Temporal Encoding of Spatial Information during Active Visual Fixation

Kuang, Xutao; Poletti, Martina; Victor, Jonathan D.; Rucci, Michele

doi:10.1016/j.cub.2012.01.050

Cited by 192 publications

(312 citation statements)

References 31 publications

Supporting

Mentioning

272

Contrasting

Order By: Relevance

“…The small, ongoing movements of the eye during fixation do not represent a disturbing signal, but rather help the visual system to process fine spatial details. The beneficial role of fixational drift is thought to unfold already during retinal processing by redistributing the temporal frequency power into a range of increased retinal sensitivity (Kuang et al, 2012) and by decorrelating highly redundant input from natural scenes (Rucci and Victor, 2015). Therefore, the view has emerged that fixational drift is adapted to an image to transform visual signals into an optimized spatiotemporal code for further visual processing (Kagan, 2012).…”

Section: Introductionmentioning

confidence: 99%

Microsaccades Are Coupled to Heartbeat

et al. 2016

View full text Add to dashboard Cite

During visual fixation, the eye generates microsaccades and slower components of fixational eye movements that are part of the visual processing strategy in humans. Here, we show that ongoing heartbeat is coupled to temporal rate variations in the generation of microsaccades. Using coregistration of eye recording and ECG in humans, we tested the hypothesis that microsaccade onsets are coupled to the relative phase of the R-R intervals in heartbeats. We observed significantly more microsaccades during the early phase after the R peak in the ECG. This form of coupling between heartbeat and eye movements was substantiated by the additional finding of a coupling between heart phase and motion activity in slow fixational eye movements; i.e., retinal image slip caused by physiological drift. Our findings therefore demonstrate a coupling of the oculomotor system and ongoing heartbeat, which provides further evidence for bodily influences on visuomotor functioning.

show abstract

Section: Introductionmentioning

confidence: 99%

Microsaccades Are Coupled to Heartbeat

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Biological systems may exploit a similar strategy. It has been suggested that fixational eye movements play a fundamental role in feature extraction by removing spatial correlations [14] [15].…”

Section: Introductionmentioning

confidence: 99%

“…In order to generate sensor motion, we employ a fixation eye movement model based on [15]. The Dynamic Vision Sensor (DVS) is mounted on a pan-tilt head that is actuated by two independent servo motors.…”

Section: Introductionmentioning

confidence: 99%

Invariant feature extraction from event based stimuli

Chandrapala

Shi

2016

2016 6th IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob)

View full text Add to dashboard Cite

Abstract-We propose a novel architecture, the event-based Generative Adaptive Subspace Self-Organizing Map (GASSOM) for learning and extracting invariant representations from event streams originating from neuromorphic vision sensors. The framework is inspired by feed-forward cortical models for visual processing. The model, which is based on the concepts of sparsity and temporal slowness, is able to learn feature extractors that resemble neurons in the primary visual cortex. Layers of units in the proposed model can be cascaded to learn feature extractors with different levels of complexity and selectivity. We explore the applicability of the framework on real world tasks by using the learned network for object recognition. The proposed model achieve higher classification accuracy compared to other stateof-the-art event based processing methods. Our results also demonstrate the generality and robustness of the method, as the recognizers for different data sets and different tasks all used the same set of learned feature detectors, which were trained on data collected independently of the testing data.

show abstract

“…Classic measurements of the TCSF, done with flickering targets set in a dark surround, showed that the luminance TCSF is bandpass with a peak ϳ8 Hz (de Lange, 1958;Kelly, 1961). However, if the surround luminance is changed from dark to the mean-gray of the target modulation, sensitivity to low frequencies increases many-fold, making the TCSF low-pass (Kelly, 1961(Kelly, , 1971.…”

Section: Introductionmentioning

confidence: 99%

“…Kelly (1969Kelly ( , 1971Kelly ( , 1972Kelly ( , 1979 proposed that fixational eye movements introduce highfrequency transients into cellular responses, resulting in lower thresholds on mean-gray surrounds, but not on dark surrounds. The eye movement hypothesis was challenged by experiments with stabilized images that claimed no differences between stabilized and regular viewing conditions, and a lateral inhibitory model was proposed (Keesey, 1970).…”

Section: Introductionmentioning

confidence: 99%

Eye Movements and the Neural Basis of Context Effects on Visual Sensitivity

Ennis

Cao

Lee

et al. 2014

Journal of Neuroscience

View full text Add to dashboard Cite

The effects of context on visual sensitivity are well established (e.g., sensitivity to luminance flicker is substantially higher on mean-gray surrounds than on white or black surrounds). The neural mechanisms generating context effects, however, remain unresolved. In the absence of direct tests, some theories invoke enhancement of edges by lateral inhibition, whereas others rely on transients caused by miniature eye movements that maintain fixation. We first replicated the luminance results on human observers and found unexpectedly that sensitivity to red-green flicker is also affected by surround color, being substantially higher on mean-gray surrounds than on red or green surrounds. To identify the neural bases of both context effects, we used in vivo electrophysiological recordings of primate magnocellular and parvocellular ganglion cell responses to luminance and red-green modulations, respectively. To test neuronal sensitivity to stationary edge contrast, neuronal responses were measured at various distances from the modulation edge against various surrounds. We found no evidence of enhanced responses to stationary edges on any surrounds, ruling out lateral inhibition-type explanations. To simulate the effects of eye movements, target patches were abruptly displaced while measuring responses. Abruptly displaced edges evoked vigorous transient responses that were selective for modulation-phase on mean-gray surrounds, but were phase-invariant on other surrounds. Eye movements could thus enhance detection of flicker on mean-gray surrounds, and neurometric analyses supported a primary role for eye movements in enhancing sensitivity. In addition, the transformation of spatial edges to transient neuronal responses by eye movements provides the signals for detecting luminance and color edges in natural scenes.

show abstract

Temporal Encoding of Spatial Information during Active Visual Fixation

Cited by 192 publications

References 31 publications

Microsaccades Are Coupled to Heartbeat

Microsaccades Are Coupled to Heartbeat

Invariant feature extraction from event based stimuli

Eye Movements and the Neural Basis of Context Effects on Visual Sensitivity

Contact Info

Product

Resources

About