Neural sources of letter and Vernier acuity.
Neural sources of letter and Vernier acuity.
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DOI：
10.1038/s41598-020-72370-3
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发表时间：
2020-09-22
影响因子：
4.6
通讯作者：
Norcia AM
中科院分区：
文献类型：
--
作者：
Barzegaran E;Norcia AM
视力可以用许多不同的方式测量，包括字母和游标偏移。先前的心理物理学研究表明，这两种视力密切相关，因为它们都强烈依赖于视网膜偏心率，并且在弱视中受到类似的影响。在这里，我们使用高密度EEG记录来询问潜在的神经源是否如心理物理学所建议的那样是共同的或不同的。为了测量字母的视敏度，我们记录了由不同大小的字母组成的完整和杂乱文本之间的3 Hz交替的诱发电位。为了测量游标偏移的视敏度，我们在有和没有一组游标偏移的条形光栅之间记录了3 Hz交替的诱发电位。这两种交替类型在3 Hz刺激频率下引起了强烈的活动，其幅度随字母和偏移量大小而缩放，从阈值附近开始。字母和游标偏移响应不同，在他们的头皮地形和时间动态。最早的诱发反应的字母发生在外侧枕叶视觉区，主要是在左半球。后来的反应是在早期视觉皮层的电极上测量的，这表明字母结构首先是在第二层外纹区提取的，而早期视觉区的反应是由于反馈。游标偏移的反应，相比之下，首先发生在内侧枕叶电极，在稍后的时间点的反应更广泛地分布与前馈通路调解一致。之前观察到的字母和游标敏锐度之间的共性可能是由于早期视觉皮层的共同瓶颈，但不是因为这两个任务是由共同的视觉区域网络subserved。
Visual acuity can be measured in many different ways, including with letters and Vernier offsets. Prior psychophysical work has suggested that the two acuities are strongly linked given that they both depend strongly on retinal eccentricity and both are similarly affected in amblyopia. Here we used high-density EEG recordings to ask whether the underlying neural sources are common as suggested by the psychophysics or distinct. To measure visual acuity for letters, we recorded evoked potentials to 3 Hz alternations between intact and scrambled text comprised of letters of varying size. To measure visual acuity for Vernier offsets, we recorded evoked potentials to 3 Hz alternations between bar gratings with and without a set of Vernier offsets. Both alternation types elicited robust activity at the 3 Hz stimulus frequency that scaled in amplitude with both letter and offset size, starting near threshold. Letter and Vernier offset responses differed in both their scalp topography and temporal dynamics. The earliest evoked responses to letters occurred on lateral occipital visual areas, predominantly over the left hemisphere. Later responses were measured at electrodes over early visual cortex, suggesting that letter structure is first extracted in second-tier extra-striate areas and that responses over early visual areas are due to feedback. Responses to Vernier offsets, by contrast, occurred first at medial occipital electrodes, with responses at later time-points being more broadly distributed—consistent with feedforward pathway mediation. The previously observed commonalities between letter and Vernier acuity may be due to common bottlenecks in early visual cortex but not because the two tasks are subserved by a common network of visual areas.
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DOI：
10.1097/opx.0b013e31829908a4
发表时间：
2013-07
期刊：
Optometry and vision science : official publication of the American Academy of Optometry
影响因子：
--
作者：
Coates DR;Chin JM;Chung ST
通讯作者：
Chung ST
影响因子：
2.5
作者：
FREEMAN, RD;BRADLEY, A
通讯作者：
BRADLEY, A
影响因子：
1.8
作者：
Hou, Chuan;Kim, Yee-Joon;Verghese, Preeti
通讯作者：
Verghese, Preeti
影响因子：
1.7
作者：
Everett, J;Bradshaw, MF;Hibbard, PB
通讯作者：
Hibbard, PB
影响因子：
3.7
作者：
Cant, Jonathan S.;Goodale, Melvyn A.
通讯作者：
Goodale, Melvyn A.