We examined the effects of visual deprivation at birth on the development of the corpus callosum in a large group of congenitally blind individuals. We acquired high-resolution T1-weighted MRI scans in 28 congenitally blind and 28 normal sighted subjects matched for age and gender. There was no overall group effect of visual deprivation on the total surface area of the corpus callosum. However,...

To investigate whether superior tactile acuity in the blind is due to alterations of attentional selection mechanisms, event-related brain potentials (ERPs) were measured in a group of early blind and a group of sighted individuals who performed a difficult tactile spatial selection task. We found systematic differences in the attentional processing of tactile events between early blind and sig...

This study explores how much speech can be temporally compressed and still understood by blind people who have daily practice with speech synthesis vs. sighted persons without such training. Three text modes were generated (formant synthesis, natural speech with and without pauses). These texts were presented to sighted listeners at rates between 9-14 s/s and to blind listeners between 17-22 s/...

It is widely accepted that spatial representation is processed by an amodal system. Recent studies show that blind subjects have a better motion ability than sighted people in performing spatial exploration guided only by auditory cues. The sonification method offers an effective tool able to transmit graphic information, overcoming the digital divide risen by a visuocentric modality in which c...

Early-blind, late-blind, and blindfolded sighted participants were presented with two haptic allocentric spatial tasks: a parallel-setting task, in an immediate and a 10-sec delay condition, and a task in which the orientation of a single bar was judged verbally. With respect to deviation size, the data suggest that mental visual processing filled a beneficial role in both tasks. In the paralle...

The study investigated mentalistic and descriptive discourse between school-aged children with visual impairment (VI) from birth, age 6-12 years, and their sighted mothers during joint book narrative (n=12), and in comparison to a group of sighted children of comparable age and verbal ability, and their mothers (n=14). The mothers of children with VI referred to the story characters' mental sta...

Functional imaging studies in blind subjects have shown tactile activation of cortical areas that normally subserve vision, but whether blind people have enhanced tactile acuity has long been controversial. We compared the passive tactile acuity of blind and sighted subjects on a fully automated grating orientation task and used multivariate Bayesian data analysis to determine predictors of acu...

Compared to conversational speech, clear speech is produced with longer vowel duration, greater intensity, increased contrasts between vowel categories, and decreased dispersion within vowel categories. Those acoustic correlates are produced by larger movements of the orofacial articulators, including visible (lips) and invisible (tongue) articulators. How are those cues produced by visually im...

The aim of this research was to examine the subjective quality of life in blind and partially sighted people in relation to the type of impairment, duration of impairment and participation in psychosocial rehabilitation. The study used a sociodemographic and health questionnaire, and the Personal Wellbeing Index for adults to examine participant satisfaction with different life domains. The res...

Visually challenged individuals often compensate for their handicap by developing supra-normal abilities in their remaining sensory systems. Here, we examined the scalp distribution of components N1 and P3 of auditory evoked potentials during a sound localization task in four totally blind subjects who had previously shown better performance than sighted subjects. Both N1 and P3 waves peaked at...