Restricted recovery of external remapping of tactile stimuli after restoring vision in a congenitally blind man

2012 ◽  
Vol 25 (0) ◽  
pp. 190
Author(s):  
Pia Ley ◽  
Davide Bottari ◽  
Bhamy Hariprasad Shenoy ◽  
Ramesh Kekunnaya ◽  
Brigitte Roeder

People with surgically removed congenital dense bilateral cataracts offer a natural model of visual deprivation and reafferentation in humans to investigate sensitive periods of multisensory development, for example regarding the recruitment of external or anatomical frames of reference for spatial representation. Here we present a single case (HS; male; 33 years; right-handed), born with congenital dense bilateral cataracts. His lenses were removed at the age of two years, but he received optical aids only at age six. At time of testing, his visual acuity was 30% in the best eye. We performed two tasks, a tactile temporal order judgment task (TOJ) in which two tactile stimuli were presented successively to the index fingers located in the two hemifields, adopting a crossed and uncrossed hand posture. The participant judged as precisely as possible which side was stimulated first. Moreover, we used a crossmodal-congruency task in which a tactile stimulus and an irrelevant visual distracter were presented simultaneously but independently to one of four positions. The participant judged the location (index or thumb) of the tactile stimulus with hands crossed or uncrossed. Speed was emphasized. In contrast to sighted controls, HS did not show a decrement of TOJ performance with hands crossed. Moreover, while the congruency gain was equivalent to sighted controls with uncrossed hands, this effect was significantly reduced with hands crossed. Thus, an external remapping of tactile stimuli still develops after a long phase of visual deprivation. However, remapping seems to be less efficient and to only take place in the context of visual stimuli.

2020 ◽  
pp. 1-23
Author(s):  
Makoto Wada ◽  
Hanako Ikeda ◽  
Shinichiro Kumagaya

Abstract Visual distractors interfere with tactile temporal order judgment (TOJ) at moderately short stimulus onset asynchronies (SOAs) in typically developing participants. Presentation of a rubber hand in a forward direction to the participant’s hand enhances this effect, while that in an inverted direction weakens the effect. Individuals with autism spectrum disorder (ASD) have atypical multisensory processing; however, effects of interferences on atypical multisensory processing in ASD remain unclear. In this study, we examined the effects of visual interference on tactile TOJ in individuals with ASD. Two successive tactile stimuli were delivered to the index and ring fingers of a participant’s right hand in an opaque box. A rubber hand was placed on the box in a forward or inverted direction. Concurrently, visual stimuli provided by light-emitting diodes on the fingers of the rubber hand were delivered in a congruent or incongruent order. Participants were required to judge the temporal order of the tactile stimuli regardless of visual distractors. In the absence of a visual stimulus, participants with ASD tended to judge the simultaneous stimuli as the ring finger being stimulated first during tactile TOJ compared with typically developing (TD) controls, and congruent visual stimuli eliminated the bias. When incongruent visual stimuli were delivered, judgment was notably reversed in participants with ASD, regardless of the direction of the rubber hand. The findings demonstrate that there are considerable effects of visual interferences on tactile TOJ in individuals with ASD.


2012 ◽  
Vol 25 (0) ◽  
pp. 35
Author(s):  
Makoto Wada ◽  
Kenji Kansaku

When people cross their arms, subjective rank ordering of successive unseen tactile stimuli delivered to both arms is affected (often being reversed) (Shore et al., 2002; Yamamoto and Kitazawa, 2001). It is also known that vision plays a significant role in modulating perceived limb position (Graziano et al., 2000). In this study, we examined the effect of vision; i.e., eyes opening and closing on tactile temporal order judgment (TOJ) with their arms crossed or uncrossed. In a psychophysical experiment, participants (, 13 males, 27.3 ± 1.8 y.o.) were required to judge temporal order of two tactile stimuli that were delivered to their both ring fingers with four conditions: uncrossed arms with eyes closed, crossed arms with eyes closed, uncrossed arms with eyes open and crossed arms with eyes open. To evaluate judgment probabilities of the participants, degree of reversals of their judgment was calculated as the sum of differences between correct response rates of the arms crossed condition and those of the arms uncrossed condition. In arms uncrossed conditions, judgment probabilities of the participants were not significantly different between eyes closed and open conditions. In contrast, reversal of the judgment with eyes closed was significantly larger than that with eyes open in arms crossed conditions (). The results suggest that vision play a significant role in tactile order judgment when the subject arms crossed.


2012 ◽  
Vol 25 (0) ◽  
pp. 120
Author(s):  
Abigail Novick ◽  
Nicola Fiddes ◽  
Eleanor Huber ◽  
Tucker Smith ◽  
Jared Medina

We presented participants with a temporal order judgment (TOJ) task with vibratory stimuli presented to the ends of held tools. We manipulated whether the hands and tools were uncrossed or crossed, predicting that participants would respond more accurately if the responding body part and tool tip were in the same hemispace (see Yamamoto and Kitazawa, 2001). Participants were split into two groups (24 subjects in each group). One group responded manually with the stimulated tools, the other group responded with foot pedals. Contrasting previous findings, we found no significant effect of manipulating tool position when the hands were uncrossed, regardless of response type. Effects of response type were also observed, as participants were significantly more accurate when responding with the stimulated tools compared to responding with foot pedals. Interactions were also found between response type and sex. Compared to males, females made a substantially greater number of confusion errors when responding with feet, but not when responding with tools. Additionally, compared to males, females made substantially more confusion errors with the arms crossed, reflecting previously reported results in tactile TOJ on the hands (Cadieux et al., 2010). These results suggest potential differences in spatial mapping and tactile processing in males and females.


Author(s):  
Ali Moharramipour ◽  
Shigeru Kitazawa

Abstract Our subjective temporal order of two successive tactile stimuli delivered one to each hand is often inverted when our hands are crossed. However, there is great variability among different individuals. We addressed the question of why some show almost complete reversal, but others show little reversal. To this end, we obtained structural MRI data from 42 participants who also participated in the tactile temporal order judgment (TOJ) task. We extracted the cortical thickness and the convoluted surface area as cortical characteristics in 68 regions. We found that the participants with a thinner, larger, and more convoluted cerebral cortex in ten regions, including the right pars-orbitalis, right and left postcentral gyri, left precuneus, left superior parietal lobule, right middle temporal gyrus, left superior temporal gyrus, right cuneus, left supramarginal gyrus, and right rostral middle frontal gyrus showed a smaller degree of judgment reversal. In light of major theoretical accounts, we suggest that cortical elaboration in the aforementioned regions improve the crossed-hand TOJ performance through better integration of the tactile stimuli with the correct spatial representations in the left parietal regions, better representation of spatial information in the postcentral gyrus, or improvement of top-down inhibitory control by the right pars-orbitalis.


2017 ◽  
Author(s):  
Virginie Crollen ◽  
Latifa Lazzouni ◽  
Mohamed Rezk ◽  
Antoine Bellemare ◽  
Franco Lepore ◽  
...  

AbstractLocalizing touch relies on the activation of skin-based and externally defined spatial frames of references. Psychophysical studies have demonstrated that early visual deprivation prevents the automatic remapping of touch into external space. We used fMRI to characterize how visual experience impacts on the brain circuits dedicated to the spatial processing of touch. Sighted and congenitally blind humans (male and female) performed a tactile temporal order judgment (TOJ) task, either with the hands uncrossed or crossed over the body midline. Behavioral data confirmed that crossing the hands has a detrimental effect on TOJ judgments in sighted but not in blind. Crucially, the crossed hand posture elicited more activity in a fronto-parietal network in the sighted group only. Psychophysiological interaction analysis revealed that the congenitally blind showed enhanced functional connectivity between parietal and frontal regions in the crossed versus uncrossed hand postures. Our results demonstrate that visual experience scaffolds the neural implementation of touch perception.Significance statementAlthough we seamlessly localize tactile events in our daily life, it is not a trivial operation because the hands move constantly within the peripersonal space. To process touch correctly, the brain has therefore to take the current position of the limbs into account and remap them to their location in the external world. In sighted, parietal and premotor areas support this process. However, while visual experience has been suggested to support the implementation of the automatic external remapping of touch, no studies so far have investigated how early visual deprivation alters the brain network supporting touch localization. Examining this question is therefore crucial to conclusively determine the intrinsic role vision plays in scaffolding the neural implementation of touch perception.


2015 ◽  
Vol 28 (1-2) ◽  
pp. 173-194 ◽  
Author(s):  
Tobias Heed ◽  
Johanna Möller ◽  
Brigitte Röder

To localize touch, the brain integrates spatial information coded in anatomically based and external spatial reference frames. Sighted humans, by default, use both reference frames in tactile localization. In contrast, congenitally blind individuals have been reported to rely exclusively on anatomical coordinates, suggesting a crucial role of the visual system for tactile spatial processing. We tested whether the use of external spatial information in touch can, alternatively, be induced by a movement context. Sighted and congenitally blind humans performed a tactile temporal order judgment task that indexes the use of external coordinates for tactile localization, while they executed bimanual arm movements with uncrossed and crossed start and end postures. In the sighted, start posture and planned end posture of the arm movement modulated tactile localization for stimuli presented before and during movement, indicating automatic, external recoding of touch. Contrary to previous findings, tactile localization of congenitally blind participants, too, was affected by external coordinates, though only for stimuli presented before movement start. Furthermore, only the movement’s start posture, but not the planned end posture affected blind individuals’ tactile performance. Thus, integration of external coordinates in touch is established without vision, though more selectively than when vision has developed normally, and possibly restricted to movement contexts. The lack of modulation by the planned posture in congenitally blind participants suggests that external coordinates in this group are not mediated by motor efference copy. Instead the task-related frequent posture changes, that is, movement consequences rather than planning, appear to have induced their use of external coordinates.


2021 ◽  
Author(s):  
Ramya Mudumba ◽  
Narayanan Srinivasan

The nature of spatiotemporal interactions in visual perception due to modulations of attention is still not well understood. Transient shifts of attention have been shown to induce a trade-off in spatiotemporal acuities at the cued location. Attention also can be varied in terms of scope and the evidence for the effects of scope on the spatiotemporal resolution for coupling or trade-offs have been equivocal. We predicted that scaling or changing the scope of attention would rather result in a spatiotemporal trade-off based on the complementary spatial and temporal frequency properties of the magnocellular and parvocellular channels. We manipulated the scope of attention by asking participants to perform a global or local target detection task with hierarchical stimuli. In addition, participants performed a temporal order judgment task with two discs presented alongside the hierarchical stimuli. We found higher temporal sensitivity with broad scope of attention or global processing compared to narrow scope of attention or local processing. The results provide evidence for a spatiotemporal processing trade-off when attention is scaled spatially. This result throws doubt on a general coupling or resource metaphor explanation irrespective of the spatial or temporal nature of the tasks. The results indicate the further need for carefully investigating the spatial and temporal properties of attention and its effect on spatiotemporal processing at different scales.


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