Cortical Correlates of the Simulated Viewpoint Oscillation Advantage for Vection

2017 ◽  
Vol 30 (7-8) ◽  
pp. 739-761 ◽  
Author(s):  
Ramy Kirollos ◽  
Robert S. Allison ◽  
Stephen Palmisano
Keyword(s):  
Optic Flow ◽  
Radial Flow ◽  
Prolonged Exposure ◽  
Insular Cortex ◽  
Vestibular Apparatus ◽  
Global Motion ◽  
Vestibular Cortex ◽  
Fmri Study ◽  
Self Motion ◽  
The Brain

Behavioural studies have consistently found stronger vection responses for oscillating, compared to smooth/constant, patterns of radial flow (the simulated viewpoint oscillation advantage for vection). Traditional accounts predict that simulated viewpoint oscillation should impair vection by increasing visual–vestibular conflicts in stationary observers (as this visual oscillation simulates self-accelerations that should strongly stimulate the vestibular apparatus). However, support for increased vestibular activity during accelerating vection has been mixed in the brain imaging literature. This fMRI study examined BOLD activity in visual (cingulate sulcus visual area — CSv; medial temporal complex — MT+; V6; precuneus motion area — PcM) and vestibular regions (parieto-insular vestibular cortex — PIVC/posterior insular cortex — PIC; ventral intraparietal region — VIP) when stationary observers were exposed to vection-inducing optic flow (i.e., globally coherent oscillating and smooth self-motion displays) as well as two suitable control displays. In line with earlier studies in which no vection occurred, CSv and PIVC/PIC both showed significantly increased BOLD activity during oscillating global motion compared to the other motion conditions (although this effect was found for fewer subjects in PIVC/PIC). The increase in BOLD activity in PIVC/PIC during prolonged exposure to the oscillating (compared to smooth) patterns of global optical flow appears consistent with vestibular facilitation.

scholarly journals Sensitivity of human visual cortical area V6 to stereoscopic depth gradients associated with self-motion

2011 ◽  
Vol 106 (3) ◽  
pp. 1240-1249 ◽  
Author(s):  
Velia Cardin ◽  
Andrew T. Smith
Keyword(s):  
Optic Flow ◽  
Vestibular Cortex ◽  
Depth Cues ◽  
Natural Flow ◽  
Visual Cortical Area ◽  
Ventral Intraparietal Area ◽  
Depth Gradients ◽  
Visual Cortical ◽  
Self Motion ◽  
The Brain

The principal visual cue to self-motion (egomotion) is optic flow, which is specified in terms of local 2D velocities in the retinal image without reference to depth cues. However, in general, points near the center of expansion of natural flow fields are distant, whereas those in the periphery are closer, creating gradients of horizontal binocular disparity. To assess whether the brain combines disparity gradients with optic flow when encoding egomotion, stereoscopic gradients were applied to expanding dot patterns presented to observers during functional MRI scanning. The gradients were radially symmetrical, disparity changing as a function of eccentricity. The depth cues were either consistent with egomotion (peripheral dots perceived as near and central dots perceived as far) or inconsistent (the reverse gradient, central dots near, peripheral dots far). The BOLD activity generated by these stimuli was compared in a range of predefined visual regions in 13 participants with good stereoacuity. Visual area V6, in the parieto-occipital sulcus, showed a unique pattern of results, responding well to all optic flow patterns but much more strongly when they were paired with consistent rather than inconsistent or zero-disparity gradients. Of the other areas examined, a region of the precuneus and parietoinsular vestibular cortex also differentiate between consistent and inconsistent gradients, but with weak or suppressive responses. V3A, V7, MT, and ventral intraparietal area responded more strongly in the presence of a depth gradient but were indifferent to its depth-flow congruence. The results suggest that depth and flow cues are integrated in V6 to improve estimation of egomotion.

Do Migraineurs have Difficulty Judging Direction of Simulated Heading?

Cephalalgia ◽  
2006 ◽  
Vol 26 (8) ◽  
pp. 949-959 ◽  
Author(s):  
AM McKendrick ◽  
A Turpin ◽  
S Webb ◽  
DR Badcock
Keyword(s):  
Flow Field ◽  
Optic Flow ◽  
Global Motion ◽  
Motion Coherence ◽  
Coherent Optic ◽  
Left And Right ◽  
Dot Motion ◽  
Self Motion

Some migraineurs have increased thresholds for the detection of global dot motion. We investigated whether migraineurs show consequential abnormalities in the determination of direction of self-motion (heading) from simulated optic flow. The ability to determine heading from optic flow is likely to be necessary for optimal determination of self-motion through the environment. Twenty-five migraineurs and 25 controls participated. Global dot motion coherence thresholds were assessed, in addition to performance on two simulated heading tasks: one with a symmetrical flow field, and the second with differing velocity of optic flow on the left and right sides of the participant. While some migraineurs demonstrated abnormal global motion coherence thresholds, there was no difference in performance on the heading tasks at either simulated walking (5 km/h) or driving (50 km/h) speeds. Increased global motion coherence thresholds in migraineurs do not result in abnormal judgements of heading from 100± coherent optic flow.

Development of cortical responses to optic flow

2007 ◽  
Vol 24 (6) ◽  
pp. 845-856 ◽  
Author(s):  
RICK O. GILMORE ◽  
C. HOU ◽  
M.W. PETTET ◽  
A.M. NORCIA
Keyword(s):  
Optic Flow ◽  
Radial Flow ◽  
Brain Activity ◽  
Flow Patterns ◽  
Motion Processing ◽  
Uniform Motion ◽  
Brain Responses ◽  
Cortical Responses ◽  
Frequency Domains ◽  
Self Motion

Humans discriminate approaching objects from receding ones shortly after birth, and optic flow associated with self-motion may activate distinctive brain networks, including the human MT+ complex. We sought evidence for evoked brain activity that distinguished radial motion from other optic flow patterns, such as translation or rotation by recording steady-state visual evoked potentials (ssVEPs), in both adults and 4–6 month-old infants to direction-reversing optic flow patterns. In adults, radial flow evoked distinctive brain responses in both the time and frequency domains. Differences between expansion/contraction and both translation and rotation were especially strong in lateral channels (PO7 and PO8), and there was an asymmetry between responses to expansion and contraction. In contrast, infants' evoked response waveforms to all flow types were equivalent, and showed no evidence of the expansion/contraction asymmetry. Infants' responses were largest and most reliable for the translation patterns in which all dots moved in the same direction. This pattern of response is consistent with an account in which motion processing systems detecting locally uniform motion develop earlier than do systems specializing in complex, globally non-uniform patterns of motion, and with evidence suggesting that motion processing undergoes prolonged postnatal development.

scholarly journals The A-Effect and Global Motion

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 13
Author(s):  
Pearl Guterman ◽  
Robert Allison
Keyword(s):  
Optic Flow ◽  
Object Motion ◽  
The Body ◽  
Body Tilt ◽  
Whole Body ◽  
Global Motion ◽  
Motion Direction ◽  
And Shifts ◽  
Self Motion ◽  
Gravitational Vertical

When the head is tilted, an objectively vertical line viewed in isolation is typically perceived as tilted. We explored whether this shift also occurs when viewing global motion displays perceived as either object-motion or self-motion. Observers stood and lay left side down while viewing (1) a static line, (2) a random-dot display of 2-D (planar) motion or (3) a random-dot display of 3-D (volumetric) global motion. On each trial, the line orientation or motion direction were tilted from the gravitational vertical and observers indicated whether the tilt was clockwise or counter-clockwise from the perceived vertical. Psychometric functions were fit to the data and shifts in the point of subjective verticality (PSV) were measured. When the whole body was tilted, the perceived tilt of both a static line and the direction of optic flow were biased in the direction of the body tilt, demonstrating the so-called A-effect. However, we found significantly larger shifts for the static line than volumetric global motion as well as larger shifts for volumetric displays than planar displays. The A-effect was larger when the motion was experienced as self-motion compared to when it was experienced as object-motion. Discrimination thresholds were also more precise in the self-motion compared to object-motion conditions. Different magnitude A-effects for the line and motion conditions—and for object and self-motion—may be due to differences in combining of idiotropic (body) and vestibular signals, particularly so in the case of vection which occurs despite visual-vestibular conflict.

scholarly journals Multisensory Interactions in Virtual Reality: Optic Flow Reduces Vestibular Sensitivity, but Only for Congruent Planes of Motion

2020 ◽  
Vol 33 (6) ◽  
pp. 625-644 ◽  
Author(s):  
Maria Gallagher ◽  
Reno Choi ◽  
Elisa Raffaella Ferrè
Keyword(s):  
Virtual Reality ◽  
Optic Flow ◽  
Random Motion ◽  
Sensory Cues ◽  
Perceptual Sensitivity ◽  
Head Mounted Display ◽  
Vestibular Cues ◽  
Multisensory Interactions ◽  
Self Motion ◽  
The Brain

Abstract During exposure to Virtual Reality (VR) a sensory conflict may be present, whereby the visual system signals that the user is moving in a certain direction with a certain acceleration, while the vestibular system signals that the user is stationary. In order to reduce this conflict, the brain may down-weight vestibular signals, which may in turn affect vestibular contributions to self-motion perception. Here we investigated whether vestibular perceptual sensitivity is affected by VR exposure. Participants’ ability to detect artificial vestibular inputs was measured during optic flow or random motion stimuli on a VR head-mounted display. Sensitivity to vestibular signals was significantly reduced when optic flow stimuli were presented, but importantly this was only the case when both visual and vestibular cues conveyed information on the same plane of self-motion. Our results suggest that the brain dynamically adjusts the weight given to incoming sensory cues for self-motion in VR; however this is dependent on the congruency of visual and vestibular cues.

scholarly journals Macaque Parieto-Insular Vestibular Cortex: Responses to Self-Motion and Optic Flow

2010 ◽  
Vol 30 (8) ◽  
pp. 3022-3042 ◽  
Author(s):  
A. Chen ◽  
G. C. DeAngelis ◽  
D. E. Angelaki
Keyword(s):  
Optic Flow ◽  
Vestibular Cortex ◽  
Self Motion

scholarly journals Shared neural mechanisms between imagined and perceived egocentric motion - A combined GVS and fMRI study

2018 ◽  
Author(s):  
Gianluca Macauda ◽  
Marius Moisa ◽  
Fred W. Mast ◽  
Christian C. Ruff ◽  
Lars Michels ◽  
...  
Keyword(s):  
Mental Rotation ◽  
Insular Cortex ◽  
Vestibular Stimulation ◽  
Brain Regions ◽  
Mental Rotation Task ◽  
Neural Mechanisms ◽  
Brain Areas ◽  
Object Based ◽  
Fmri Study ◽  
Self Motion

AbstractMany cognitive and social processes involve mental simulations of a change in perspective. Behavioral studies suggest that such egocentric mental rotations rely on brain areas that are also involved in processing actual self-motion, thus depending on vestibular input. In a combined galvanic vestibular stimulation (GVS) and functional Magnetic Resonance Imaging (fMRI) study, we investigated the brain areas that underlie both simulated changes in self-location and the processing of vestibular stimulation within the same individuals. Participants performed an egocentric mental rotation task, an object-based mental rotation task, or a pure lateralization task during GVS or sham stimulation. At the neural level, we expected an overlap between brain areas activated during vestibular processing and egocentric mental rotation (against object-based mental rotation) within area OP2 and the Posterior Insular Cortex (PIC), two core brain regions involved in vestibular processing. The fMRI data showed a small overlap within area OP2 and a larger overlap within the PIC for both egocentric mental rotation against object-based mental rotation and vestibular processing. GVS did not influence the ability to perform egocentric mental rotation.Our results provide evidence for shared neural mechanisms underlying perceived and simulated self-motion. We conclude that mental rotation of one’s body involves neural activity in the PIC and area OP2, but the behavioral results also suggest that those mental simulations of one’s body might be robust to modulatory input from vestibular stimulation.

How does the brain process time? insights from an event-related fMRI study

NeuroImage ◽  
2000 ◽  
Vol 11 (5) ◽  
pp. S49
Author(s):  
D.L. Harrington ◽  
L.A. Mead ◽  
A.R. Mayer ◽  
K.Y. Haaland ◽  
S.M. Rao
Keyword(s):  
Process Time ◽  
Brain Process ◽  
Fmri Study ◽  
The Brain

scholarly journals Neurodegeneration in friedreich's ataxia is associated with a mixed activation pattern of the brain. A fMRI study

2011 ◽  
Vol 33 (8) ◽  
pp. 1780-1791 ◽  
Author(s):  
Andrea Ginestroni ◽  
Stefano Diciotti ◽  
Paolo Cecchi ◽  
Ilaria Pesaresi ◽  
Carlo Tessa ◽  
...  
Keyword(s):  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Activation Pattern ◽  
Fmri Study ◽  
The Brain

Abstract 306: Alamandine but not angiotensin-(1-7) produces cardiovascular effects in the Insular Cortex

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Fernanda R Marins ◽  
Aline C Oliveira ◽  
Fatimunnisa Qadri ◽  
Natalia Alenina ◽  
Michael Bader ◽  
...  
Keyword(s):  
Brain Region ◽  
Insular Cortex ◽  
Cardiovascular Effects ◽  
Endogenous Ligand ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Equimolar Dose ◽  
The Brain ◽  
Renal Sympathetic ◽  
Made In

In the course of experiments aimed to evaluate the immunofluorescence distribution of MrgD receptors we observed the presence of immunoreactivity for the MrgD protein in the Insular Cortex. In order to evaluate the functional significance of this finding, we investigated the cardiovascular effects produced by the endogenous ligand of MrgD, alamandine, in this brain region. Urethane (1.4g/kg) anesthetized rats were instrumented for measurement of MAP, HR and renal sympathetic nerve activity (RSNA). Unilateral microinjection of alamandine (40 pmol/100nl), Angiotensin-(1-7) (40pmol/100nl), Mas/MrgD antagonista D-Pro7-Ang-1-7 (50pmol/100nl), Mas agonist A779 (100 pmol/100nl) or vehicle (0,9% NaCl) were made in different rats (N=4-6 per group) into posterior insular cortex (+1.5mm rostral to the bregma). Microinjection of alamandine in this region produced a long-lasting (> 18 min) increase in MAP (Δ saline= -2±1 vs. alamandine= 12±2 mmHg, p< 0.05) associated to increases in HR (Δ saline= 2±2 vs. alamandine= 35±5 bpm; p< 0.05) and in the amplitude of renal nerve discharges (Δ saline = -2±1 vs. alamandine= 35±5.5 % of the baseline; p< 0.05). Strikingly, an equimolar dose of angiotensin-(1-7) did not produce any change in MAP or HR (Δ MAP=-0.5±0.3 mmHg and +2.7±1.2 bpm, respectively; p> 0.05) and only a slight increase in RSNA (Δ =7.3±3.2 %) . In keeping with this observation the effects of alamandine were not significantly influenced by A-779 (Δ MAP=+13± 2.5 mmHg, Δ HR= +26±3.6 bpm; Δ RSNA = 25± 3.4%) but completely blocked by the Mas/MrgD antagonist D-Pro7-Ang-(1-7) (Δ MAP=+0 ± 1 mmHg Δ HR= +4±2.6 bpm; Δ RSNA = 0.5± 2.2 %). Therefore, we have identified a brain region in which alamandine/MrgD receptors but not Ang-(1-7)/Mas could be involved in the modulation of cardiovascular-related neuronal activity. This observation also suggests that alamandine might possess unique effects unrelated to Ang-(1-7) in the brain.

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