Derealization and motion-perception related to repeated exposure to 3T Magnetic Resonance Image scanner in healthy adults

2020 ◽  
pp. 1-12
Author(s):  
Sergio Martínez-Gallardo ◽  
José A. Miguel-Puga ◽  
Davis Cooper-Bribiesca ◽  
Adolfo M. Bronstein ◽  
Kathrine Jáuregui-Renaud
Keyword(s):  
Magnetic Resonance ◽  
Motion Perception ◽  
State Anxiety ◽  
Random Order ◽  
Vestibular Stimulation ◽  
Psychological Effects ◽  
Psychological Reactions ◽  
Exposure Effect ◽  
Individual Susceptibility ◽  
Magnetic Exposure

BACKGROUND: Magnetic Resonance Imaging (MRI) scanning can induce psychological effects. No studies have investigated the role of magnetic vestibular stimulation (MVS) in 3TMRI scanner-induced psychological reactions. OBJECTIVE: To assess depersonalization/derealization(DD), state anxiety and motion-perception in a 3TMRI scanner, acutely and long-term. PARTICIPANTS: 48 healthcare professionals and students were included, after preliminary rejection of claustrophobes and neuro-otology and psychiatry assessments. PROCEDURES: Participants completed questionnaires on personal habits, dissociation, anxiety/depression and motion sickness susceptibility. Validated DD and state anxiety questionnaires were administered before and after magnetic exposure twice, entering the bore head and feet first in random order, one week apart. During the following week, dizziness/disorientation was reported daily. One month later, 11 subjects repeated the procedure to assess reproducibility. RESULTS: Considerable individual susceptibility was observed, circa 40% of the subjects reported self-motion perception related to the exposure, with variable increase on DD symptoms. Multivariate analysis showed that DD scores after any exposure were influenced by entering the bore “feet first”, motion-perception, and the mean sleep hours/week (MANCOVA, R = 0.58, p = 0.00001). There was no clear effect of scanner exposure on state anxiety, which was related to trait anxiey but not to DD scores. During repeated exposures, about half of all subjects re-entering the scan reported motion-perception, but DD or anxiety symptoms were not consistent. CONCLUSION: Psychological effects during 3TMRI scanning result from multiple, interacting factors, including novelty of the procedure (first-exposure effect), motion-perception due to MVS, head/body orientation, sleeping habits and individual susceptibility. Forewarning subjects of these predisposing factors may increase tolerance to MRI scanning.

Vertical linear self-motion perception during visual and inertial motion: More than weighted summation of sensory inputs

2005 ◽  
Vol 15 (4) ◽  
pp. 185-195 ◽  
Author(s):  
W.G. Wright ◽  
P. DiZio ◽  
J.R. Lackner
Keyword(s):  
Motion Perception ◽  
Visual Motion ◽  
Test Chamber ◽  
Vestibular Stimulation ◽  
Visual Scene ◽  
Inertial Motion ◽  
Physical Test ◽  
Head Mounted Display ◽  
Linear Oscillation ◽  
Self Motion

We evaluated visual and vestibular contributions to vertical self motion perception by exposing subjects to various combinations of 0.2 Hz vertical linear oscillation and visual scene motion. The visual stimuli presented via a head-mounted display consisted of video recordings of the test chamber from the perspective of the subject seated in the oscillator. In the dark, subjects accurately reported the amplitude of vertical linear oscillation with only a slight tendency to underestimate it. In the absence of inertial motion, even low amplitude oscillatory visual motion induced the perception of vertical self-oscillation. When visual and vestibular stimulation were combined, self-motion perception persisted in the presence of large visual-vestibular discordances. A dynamic visual input with magnitude discrepancies tended to dominate the resulting apparent self-motion, but vestibular effects were also evident. With visual and vestibular stimulation either spatially or temporally out-of-phase with one another, the input that dominated depended on their amplitudes. High amplitude visual scene motion was almost completely dominant for the levels tested. These findings are inconsistent with self-motion perception being determined by simple weighted summation of visual and vestibular inputs and constitute evidence against sensory conflict models. They indicate that when the presented visual scene is an accurate representation of the physical test environment, it dominates over vestibular inputs in determining apparent spatial position relative to external space.

Acute Psychological Responses to Qigong Exercise of Varying Durations

2008 ◽  
Vol 36 (03) ◽  
pp. 449-458 ◽  
Author(s):  
Mattias Johansson ◽  
Peter Hassmén
Keyword(s):  
State Anxiety ◽  
Exercise Bout ◽  
Positive Mood ◽  
Psychological Effects ◽  
Psychological Benefits ◽  
Hedonic Tone ◽  
Post Exercise ◽  
Knowing That ◽  
Positive Nature ◽  
Reduced State

Qigong exercise has been shown to induce acute psychological changes of a positive nature; but whether longer durations have greater effects than shorter ones is not known. Forty-one regular qigong practitioners therefore engaged in either 30 or 60 min of qigong exercise within a randomized cross-over design. Measures of mood, anxiety, activation, and hedonic tone were obtained pre- and post-exercise. Results showed benefits of the same magnitude in the two conditions: more positive mood states, reduced state anxiety, and enhanced perceived pleasure. Thirty minutes of qigong exercise thereby seems to be sufficient to provide psychological benefits, and with no additional benefits detected after 60 min. This finding is important for those having little time or motivation to engage in activities of longer durations. In addition, health professionals prescribing exercise for health benefits can prescribe shorter exercise sessions with confidence knowing that positive psychological effects can also occur after a shorter exercise bout.

Motion perception during selfmotion: The direct versus inferential controversy revisited

1994 ◽  
Vol 17 (2) ◽  
pp. 293-311 ◽  
Author(s):  
Alexander H. Wertheim
Keyword(s):  
Eye Movements ◽  
Motion Perception ◽  
Present Theory ◽  
Vestibular Stimulation ◽  
Object Motion ◽  
Image Motion ◽  
Just Noticeable Difference ◽  
Direct Perception ◽  
Unified Framework ◽  
Reference Signals

AbstractAccording to the traditional inferential theory of perception, percepts of object motion or stationarity stem from an evaluation of afferent retinal signals (which encode image motion) with the help of extraretinal signals (which encode eye movements). According to direct perception theory, on the other hand, the percepts derive from retinally conveyed information only. Neither view is compatible with a perceptual phenomenon that occurs during visually induced sensations of ego motion (vection). A modified version of inferential theory yields a model in which the concept of extraretinal signals is replaced by that of reference signals, which do not encode how the eyes move in their orbits but how they move in space. Hence reference signals are produced not only during eye movements but also during ego motion (i.e., in response to vestibular stimulation and to retinal image flow, which may induce vection). The present theory describes the interface between self-motion and object-motion percepts. An experimental paradigm that allows quantitative measurement of the magnitude and gain of reference signals and the size of the just noticeable difference (JND) between retinal and reference signals reveals that the distinction between direct and inferential theories largely depends on: (1) a mistaken belief that perceptual veridicality is evidence that extraretinal information is not involved, and (2) a failure to distinguish between (the perception of) absolute object motion in space and relative motion of objects with respect to each other. The model corrects these errors, and provides a new, unified framework for interpreting many phenomena in the field of motion perception.

Psychological effects of sedation in oculoplastic surgery: State anxiety, visuo-motor functioning, pain and post-surgical subjective amnesia

2001 ◽  
Vol 6 (3) ◽  
pp. 277-282
Author(s):  
J. Kincey ◽  
M. Bhatnagar ◽  
S. Biswas ◽  
B. Leatherbarrow ◽  
M. Rhatigan ◽  
...  
Keyword(s):  
State Anxiety ◽  
Psychological Effects ◽  
Motor Functioning ◽  
Oculoplastic Surgery

Psychological Effects of Victimization: Implications for the Criminal Justice System

1987 ◽  
Vol 33 (4) ◽  
pp. 468-478 ◽  
Author(s):  
Patricia A. Resick
Keyword(s):  
Criminal Justice ◽  
Criminal Justice System ◽  
Justice System ◽  
Psychological Effects ◽  
Criminal Prosecution ◽  
Rape Victims ◽  
Long Term Effects ◽  
Psychological Reactions ◽  
The Past

The purposes of this article are to review research on psychological reactions to criminal victimization, to consider how victims might be affected by participation in the criminal justice system, and to offer some recommendations for the treatment of victims and their families within the criminal justice system. Over the past ten years there have been a series of studies conducted to examine the long-term effects of rape victims. Recently a study was conducted to compare the reactions of robbery victims with rape victims and to compare female and male robbery victims. This article will review the findings from these longitudinal studies with particular attention to victim reactions that may affect or be affected by participation in criminal prosecution.

Effect of Motion Perception on Intertemporal Choice Is Associated With the Altered Time Perception

2018 ◽  
Vol 122 (1) ◽  
pp. 117-134 ◽  
Author(s):  
Xianchun Li ◽  
Di Yuan ◽  
Ying Fan ◽  
Chao Yan ◽  
Liangcai Gao
Keyword(s):  
Motion Perception ◽  
Time Perception ◽  
Intertemporal Choice ◽  
Critical Role ◽  
Random Order ◽  
Forward Motion ◽  
Reproduction Task ◽  
Perception Task ◽  
Time Reproduction ◽  
Motion Condition

Intertemporal choice refers to the choice between receiving a small immediate reward or a large delayed one. Previous studies have indicated that time perception plays a critical role in the intertemporal choice, and it could be affected by the features of the target stimulus in the time reproduction task, such as speed of movement and state of motion. However, there is no evidence about whether backward or forward motion perception could alter the intertemporal choice. Thus, in our current study, 29 participants were asked to perform two tasks in a random order. One was the intertemporal choice task after viewing videos containing moving elements with forward/backward directions as well as stationary ones, and another was the time perception task. We found that the discounting rate in intertemporal choice was significantly larger in backward motion condition than in both forward motion and stationary conditions, indicating that backward motion perception made participants more myopic (specifically, more likely to choose the smaller immediate reward instead of the large delayed one) during their decision-makings. Meanwhile, participants overestimated the temporal duration in a time perception task in backward motion condition compared to the other two conditions. Furthermore, the Pearson’s correlation analysis showed that the changes of the intertemporal choice induced by backward motion perception could be associated with the altered time perception. As far as we know, we provide the first evidence on influence of motion perception on the intertemporal choice as well as its possible cognitive correlates, which extend previous studies on cognitive basis of the intertemporal choices.

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