scholarly journals Canonical retinotopic shifts under an inverse force field explain predictive remapping

2021 ◽  
Author(s):  
Ifedayo-EmmanuEL Adeyefa-Olasupo ◽  
Zixuan Xiao ◽  
Anirvan S. Nandy
Keyword(s):  
Force Field ◽  
Temporal Dynamics ◽  
Human Subjects ◽  
Receptive Fields ◽  
Saccadic Eye Movements ◽  
Saccade Target ◽  
Brain Areas ◽  
Predictive Remapping ◽  
Spatio Temporal ◽  
Inverse Force

ABSTRACTSaccadic eye-movements allow us to bring visual objects of interest to high-acuity central vision. Although saccades cause large displacements of retinal images, our percept of the visual world remains stable. Predictive remapping — the ability of cells in retinotopic brain areas to transiently exhibit spatio-temporal retinotopic shifts beyond the spatial extent of their classical receptive fields — has been proposed as a primary mechanism that mediates this seamless visual percept. Despite the well documented effects of predictive remapping, no study to date has been able to provide a mechanistic account of the neural computations and architecture that actively mediate this ubiquitous phenomenon. Borne out by the spatio-temporal dynamics of peri-saccadic sensitivity to probe stimuli in human subjects, we propose a novel neurobiologically inspired phenomenological model in which the underlying peri-saccadic attentional and oculomotor signals manifest as three temporally overlapping forces that act on retinotopic brain areas. These three forces – a compressive one toward the center of gaze, a convergent one toward the saccade target and a translational one parallel to the saccade trajectory – act in an inverse force field and specify the spatio-temporal window of predictive remapping of population receptive fields.

scholarly journals Spreading pre-saccadic attentional resources without trade-off

2017 ◽  
Author(s):  
Michael Puntiroli ◽  
Heiner Deubel ◽  
Martin Szinte
Keyword(s):  
Temporal Dynamics ◽  
Receptive Fields ◽  
Limited Resources ◽  
Saccade Target ◽  
Orientation Sensitivity ◽  
Trade Off ◽  
Attentional Resources ◽  
Visible Target ◽  
Spatio Temporal ◽  
Spatial Area

SummaryWhen preparing a saccade, attentional resources are focused at the saccade target and its immediate vicinity. Here we show that this does not hold true when saccades are prepared towards a recently extinguished target. We obtained detailed maps of orientation sensitivity when participants prepared a saccade toward a target that either remained on the screen or disappeared before the eyes moved. We found that attention was mainly focused at the immediate surround of the visible target and increasingly spread to more peripheral locations as a function of the delay between the target’s disappearance and the saccade. Interestingly, this spread was accompanied by an overall increase in sensitivity, speaking against a dilution of limited resources over a larger spatial area. We hypothesize that these results reflect the behavioral consequences of the spatio-temporal dynamics of visual receptive fields in the presence and in the absence a structured visual cue.

Spatio-Temporal Subthreshold Receptive Fields in the Vibrissa Representation of Rat Primary Somatosensory Cortex

1998 ◽  
Vol 80 (6) ◽  
pp. 2882-2892 ◽  
Author(s):  
Christopher I. Moore ◽  
Sacha B. Nelson
Keyword(s):  
Receptive Field ◽  
Somatosensory Cortex ◽  
Rise Time ◽  
Cortical Plasticity ◽  
Temporal Dynamics ◽  
Receptive Fields ◽  
Excitatory Input ◽  
Primary Somatosensory Cortex ◽  
Spatio Temporal ◽  
Sensory Evoked

Moore, Christopher I. and Sacha B. Nelson. Spatio-temporal subthreshold receptive fields in the vibrissa representation of rat primary somatosensory cortex. J. Neurophysiol. 80: 2882–2892, 1998. Whole cell recordings of synaptic responses evoked by deflection of individual vibrissa were obtained from neurons within adult rat primary somatosensory cortex. To define the spatial and temporal properties of subthreshold receptive fields, the spread, amplitude, latency to onset, rise time to half peak amplitude, and the balance of excitation and inhibition of subthreshold input were quantified. The convergence of information onto single neurons was found to be extensive: inputs were consistently evoked by vibrissa one- and two-away from the vibrissa that evoked the largest response (the “primary vibrissa”). Latency to onset, rise time, and the incidence and strength of inhibitory postsynaptic potentials (IPSPs) varied as a function of position within the receptive field and the strength of evoked excitatory input. Nonprimary vibrissae evoked smaller amplitude subthreshold responses [primary vibrissa, 9.1 ± 0.84 (SE) mV, n = 14; 1-away, 5.1 ± 0.5 mV, n = 38; 2-away, 3.7 ± 0.59 mV, n = 22; 3-away, 1.3 ± 0.70 mV, n = 8] with longer latencies (primary vibrissa, 10.8 ± 0.80 ms; 1-away, 15.0 ± 1.2 ms; 2-away, 15.7 ± 2.0 ms). Rise times were significantly faster for inputs that could evoke action potential responses (suprathreshold, 4.1 ± 1.3 ms, n = 8; subthreshold, 12.4 ± 1.5 ms, n = 61). In a subset of cells, sensory evoked IPSPs were examined by deflecting vibrissa during injection of hyperpolarizing and depolarizing current. The strongest IPSPs were evoked by the primary vibrissa ( n = 5/5), but smaller IPSPs also were evoked by nonprimary vibrissae ( n = 8/13). Inhibition peaked by 10–20 ms after the onset of the fastest excitatory input to the cortex. This pattern of inhibitory activity led to a functional reversal of the center of the receptive field and to suppression of later-arriving and slower-rising nonprimary inputs. Together, these data demonstrate that subthreshold receptive fields are on average large, and the spatio-temporal dynamics of these receptive fields vary as a function of position within the receptive field and strength of excitatory input. These findings constrain models of suprathreshold receptive field generation, multivibrissa interactions, and cortical plasticity.

Neurons in the monkey superior colliculus predict the visual result of impending saccadic eye movements

1995 ◽  
Vol 73 (5) ◽  
pp. 1988-2003 ◽  
Author(s):  
M. F. Walker ◽  
E. J. Fitzgibbon ◽  
M. E. Goldberg
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Eye Movement ◽  
Receptive Fields ◽  
Saccadic Eye Movements ◽  
Superficial Layer ◽  
Saccade Target ◽  
Visual Response ◽  
Intermediate Layers ◽  
Movement Field

1. Previous experiments have shown that visual neurons in the lateral intraparietal area (LIP) respond predictively to stimuli outside their classical receptive fields when an impending saccade will bring those stimuli into their receptive fields. Because LIP projects strongly to the intermediate layers of the superior colliculus, we sought to demonstrate similar predictive responses in the monkey colliculus. 2. We studied the behavior of 90 visually responsive neurons in the superficial and intermediate layers of the superior colliculus of two rhesus monkeys (Macaca mulatta) when visual stimuli or the locations of remembered stimuli were brought into their receptive fields by a saccade. 3. Thirty percent (18/60) of intermediate layer visuomovement cells responded predictively before a saccade outside the movement field of the neuron when that saccade would bring the location of a stimulus into the receptive field. Each of these neurons did not respond to the stimulus unless an eye movement brought it into its receptive field, nor did it discharge in association with the eye movement unless it brought a stimulus into its receptive field. 4. These neurons were located in the deeper parts of the intermediate layers and had relatively larger receptive fields and movement fields than the cells at the top of the intermediate layers. 5. The predictive responses of most of these neurons (16/18, 89%) did not require that the stimulus be relevant to the monkey's rewarded behavior. However, for some neurons the predictive response was enhanced when the stimulus was the target of a subsequent saccade into the neuron's movement field. 6. Most neurons with predictive responses responded with a similar magnitude and latency to a continuous stimulus that remained on after the saccade, and to the same stimulus when it was only flashed for 50 ms coincident with the onset of the saccade target and thus never appeared within the cell's classical receptive field. 7. The visual response of neurons in the intermediate layers of the colliculus is suppressed during the saccade itself. Neurons that showed predictive responses began to discharge before the saccade, were suppressed during the saccade, and usually resumed discharging after the saccade. 8. Three neurons in the intermediate layers responded tonically from stimulus appearance to saccade without a presaccadic burst. These neurons responded predictively to a stimulus that was going to be the target for a second saccade, but not to an irrelevant flashed stimulus. 9. No superficial layer neuron (0/27) responded predictively when a stimulus would not be brought into their receptive fields by a saccade.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Robotic Vision with the Conformal Camera: Modeling Perisaccadic Perception

2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Jacek Turski
Keyword(s):  
Fourier Transform ◽  
Visual Information ◽  
Euclidean Geometry ◽  
Human Subjects ◽  
Receptive Fields ◽  
Saccadic Eye Movements ◽  
Robotic Vision ◽  
Non Euclidean Geometry ◽  
Silicon Retina ◽  
High Acuity

Humans make about 3 saccades per second at the eyeball's speed of 700 deg/sec to reposition the high-acuity fovea on the targets of interest to build up understanding of a scene. The brain's visuosaccadic circuitry uses the oculomotor command of each impending saccade to shift receptive fields (RFs) to cortical locations before the eyes take them there, giving a continuous and stable view of the world. We have developed a model for image representation based on projective Fourier transform (PFT) intended for robotic vision, which may efficiently process visual information during the motion of a camera with silicon retina that resembles saccadic eye movements. Here, the related neuroscience background is presented, effectiveness of the conformal camera's non-Euclidean geometry in intermediate-level vision is discussed, and the algorithmic steps in modeling perisaccadic perception with PFT are proposed. Our modeling utilizes basic properties of PFT. First, PFT is computable by FFT in complex logarithmic coordinates that also approximate the retinotopy. Second, the shift of RFs in retinotopic (logarithmic) coordinates is modeled by the shift property of discrete Fourier transform. The perisaccadic mislocalization observed by human subjects in laboratory experiments is the consequence of the fact that RFs' shifts are in logarithmic coordinates.

scholarly journals Conjunction of Factors Triggering Waves of Seasonal Influenza

2017 ◽  
Author(s):  
Ishanu Chattopadhyay ◽  
Emre Kıcıman ◽  
Joshua W. Elliott ◽  
Jeffrey L. Shaman ◽  
Andrey Rzhetsky
Keyword(s):  
Temporal Dynamics ◽  
Human Subjects ◽  
Characteristic Curve ◽  
Human Movement ◽  
Antigenic Drift ◽  
Specific Humidity ◽  
Weather Data ◽  
The Us ◽  
Spatio Temporal ◽  
Socioeconomic And Demographic Factors

AbstractUnderstanding the subtle confluence of factors triggering pan-continental, seasonal epidemics of influenza-like illness is an extremely important problem, with the potential to save tens of thousands of lives and billions of dollars every year in the US alone. Beginning with several large, longitudinal datasets on putative factors and clinical data on the disease and health status of over 150 million human subjects observed over a decade, we investigated the source and the mechanistic triggers of epidemics. Our analysis included insurance claims for a significant cross-section of the US population in the past decade, human movement patterns inferred from billions of tweets, whole-US weekly weather data covering the same time span as the medical records, data on vaccination coverage over the same period, and sequence variations of key viral proteins. We also explicitly accounted for the spatio-temporal auto-correlations of infectious waves, and a host of socioeconomic and demographic factors. We carried out multiple orthogonal statistical analyses on these diverse, large geo-temporal datasets to bolster and corroborate our findings. We conclude that the initiation of a pan-continental influenza wave emerges from the simultaneous realization of a complex set of conditions, the strongest predictor groups are as follows, ranked by importance: (1) the host population’s socio- and ethno-demographic properties; (2) weather variables pertaining to relevant area specific humidity, temperature, and solar radiation; (3) the virus’ antigenic drift over time; (4) the host population’s land-based travel habits, and; (5) the spatio-temporal dynamics’ immediate history, as reflected in the influenza wave autocorrelation. The models we infer are demonstrably predictive (area under the Receiver Operating Characteristic curve ≈ 80%) when tested with out-of-sample data, opening the door to the potential formulation of new population-level intervention and mitigation policies.

scholarly journals Conjunction of factors triggering waves of seasonal influenza

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Ishanu Chattopadhyay ◽  
Emre Kiciman ◽  
Joshua W Elliott ◽  
Jeffrey L Shaman ◽  
Andrey Rzhetsky
Keyword(s):  
Temporal Dynamics ◽  
Human Subjects ◽  
Characteristic Curve ◽  
Population Level ◽  
Host Population ◽  
Antigenic Drift ◽  
Specific Humidity ◽  
Factors Affecting ◽  
Out Of Sample ◽  
Spatio Temporal

Using several longitudinal datasets describing putative factors affecting influenza incidence and clinical data on the disease and health status of over 150 million human subjects observed over a decade, we investigated the source and the mechanistic triggers of influenza epidemics. We conclude that the initiation of a pan-continental influenza wave emerges from the simultaneous realization of a complex set of conditions. The strongest predictor groups are as follows, ranked by importance: (1) the host population’s socio- and ethno-demographic properties; (2) weather variables pertaining to specific humidity, temperature, and solar radiation; (3) the virus’ antigenic drift over time; (4) the host population’€™s land-based travel habits, and; (5) recent spatio-temporal dynamics, as reflected in the influenza wave auto-correlation. The models we infer are demonstrably predictive (area under the Receiver Operating Characteristic curve 80%) when tested with out-of-sample data, opening the door to the potential formulation of new population-level intervention and mitigation policies.

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