Details

Autor(en) / Beteiligte

• Yu, Alexander
• Zhang, Ruizhe
• Silva, Andrew E.
• Xing, Yang
• Thompson, Benjamin
• Liu, Zili

Titel

Motion opponency at the middle temporal cortex: Preserved motion information and the effect of perceptual learning

Ist Teil von

• The European journal of neuroscience, 2022-12, Vol.56 (12), p.6215-6226

Ort / Verlag

France: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Motion opponency, first observed within the primate middle temporal cortex (MT), refers to the suppressing effect of opposite motion directions on neuronal activity. Namely, when opposing motion directional signals stimulate an MT neuron's receptive field, this neuron's response is comparable with that induced by flicker noise. Under such suppression, it is unknown whether any directional information is still represented at MT. In this study, we applied support vector machine (SVM) learning to human functional magnetic resonance imaging data to investigate if any motion defined orientation information was still available from suppressed MT. We found that, at least at the level of ±45° discrimination, such orientation information was still available. Interestingly, after behavioural perceptual learning that improved human discrimination of fine orientation discrimination (e.g. 42° vs. 48°) using the MT‐suppressive motion stimuli, the SVM discrimination of ±45° worsened when functional magnetic resonance imaging (fMRI) signals at post‐learning MT were used. This result is consistent with findings in Thompson et al. (2013) that, post‐perceptual learning, MT suppression was not released, suggesting that motion opponency was perhaps functionally too important for perceptual learning to overcome. The middle temporal cortex (MT) of the brain is suppressed when stimulated by opposing motion signals. We analysed functional magnetic resonance imaging (fMRI) signals from suppressed MT using a support vector machine (SVM). We found that 45° or −45° orientations defined by the opposing motion directions could still be reliably identified within the fMRI signals. Interestingly, after perceptual learning requiring the discrimination of fine orientations (e.g. 42° vs. 48°) defined by opposing motions, SVM discrimination between ±45° worsened, suggesting that MT suppression was not released post‐perceptual learning.