Opposite Dependencies on Visual Motion Coherence in Human Area MT+ and Early Visual Cortex

The objectives of this study were 1) to probe the effects of visual motion adaptation on early visual and V5/MT cortical excitability and 2) to investigate whether changes in cortical excitability following visual motion adaptation are related to the degree of visual dependency, i.e., an overreliance on visual cues compared with vestibular or proprioceptive cues. Participants were exposed to a roll motion visual stimulus before, during, and after visual motion adaptation. At these stages, 20 transcranial magnetic stimulation (TMS) pulses at phosphene threshold values were applied over early visual and V5/MT cortical areas from which the probability of eliciting a phosphene was calculated. Before and after adaptation, participants aligned the subjective visual vertical in front of the roll motion stimulus as a marker of visual dependency. During adaptation, early visual cortex excitability decreased whereas V5/MT excitability increased. After adaptation, both early visual and V5/MT excitability were increased. The roll motion-induced tilt of the subjective visual vertical (visual dependence) was not influenced by visual motion adaptation and did not correlate with phosphene threshold or visual cortex excitability. We conclude that early visual and V5/MT cortical excitability is differentially affected by visual motion adaptation. Furthermore, excitability in the early or late visual cortex is not associated with an increase in visual reliance during spatial orientation. Our findings complement earlier studies that have probed visual cortical excitability following motion adaptation and highlight the differential role of the early visual cortex and V5/MT in visual motion processing. NEW & NOTEWORTHY We examined the influence of visual motion adaptation on visual cortex excitability and found a differential effect in V1/V2 compared with V5/MT. Changes in visual excitability following motion adaptation were not related to the degree of an individual's visual dependency.

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Downregulation of early visual cortex excitability mediates oscillopsia suppression

Neurology ◽

10.1212/wnl.0000000000004360 ◽

2017 ◽

Vol 89 (11) ◽

pp. 1179-1185 ◽

Cited By ~ 9

Author(s):

Hena Ahmad ◽

R. Edward Roberts ◽

Mitesh Patel ◽

Rhannon Lobo ◽

Barry Seemungal ◽

...

Keyword(s):

Visual Cortex ◽

Visual Motion ◽

Cortical Excitability ◽

Critical Role ◽

Adaptive Mechanism ◽

Motion Adaptation ◽

Adaptive Mechanisms ◽

Symptom Load ◽

Early Visual Cortex ◽

Adaptation Condition

Objective:To identify in an observational study the neurophysiologic mechanisms that mediate adaptation to oscillopsia in patients with bilateral vestibular failure (BVF).Methods:We directly probe the hypothesis that adaptive changes that mediate oscillopsia suppression implicate the early visual-cortex (V1/V2). Accordingly, we investigated V1/V2 excitability using transcranial magnetic stimulation (TMS) in 12 avestibular patients and 12 healthy controls. Specifically, we assessed TMS-induced phosphene thresholds at baseline and cortical excitability changes while performing a visual motion adaptation paradigm during the following conditions: baseline measures (i.e., static), during visual motion (i.e., motion before adaptation), and during visual motion after 5 minutes of unidirectional visual motion adaptation (i.e., motion adapted).Results:Patients had significantly higher baseline phosphene thresholds, reflecting an underlying adaptive mechanism. Individual thresholds were correlated with oscillopsia symptom load. During the visual motion adaptation condition, no differences in excitability at baseline were observed, but during both the motion before adaptation and motion adapted conditions, we observed significantly attenuated cortical excitability in patients. Again, this attenuation in excitability was stronger in less symptomatic patients.Conclusions:Our findings provide neurophysiologic evidence that cortically mediated adaptive mechanisms in V1/V2 play a critical role in suppressing oscillopsia in patients with BVF.

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Faculty Opinions recommendation of Neural activity in early visual cortex reflects behavioral experience and higher-order perceptual saliency.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1007232.90607 ◽

2002 ◽

Author(s):

Shimon Ullman

Keyword(s):

Visual Cortex ◽

Neural Activity ◽

Higher Order ◽

Early Visual Cortex

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Faculty Opinions recommendation of Neuronal synchrony does not correlate with motion coherence in cortical area MT.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1013768.191900 ◽

2003 ◽

Author(s):

Dora Angelaki

Keyword(s):

Cortical Area ◽

Area Mt ◽

Neuronal Synchrony ◽

Motion Coherence

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Faculty Opinions recommendation of Bottom-up dependent gating of frontal signals in early visual cortex.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1161778.623380 ◽

2009 ◽

Author(s):

Jitendra Sharma ◽

Hiroki Sugihara

Keyword(s):

Visual Cortex ◽

Bottom Up ◽

Early Visual Cortex

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Faculty Opinions recommendation of Confuse your illusion: feedback to early visual cortex contributes to perceptual completion.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717976773.793470558 ◽

2013 ◽

Author(s):

Chris Baker

Keyword(s):

Visual Cortex ◽

Perceptual Completion ◽

Early Visual Cortex

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Decoding the future from past experience: learning shapes predictions in early visual cortex

Journal of Neurophysiology ◽

10.1152/jn.00753.2014 ◽

2015 ◽

Vol 113 (9) ◽

pp. 3159-3171 ◽

Cited By ~ 7

Author(s):

Caroline D. B. Luft ◽

Alan Meeson ◽

Andrew E. Welchman ◽

Zoe Kourtzi

Keyword(s):

Visual Cortex ◽

Large Scale ◽

Sequence Structure ◽

Neural Populations ◽

Early Visual Cortex ◽

Temporal Structures ◽

Future Events ◽

Sensory Predictions ◽

Actual Stimulus ◽

The Brain

Learning the structure of the environment is critical for interpreting the current scene and predicting upcoming events. However, the brain mechanisms that support our ability to translate knowledge about scene statistics to sensory predictions remain largely unknown. Here we provide evidence that learning of temporal regularities shapes representations in early visual cortex that relate to our ability to predict sensory events. We tested the participants' ability to predict the orientation of a test stimulus after exposure to sequences of leftward- or rightward-oriented gratings. Using fMRI decoding, we identified brain patterns related to the observers' visual predictions rather than stimulus-driven activity. Decoding of predicted orientations following structured sequences was enhanced after training, while decoding of cued orientations following exposure to random sequences did not change. These predictive representations appear to be driven by the same large-scale neural populations that encode actual stimulus orientation and to be specific to the learned sequence structure. Thus our findings provide evidence that learning temporal structures supports our ability to predict future events by reactivating selective sensory representations as early as in primary visual cortex.

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