Motion Streak Neurons in the Mouse Visual Cortex
Authors: Seiji Tanabe
Jianhua Cang
Manavu Tohmi
Journal: Cell Reports (2021)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: direction selectivity; higher visual areas; motion perception; mouse visual cortex; moving dots
Affiliations: Department of Biology, University of Virginia, Charlottesville, VA 22904, USA. Electronic address: ., Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA., Department of Biology, University of Virginia, Charlottesville, VA 22904, USA; Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA.

Abstract:  Motion streaks are smeared representation of fast-moving objects due to temporal integration. Here, we test for motion streak signals in mice with two-photon calcium imaging. For small dots moving at low speeds, neurons in primary visual cortex (V1) encode the component motion, with preferred direction along the axis perpendicular to their preferred orientation. At high speeds, V1 neurons prefer the direction along the axis parallel to their preferred orientation, as expected for encoding motion streaks. Whereas some V1 neurons (∼20%) display a switch of preferred motion axis with increasing speed, others (&gt;40%) respond specifically to high speeds at the parallel axis. Motion streak neurons are also seen in higher visual lateromedial (LM), anterolateral (AL), and rostrolateral (RL) areas, but with higher transition speeds, and many still prefer the perpendicular axis even with fast motion. Our results thus indicate that diverse motion encoding exists in mouse visual cortex, with intriguing differences among visual areas. 

Retracted: No

PubPeer comments:
  However, RFs are spatially localized, thus creating the so-called u201caperture problem,u201d in which the direction-selective signals of V1 neurons are ambiguous as to what the true object motion is (Adelson and Movshon, 1982... Adelson Movshon (1982) did not involve neurons, V1 or otherwise. In fact, I don t see them referring to V1 neurons at all. u201cMotion streaks are smeared representation of fast-moving objects due to temporal integration.u201d This is not an empirical claim, but rather a popular common-sense assumption. Empirical evidence and theoretical consideration render it worthy of a high degree of skepticism. Empirical evidence shows that both the perception of object motion and motion streaks are a high level, global phenomenon that can t be reduced to the summation of local phenomena. The phenomenon of stroboscopic motion (the basis of movies) makes this abundantly clear; a pair of flashed dots, lines or other units may be made to appear to move from point  a to point  b by appropriately adjusting the timing and location of the appearances of each item (similar to the apparent movement effect we may create with flashing bulbs in a cinema marquee). When timing distance are adjusted properly, observers also get the experience of u201cmotion streaks ([Dimmack, 1920 The American Journal of Psychology] ):u201d u201cA black line appeared in the upper part of the field. Below and detached from it by a *bright streak* was a rather indefinite grey, which fused into a black line lower in the field. u201cFirst came a line in the upper part, then a grey, and another line below. The grey joined the lower line but was separated from the upper by a *bright streak.*u201d Dimmick refers to  The grey flash which we have found to be the psychological correlate of the perception of movement... There is no way the streaks observed above may be attributed to u201ctemporal integrationu201d of local events even by the most casual of theoreticians. Do we want to attribute radically different mechanisms to perceptually similar phenomena? The form of experiments such as Tohmi et al is not such as to allow the u201ctemporal integrationu201d formulation to be falsified even if it is false; data u2013 recorded activities of neurons - are interpreted as though it is true u2013 as though, in other words, a particular firing rate were an indication that a particular neuron is or is not responsible for a designated perceptual event such as a motion streak. But such interpetations are notoriously confounded and tend to [fail to replicate] . Indeed, they are [arguably a form of p-hacking] . ,