scholarly journals Author response: Attentional amplification of neural codes for number independent of other quantities along the dorsal visual stream

2019 ◽  
Author(s):  
Elisa Castaldi ◽  
Manuela Piazza ◽  
Stanislas Dehaene ◽  
Alexandre Vignaud ◽  
Evelyn Eger
Keyword(s):  
Author Response ◽  
Neural Codes ◽  
Visual Stream ◽  
Dorsal Visual Stream

scholarly journals Visuopathy of prematurity: is retinopathy just the tip of the iceberg?

2021 ◽  
Author(s):  
Sigrid Hegna Ingvaldsen ◽  
Tora Sund Morken ◽  
Dordi Austeng ◽  
Olaf Dammann
Keyword(s):  
Visual Processing ◽  
Structural Changes ◽  
Developmental Trajectories ◽  
Visual Pathway ◽  
Visual Stream ◽  
Visual Deficits ◽  
Cortical Areas ◽  
Cellular Architecture ◽  
Increased Risk ◽  
Dorsal Visual Stream

AbstractResearch on retinopathy of prematurity (ROP) focuses mainly on the abnormal vascularization patterns that are directly visible for ophthalmologists. However, recent findings indicate that children born prematurely also exhibit changes in the retinal cellular architecture and along the dorsal visual stream, such as structural changes between and within cortical areas. Moreover, perinatal sustained systemic inflammation (SSI) is associated with an increased risk for ROP and the visual deficits that follow. In this paper, we propose that ROP might just be the tip of an iceberg we call visuopathy of prematurity (VOP). The VOP paradigm comprises abnormal vascularization of the retina, alterations in retinal cellular architecture, choroidal degeneration, and abnormalities in the visual pathway, including cortical areas. Furthermore, VOP itself might influence the developmental trajectories of cerebral structures and functions deemed responsible for visual processing, thereby explaining visual deficits among children born preterm.

scholarly journals fMRI reveals a lower visual field preference in dorsal visual stream regions during hand actions

2011 ◽  
Vol 11 (11) ◽  
pp. 952-952 ◽  
Author(s):  
S. Rossit ◽  
T. McAdam ◽  
A. Mclean ◽  
M. Goodale ◽  
J. Culham
Keyword(s):  
Visual Field ◽  
Lower Visual Field ◽  
Visual Stream ◽  
Dorsal Visual Stream

scholarly journals Conscious awareness of visual space: A tripartite encoding model.

2020 ◽  
Author(s):  
Dhanraj Vishwanath
Keyword(s):  
Visual Space ◽  
Spatial Separation ◽  
Ideal Observer ◽  
Conscious Awareness ◽  
Relative Depth ◽  
Visual Stream ◽  
3D Vision ◽  
Fine Grained ◽  
Near Space ◽  
Dorsal Visual Stream

The prevailing model of 3D vision proposes that the visual system recovers a single objective and internally consistent representation of physical 3D space based on a process of ideal-observer probabilistic inference. A significant challenge for this model has been in explaining the contents of our subjective awareness of visual space. Here I argue that integrating phenomenological observations, empirical data, evolutionary logic and neurophysiological evidence leads to the conjecture that the human conscious awareness of visual space is underwritten by multiple, sometimes mutually inconsistent, spatial encodings. By assessing four primary competencies in the conscious awareness of space, three major types of spatial encodings are conjectured. Among the most primitive of these is proposed to support the competency of the conscious awareness of distance at an ambulatory scale (operationally defined as egocentric distance) and is hypothesised to involve temporal archicortex regions. The second is proposed to support the competency of awareness of object layout and 3D shape without scale (operationally, relative depth), likely instantiated in the ventral visual stream of the neocortex. This encoding is hypothesised to have evolved from more primitive encodings that provide a depth-ordered segmentation of the visual field. The third encoding is proposed to support the competency of fine-grained awareness of intra- and inter-object spatial separation in near space (operationally, scaled or absolute depth) and instantiated in the dorsal visual stream. This encoding is conjectured to underlie the phenomenology of object solidity, spatial separation, tangibility and object realness that is often referred to as stereopsis. The combined effect of the first and third competencies (ambulatory distance and near-space scaled spatial separation) is conjectured to contribute to the feeling of spatial immersion and presence.

Age-Related Changes in the Allocation of Vertical Attention

2018 ◽  
Vol 24 (10) ◽  
pp. 1121-1124 ◽  
Author(s):  
Aleksandra Mańkowska ◽  
Kenneth M. Heilman ◽  
John B. Williamson ◽  
Michał Harciarek
Keyword(s):  
Spatial Attention ◽  
Right Hemisphere ◽  
Ventral Stream ◽  
Midsagittal Plane ◽  
Visual Stream ◽  
Leftward Bias ◽  
Healthy Elderly ◽  
Age Related ◽  
The Right ◽  
Dorsal Visual Stream

AbstractObjectives: Healthy individuals often have a leftward and upward attentional spatial bias; however, there is a reduction of this leftward bias with aging. The right hemisphere mediates leftward spatial attention and age-related reduction of right hemispheric activity may account for this reduced leftward bias. The right hemisphere also appears to be responsible for upward bias, and this upward bias might reduce with aging. Alternatively, whereas the dorsal visual stream allocates attention downward, the ventral stream allocates attention upward. Since with aging there is a greater atrophy of the dorsal than ventral stream, older participants may reveal a greater upward bias. The main purpose of this study was to learn if aging influences the vertical allocation of spatial attention. Methods: Twenty-six young (17 males; mean age 44.62±2.57 years) and 25 healthy elderly (13 males; mean age 72.04±.98 years), right-handed adults performed line bisections using 24 vertical lines (24 cm long and 2 mm thick) aligned with their midsagittal plane. Results: Older adults had a significantly greater upward bias than did younger adults. Conclusions: Normal upward attentional bias increases with aging, possibly due to an age-related reduction of the dorsal attentional stream that is responsible for the allocation of downward attention. (JINS, 2018, 24, 1121–1124)

Dorsal visual stream is preferentially engaged during externally guided action selection in Parkinson Disease

2021 ◽  
Author(s):  
Hiro Sparks ◽  
Katy A. Cross ◽  
Jeong Woo Choi ◽  
Hristos Courellis ◽  
Jasmine Thum ◽  
...  
Keyword(s):  
Parkinson Disease ◽  
Action Selection ◽  
Visual Stream ◽  
Dorsal Visual Stream

Exploratory study of dorsal visual stream dysfunction in autism; A case series

2020 ◽  
Vol 69 ◽  
pp. 101456
Author(s):  
I Hay ◽  
G N Dutton ◽  
S Biggar ◽  
H Ibrahim ◽  
D Assheton
Keyword(s):  
Exploratory Study ◽  
Case Series ◽  
Visual Stream ◽  
Dorsal Visual Stream

scholarly journals Neural Modulation by Binocular Disparity Greatest in Human Dorsal Visual Stream

2010 ◽  
Vol 104 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Loredana Minini ◽  
Andrew J. Parker ◽  
Holly Bridge
Keyword(s):  
Binocular Disparity ◽  
Large Range ◽  
Dorsal Stream ◽  
Cortical Activation ◽  
Bold Signal ◽  
Visual Stream ◽  
Neural Modulation ◽  
Visual Areas ◽  
Parietal Cortices ◽  
Dorsal Visual Stream

Although cortical activation to binocular disparity can be demonstrated throughout occipital and parietal cortices, the relative contributions to depth perception made by different human cortical areas have not been established. To investigate whether different regions are optimized for specific disparity ranges, we have measured the responses of occipital and parietal areas to different magnitudes of binocular disparity. Using stimuli consisting of sinusoidal depth modulations, we measured cortical activation when the stimuli were located at pedestal disparities of 0, 0.1, 0.35, and 0.7° from fixation. Across all areas, occipital and parietal, there was an increase in BOLD signal with increasing pedestal disparity, compared with a plane at zero disparity. However, the greatest modulation of response by the different pedestals was found in the dorsal visual areas and the parietal areas. These differences contrast with the response to the zero disparity plane, compared with fixation, which is greatest in the early visual areas, smaller in the ventral and dorsal visual areas, and absent in parietal areas. Using the simultaneously acquired psychophysical data we also measured a greater response to correct than to incorrect trials, an effect that increased with rising pedestal disparity and was greatest in dorsal visual and parietal areas. These results illustrate that the dorsal stream, along both its occipital and parietal branches, can reliably discriminate a large range of disparities.

Sign in / Sign up

Export Citation Format

Share Document