Search results for "Gaze"
showing 10 items of 146 documents
50,000 years of ice and seals: Impacts of the Last Glacial Maximum on Antarctic fur seals
2021
Abstract Ice is one of the most important drivers of population dynamics in polar organisms, influencing the locations, sizes, and connectivity of populations. Antarctic fur seals, Arctocephalus gazella, are particularly interesting in this regard, as they are concomitantly reliant on both ice‐associated prey and ice‐free coastal breeding areas. We reconstructed the history of this species through the Last Glacial Maximum (LGM) using genomic sequence data from seals across their range. Population size trends and divergence events were investigated using continuous‐time size estimation analysis and divergence time estimation models. The combined results indicated that a panmictic population …
Luminance Information Is Required for the Accurate Estimation of Contrast in Rapidly Changing Visual Contexts.
2020
Summary Visual perception scales with changes in the visual stimulus, or contrast, irrespective of background illumination. However, visual perception is challenged when adaptation is not fast enough to deal with sudden declines in overall illumination, for example, when gaze follows a moving object from bright sunlight into a shaded area. Here, we show that the visual system of the fly employs a solution by propagating a corrective luminance-sensitive signal. We use in vivo 2-photon imaging and behavioral analyses to demonstrate that distinct OFF-pathway inputs encode contrast and luminance. Predictions of contrast-sensitive neuronal responses show that contrast information alone cannot ex…
How Long Did You Look At Me? The Influence of Gaze Direction on Perceived Duration and Temporal Sensitivity.
2016
Faces that exhibit emotionally negative expressions in mutual gaze have been shown to induce a dilation of perceived duration. The influence of gaze by itself on duration judgments, however, has rarely been investigated. We argue for a social interaction hypothesis, according to which humans should be highly accurate and precise (sensitive) when processing the temporal dynamics of mutual gaze. In three experiments, we investigated whether the direction of observed gaze affects perceived duration and temporal sensitivity. In Experiment 1, subjects did indeed estimate the duration of direct gaze more accurately as compared to the duration of averted gaze. In Experiments 2 and 3, subjects had…
Prosodic modulation as a mark to express pragmatic values: The case of mitigation in Spanish
2021
Abstract One of the functions of prosody in discourse is to convey pragmatic values that add up to the core semantic meaning of spoken units or segments. Regarding mitigation, Caffi (1999: 890) specifically discusses “the very important prosodic and kinesic means of mitigation, such as changes in pitch prominence, rhythm, speech rate, as well as eye-contact, gaze, gaze aversion, smile, particular postures, etc.” In this paper, I focus on some prosodic factors such as pitch, intensity, duration and speech rate that can be used in European Spanish, in combination with pragmatic meanings. The first aim is to establish a theoretical deliberation on prosody as a clear marker to convey pragmatic …
“Do you understand (me)?” negotiating mutual understanding by using gaze and environmentally coupled gestures between two deaf signing participants
2020
Abstract In this paper we explore the use of multimodal and multilingual semiotic resources in interactions between two deaf signing participants, a researcher and an asylum seeker. The focus is on the use of gaze and environmentally coupled gestures. Drawing on multimodal analysis and linguistic ethnography, we demonstrate how gaze and environmentally coupled gestures are effective semiotic resources for reaching mutual understanding. The study provides insight into the challenges and opportunities (deaf) asylum seekers, researchers, and employees of reception centres or the state may encounter because of the asymmetrical language competencies. Our concern is that such asymmetrical situati…
Alexandre Brierre de Boismont and the limits of the psychopathological gaze
2018
One of the most remarkable implications of psychological medicine in the transition from the 18th to the 19th century was the advent of a new way of looking at the human being and new tools for analysing not only behaviour and individual experience, but also historical events, collective behavioural patterns or complex cultural achievements. Unsurprisingly, the deployment of this gaze could not advance without there being a series of disputes and controversies about its reach and the limits to its indiscriminate application. Focusing on the figure of French alienist Alexandre Brierre de Boismont and on the controversial cases of hallucinations and suicide, this article addresses the confli…
Visual-motion suppression in congenital pendular nystagmus.
2009
Patients with a congenital pendular nystagmus are known not to experience oscillopsia in a normal visual environment. The data of a 31-year-old female patient suffering from a congenital pendular nystagmus are presented. The aim of the fluorodeoxyglucose positron emission tomography (FDG-PET) experiment was to analyze the regional cerebral glucose metabolism (rCGM) during minimal as well as maximal nystagmus. Video-oculography showed a maximum in frequency of the horizontal pendular nystagmus during gaze to the left, whereas the zone of minimal nystagmus was 10 degrees to the right. Two sessions with an 18F-fluorodeoxyglucose tracer were performed to analyze cerebral blood-glucose utilizati…
A Slippery Slope: Estimated Slant of Hills Increases with Distance
2014
The slopes of hills tend to be greatly overestimated. Previous studies have found that slope estimates are significantly greater when estimated verbally than with a proprioceptive measure. It has yet to be determined whether these estimates are made for the entire extent of the slope, or whether the estimates in closest proximity are estimated using a different process. Since some parietal cortex neurons respond differently to objects within arm's reach, short-distance slope estimation may utilize these or analogous neurons. Alternatively, greater implied effort might make longer slopes seem steeper. We determined that both verbal and proprioceptive reports of slope are overestimates that …
Associations of reading posture, gaze angle and reading distance with myopia and myopic progression
2016
Purpose To study the associations of habitual reading posture, gaze angle in reading and reading distance with myopia and changes in myopia among myopic children. Methods A total of 240 myopic schoolchildren (mean age 10.9 years), with no previous spectacles, were recruited during 1983–1984 to a randomized 3-year clinical trial of bifocal treatment of myopia. Three annual examinations with subjective cycloplegic refraction were conducted for 237–238 subjects. A further examination was conducted at the mean age of 23.2 years for 178 subjects. Habitual reading posture was elicited by questionnaire at study outset. Reading distance was measured with a Clement Clark accommodometer and gaze angl…
Increasing the default interletter spacing of words can help drivers to read traffic signs at longer distances
2018
Would an increase in the default interletter spacing improve the legibility of words in traffic signs? Previous evidence on traffic sign design and recent studies on the cognitive processes involved in visual word recognition have provided conflicting results. The present work examined whether an increase in the default interletter spacing would improve the search of a word in direction traffic signs. To achieve this objective, twenty-two drivers participated in a driving simulation experiment. They followed a highway route and indicated whether a target place name was present among a set of distractors shown on direction traffic signs along the route. We compared the default interletter sp…