scholarly journals Task demands affect spatial reference frame weighting during tactile localization in sighted and congenitally blind adults

2016 ◽  
Author(s):  
Jonathan T.W. Schubert ◽  
Stephanie Badde ◽  
Brigitte Röder ◽  
Tobias Heed
Keyword(s):  
Task Demands ◽  
Task Instruction ◽  
External Information ◽  
Hand Posture ◽  
Spatial Integration ◽  
Tactile Localization ◽  
Task Instructions ◽  
Tactile Attention ◽  
Congenitally Blind ◽  
Blind Individuals

ABSTRACTTask demands modulate tactile localization in sighted humans, presumably through weight adjustments in the spatial integration of anatomical, skin-based, and external, posture-based information. In contrast, previous studies have suggested that congenitally blind humans, by default, refrain from automatic spatial integration and localize touch using only skin-based information. Here, sighted and congenitally blind participants localized tactile targets on the palm or back of one hand, while ignoring simultaneous tactile distractors at congruent or incongruent locations on the other hand. We probed the interplay of anatomical and external location codes for spatial congruency effects by varying hand posture: the palms either both faced down, or one faced down and one up. In the latter posture, externally congruent target and distractor locations were anatomically incongruent and vice versa. Target locations had to be reported either anatomically (“palm” or “back” of the hand), or externally (“up” or “down” in space). Under anatomical instructions, performance was better for anatomically congruent than incongruent target-distractor pairs. In contrast, under external instructions, performance was better for externally congruent than incongruent pairs. These modulations were evident in sighted and blind individuals. Notably, distractor effects were overall far smaller in blind than in sighted participants, despite comparable target-distractor identification performance. Thus, the absence of developmental vision seems to be associated with an increased ability to focus tactile attention towards a non-spatially defined target. Nevertheless, that blind individuals exhibited effects of hand posture and task instructions in their congruency effects suggests that, like the sighted,, they automatically integrate anatomical and external information during tactile localization. Moreover, spatial integration in tactile processing is, thus, flexibly adapted by top-down information – here, task instruction – even in the absence of developmental vision.

scholarly journals Task demands affect spatial reference frame weighting during tactile localization in sighted and congenitally blind adults

PLoS ONE ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. e0189067 ◽  
Author(s):  
Jonathan T. W. Schubert ◽  
Stephanie Badde ◽  
Brigitte Röder ◽  
Tobias Heed
Keyword(s):  
Reference Frame ◽  
Task Demands ◽  
Spatial Reference ◽  
Tactile Localization ◽  
Congenitally Blind ◽  
Spatial Reference Frame

Movement Induces the Use of External Spatial Coordinates for Tactile Localization in Congenitally Blind Humans

2015 ◽  
Vol 28 (1-2) ◽  
pp. 173-194 ◽  
Author(s):  
Tobias Heed ◽  
Johanna Möller ◽  
Brigitte Röder
Keyword(s):  
Reference Frames ◽  
Spatial Information ◽  
Temporal Order Judgment ◽  
Arm Movement ◽  
Judgment Task ◽  
Spatial Reference Frames ◽  
Tactile Localization ◽  
Congenitally Blind ◽  
Blind Individuals ◽  
Blind Humans

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.

Examining the Effects of Task Instructions to Induce Implicit Theories of Intelligence on a Rational Thinking Task

2017 ◽  
Vol 225 (2) ◽  
pp. 146-156 ◽  
Author(s):  
Ivar Bråten ◽  
Andreas Lien ◽  
John Nietfeld
Keyword(s):  
Implicit Theories ◽  
Male Students ◽  
Task Instruction ◽  
Rational Thinking ◽  
Implicit Theories Of Intelligence ◽  
Entity Theory ◽  
Theories Of Intelligence ◽  
Theory Of Intelligence ◽  
Task Instructions ◽  
Culture Specificity

Abstract. In two experiments with Norwegian undergraduates and one experiment with US undergraduates, we examined the potential effects of brief task instructions aligned with incremental and entity views of intelligence on students’ performance on a rational thinking task. The research demonstrated that even brief one-shot task instructions that deliver a mindset about intelligence intervention can be powerful enough to affect students’ performance on such a task. This was only true for Norwegian male students, however. Moreover, it was the task instruction aligned with an entity theory of intelligence that positively affected Norwegian male students’ performance on the rational thinking task, with this unanticipated finding speaking to the context- and culture-specificity of implicit theories of intelligence interventions.

scholarly journals Occipital Cortex of Blind Individuals Is Functionally Coupled with Executive Control Areas of Frontal Cortex

2015 ◽  
Vol 27 (8) ◽  
pp. 1633-1647 ◽  
Author(s):  
Ben Deen ◽  
Rebecca Saxe ◽  
Marina Bedny
Keyword(s):  
Working Memory ◽  
Functional Connectivity ◽  
Sentence Comprehension ◽  
Memory Load ◽  
Memory Task ◽  
Occipital Cortex ◽  
Memory Systems ◽  
Functional Responses ◽  
Congenitally Blind ◽  
Blind Individuals

In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.

scholarly journals Spatial navigation by congenitally blind individuals

2015 ◽  
Vol 7 (1) ◽  
pp. 37-58 ◽  
Author(s):  
Victor R. Schinazi ◽  
Tyler Thrash ◽  
Daniel-Robert Chebat
Keyword(s):  
Spatial Navigation ◽  
Congenitally Blind ◽  
Blind Individuals

scholarly journals How visual experience and task context modulate the use of internal and external spatial coordinate for perception and action

2018 ◽  
Author(s):  
Virginie Crollen ◽  
Tiffany Spruyt ◽  
Pierre Mahau ◽  
Roberto Bottini ◽  
Olivier Collignon
Keyword(s):  
Coordinate System ◽  
Visual Experience ◽  
Simon Task ◽  
Frame Of Reference ◽  
The Body ◽  
Blind People ◽  
Coordinate Systems ◽  
Task Instructions ◽  
Congenitally Blind ◽  
External Frame

Recent studies proposed that the use of internal and external coordinate systems may be more flexible in congenitally blind when compared to sighted individuals. To investigate this hypothesis further, we asked congenitally blind and sighted people to perform, with the hands uncrossed and crossed over the body midline, a tactile TOJ and an auditory Simon task. Crucially, both tasks were carried out under task instructions either favoring the use of an internal (left vs. right hand) or an external (left vs. right hemispace) frame of reference. In the internal condition of the TOJ task, our results replicated previous findings (Röder et al., 2004) showing that hand crossing only impaired sighted participants’ performance, suggesting that blind people did not activate by default a (conflicting) external frame of reference. However, under external instructions, a decrease of performance was observed in both groups, suggesting that even blind people activated an external coordinate system in this condition. In the Simon task, and in contrast with a previous study (Roder et al., 2007), both groups responded more efficiently when the sound was presented from the same side of the response (‘‘Simon effect’’) independently of the hands position. This was true under the internal and external conditions, therefore suggesting that blind and sighted by default activated an external coordinate system in this task. All together, these data comprehensively demonstrate how visual experience shapes the default weight attributed to internal and external coordinate systems for action and perception depending on task demand.

scholarly journals Shared understanding of color among congenitally blind and sighted adults

2020 ◽  
Author(s):  
Judy Sein Kim ◽  
Brianna Aheimer ◽  
Veronica Montane Manrara ◽  
Marina Bedny
Keyword(s):  
Visual Experience ◽  
Natural Kinds ◽  
Shared Understanding ◽  
Linguistic Communication ◽  
Causal Explanations ◽  
Stop Sign ◽  
Congenitally Blind ◽  
Novel Objects ◽  
Blind Individuals

Empiricist philosophers such as Locke famously argued that people born blind could only acquire shallow, fragmented facts about color. Contrary to this intuition, we report that blind and sighted people share an in-depth understanding of color, despite disagreeing about arbitrary color facts. Relative to the sighted, blind individuals are less likely to generate ‘yellow’ for banana and ‘red’ for stop-sign. However, blind and sighted adults are equally likely to infer that two bananas (natural kinds) and two stop-signs (artifacts with functional colors) are more likely to have the same color than two cars (artifacts with non-functional colors), make similar inferences about novel objects’ colors, and provide similar causal explanations. We argue that people develop inferentially-rich and intuitive “theories” of color regardless of visual experience. Linguistic communication is more effective at aligning people’s theories than their knowledge of verbal facts.

scholarly journals Changes in thalamocortical connectivity as a potential mechanism of cross-modal plasticity in congenitally blind individuals

2018 ◽  
Author(s):  
Theo Marins ◽  
Maite Russo ◽  
Erika Rodrigues ◽  
jorge Moll ◽  
Daniel Felix ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Cortical Thickness ◽  
Visual Information ◽  
Brain Plasticity ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Brain Structures ◽  
Congenitally Blind ◽  
Blind Individuals ◽  
Neuroimaging Techniques

ABSTRACTEvidence of cross-modal plasticity in blind individuals has been reported over the past decades showing that non-visual information is carried and processed by classical “visual” brain structures. This feature of the blind brain makes it a pivotal model to explore the limits and mechanisms of brain plasticity. However, despite recent efforts, the structural underpinnings that could explain cross-modal plasticity in congenitally blind individuals remain unclear. Using advanced neuroimaging techniques, we mapped the thalamocortical connectivity and assessed cortical thickness and integrity of white matter of congenitally blind individuals and sighted controls to test the hypothesis that aberrant thalamocortical pattern of connectivity can pave the way for cross-modal plasticity. We described a direct occipital takeover by the temporal projections from the thalamus, which would carry non-visual information (e.g. auditory) to the visual cortex in congenitally blinds. In addition, the amount of thalamo-occipital connectivity correlated with the cortical thickness of primary visual cortex (V1), supporting a probably common (or related) reorganization phenomena. Our results suggest that aberrant thalamocortical connectivity as one possible mechanism of cross-modal plasticity in blinds, with potential impact on cortical thickness of V1.SIGNIFICANT STATEMENTCongenitally blind individuals often develop greater abilities on spared sensory modalities, such as increased acuity in auditory discrimination and voice recognition, when compared to sighted controls. These functional gains have been shown to rely on ‘visual’ cortical areas of the blind brain, characterizing the phenomenon of cross-modal plasticity. However, its anatomical underpinnings in humans have been unsuccessfully pursued for decades. Recent advances of non-invasive neuroimaging techniques allowed us to test the hypothesis of abnormal thalamocortical connectivity in congenitally blinds. Our results showed an expansion of the thalamic connections to the temporal cortex over those that project to the occipital cortex, which may explain, the cross-talk between the visual and auditory systems in congenitally blind individuals.

scholarly journals Mental Imagery Follows Similar Cortical Reorganization as Perception: Intra-Modal and Cross-Modal Plasticity in Congenitally Blind

2018 ◽  
Vol 29 (7) ◽  
pp. 2859-2875 ◽  
Author(s):  
A W de Borst ◽  
B de Gelder
Keyword(s):  
Visual Cortex ◽  
Mental Imagery ◽  
Cortical Plasticity ◽  
Tactile Perception ◽  
Cortical Reorganization ◽  
Area V4 ◽  
Congenitally Blind ◽  
Early Visual Cortex ◽  
Blind Individuals ◽  
Discriminative Patterns

Abstract Cortical plasticity in congenitally blind individuals leads to cross-modal activation of the visual cortex and may lead to superior perceptual processing in the intact sensory domains. Although mental imagery is often defined as a quasi-perceptual experience, it is unknown whether it follows similar cortical reorganization as perception in blind individuals. In this study, we show that auditory versus tactile perception evokes similar intra-modal discriminative patterns in congenitally blind compared with sighted participants. These results indicate that cortical plasticity following visual deprivation does not influence broad intra-modal organization of auditory and tactile perception as measured by our task. Furthermore, not only the blind, but also the sighted participants showed cross-modal discriminative patterns for perception modality in the visual cortex. During mental imagery, both groups showed similar decoding accuracies for imagery modality in the intra-modal primary sensory cortices. However, no cross-modal discriminative information for imagery modality was found in early visual cortex of blind participants, in contrast to the sighted participants. We did find evidence of cross-modal activation of higher visual areas in blind participants, including the representation of specific-imagined auditory features in visual area V4.

Parenting Styles and the Depressive Syndrome in Congenitally Blind Individuals

1980 ◽  
Vol 74 (9) ◽  
pp. 333-337 ◽  
Author(s):  
Robert Lambert ◽  
Malcolm West
Keyword(s):  
Parenting Styles ◽  
Depressive Syndrome ◽  
Sense Of Competence ◽  
Ego Ideal ◽  
Blind Children ◽  
Congenitally Blind ◽  
Blind Individuals

This article discusses the effect on congenitally blind children of three types of parents: those who are over-protective, those who push the child toward independence too soon, and those who are “good enough.” The authors focus on how the three styles of parenting affect the blind child's ability to give and receive and develop a sense of competence. These effects are discussed in the context of the ego ideal. The authors also examine the depressive core that is often the result of the blind child's inability to live up to the dictates of the ego ideal. Finally, they suggest a fourth style of parenting that would prepare blind children better for the problems they will encounter in the sighted world.

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