Texture Segmentation and Visual Search in Deaf and Hearing Subjects: Evidence for Compensation?

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 143-143
Author(s):  
R Sireteanu ◽  
R Rettenbach ◽  
G Diller

Do deaf people develop capacities of their remaining senses that exceed those of hearing individuals? Are the compensatory effects due to attention-dependent strategies? We investigated these questions, using texture segmentation and visual search tasks. The advantage of these tasks is that they contain attention-dependent and attention-independent components. We investigated 8 hearing adult observers, and 99 hearing and 89 deaf subjects aged between 6 and 20 years. The subject's task was to search for a discrepant stimulus among a number of distracting items. We used four different visual search tasks (circles with and without a 90° gap; circles with and without an added vertical line; pairs of convergent and parallel lines; tilted and vertical single lines) and oriented textures containing either a single line or a group of 16 discrepant lines. Visual search and texture segmentation tasks were randomly intermingled. Each subject participated in eight experimental runs, on two consecutive days. Both groups of subjects showed consistent learning effects for all tasks. In both groups, reaction times for all tasks decreased with age and reached an optimum at about 16 – 18 years. However, statistical comparisons do not indicate compensatory effects for deafness: reaction times and error rates of the deaf subjects were higher than those of the age-matched hearing subjects, for both the serial and the parallel tasks. These results were independent of the age and gender of the subjects and occurred for all etiologies for deafness. These results suggest deficiencies in the visual processing capacity of deaf subjects in tasks with and without attentional load.

1999 ◽  
Vol 11 (5) ◽  
pp. 560-583 ◽  
Author(s):  
Regina Rettenbach ◽  
Gottfried Diller ◽  
Ruxandra Sireteanu

The research concerning the visual perception in deaf subjects has led to contradictory results: Deaf subjects have been reported to show enhanced visual perceptual skills compared to hearing subjects (Neville & Lawson, 1987). On the other hand, there are indications that acoustic deprivation may produce an inferiority in all sensory modalities (Myklebust, 1964). These contradictions may be due to methodological differences: The investigators selected different conditions (e.g. attentive/nonattentive) and various samples of deaf subjects (e.g., different age, language, and aetiology groups). In our study, we tested a large sample of deaf subjects with texture segmentation and visual search conditions, which allowed us to differentiate between visual processing with and without attentional load. All deaf subjects had profound hearing loss within the first year of life. Our results suggest that the visual processing capacity of deaf children and adolescents does not exceed that of age- and gender-matched hearing subjects. Rather, deaf school children show deficits in visual processing in conditions with and without attentional load. Age (6 to 20 years), language used (oral, sign, oral + sign), and aetiology for deafness (genetic, maternal rubella, perinatal, infection in the first year of life, unknown) did not consistently influence the results. The deficits in visual processing were partially compensated for in adult deaf subjects. The performances of deaf and hearing adults in trials that could be solved preattentively did not differ statistically significantly, but in attention-dependent trials the deaf subjects were more efficient than the hearing controls. We conclude that visual compensation for deafness is limited to attention-dependent tasks and does not develop until adulthood.


2020 ◽  
Author(s):  
Anne-Sophie Laurin ◽  
Julie Ouerfelli-Éthier ◽  
Laure Pisella ◽  
Aarlenne Zein Khan

Older adults show declines performing visual search, but their nature is unclear. We propose that it is related to greater attentional reliance on central vision. To investigate this, we tested how occluding central vision would affect younger and older adults in visual search. Participants (14 younger, M = 21.6 years; 16 older, M = 69.6 years) performed pop-out and serial search tasks in full view and with different sized gaze-contingent artificial central scotomas (no scotoma, 3°, 5° or 7° diameter).In pop-out search, older adults showed longer search times for peripheral targets during full viewing. Their reaction times, saccades and fixation durations also increased as a function of scotoma size, contrary to younger adults. These declines may reflect a relative impairment in peripheral visual attention for global processing in aging.In serial search, despite older adults being generally slower, we found no difference between groups in reaction time increases for eccentric targets and for bigger scotomas. These results may come from the difficulty of serial search, in which both groups used centrally limited attentional windows.We conclude that older adults allocate more attentional resources towards central vision compared to younger adults, impairing their peripheral processing primarily in pop-out visual search.


2017 ◽  
Vol 40 ◽  
Author(s):  
Alejandro Lleras ◽  
Deborah A. Cronin ◽  
Anna M. Madison ◽  
Marshall Wang ◽  
Simona Buetti

AbstractWe highlight the importance of considering the variance produced during the parallel processing stage in vision and present a case for why it is useful to consider the “item” as a meaningful unit of study when investigating early visual processing in visual search tasks.


Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 232-232 ◽  
Author(s):  
U Leonards ◽  
R Rettenbach ◽  
R Sireteanu

Serial visual search can become parallel with practice (Sireteanu and Rettenbach, 1995 Vision Research35 2037 – 2043). Our purpose was to examine whether psychophysiological indices reflect the changes in reaction time during training. We used targets and distractors that differed either in orientation (‘tilt’), or in local brightness: closed circles with or without an additional line element (‘added line’), or circles with gaps of different width (‘gap’). The subjects’ task was to indicate the presence or absence of a target on a computer screen by immediately pressing a button and pointing to the location of the target if the trial was positive, or raise the hand if negative. No feedback was given. Response time and error rate were recorded. In addition, electrocardiograms, galvanic skin response, respiration rate and amplitude, horizontal eye movements, and electromyograms were monitored. Two naive and two experienced subjects participated in at least 16 experimental sessions. Before training, slopes differed for the three tasks, ranging from parallel search for the feature ‘tilt’ to a very steep serial search for the feature ‘gap’. These differences were reflected in the psychophysiological parameters. Reaction time and error rate decreased continuously with learning, leading to parallel search after prolonged practice for all three tasks (see Nase et al, 1995 Perception24 Supplement, 84). Preliminary results indicate that the psychophysiological measures do not follow the perceptual changes during learning. We conclude that, despite the perceptual parallelisation with practice, the attentional load remains high for initially serial tasks.


Autism ◽  
2016 ◽  
Vol 21 (8) ◽  
pp. 942-951 ◽  
Author(s):  
Aya Shirama ◽  
Nobumasa Kato ◽  
Makio Kashino

Although superior visual search skills have been repeatedly reported for individuals with autism spectrum disorder, the underlying mechanisms remain controversial. To specify the locus where individuals with autism spectrum disorder excel in visual search, we compared the performance of autism spectrum disorder adults and healthy controls in briefly presented search tasks, where the search display was replaced by a noise mask at a stimulus-mask asynchrony of 160 ms to interfere with a serial search process while bottom-up visual processing remains intact. We found that participants with autism spectrum disorder show faster overall reaction times regardless of the number of stimuli and the presence of a target with higher accuracy than controls in a luminance and shape conjunction search task as well as a hard feature search task where the target feature information was ineffective in prioritizing likely target stimuli. In addition, the analysis of target eccentricity illustrated that the autism spectrum disorder group has better target discriminability regardless of target eccentricity, suggesting that the autism spectrum disorder advantage does not derive from a reduced crowding effect, which is known to be enhanced with increasing retinal eccentricity. The findings suggest that individuals with autism spectrum disorder excel in non-search processes, especially in the simultaneous discrimination of multiple visual stimuli.


2012 ◽  
Author(s):  
Stephen R. Mitroff ◽  
Adam T. Biggs ◽  
Matthew S. Cain ◽  
Elise F. Darling ◽  
Kait Clark ◽  
...  

Author(s):  
Timnit Gebru

This chapter discusses the role of race and gender in artificial intelligence (AI). The rapid permeation of AI into society has not been accompanied by a thorough investigation of the sociopolitical issues that cause certain groups of people to be harmed rather than advantaged by it. For instance, recent studies have shown that commercial automated facial analysis systems have much higher error rates for dark-skinned women, while having minimal errors on light-skinned men. Moreover, a 2016 ProPublica investigation uncovered that machine learning–based tools that assess crime recidivism rates in the United States are biased against African Americans. Other studies show that natural language–processing tools trained on news articles exhibit societal biases. While many technical solutions have been proposed to alleviate bias in machine learning systems, a holistic and multifaceted approach must be taken. This includes standardization bodies determining what types of systems can be used in which scenarios, making sure that automated decision tools are created by people from diverse backgrounds, and understanding the historical and political factors that disadvantage certain groups who are subjected to these tools.


2011 ◽  
Vol 15 (1) ◽  
pp. 22-38 ◽  
Author(s):  
PEGGY F. JACOBSON

This study examined object clitic pronouns (OCPs) and verb inflections in twenty-five school-age children with typical development (TD) and twenty children with bilingual language impairment (BLI). MANOVA and ANOVA were used to explore differences according to grade level and language status (TD vs. BLI). Although children with BLI produced higher rates of grammatical errors overall, accuracy on number and gender assignment for OCPs was better for both groups in the higher grades. Although the rate of verb inflection errors did not differ for children with TD and BLI in the lower grades, a significant interaction yielded higher error rates on subject–verb agreement for third person singular and plural inflections in the later grades for children with BLI. Greater accuracy on OCP use in later grades weakens claims that bilingualism exacerbates language impairment. For BLI, whether incomplete acquisition or delayed development is the determining factor for verb inflection errors remains undetermined.


1998 ◽  
Vol 6 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Philippe Stivalet ◽  
Yvan Moreno ◽  
Joëlle Richard ◽  
Pierre-Alain Barraud ◽  
Christian Raphel
Keyword(s):  

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