The Role of Visual Experience in Mental Scanning of Actual Pathways: Evidence from Blind and Sighted People

Perception ◽  
10.1068/p6457 ◽  
2010 ◽  
Vol 39 (7) ◽  
pp. 953-969 ◽  
Author(s):  
Tina Iachini ◽  
Gennaro Ruggiero
Keyword(s):  
Visual Experience

scholarly journals Collicular Vision Guides Nonconscious Behavior

2010 ◽  
Vol 22 (5) ◽  
pp. 888-902 ◽  
Author(s):  
Marco Tamietto ◽  
Franco Cauda ◽  
Luca Latini Corazzini ◽  
Silvia Savazzi ◽  
Carlo A. Marzi ◽  
...  
Keyword(s):  
Visual Experience ◽  
Striate Cortex ◽  
Visual Signals ◽  
Visually Guided ◽  
Visuomotor Integration ◽  
Motor Processing ◽  
Pupillary Responses ◽  
Cortex Area ◽  
Extrastriate Areas

Following destruction or deafferentation of primary visual cortex (area V1, striate cortex), clinical blindness ensues, but residual visual functions may, nevertheless, persist without perceptual consciousness (a condition termed blindsight). The study of patients with such lesions thus offers a unique opportunity to investigate what visual capacities are mediated by the extrastriate pathways that bypass V1. Here we provide evidence for a crucial role of the collicular–extrastriate pathway in nonconscious visuomotor integration by showing that, in the absence of V1, the superior colliculus (SC) is essential to translate visual signals that cannot be consciously perceived into motor outputs. We found that a gray stimulus presented in the blind field of a patient with unilateral V1 loss, although not consciously seen, can influence his behavioral and pupillary responses to consciously perceived stimuli in the intact field (implicit bilateral summation). Notably, this effect was accompanied by selective activations in the SC and in occipito-temporal extrastriate areas. However, when instead of gray stimuli we presented purple stimuli, which predominantly draw on S-cones and are thus invisible to the SC, any evidence of implicit visuomotor integration disappeared and activations in the SC dropped significantly. The present findings show that the SC acts as an interface between sensory and motor processing in the human brain, thereby providing a contribution to visually guided behavior that may remain functionally and anatomically segregated from the geniculo-striate pathway and entirely outside conscious visual experience.

The role of visual experience for spatial numerical associations

2012 ◽  
Vol 25 (0) ◽  
pp. 222 ◽  
Author(s):  
Michael J. Proulx ◽  
Achille Pasqualotto ◽  
Shuichiro Taya
Keyword(s):  
Visual Experience ◽  
Opposite Effect ◽  
Random Number Generation ◽  
Number Line ◽  
Mental Number Line ◽  
Generation Task ◽  
Congenitally Blind ◽  
Left And Right ◽  
The Right

The topographic representation of space interacts with the mental representation of number. Evidence for such number–space relations have been reported in both synaesthetic and non-synaesthetic participants. Thus far most studies have only examined related effects in sighted participants. For example, the mental number line increases in magnitude from left to right in sighted individuals (Loetscher et al., 2008, Curr. Biol.). What is unclear is whether this association arises from innate mechanisms or requires visual experience early in life to develop in this way. Here we investigated the role of visual experience for the left to right spatial numerical association using a random number generation task in congenitally blind, late blind, and blindfolded sighted participants. Participants orally generated numbers randomly whilst turning their head to the left and right. Sighted participants generated smaller numbers when they turned their head to the left than to the right, consistent with past results. In contrast, congenitally blind participants generated smaller numbers when they turned their head to the right than to the left, exhibiting the opposite effect. The results of the late blind participants showed an intermediate profile between that of the sighted and congenitally blind participants. Visual experience early in life is therefore necessary for the development of the spatial numerical association of the mental number line.

Blindsight and the Role of the Phenomenal Qualities of Visual Perceptions

1998 ◽  
pp. 205-209
Author(s):  
Ralph Schumacher
Keyword(s):  
Visual Perception ◽  
Visual Information ◽  
Visual Experience ◽  
Sufficient Condition ◽  
Broad Concept ◽  
Essential Properties

The aim of this paper is to defend a broad concept of visual perception, according to which it is a sufficient condition for visual perception that subjects receive visual information in a way which enables them to give reliably correct answers about the objects presented to them. According to this view, blindsight, non-epistemic seeing, and conscious visual experience count as proper types of visual perception. This leads to two consequences concerning the role of the phenomenal qualities of visual experiences. First, phenomenal qualities are not necessary in order to see something, because in the case of blindsight, subjects can see objects without experiences phenomenal qualities. Second, they cannot be intentional properties, since they are not essential properties of visual experiences, and because the content of visual experiences cannot be constituted by contingent properties.

scholarly journals The Role of Visual Experience in Auditory Space Perception around the Legs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elena Aggius-Vella ◽  
Claudio Campus ◽  
Andrew Joseph Kolarik ◽  
Monica Gori
Keyword(s):  
Visual Experience ◽  
Space Perception ◽  
Auditory Space

scholarly journals A Protracted Sensitive Period Regulates the Development of Cross-Modal Sound–Shape Associations in Humans

2019 ◽  
Vol 30 (10) ◽  
pp. 1473-1482 ◽  
Author(s):  
Suddha Sourav ◽  
Ramesh Kekunnaya ◽  
Idris Shareef ◽  
Seema Banerjee ◽  
Davide Bottari ◽  
...  
Keyword(s):  
Visual Experience ◽  
Sensitive Period ◽  
Congenital Blindness ◽  
Transient Period ◽  
History Of ◽  
Modality Combinations

Humans preferentially match arbitrary words containing higher- and lower-frequency phonemes to angular and smooth shapes, respectively. Here, we investigated the role of visual experience in the development of audiovisual and audiohaptic sound–shape associations (SSAs) using a unique set of five groups: individuals who had suffered a transient period of congenital blindness through congenital bilateral dense cataracts before undergoing cataract-reversal surgeries (CC group), individuals with a history of developmental cataracts (DC group), individuals with congenital permanent blindness (CB group), individuals with late permanent blindness (LB group), and controls with typical sight (TS group). Whereas the TS and LB groups showed highly robust SSAs, the CB, CC, and DC groups did not—in any of the modality combinations tested. These results provide evidence for a protracted sensitive period during which aberrant vision prevents SSA acquisition. Moreover, the finding of a systematic SSA in the LB group demonstrates that representations acquired during the sensitive period are resilient to loss despite dramatically changed experience.

The Mental Maps of the Blind: The Role of Previous Visual Experience

1982 ◽  
Vol 76 (1) ◽  
pp. 5-12 ◽  
Author(s):  
A. G. Dodds ◽  
C. I. Howarth ◽  
D. C. Carter
Keyword(s):  
Visual Experience ◽  
Spatial Reasoning ◽  
Mental Maps ◽  
Spatial Coding ◽  
Spatial Understanding ◽  
Spatial Strategies ◽  
Blind Children ◽  
Coding Strategies ◽  
Congenitally Blind

The structure of spatial representation in congenitally and adventitiously blind 11-year-old children was examined by means of pointing, map-drawing, and spatial reasoning on two simple routes over repeated trials. Although all the children learned how to travel each route successfully after only one trial, three out of four of the congenitally blind children showed a complete lack of spatial understanding, as evinced by “egocentric” or “self-referent” spatial coding strategies, whereas all the adventitiously blind subjects exhibited appropriate externally referent spatial strategies compatible with convential two-dimensional maps. The role of previous visual experience in the encoding and decoding of spatial material in memory is discussed.

Sign language poetry and Deaf identity

2005 ◽  
Vol 8 (1-2) ◽  
pp. 177-212
Author(s):  
Rachel Sutton-Spence ◽  
Ronice Müller de Quadros
Keyword(s):  
Sign Language ◽  
Visual Experience ◽  
Deaf People ◽  
Poetic Language ◽  
Language Poetry ◽  
Cultural Backgrounds ◽  
National Community ◽  
Deaf Identity ◽  
The World

In this paper, we consider the role of sign language poetry in creating and expressing the Deaf poet’s identity as a “visual person” in a community living within a wider national community. We show how two Deaf poets from different linguistic, national and cultural backgrounds nevertheless have both created similar effects through their sign language poems, drawing on the folkloric knowledge of their Deaf communities and wider national folklore. Analysis of the language and themes in the poems reveals that sign language components including neologism and use of symmetry can be manipulated directly to celebrate the visual experience of Deaf people. The poetic language can be seen as a way to empower poets and their audiences to understand their place better within the world Deaf community and their own national communities.

Functional postnatal development of the rat primary visual cortex and the role of visual experience: Dark rearing and monocular deprivation

1994 ◽  
Vol 34 (6) ◽  
pp. 709-720 ◽  
Author(s):  
Michela Fagiolini ◽  
Tommaso Pizzorusso ◽  
Nicoletta Berardi ◽  
Luciano Domenici ◽  
Lamberto Maffei
Keyword(s):  
Visual Cortex ◽  
Postnatal Development ◽  
Primary Visual Cortex ◽  
Visual Experience ◽  
Monocular Deprivation ◽  
Dark Rearing
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