AUTHOR=Hu Xia , Qin Yi , Ying Xiaoxiao , Yuan Junli , Cui Rong , Ruan Xiaowei , He Xianghang , Lu Zhong-Lin , Lu Fan , Hou Fang 

TITLE=Temporal Characteristics of Visual Processing in Amblyopia

JOURNAL=Frontiers in Neuroscience

VOLUME=15

YEAR=2021

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2021.673491

DOI=10.3389/fnins.2021.673491

ISSN=1662-453X

ABSTRACT=<sec><title>Purpose</title><p>Amblyopia affects not only spatial vision but also temporal vision. In this study, we aim to investigate temporal processing deficits in amblyopia.</p></sec><sec><title>Methods</title><p>Twenty amblyopic patients (age: 27.0 ± 5.53 years, 15 males), and 25 normal observers (age: 25.6 ± 4.03 years, 15 males) were recruited in this study. Contrast thresholds in an orientation discrimination task in five target-mask stimulus onset asynchronies (SOA) conditions (16.7 ms, 33.4 ms, 50.0 ms, 83.4 ms, and ∞/no noise) were measured. An elaborated perceptual template model (ePTM) was fit to the behavioral data to derive the temporal profile of visual processing for each participant.</p></sec><sec><title>Results</title><p>There were significant threshold differences between the amblyopic and normal eyes [<italic>F</italic>(1,43) = 10.6, <italic>p</italic> = 0.002] and a significant group × SOA interaction [<italic>F</italic>(2.75,118) = 4.98, <italic>p</italic> = 0.004], suggesting different temporal processing between the two groups. The ePTM fitted the data well (<italic>χ</italic><sup>2</sup> test, all <italic>p</italic>s &gt; 0.50). Compared to the normal eye, the amblyopic eye had a lower template gain (<italic>p</italic> = 0.046), and a temporal window with lower peak and broader width (all <italic>p</italic>s &lt; 0.05). No significant correlation was found between the observed temporal deficits and visual acuity in amblyopia (<italic>p</italic>s &gt; 0.50). Similar results were found in the anisometropic amblyopia subgroup. No significant difference was found between the fellow eyes of the monocular amblyopia and the normal eyes.</p></sec><sec><title>Conclusion</title><p>Amblyopia is less efficient in processing dynamic visual stimuli. The temporal deficits in amblyopia, represented by a flattened temporal window, are likely independent of spatial vision deficits.</p></sec>