Do we rely on good-enough processing in reading under auditory and visual noise?

Noise, as part of real-life communication flow, degrades the quality of linguistic input and affects language processing. According to predictions of the noisy-channel model, noisemakes comprehenders rely more on word-level semantics and good-enough processing instead of actual syntactic relations. However, empirical evidence of such qualitative effect of noise on sentence processing is still lacking. For the first time, we investigated the qualitative effect of both auditory (three-talker babble) and visual (short idioms appearing next to target sentence on the screen) noise on sentence reading within one study in two eye-trackingexperiments. In both of them, we used the same stimuli — unambiguous grammatical Russian sentences — and manipulated their semantic plausibility. Our findings suggest that although readers relied on good-enough processing in Russian, neither auditory nor visualnoise qualitatively increased reliance on semantics in sentence comprehension. The only effect of noise was found in reading speed: only without noise, semantically implausible sentences were read slower than semantically plausible ones, as measured by both early and late eye-movement measures. These results do not support the predictions of the noisy-channel model. With regard to quantitative effects, we found a detrimental effect ofauditory noise on overall comprehension accuracy, and an accelerating effect of visual noise on sentence processing without accuracy decrease.

Uncertainty-based inference of a common cause for body ownership

How do we perceive the fundamental distinction between the physical self and the external world, and how do we come to sense that an object in view, for example, a hand, is part of our own body or not? Over the past two decades, many studies have investigated the contributions of vision, touch, and proprioception to the sense of body ownership, i.e., the multisensory perception of limbs and body parts as our own. However, the processes involved in subjectively experienced body ownership have only been qualitatively described, and the computational principles that determine such sensations remain unclear. To address this issue, we developed a detection-like psychophysics task based on the classic rubber hand illusion paradigm where participants were asked to report whether the rubber hand felt like their own (the illusion) or not. We manipulated illusion strength by varying the asynchrony of visual and tactile stimuli delivered to the rubber hand and the hidden real hand under different levels of visual noise. We found that (1) the probability of the emergence of the rubber hand illusion increased with the addition of visual noise and was well predicted by a causal inference model involving the observer computing the probability of the visual and tactile signals coming from a common source; (2) the causal inference model outperformed a non-Bayesian model involving the observer not taking into account sensory uncertainty; and (3) by comparing the casual inference of ownership and visuotactile synchrony detection, we found that the prior probability of inferring a common cause for the two types of multisensory precepts was correlated but greater for ownership, which suggests that individual differences in rubber hand illusion can be explained at the computational level as differences in how priors are used in the multisensory integration process. Collectively, these results demonstrate that the sense of body ownership is determined by Bayesian causal inference, which implies that the same statistical principles determine the perception of the bodily self and the external world.

Synesthesia does not help to recover perceptual dominance following flash suppression

Grapheme-colour synesthesia occurs when letters or numbers elicit an abnormal colour sensation (e.g., printed black letters are perceived as coloured). This phenomenon is typically reported following explicit presentation of graphemes. Very few studies have investigated colour sensations in synesthesia in the absence of visual awareness. We took advantage of the dichoptic flash suppression paradigm to temporarily render a stimulus presented to one eye invisible. Synesthetic alphanumeric and non-synesthetic stimuli were presented to 21 participants (11 synesthetes) in achromatic and chromatic experimental conditions. The test stimulus was first displayed to one eye and then masked by a sudden presentation of visual noise in the other eye (flash suppression). The time for an image to be re-perceived following the onset of the suppressive noise was calculated. Trials where there was no flash suppression performed but instead mimicked the perceptual suppression of the flash were also tested. Results showed that target detection by synesthetes was significantly better than by controls in the absence of flash suppression. No difference was found between the groups in the flash suppression condition. Our findings suggest that synesthesia is associated with enhanced perception for overt recognition, but does not provide an advantage in recovering from a perceptual suppression. Further studies are needed to investigate synesthesia in relation to visual awareness.

Impact of a visual indicator on the noise level in an emergency medical dispatch centre - a pilot study

Background Noise levels are monitored in call centres. A maximum of 52 to 55 dB(A) is recommended in order to prevent adverse events. We aimed at assessing the noise level and the impact of a visual noise indicator on the ambient noise level in a French Regional Emergency Medical Dispatch Centre (EMDC). Methods We conducted an observational study in the EMDC of the SAMU25 (University Hospital of Besancon). We measured the noise level using a SoundEarII® noise indicator (Dräger Medical SAS, France). The measurement took place in two phases on three consecutive days from 00:00 to 11:59 PM. At baseline, phase 1, the device recorded the average ambient noise for each minute without visual indication. Secondly, phase 2 included a sensor mounted with a light that would turn on green if noise was below 65 dB(A), orange if noise ever exceeded 65 and red if it exceeded 75 dB(A). Results In the presence of the visual noise indicator, the LAeq was significantly lower than in the absence of visual noise indicator (a mean difference of − 4.19 dB; P < 10–3). It was higher than 55 dB(A) in 84.9 and 43.9% of the time in phases 1 and 2, respectively. Conclusions The noise levels were frequently higher than the standards, and sometimes close to recommended limits, requiring preventive measures. The noise indicator had a positive effect on the ambient noise level. This work will allow the implementation of effective prevention solutions and, based on future assessments, could improve operators’ well-being and better care for patient.

Visual Noise Effect on Contour Integration and Gaze Allocation in Autism Spectrum Disorder

Contradictory results have been obtained in the studies that compare contour integration abilities in Autism Spectrum Disorders (ASDs) and typically developing individuals. The present study aimed to explore the limiting factors of contour integration ability in ASD and verify the role of the external visual noise by a combination of psychophysical and eye-tracking approaches. To this aim, 24 children and adolescents with ASD and 32 age-matched participants with typical development had to detect the presence of contour embedded among similar Gabor elements in a Yes/No procedure. The results obtained showed that the responses in the group with ASD were not only less accurate but also were significantly slower compared to the control group at all noise levels. The detection performance depended on the group differences in addition to the effect of the intellectual functioning of the participants from both groups. The comparison of the agreement and accuracy of the responses in the double-pass experiment showed that the results of the participants with ASD are more affected by the increase of the external noise. It turned out that the internal noise depends on the level of the added external noise: the difference between the two groups was non-significant at the low external noise and significant at the high external noise. In accordance with the psychophysical results, the eye-tracking data indicated a larger gaze allocation area in the group with autism. These findings may imply higher positional uncertainty in ASD due to the inability to maintain the information of the contour location from previous presentations and interference from noise elements in the contour vicinity. Psychophysical and eye-tracking data suggest lower efficiency in using stimulus information in the ASD group that could be caused by fixation instability and noisy and unstable perceptual template that affects noise filtering.

Experimental study for revising visual noise measurement of ISO 15739

Fast track article for IS&T International Symposium on Electronic Imaging 2021: Image Quality and System Performance XVIII proceedings.