Description:
An Out of Body Experience (OBE) occurs when the centre of a person's awareness appears to temporarily occupy a position which is spatially remote from their body. Prior research suggests that fantasy proneness factors are predictors of OBE likelihood, specifically prior auditory, visual, and kinaesthetic hallucinations. Three hundred and seventy participants completed an online questionnaire investigating variables that, potentially, contributed to their OBEs. Binary Logistic Regression identified one item that predicted whether or not a person had experienced an OBE: whether a participant had, or had not, previously experienced an auditory hallucination.
Description:
Although simulated environments are improved by adding sensory information, temperature is one input that has rarely featured in them. Here we report findings from experiments that examine the efficacy of adding temperature information to the multimodal complex known to be of benefit in simulations. In the first experiment, Peltier tiles added thermal information to the kinesthetic feedback given by a hand-worn exoskeletal device and this increased ratings for 'presence' during interactions with simulated objects. In an experiment in which exploratory movements across surfaces of differing temperatures were either active or passive-guided, the degree of 'coldness' felt at the fingertip was reported as less intense when movement was active, suggesting that intentionality of movement plays a role in the attenuation of the thermal stimulus. Other work reported here suggests that the perception of temperature is not influenced by a simultaneously presented colour. For example, the perception of coldness is not enhanced when it is processed in conjunction with a blue colour. We discuss the potential value of thermal information within the context of the hypothesis that presence in simulated environments is enhanced by multisensory inputs that include redundant information.
Description:
Amongst other changes, ecodriving requires drivers to drive more smoothly – to “flow” the vehicle. In order to save fuel and reduce emissions drivers must operate at lower engine revolutions, change up gears as soon as possible, and anticipate traffic conditions and drive defensively. A field trial was conducted using a 30 km metropolitan circuit and B-double heavy vehicles. Compared to their pre-course measures, the trained group reduced their fuel consumption by an average of 27%, the number of gear changes by 29%, and the number of brake applications by 41%. Importantly, these gains were not offset by increases in the time taken to complete the circuit – indeed average speed increased slightly. Further, the benefits did not lose any strength 12 weeks after the training, at which point the pilot trial concluded – in fact for some variables the results continued to improve over time. The number of drivers participating in the trial was relatively small and some questions remain unanswered, including actual road safety implications, building a strong case for a larger trial.
Description:
Amongst other changes, ecodriving requires drivers to drive more smoothly – to “flow” the vehicle. In order to save fuel and reduce emissions drivers must operate at lower engine revolutions, change up gears as soon as possible, and anticipate traffic conditions and drive defensively. A field trial was conducted using a 30 km metropolitan circuit and B-double heavy vehicles. Compared to their pre-course measures, the trained group reduced their fuel consumption by an average of 27%, the number of gear changes by 29%, and the number of brake applications by 41%. Importantly, these gains were not offset by increases in the time taken to complete the circuit – indeed average speed increased slightly. Further, the benefits did not lose any strength 12 weeks after the training, at which point the pilot trial concluded – in fact for some variables the results continued to improve over time. The number of drivers participating in the trial was relatively small and some questions remain unanswered, including actual road safety implications, building a strong case for a larger trial.
Description:
In six experiments, subjects judged the sizes of squares that were presented visually and/or haptically, in unimodal or bimodal conditions. We were interested in which mode most affected size judgments in the bimodal condition when the squares presented to each mode actually differed in size. Three factors varied: whether haptic exploration was passive or active, whether the choice set from which the subjects selected their responses was visual or haptic, and whether cutaneous information was provided in addition to kinesthetic information. To match the task for each mode, visual presentations consisted of a cursor that moved along a square pathway to correspond to the haptic experience of successive segments revealed during exploration. We found that the visual influence on size judgments was greater than the influence of haptics when the haptic experience involved only kinesthesis, passive movement, and a visual choice set. However, when cutaneous input was added to kinesthetic information, size judgments were most influenced by the haptic mode. The results support hypotheses of sensory integration, rather than capture of one sense by the other.
Description:
Participants attempted to create squares of four different sizes in two orientations in one of three modality conditions - physically adjusting a tangible template while blindfolded (haptic condition), directing the experimenter to adjust the template (vision condition), or adjusting the template themselves without the blindfold (mixed-mode condition). The side of square was robustly overestimated, resulting in a rectangle elongated in the horizontal direction - evidence for the horizontal-vertical illusion. There was no difference in the illusion’s strength as a function of modality conditions or orientation
Description:
The effect of a white noise stimulus on perceived length was investigated. In contrast to our expectations, stimulus lengths presented in the radial-vertical axis were underestimated relative to those presented in the horizontal axis. Surprisingly, differing stimulus lengths and exposure times had no influence on percentage error scores, suggesting that these factors play no role in what we are calling a 'reverse auditory horizontal-vertical illusion'. This article reviews the relevant literature and, in conjunction with the data we have collected, discusses the importance of stimulus frequency, a topic of importance to builders of virtual reality interfaces and environments.
Description:
Participants felt, saw and heard stimuli travel over predetermined distances in three orientations – gravitational-vertical, radial and horizontal. On all trials participants were required to judge the length of the distance travelled. Judgments based on visual information over-estimated length in the radial direction, while those based on haptic information overestimated length in the gravitational-vertical direction. Length estimates based on auditory information were similar across the three orientations. A combined modality condition using visual, haptic and auditory information mimicked the vision condition. Results are interpreted in light of the horizontal-vertical illusion.
Description:
Thermal input is an important, but often unacknowledged, source of information in our interactions with the environment. Besides the extremes that alert us to discomfort and danger, even a small change in temperature adds to the richness of the haptic experience. Temperature assists us in establishing that we have made contact with a surface and it helps to determine what that surface might be. It is not yet clear how important or redundant that temperature information is, a question of particular importance to builders of virtual reality interfaces and environments. Indeed, it is possible that as an under-exploited channel, temperature could be used to code for other information not easily conveyed with current technologies. For example, temperature conveyed by Peltier tiles may intuitively code for hardness - and therefore material type - in simulations or teleremote applications. Temperature may also enhance the learning experience by increasing presence or immersion. The findings from several experiments are brought together to discuss the efficacy of adding temperature feedback to simulation applications. In the first, Peltier tiles are added to an exoskeleton device designed to provide kinaesthetic feedback when interacting in a virtual environment. The effects are explored in terms of useability and the potential to increase presence or realism of virtual objects. We also describe an experiment in which movement was either active or passive-guided. In the active condition the degree of "coldness" felt at the fingertip was reported as less intense than when movement was passive. It appears that intentionality of movement played some role in the attenuation of the stimulus. Other work suggests that the perception of temperature is not influenced by a simultaneously present colour. For example, perceiving cold is not enhanced when it is processed in conjunction with a blue colour. This article will review the relevant literature and, in conjunction with the data we have collected, establish whether introducing temperature to virtual training environments is advisable.
Description:
Individuals who have had an out-of-body experience (OBE) report that the centre of their awareness appears to, temporarily, shift to a location that is spatially distinct from the location of their physical body. Research suggests that some OBErs report a sensation of leaving their physical body prior to their OBEs, while others instead report spontaneously finding themselves outside of their body. The present study evaluated data collected from 194 participants who claimed to have had an OBE. Instances of spontaneous and autonomously induced OBEs were considered. Binary Logistic Regression identified one item that predicted whether a participant was more likely to have had an induced, rather than a spontaneous, OBE: whether a participant had experienced a sensation of leaving their physical body prior to the OBE.
Description:
Two experiments were designed to investigate the contribution of touch and kinaesthesis to haptic perception of the length of raised lines. Experiment 1 showed that judgements based on kinaesthetic information were not more accurate than those based on cutaneous information. Instead, kinaesthetic and cutaneous inputs appear to be weighted almost equally in the haptic percept, with haptic performance more closely approximated by cutaneous performance than by kinaesthetic. In Experiment 2 it was shown that effects attributed to condition (modality) were not due to the speed with which the stimulus or exploring finger moved. Our results challenge the view that kinaesthesis is more important than touch for identification of raised line drawings.
Description:
Haptic perception is mediated by tactile (skin-surface stimulation) and kinesthetic (perception of movement indicating limb position) inputs. In a recognition experiment, participants were asked to match stimuli of different curvatures to those in a visual choice set. They used tactile-only information, kinesthesis-only information, and a combination of both. Movements were either self-generated or passively-guided. The experiment showed that judgements based on self-generated kinesthetic information were more accurate than those based on tactile-only information.
Description:
In four experiments, blindfolded participants were presented with pairs of stimuli simultaneously, one to each index finger. Participants moved one index finger, which was presented with cutaneous and/or kinesthetic stimuli, and this movement caused a raised line to move underneath the other, stationary index finger in a yoked manner. The stimuli were 180 masculine rotations of each other (e.g., < and >), and thus when a < was traced with the moving finger, it caused a > to be felt at the stationary finger. When asked to report the experience, participants predominantly reported the cutaneous stimulus, seemingly being ignorant of the kinesthetic stimulus. This appears to be an intrahaptic capture phenomenon, which is of interest because it suggests that conflict between intrahaptic sensory stimuli can go unnoticed; sometimes we are unaware of how we moved, and sometimes we do not know what we touched. The results are interpreted in light of optimal integration, perceptual suppression, reafference suppression, and inattentional blindness.
Description:
Active touch is often described as yielding “better-quality” information than passive touch. However, some authors have argued that passive-guided movements generate superior percepts due to a reduction in demands on the haptic sensory system. We consider the possibility that passive-guided conditions, as used in most active-passive comparisons, are relatively free from cognitive decision-making, while active conditions involve cognitive loads that are quite high and uncharacteristic of normal sensory processes. Thus studies that purport to show differences in active and passive touch may instead be revealing differences in the amount of cognition involved in active and passive tasks. We hypothesized that passive-guided conditions reduce not the sensory load but the cognitive load that active explorers must bear. To test this hypothesis Blood Oxygen Level Dependent (BOLD) activity was measured using functional Magnetic Resonance Imaging (fMRI) during active and passive-guided fingertip exploration of 2D raised line drawings. Active movements resulted in greater activation (compared with passive movements) in areas implicated in higher order processes such as monitoring and controlling of goal-directed behavior, attention, execution of movements, and error detection. Passive movements, in contrast, produced greater BOLD activity in areas associated with touch perception, length discrimination, tactile object recognition, and efference copy. The activation of a greater number of higher-order processing areas during active relative to passive-guided exploration suggests that instances of passive-guided superiority may not be due to the haptic system’s limited ability to cope with sensory inputs, but rather the restriction imposed by the use of a single finger such that active exploration may require cognitive strategies not demanded in the passive condition. Our findings suggest that previous attempts to compare active and passive touch have, in order to simplify tasks, inadvertently introduced cognitive load at the expense of normal sensory inputs.
Description:
Eye-tracking methodology was used to investigate lapses in the appropriate treatment of ward patients due to not noticing critical cues of deterioration. Forty nursing participants with different levels of experience participated in an interactive screen-based simulation of hypovolemic shock. The results show that 65% of the participants exhibited at least one episode of non-fixation on clinically relevant, fully visible cues that were in plain sight. Thirty-five percent of participants dwelt for sufficient time (>200 ms) on important cues for perception to take place, but no action followed, indicating they had pattern-matching failure. When participants fail to notice what, they should notice in patient status until it is too late, this can have serious consequences. Much work needs to be done, since these human perceptual limitations can affect patient safety in general wards.
Description:
In six experiments, subjects judged the sizes of squares that were presented visually and/or haptically, in unimodal or bimodal conditions. We were interested in which mode most affected size judgments in the bimodal condition when the squares presented to each mode actually differed in size. Three factors varied: whether haptic exploration was passive or active, whether the choice set from which the subjects selected their responses was visual or haptic, and whether cutaneous information was provided in addition to kinesthetic information. To match the task for each mode, visual presentations consisted of a cursor that moved along a square pathway to correspond to the haptic experience of successive segments revealed during exploration. We found that the visual influence on size judgments was greater than the influence of haptics when the haptic experience involved only kinesthesis, passive movement, and a visual choice set. However, when cutaneous input was added to kinesthetic information, size judgments were most influenced by the haptic mode. The results support hypotheses of sensory integration, rather than capture of one sense by the other.
Description:
The effect of the body transfer illusion on the perceived strength of self- and externally-generated "tickle" sensations was investigated. As expected, externally generated movement produced significantly higher ratings of tickliness than those associated with self-generated movements. Surprisingly, the body transfer illusion had no influence on the ratings of tickliness, suggesting that highly surprising, and therefore hard to predict, experiences of body image and first-person perspective do not abolish the attenuation of tickle sensations. In addition, evidence was found that a version of the rubber hand illusion exists within the body transfer illusion. We situate our findings within the larger debate over sensory attenuation: (1) there is an attenuation of prediction errors that depends upon the context in which sensory input is predicted (i.e., efference copy), and (2) sensory attenuation is a necessary consequence of self-generated movement irrespective of context (i.e., active inference). The results support the notion of active inference.