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:
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:
The efference copy account of the tickle effect (i.e., our inability to tickle ourselves) predicts no tickle effect (i.e., an ability to tickle ourselves) when the trajectory of a tactile stimulus is perturbed relative to the associated movement, and there is evidence in support of this. The active inference account, however, predicts the tickle effect should survive trajectory perturbation. We test these accounts of the tickle effect under the hypothesis that previous findings are due to attentional modulation, and that the tickle effect will be found in a paradigm with no conscious attention directed to the trajectory perturbation. We thus expected to find support for active inference. Our first experiment confirms this hypothesis, while our second seeks to explain previous findings in terms of the modulation of the tickle sensation when there is awareness of, and different degrees of attention to, the spatial tactile and kinesthetic trajectories.
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:
Time judgement and time experience are distinct elements of time perception. It is known that time experience tends to be slow, or dilated, when depressed, but there is less certainty or clarity concerning how depression affects time judgement. Here, we use a Bayesian Prediction Error Minimisation (PEM) framework called 'distrusting the present' as an explanatory and predictive model of both aspects of time perception. An interval production task was designed to probe and modulate the relationship between time perception and depression. Results showed that hopelessness, a symptom of severe depression, was associated with the ordering of interval lengths, reduced overall error, and dilated time experience. We propose that 'distrusting the future' is accompanied by 'trusting the present', leading to the experiences of time dilation when depressed or hopeless. Evidence was also found to support a relative difference model of how hopelessness dilates, and arousal accelerates, the rate of experienced time.
Description:
Time judgement and time experience are distinct elements of time perception. It is known that time experience tends to be slow, or dilated, when depressed, but there is less certainty or clarity concerning how depression affects time judgement. Here, we use a Bayesian Prediction Error Minimisation (PEM) framework called 'distrusting the present' as an explanatory and predictive model of both aspects of time perception. An interval production task was designed to probe and modulate the relationship between time perception and depression. Results showed that hopelessness, a symptom of severe depression, was associated with the ordering of interval lengths, reduced overall error, and dilated time experience. We propose that 'distrusting the future' is accompanied by 'trusting the present', leading to the experiences of time dilation when depressed or hopeless. Evidence was also found to support a relative difference model of how hopelessness dilates, and arousal accelerates, the rate of experienced time.
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:
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.
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:
In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant's responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented.
Description:
In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant's responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented.
Description:
Background We investigated whether consumers’ perception of a café latte beverage would be influenced by the colour (transparent, white or blue) of the mug from which it was drunk. Results In experiment 1, the white mug enhanced the rated “intensity” of the coffee flavour relative to the transparent mug. However, given slight physical differences in the mugs used, a second experiment was conducted using identical glass mugs with coloured sleeves. Once again, the colour of the mug was shown to influence participants’ rating of the coffee. In particular, the coffee was rated as less sweet in the white mug as compared to the transparent and blue mugs. Conclusions Both experiments demonstrate that the colour of the mug affects people’s ratings of a hot beverage. Given that ratings associated with the transparent glass mug were not significantly different from those associated with the blue mug in either experiment, an explanation in terms of simultaneous contrast can be ruled out. However, it is possible that colour contrast between the mug and the coffee may have affected the perceived intensity/sweetness of the coffee. That is, the white mug may have influenced the perceived brownness of the coffee and this, in turn, may have influenced the perceived intensity (and sweetness) of the coffee. These results support the view that the colour of the mug should be considered by those serving coffee as it can influence the consumer’s multisensory coffee drinking experience. These results add to a large and growing body of research highlighting the influence of product-extrinsic colour on the multisensory perception of food and drink.
Description:
Background We investigated whether consumers’ perception of a café latte beverage would be influenced by the colour (transparent, white or blue) of the mug from which it was drunk. Results In experiment 1, the white mug enhanced the rated “intensity” of the coffee flavour relative to the transparent mug. However, given slight physical differences in the mugs used, a second experiment was conducted using identical glass mugs with coloured sleeves. Once again, the colour of the mug was shown to influence participants’ rating of the coffee. In particular, the coffee was rated as less sweet in the white mug as compared to the transparent and blue mugs. Conclusions Both experiments demonstrate that the colour of the mug affects people’s ratings of a hot beverage. Given that ratings associated with the transparent glass mug were not significantly different from those associated with the blue mug in either experiment, an explanation in terms of simultaneous contrast can be ruled out. However, it is possible that colour contrast between the mug and the coffee may have affected the perceived intensity/sweetness of the coffee. That is, the white mug may have influenced the perceived brownness of the coffee and this, in turn, may have influenced the perceived intensity (and sweetness) of the coffee. These results support the view that the colour of the mug should be considered by those serving coffee as it can influence the consumer’s multisensory coffee drinking experience. These results add to a large and growing body of research highlighting the influence of product-extrinsic colour on the multisensory perception of food and drink.
Description:
In this review, we summarize the latest evidence demonstrating that the shape and feel of the glassware (and other receptacles) that we drink from can influence our perception of the taste/flavour of the contents. Such results, traditionally obtained in the world of wine, have often been interpreted in terms of changes in physico-chemical properties (resulting from the retention, or generation, of specific volatile aromatic molecules), or the differing ways in which the shape of the glassware funnels the flow of the liquid across the tongue. It is, however, not always clear that any such physico-chemical differences do, in fact, lead to perceptible differences. Others, meanwhile, have stressed the importance of cultural factors, and the perceived appropriateness, or congruency, of the receptacle to the drink, based on prior experience. Here, though, we argue that there is also a much more fundamental association at work between shape properties and taste/flavour. In particular, the suggestion is made that the shape properties of the drinking receptacle (e.g., whether it be more rounded or angular) – regardless of whether the receptacle is seen, felt, or both – can prime certain expectations in the mind of the drinker. And, based on the theory of crossmodal correspondence, this priming is thought to accentuate certain aspects of the tasting experience, likely as a result of a taster’s attention being focused on the attributes that have been subtly primed.
Description:
In this review, we summarize the latest evidence demonstrating that the shape and feel of the glassware (and other receptacles) that we drink from can influence our perception of the taste/flavour of the contents. Such results, traditionally obtained in the world of wine, have often been interpreted in terms of changes in physico-chemical properties (resulting from the retention, or generation, of specific volatile aromatic molecules), or the differing ways in which the shape of the glassware funnels the flow of the liquid across the tongue. It is, however, not always clear that any such physico-chemical differences do, in fact, lead to perceptible differences. Others, meanwhile, have stressed the importance of cultural factors, and the perceived appropriateness, or congruency, of the receptacle to the drink, based on prior experience. Here, though, we argue that there is also a much more fundamental association at work between shape properties and taste/flavour. In particular, the suggestion is made that the shape properties of the drinking receptacle (e.g., whether it be more rounded or angular) – regardless of whether the receptacle is seen, felt, or both – can prime certain expectations in the mind of the drinker. And, based on the theory of crossmodal correspondence, this priming is thought to accentuate certain aspects of the tasting experience, likely as a result of a taster’s attention being focused on the attributes that have been subtly primed.
Description:
Introduction: “Body swapping” illusions have been used to explore factors contributing to the experience of “owning” an artificial body. Preliminary research indicated that those people diagnosed with schizophrenia experience more vivid illusions of this kind than do “normal” individuals. Objectives: Here, we explored whether participants who rated themselves “high” on the cognitive-perceptual factor of the Schizotypal Personality Questionnaire (SPQ) experienced a more compelling sense of immersion in a variation of the body swapping illusion: The Barbie Doll Illusion. We also hypothesised that these individuals would experience a change in size perception when immersed in the illusion. Method: Forty-four participants wore a pair of Head-Mounted Display goggles connected to a video-camera, and thus a doll’s body replaced their own body in their visual field. In two conditions, touch was either applied synchronously or asynchronously to the doll’s and each participant’s leg. After each condition, participants filled out a questionnaire relating to their experience in the illusion. When both conditions were completed, they filled out the SPQ. Results: Our first hypothesis was confirmed, which suggested that people with higher cognitive-perceptual SPQ scores do indeed experience a more compelling Barbie Doll Illusion; however, our second hypothesis was not supported. Conclusion: Our study demonstrated, for the first time, that proneness to the positive and interpersonal factors of schizotypy in a normal population is sufficient to produce a compelling sense of swapping bodies.
Description:
Introduction: “Body swapping” illusions have been used to explore factors contributing to the experience of “owning” an artificial body. Preliminary research indicated that those people diagnosed with schizophrenia experience more vivid illusions of this kind than do “normal” individuals. Objectives: Here, we explored whether participants who rated themselves “high” on the cognitive-perceptual factor of the Schizotypal Personality Questionnaire (SPQ) experienced a more compelling sense of immersion in a variation of the body swapping illusion: The Barbie Doll Illusion. We also hypothesised that these individuals would experience a change in size perception when immersed in the illusion. Method: Forty-four participants wore a pair of Head-Mounted Display goggles connected to a video-camera, and thus a doll’s body replaced their own body in their visual field. In two conditions, touch was either applied synchronously or asynchronously to the doll’s and each participant’s leg. After each condition, participants filled out a questionnaire relating to their experience in the illusion. When both conditions were completed, they filled out the SPQ. Results: Our first hypothesis was confirmed, which suggested that people with higher cognitive-perceptual SPQ scores do indeed experience a more compelling Barbie Doll Illusion; however, our second hypothesis was not supported. Conclusion: Our study demonstrated, for the first time, that proneness to the positive and interpersonal factors of schizotypy in a normal population is sufficient to produce a compelling sense of swapping bodies.
Description:
Social networking offers teachers and learners exciting opportunities to communicate. Web 2.0 and its synchronous communications platforms provide new avenues for teachers to deliver curriculum and facilitate learning. Further, they provide new avenues for students to engage and intensify their own learning. Being able to chat in real-time with a teacher, usually via face-to-face discussions, is something that many students studying in on-campus (or day) mode take for granted, and is something that distance or off-campus students are generally unable to experience. In the evolving, flexible-learning tertiary environment, viable and effective computer mediated communication (CMC) alternatives to face-to-face teaching need to be explored. These alternatives will only work if they prove useful to students. This article considers student reactions to social media as a teaching tool, probing its benefits and limitations. Over the course of a semester, third year on- and off-campus students communicated with an academic, outside lecture times, via the social networking site facebook®. Students were allowed to ask any questions they had that related to the unit. At the end of the semester students were provided with a 10-item questionnaire asking them to evaluate their experience. This study looked at a specific aspect of social networking — synchronous text-based chat — and the students’ perceptions of its usefulness for their learning
Description:
The function of any visual prosthetic will be to generate patterned stimulation of the visual cortex arising from either direct stimulation (e.g. using cortical implants) or more peripheral inputs (e.g. an artificial retina). Direct cortical stimulation may result in patterns containing relatively few elements (say 10-100) while an artificial retina may deliver more complex patterns. We propose that regardless of the site of intervention, a tactile copy of the input, delivered to the skin at the same time as it is sent to the visual cortex, will offer significant advantages, especially during early stages of testing and development in which the user must 'make sense' of the novel input. The advantages of such a display include: (1) exploitation of multisensory processes such as cross-calibration, learning to discriminate sub-threshold stimuli and perceptual redundancy, (2) a means of measuring strengths and weaknesses of the prosthetic's visual input and evaluation of improvements and (3) a way of quickly adapting the congenitally- or late-blind user to the prosthetic.