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Journal of Speech, Language, and... Oct 2018Visual recognition of interrupted text may predict speech intelligibility under adverse listening conditions. This study investigated the nature of the linguistic... (Comparative Study)
Comparative Study
PURPOSE
Visual recognition of interrupted text may predict speech intelligibility under adverse listening conditions. This study investigated the nature of the linguistic information and perceptual processes underlying this relationship.
METHOD
To directly compare the perceptual organization of interrupted speech and text, we examined the recognition of spoken and printed sentences interrupted at different rates in 14 adults with normal hearing. The interruption method approximated deletion and retention of rate-specific linguistic information (0.5-64 Hz) in speech by substituting either white space or silent intervals for text or speech in the original sentences.
RESULTS
A similar U-shaped pattern of cross-rate variation in performance was observed in both modalities, with minima at 2 Hz. However, at the highest and lowest interruption rates, recognition accuracy was greater for text than speech, whereas the reverse was observed at middle rates. An analysis of word duration and the frequency of word sampling across interruption rates suggested that the location of the function minima was influenced by perceptual reconstruction of whole words. Overall, the findings indicate a high degree of similarity in the perceptual organization of interrupted speech and text.
CONCLUSION
The observed rate-specific variation in the perception of speech and text may potentially affect the degree to which recognition accuracy in one modality is predictive of the other.
Topics: Acoustic Stimulation; Adult; Humans; Pattern Recognition, Visual; Perceptual Masking; Photic Stimulation; Reading; Speech Intelligibility; Speech Perception; Young Adult
PubMed: 30458532
DOI: 10.1044/2018_JSLHR-H-17-0477 -
Philosophical Transactions of the Royal... May 2014Given that multiple senses are often stimulated at the same time, perceptual awareness is most likely to take place in multisensory situations. However, theories of... (Review)
Review
Given that multiple senses are often stimulated at the same time, perceptual awareness is most likely to take place in multisensory situations. However, theories of awareness are based on studies and models established for a single sense (mostly vision). Here, we consider the methodological and theoretical challenges raised by taking a multisensory perspective on perceptual awareness. First, we consider how well tasks designed to study unisensory awareness perform when used in multisensory settings, stressing that studies using binocular rivalry, bistable figure perception, continuous flash suppression, the attentional blink, repetition blindness and backward masking can demonstrate multisensory influences on unisensory awareness, but fall short of tackling multisensory awareness directly. Studies interested in the latter phenomenon rely on a method of subjective contrast and can, at best, delineate conditions under which individuals report experiencing a multisensory object or two unisensory objects. As there is not a perfect match between these conditions and those in which multisensory integration and binding occur, the link between awareness and binding advocated for visual information processing needs to be revised for multisensory cases. These challenges point at the need to question the very idea of multisensory awareness.
Topics: Attentional Blink; Awareness; Consciousness; Humans; Models, Psychological; Perception; Perceptual Masking; Vision Disparity
PubMed: 24639579
DOI: 10.1098/rstb.2013.0207 -
ELife Jan 2022Can direct stimulation of primate V1 substitute for a visual stimulus and mimic its perceptual effect? To address this question, we developed an optical-genetic toolkit...
Can direct stimulation of primate V1 substitute for a visual stimulus and mimic its perceptual effect? To address this question, we developed an optical-genetic toolkit to 'read' neural population responses using widefield calcium imaging, while simultaneously using optogenetics to 'write' neural responses into V1 of behaving macaques. We focused on the phenomenon of visual masking, where detection of a dim target is significantly reduced by a co-localized medium-brightness mask (Cornsweet and Pinsker, 1965; Whittle and Swanston, 1974). Using our toolkit, we tested whether V1 optogenetic stimulation can recapitulate the perceptual masking effect of a visual mask. We find that, similar to a visual mask, low-power optostimulation can significantly reduce visual detection sensitivity, that a sublinear interaction between visual- and optogenetic-evoked V1 responses could account for this perceptual effect, and that these neural and behavioral effects are spatially selective. Our toolkit and results open the door for further exploration of perceptual substitutions by direct stimulation of sensory cortex.
Topics: Animals; Macaca mulatta; Male; Neurons; Optogenetics; Perceptual Masking; Photic Stimulation; Proof of Concept Study; Visual Cortex; Visual Perception
PubMed: 34982033
DOI: 10.7554/eLife.68393 -
Journal of Vision Jul 2023To investigate the mechanisms underlying elongated spatial summation with a pattern-masking paradigm, we measured the contrast detection thresholds for elongated Gabor...
To investigate the mechanisms underlying elongated spatial summation with a pattern-masking paradigm, we measured the contrast detection thresholds for elongated Gabor targets situated at 3° eccentricity to either the left or right of the fixation and elongated along an arc of the same radius to access homogeneous retinal sensitivity. The mask was a ring with a Gabor envelope of the same 3° center radius containing either a concentric (iso-orientation mask) or a radial (orthogonal mask) modulation. The task of the observer was to indicate whether the target in each trial was on the left or the right of the fixation. With orthogonal or low contrast iso-orientation masks, target thresholds first decreased with size with slope -1 on log-log coordinates until the target length reached 45' (specified as the half-height full-width of the Gabor envelope) and then further decreased according to a slope of -1/2, the latter being the signature of an ideal summation process. When the contrast of the iso-orientation mask was sufficiently high, however, the target thresholds, while still showing a -1 slope up to ∼10', asymptoted up to about 50' length, suggesting that the presence of the mask eliminated the ideal summation regime. Beyond about 50', the data approximated another -1 slope decrease in threshold, suggesting the existence of an extra-long channel that is not revealed by the conventional spatial summation paradigm. The full results could be explained by a divisive inhibition model, in which second-order filters sum responses across local oriented channels, combined with a single extra-long filter at least 300' in extent. In this model, the local filter response is given by the linear excitation of the local channels raised to a power, and scaled by divisive inhibition from all channels in the neighborhood. With the high-contrast iso-orientation masks, such divisive inhibition swamps the response to eliminate the ideal summation regime until the stimulus is long enough to activate the extra-long filter.
Topics: Humans; Contrast Sensitivity; Sensory Thresholds; Perceptual Masking; Inhibition, Psychological
PubMed: 37505916
DOI: 10.1167/jov.23.7.17 -
Animal Cognition Oct 2022Anthropogenic noise is an increasing threat to marine mammals that rely on sound for communication, navigation, detecting prey and predators, and finding mates. Auditory... (Review)
Review
Anthropogenic noise is an increasing threat to marine mammals that rely on sound for communication, navigation, detecting prey and predators, and finding mates. Auditory masking is one consequence of anthropogenic noise, the study of which is approached from multiple disciplines including field investigations of animal behavior, noise characterization from in-situ recordings, computational modeling of communication space, and hearing experiments conducted in the laboratory. This paper focuses on laboratory hearing experiments applying psychophysical methods, with an emphasis on the mechanisms that govern auditory masking. Topics include tone detection in simple, complex, and natural noise; mechanisms for comodulation masking release and other forms of release from masking; the role of temporal resolution in auditory masking; and energetic vs informational masking.
Topics: Animals; Caniformia; Hearing; Noise; Perceptual Masking
PubMed: 36018474
DOI: 10.1007/s10071-022-01671-z -
Journal of Vision Jun 2019Previously, it has been shown that dichoptic color-contrast masking can be dramatically reduced by the introduction of task-irrelevant binocular features. It is unclear,...
Previously, it has been shown that dichoptic color-contrast masking can be dramatically reduced by the introduction of task-irrelevant binocular features. It is unclear, however, whether or not the task-irrelevant features need to be matched in the two eyes in order to reduce dichoptic masking. We measured dichoptic masking between target and mask luminance decrement patches and between target and mask isoluminant violet patches. The stimuli were surrounded by a task-irrelevant feature that consisted of a ring of various widths: either a luminance decrement, an isoluminant violet, or an isoluminant red. When the ring was presented to just the target eye-that is, the eye opposite to that of the mask-dichoptic masking was reduced just as much as when the ring was binocular-that is, presented to both eyes. A model that incorporated the combined influence of interocular inhibition from all stimulus components-that is, mask, target, and rings-was found to give a good account of the pattern of dichoptic masking across the full range of conditions.
Topics: Color Perception; Contrast Sensitivity; Humans; Inhibition, Psychological; Perceptual Masking; Vision, Binocular; Visual Acuity
PubMed: 31173628
DOI: 10.1167/19.6.3 -
Journal of Vision 2015Masking and crowding are major phenomena associated with contextual modulations, but the relationship between them remains unclear. We have recently shown that crowding...
Masking and crowding are major phenomena associated with contextual modulations, but the relationship between them remains unclear. We have recently shown that crowding is apparent in the fovea when the time available for processing is limited, pointing to the strong relationship between crowding in the spatial and temporal domains. Models of crowding emphasize the size (acuity) of the target and the spacing between the target and flankers as the main determinants that predict crowding. Our model, which is based on lateral interactions, posits that masking and crowding are related in the spatial and temporal domains at the fovea and periphery and that both can be explained by the increasing size of the human perceptive field (PF) with increasing eccentricity. We explored the relations between masking and crowding using letter identification and contrast detection by correlating the crowding effect with the estimated size of the PF and with masking under different spatiotemporal conditions. We found that there is a large variability in PF size and crowding effects across observers. Nevertheless, masking and crowding were both correlated with the estimated size of the PF in the fovea and periphery under a specific range of spatiotemporal parameters. Our results suggest that under certain conditions, crowding and masking share common neural mechanisms that underlie the spatiotemporal properties of these phenomena in both the fovea and periphery. These results could explain the transfer of training gains from spatiotemporal Gabor masking to letter acuity, reading, and reduced crowding.
Topics: Adolescent; Adult; Contrast Sensitivity; Crowding; Fovea Centralis; Humans; Perceptual Masking; Reading; Space Perception; Young Adult
PubMed: 26381841
DOI: 10.1167/15.13.10 -
Brain and Behavior Sep 2019The perception of a target stimulus can be impaired by a subsequent mask stimulus, even if they do not overlap temporally or spatially. This "backward masking" is...
INTRODUCTION
The perception of a target stimulus can be impaired by a subsequent mask stimulus, even if they do not overlap temporally or spatially. This "backward masking" is commonly used to modulate a subject's awareness of a target and to characterize the temporal dynamics of vision. Masking is most apparent with brief, low-contrast targets, making detection difficult even in the absence of a mask. Although necessary to investigate the underlying neural mechanisms, evaluating masking phenomena in animal models is particularly challenging, as the task structure and critical stimulus features to be attended must be learned incrementally through rewards and feedback. Despite the increasing popularity of rodents in vision research, it is unclear if they are susceptible to masking illusions.
METHODS
We characterized how spatially surrounding masks affected the detection of sine-wave grating targets.
RESULTS
In humans (n = 5) and rats (n = 7), target detection improved with contrast and was reduced by the presence of a mask. After controlling for biases to respond induced by the presence of the mask, a clear reduction in detectability was caused by masks. This reduction was evident when data were averaged across all animals, but was only individually significant in three animals.
CONCLUSIONS
While perceptual masking occurs in rats, it may be difficult to observe consistently in individual animals because the complexity of the requisite task pushes the limits of their behavioral capabilities. We suggest methods to ensure that masking, and similarly subtle effects, can be reliably characterized in future experiments.
Topics: Adult; Animals; Female; Humans; Male; Models, Animal; Orientation, Spatial; Perceptual Masking; Photic Stimulation; Rats
PubMed: 31444998
DOI: 10.1002/brb3.1368 -
Journal of Vision Aug 2016Static visual stimuli are smeared across the retina during saccades, but in normal conditions this smear is not perceived. Instead, we perceive the visual scene as... (Review)
Review
Static visual stimuli are smeared across the retina during saccades, but in normal conditions this smear is not perceived. Instead, we perceive the visual scene as static and sharp. However, retinal smear is perceived if stimuli are shown only intrasaccadically, but not if the stimulus is additionally shown before a saccade begins, or after the saccade ends (Campbell & Wurtz, 1978). This inhibition has been compared to forward and backward metacontrast masking, but with spatial relations between stimulus and mask that are different from ordinary metacontrast during fixation. Previous studies of smear masking have used subjective measures of smear perception. Here we develop a new, objective technique for measuring smear masking, based on the spatial localization of a gap in the smear created by very quickly blanking the stimulus at various points during the saccade. We apply this technique to show that smear masking survives dichoptic presentation (suggesting that it is therefore cortical in origin), as well as separations of as much as 6° between smear and mask.
Topics: Humans; Perceptual Masking; Retina; Saccades; Visual Perception
PubMed: 27479918
DOI: 10.1167/16.10.1 -
Consciousness and Cognition Jul 2022Visual scenes typically contain redundant information. One mechanism by which the visual system compresses such redundancies is 'redundancy masking' - the reduction of...
Visual scenes typically contain redundant information. One mechanism by which the visual system compresses such redundancies is 'redundancy masking' - the reduction of the perceived number of items in repeating patterns. For example, when presented with three lines in the periphery, observers frequently report only two lines. Redundancy masking is strong in radial arrangements and absent in tangential arrangements. Previous studies suggested that redundancy-masked percepts predominate in stimuli susceptible to redundancy masking. Here, we investigated whether strong redundancy masking is associated with high confidence in perceptual judgements. Observers viewed three to seven radially or tangentially arranged lines at 10° eccentricity. They first indicated the number of lines, and then rated their confidence in their responses. As expected, redundancy masking was strong in radial arrangements and weak in tangential arrangements. Importantly, with radial arrangements, observers were more confident in their responses when redundancy masking occurred (i.e., lower number of lines reported) than when it did not occur (i.e., correct number of lines reported). Hence, observers reported higher confidence for erroneous than for correct judgments. In contrast, with tangential arrangements, observers were similarly confident in their responses whether redundancy masking occurred or not. The inversion of confidence in the radial condition (higher confidence when accuracy was low and lower confidence when accuracy was high) suggests that redundancy-masked appearance trumps 'veridical' perception. The often-reported richness of visual consciousness may partly be due to overconfidence in erroneous judgments in visual scenes that are subject to redundancy masking.
Topics: Consciousness; Humans; Judgment; Perceptual Masking; Visual Perception
PubMed: 35598518
DOI: 10.1016/j.concog.2022.103349