the pupil signal remains. Importantly, we show that, contrary to common belief, pupil size does not increase during inhalation, but rather during exhalation. Furthermore, we did not find any changes in pupil size in the time around inhalation and exhalation, and our results were not affected by the breathing route. In conclusion, we confirmed the influence of breathing on pupil size dynamics, while uncovering a more complex and intricate relationship than previously conceived. In Study III, we investigated the influence of breathing phase and breathing route on performance in a visual recognition memory task with a within-subject design and with stimuli presentation phase-locked to the inhalation or exhalation onset. We show that neither breathing phase nor breathing route affect memory performance. However, we did find an effect of breathing phase on response bias, with participants using a more conservative response bias during exhalation. Furthermore, we found that breathing route and breathing phase shape the Late Parietal Effect (LPE), but not the Frontal Negative Component (FN400), amplitude during encoding. Additionally, during recognition, both the LPE and FN400 component amplitudes were not, or only to a small extent, affected by breathing route and phase. While we demonstrated that breathing does not shape visual recognition memory performance, we also showed that breathing influences brain activity related to memory functions. Therefore, we highlight the importance of further research to elucidate the extent of respiratory influence on perception, cognition, and behavior. In Study IV, we further investigated the impact of breathing on visual memory performance by investigating the effects of nasal breathing phase on memory of repeated images presented in a rapid serial visual presentation (RSVP) task. In two separate, high-powered experiments, we did not find an effect of breathing phase on task performance. An exploratory analysis in the first experiment discovered a potential performance increase for stimuli presented approximately one second after inhalation. However, this was not replicated in the second, larger, and pre-registered study. Thus, we find no effect of breathing phase on performance in this RSVP task and urge for caution regarding the notion that visual memory is broadly affected by the breathing phase. Finally, in Study V, we investigated whether oral hormonal contraceptives (OC) affect chemosensory sensitivity and perception. Whereas previous research focused nearly exclusively on olfaction, we expanded this to also study the taste and trigeminal sense. Making use of Bayesian statistics, we evaluated the performance differences between a group of women taking OC, and a control group of normal cycling women. Our results indicated that the use of OC does not affect odor, trigeminal, or taste detection thresholds. Furthermore, neither odor nor taste perception were affected, with Bayes factors weighing the evidence in favor of the null hypothesis. We therefore conclude it to be unlikely that OC affect chemosensory perception to a degree that is of behavioral relevance. Collectively, this doctoral thesis challenges prevailing myths while paving the way for a more intricate understanding of the relationship between respiration and pupil size, and perceptual and cognitive processes. Importantly, it underscores the importance of implementing rigorous methodological paradigms in future research

PLANNING AND COORDINATION IN DRIVING SIMULATION

We present an overview of coordination and planning tasks that we face with during the development of the AgentDrive simulation platform. We particularly describe an integration of the AgentDrive with a driving simulator OpenDS. We demonstrate how the planning and coordination mechanisms can be applied in a driving simulator for automated driving applications or realistic traffic generation. We emphasize particular planning and/or coordination methods that were already developed using AgentDrive platform

Are fruit colors adapted to consumer vision and birds equally efficient in detecting colorful signals?

Reproduction in plants often requires animal vectors. Fruit and flower colors are traditionally viewed as an adaptation to facilitate detection for pollinators and seed dispersers. This long-standing hypothesis predicts that fruits are easier to detect against their own leaves compared with those of different species. We tested this hypothesis by analyzing the chromatic contrasts between 130 bird-dispersed fruits and their respective backgrounds according to avian vision. From a bird's view, fruits are not more contrasting to their own background than to those of other plant species. Fruit colors are therefore not adapted toward maximized conspicuousness for avian seed dispersers. However, secondary structures associated with fruit displays increase their contrasts. We used fruit colors to assess whether the ultraviolet and violet types of avian visual systems are equally efficient in detecting color signals. In bright light, the chromatic contrasts between fruit and background are stronger for ultraviolet vision. This advantage is due to the lesser overlap in spectral sensitivities of the blue and ultraviolet cones, which disappears in dim light conditions. We suggest that passerines with ultraviolet cones might primarily use epigamic signals that are less conspicuous to their avian predators (presumably with violet vision). Possible examples for such signals are carotenoid-based signals

The Common Crow as a sentinel species of rabies in wildlife populations

There is, at present, no unbiased, convenient, and economically feasible means available to determine the true prevalence of rabies in wildlife. Four projects were undertaken to test the feasibility of using the Common Crow as a reliable sentinel species of sylvatic rabies. In one project, captive crows contracted rabies orally when fed rabies infected mice brains. One-year-old crows developed an earlier humoral immune response with a greater mean antibody titer than did 2-year-old birds. Antibody levels persisted for about 2 weeks. No birds died or showed overt clinical signs of rabies disease during the experiment;In another project, rabies virus remained viable in striped skunk carcasses for about 2 weeks at 24(DEGREES)C and throughout the 22-day study period at 10(DEGREES)C. The skunks with experimentally induced furious rabies had a higher mean titer than did the other skunks;In order to determine the geographic area that a crow survey of rabies would monitor, information was collected on crow foraging areas and movement patterns. The mean foraging area around the nest site was 151 ha with the longest recorded flight from a nest of 4.8 km. During July and August, crow families continued to feed in their respective nest areas but joined other crows at nighttime roosts. Northern breeders migrated into central Iowa during November. Some crows were year-around residents. The mean foraging area for winter roosting crows was 110.8 km(\u272) and varied directly with the number of birds in the roost;In the fourth project, vertebrate foods occurred in more than 40% of the food samples collected from November to June. Fifty observations of crows scavenging on road-killed carcasses were recorded. On 8 of these occasions, crows were feeding on Striped Skunks. The prevalence of rabies antibodies in 332 wild adult crows and 70 crow broods was 18.3% and 31.4%, respectively. No statistical correlations were found between the prevalence of rabies antibodies in crows and rabies antigens in skunks. Sampling 4-week-old nestling crows is recommended as the best index of rabies prevalence in wildlife