scholarly journals Does Congenital Deafness Affect the Structural and Functional Architecture of Primary Visual Cortex?

2016 ◽  
Vol 10 (1) ◽  
pp. 1-19 ◽  
Author(s):  
C.R. Smittenaar ◽  
M. MacSweeney ◽  
M.I. Sereno ◽  
D.S. Schwarzkopf
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Deaf People ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Functional Plasticity ◽  
Visual Skills ◽  
Coding Strategy ◽  
Coarse Coding ◽  
Cortical Architecture

Deafness results in greater reliance on the remaining senses. It is unknown whether the cortical architecture of the intact senses is optimized to compensate for lost input. Here we performed widefield population receptive field (pRF) mapping of primary visual cortex (V1) with functional magnetic resonance imaging (fMRI) in hearing and congenitally deaf participants, all of whom had learnt sign language after the age of 10 years. We found larger pRFs encoding the peripheral visual field of deaf compared to hearing participants. This was likely driven by larger facilitatory center zones of the pRF profile concentrated in the near and far periphery in the deaf group. pRF density was comparable between groups, indicating pRFs overlapped more in the deaf group. This could suggest that a coarse coding strategy underlies enhanced peripheral visual skills in deaf people. Cortical thickness was also decreased in V1 in the deaf group. These findings suggest deafness causes structural and functional plasticity at the earliest stages of visual cortex.

The basis of orientation decoding in human primary visual cortex: fine- or coarse-scale biases?

2015 ◽  
Vol 113 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Ryan T. Maloney
Keyword(s):  
Magnetic Resonance Imaging ◽  
Visual Cortex ◽  
Magnetic Resonance ◽  
Receptive Field ◽  
Primary Visual Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Coarse Scale ◽  
Multivariate Pattern ◽  
Open Question

Orientation signals in human primary visual cortex (V1) can be reliably decoded from the multivariate pattern of activity as measured with functional magnetic resonance imaging (fMRI). The precise underlying source of these decoded signals (whether by orientation biases at a fine or coarse scale in cortex) remains a matter of some controversy, however. Freeman and colleagues ( J Neurosci 33: 19695–19703, 2013) recently showed that the accuracy of decoding of spiral patterns in V1 can be predicted by a voxel's preferred spatial position (the population receptive field) and its coarse orientation preference, suggesting that coarse-scale biases are sufficient for orientation decoding. Whether they are also necessary for decoding remains an open question, and one with implications for the broader interpretation of multivariate decoding results in fMRI studies.

Acupuncture Stimulation of the Vision-Related Acupoint (Bl-67) Increases c-Fos Expression in the Visual Cortex of Binocularly Deprived Rat Pups

2002 ◽  
Vol 30 (02n03) ◽  
pp. 379-385 ◽  
Author(s):  
Hyangsook Lee ◽  
Hi-Joon Park ◽  
Soon Ae Kim ◽  
Hee Jae Lee ◽  
Mi Ja Kim ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Acupuncture Stimulation ◽  
Rat Pups ◽  
Fos Expression ◽  
Magnetic Resonance Imaging Mri ◽  
Binocular Deprivation ◽  
Stimulation Of

Our previous study with functional magnetic resonance imaging (MRI) demonstrated that acupuncture stimulation of the vision-related acupoint, Bl-67, activates the visual cortex of the human brain. As a further study on the effect of Bl-67 acupuncture stimulation on the visual cortex, we examined c-Fos expression in binocularly deprived rat pups. Binocular deprivation significantly reduced the number of c-Fos-positive cells in the primary visual cortex, compared with that of normal control rat pups. Interestingly, acupuncture stimulation of Bl-67 resulted in a significant increase in the number of c-Fos-positive cells in the primary visual cortex, while acupuncture stimulation of other acupoints less important for visual function had no significant effect on c-Fos expression in the primary visual cortex. The results suggest the possibility of vision-related acupoint (Bl-67) having an influence over the activity of the primary visual cortex.

Attention-Regulated Activity in Human Primary Visual Cortex

1998 ◽  
Vol 79 (4) ◽  
pp. 2218-2221 ◽  
Author(s):  
Takeo Watanabe ◽  
Yuka Sasaki ◽  
Satoru Miyauchi ◽  
Benno Putz ◽  
Norio Fujimaki ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Cerebral Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Attention Condition ◽  
Passive Condition ◽  
First Finding ◽  
Cortex Area ◽  
Moving Wedge

Watanabe, Takeo, Yuka Sasaki, Satoru Miyauchi, Benno Putz, Norio Fujimaki, Matthew Nielsen, Ryosuke Takino, and Satoshi Miyakawa. Attention-regulated activity in human primary visual cortex. J. Neurophysiol. 79: 2218–2221, 1998. Effects of attention to a local contour of a moving object on the activation of human primary visual cortex (area V1) were examined. Local cerebral oxygenation changes (an index of neuronal activity) in human area V1 were measured with functional magnetic resonance imaging (fMRI) in conditions including the following two: 1) when attention was selectively directed toward one side of a moving wedge (the attention condition) and 2) when the wedges were viewed passively (the passive condition). Activation in area V1 was found to be higher in the attention condition than in the passive condition. To our knowledge, this is the first finding that attention to motion activates as early as area V1. We suggest that attentional activation of area V1 is task dependent.

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