scholarly journals Tactile temporal offset cues reduce visual representational momentum

2021 ◽  
Author(s):  
Simon Merz ◽  
Christian Frings ◽  
Charles Spence
Keyword(s):  
Strong Interaction ◽  
Tactile Stimulation ◽  
Visual Target ◽  
Representational Momentum ◽  
Vibrotactile Stimulus ◽  
Multisensory Perception ◽  
Perceptual Shift ◽  
First Time ◽  
Temporal Offset ◽  
Temporal Illusions

AbstractThe perception of dynamic objects is sometimes biased. For example, localizing a moving object after it has disappeared results in a perceptual shift in the direction of motion, a bias known as representational momentum. We investigated whether the temporal characteristics of an irrelevant, spatially uninformative vibrotactile stimulus bias the perceived location of a visual target. In two visuotactile experiments, participants judged the final location of a dynamic, visual target. Simultaneously, a continuous (starting with the onset of the visual target, Experiments 1 and 2) or brief (33-ms stimulation, Experiment 2) vibrotactile stimulus (at the palm of participant’s hands) was presented, and the offset disparity between the visual target and tactile stimulation was systematically varied. The results indicate a cross-modal influence of tactile stimulation on the perceived final location of the visual target. Closer inspection of the nature of this cross-modal influence, observed here for the first time, reveals that the vibrotactile stimulus was likely just taken as a temporal cue regarding the offset of the visual target, but no strong interaction and combined processing of the two stimuli occurred. The present results are related to similar cross-modal temporal illusions and current accounts of multisensory perception, integration, and cross-modal facilitation.

scholarly journals Embodied precision: Intranasal oxytocin modulates multisensory integration

2018 ◽  
Author(s):  
Laura Crucianelli ◽  
Yannis Paloyelis ◽  
Lucia Ricciardi ◽  
Paul M Jenkinson ◽  
Aikaterini Fotopoulou
Keyword(s):  
Multisensory Integration ◽  
Tactile Stimulation ◽  
Estimation Error ◽  
The Body ◽  
Multisensory Perception ◽  
Subjective Feeling ◽  
Rubber Hand ◽  
Perceptual Inference ◽  
Double Blind ◽  
Multisensory Input

AbstractMultisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size-weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant’s hidden hand and a visible rubber hand creates illusory bodily ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision or salience of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossed-over study (N = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased the embodied version of the SWI (quantified as weight estimation error). These findings suggest that oxytocin might modulate processes of visuo-tactile multisensory integration by increasing the precision of top-down signals against bottom-up sensory input.

scholarly journals Introspection, opposition and freedom: influence of habits and inhibitory control on choice

2020 ◽  
Author(s):  
Ashild Kummen ◽  
Patrick Haggard ◽  
Gwydion Williams ◽  
Lucie Charles
Keyword(s):  
Free Choice ◽  
Subjective Experience ◽  
Visual Target ◽  
Strong Relationship ◽  
Subjective Feeling ◽  
Response Mapping ◽  
Stimulus Response ◽  
Human Decision ◽  
Extraneous Information ◽  
First Time

How do we avoid unwanted influence when making a choice, and how do we know when our choices are free from such influences? Research shows that human decision processes are often biased by extraneous information and by previous habits. In the present study, we investigated whether free choices are biased in the same ways, and whether the subjective feeling of choosing freely can accurately track these sources of bias. Across three studies, we presented participants with a visual target cueing one of two directions. Participants were instructed to respond by adhering to the suggested direction, to oppose it, or to ignore it and make a ‘free’ choice. We varied the frequency of occurrence of each instruction (experiment 1), of each motor response (experiment 2), and of each visual cue (experiment 3). We found that previously learned stimulus-response mapping affected the ability to make free choices, as participants tended to follow the trained mapping. Moreover, in the detachment condition, participants consistently reported stronger subjective sense of freedom when their actions opposed the cue, rather than followed it. Strikingly, when participants learned through experience to oppose a cue, subsequent free choices evoked by that cue were associated with a boost in subjective freedom, irrespective of whether the response followed or opposed the cue. Thus, the increased subjective sense of freedom associated with opposition appeared to stick to the stimulus that had been repeatedly opposed. Taken together, these findings demonstrate the strong relationship between oppositional responding and subjective experience of freedom, showing for the first time that an illusory sense of autonomy can be acquired through trained opposition.

scholarly journals Action-based attention in Drosophila melanogaster

2019 ◽  
Vol 121 (6) ◽  
pp. 2428-2432 ◽  
Author(s):  
Giovanni Frighetto ◽  
Mauro A. Zordan ◽  
Umberto Castiello ◽  
Aram Megighian
Keyword(s):  
Drosophila Melanogaster ◽  
Visual Target ◽  
Motor Program ◽  
Action Selection ◽  
Wild Type ◽  
Fundamental Process ◽  
Directed Action ◽  
Selection For ◽  
First Time ◽  
Selection For Action

The mechanism of action selection is a widely shared fundamental process required by animals to interact with the environment and adapt to it. A key step in this process is the filtering of the “distracting” sensory inputs that may disturb action selection. Because it has been suggested that, in principle, action selection may also be processed by shared circuits in vertebrate and invertebrates, we wondered whether invertebrates show the ability to filter out “distracting” stimuli during a goal-directed action, as seen in vertebrates. In this experiment, action selection was studied in wild-type Drosophila melanogaster by investigating their reaction to the abrupt appearance of a visual distractor during an ongoing locomotor action directed to a visual target. We found that when the distractor was present, flies tended to shift the original trajectory toward it, thus acknowledging its presence, but they did not fully commit to it, suggesting that an inhibition process took place to continue the unfolding of the planned goal-directed action. To some extent flies appeared to take into account and represent motorically the distractor, but they did not engage in a complete change of their initial motor program in favor of the distractor. These results provide interesting insights into the selection-for-action mechanism, in a context requiring action-centered attention, that might have appeared rather early in the course of evolution. NEW & NOTEWORTHY Action selection and maintenance of a goal-directed action require animals to ignore irrelevant “distracting” stimuli that might elicit alternative motor programs. In this study we observed, in Drosophila melanogaster, a top-down mechanism inhibiting the response toward salient stimuli, to accomplish a goal-directed action. These data highlight, for the first time in an invertebrate organism, that the action-based attention shown by higher organisms, such as humans and nonhuman primates, might have an ancestral origin.

scholarly journals Embodied Precision: Intranasal Oxytocin Modulates Multisensory Integration

2019 ◽  
Vol 31 (4) ◽  
pp. 592-606 ◽  
Author(s):  
Laura Crucianelli ◽  
Yannis Paloyelis ◽  
Lucia Ricciardi ◽  
Paul M. Jenkinson ◽  
Aikaterini Fotopoulou
Keyword(s):  
Multisensory Integration ◽  
Tactile Stimulation ◽  
Estimation Error ◽  
The Body ◽  
Multisensory Perception ◽  
Subjective Feeling ◽  
Body Ownership ◽  
Rubber Hand ◽  
Perceptual Inference ◽  
Multisensory Input

Multisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size–weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant's hidden hand and a visible rubber hand creates illusory body ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine, and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossover study ( n = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased an embodied version of the SWI (quantified as estimation error during a weight estimation task). These findings suggest that oxytocin might modulate processes of visuotactile multisensory integration by increasing the precision of top–down signals against bottom–up sensory input.

scholarly journals Direct coupling of haptic signals between hands

2014 ◽  
Vol 112 (2) ◽  
pp. 619-624 ◽  
Author(s):  
Lucile Dupin ◽  
Vincent Hayward ◽  
Mark Wexler
Keyword(s):  
Tactile Stimulation ◽  
Haptic Perception ◽  
Direct Coupling ◽  
Body Parts ◽  
Stationary Object ◽  
General Phenomenon ◽  
Sensory Inputs ◽  
Motor Actions ◽  
The Brain ◽  
Temporal Offset

Although motor actions can profoundly affect the perceptual interpretation of sensory inputs, it is not known whether the combination of sensory and movement signals occurs only for sensory surfaces undergoing movement or whether it is a more general phenomenon. In the haptic modality, the independent movement of multiple sensory surfaces poses a challenge to the nervous system when combining the tactile and kinesthetic signals into a coherent percept. When exploring a stationary object, the tactile and kinesthetic signals come from the same hand. Here we probe the internal structure of haptic combination by directing the two signal streams to separate hands: one hand moves but receives no tactile stimulation, while the other hand feels the consequences of the first hand’s movement but remains still. We find that both discrete and continuous tactile and kinesthetic signals are combined as if they came from the same hand. This combination proceeds by direct coupling or transfer of the kinesthetic signal from the moving to the feeling hand, rather than assuming the displacement of a mediating object. The combination of signals is due to perception rather than inference, because a small temporal offset between the signals significantly degrades performance. These results suggest that the brain simplifies the complex coordinate transformation task of remapping sensory inputs to take into account the movements of multiple body parts in haptic perception, and they show that the effects of action are not limited to moving sensors.

scholarly journals A Brief Review of Chiral Chemical Potential and Its Physical Effects

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2095
Author(s):  
Li-Kang Yang ◽  
Xiao-Feng Luo ◽  
Jorge Segovia ◽  
Hong-Shi Zong
Keyword(s):  
Strong Interaction ◽  
Chemical Potential ◽  
Chiral Anomaly ◽  
Left Hand ◽  
Quark Stars ◽  
Physical Effects ◽  
Physical Phenomena ◽  
First Time ◽  
Natural Laboratory ◽  
Right And Left Hand

Nontrivial topological gluon configuration is one of the remarkable features of the Quantum Chromodynamics (QCD). Due to chiral anomaly, the chiral imbalance between right- and left-hand quarks can be induced by the transition of the nontrivial gluon configurations between different vacuums. In this review, we will introduce the origin of the chiral chemical potential and its physical effects. These include: (1) the chiral imbalance in the presence of strong magnetic and related physical phenomena; (2) the influence of chiral chemical potential on the QCD phase structure; and (3) the effects of chiral chemical potential on quark stars. Moreover, we propose for the first time that quark stars are likely to be a natural laboratory for testing the destruction of strong interaction CP.

Braille and Morse Code Based Tactile Information Coding and its Applications

2020 ◽  
pp. 2150014
Author(s):  
Wenbo Huang ◽  
Changyuan Wang ◽  
Hongbo Jia
Keyword(s):  
Spatial Distribution ◽  
Tactile Stimulation ◽  
Recognition Rate ◽  
Tactile Sensing ◽  
Information Coding ◽  
Tactile Information ◽  
Morse Code ◽  
Coding Scheme ◽  
Coding Schemes ◽  
First Time

Tactile sensing has recently been used in pattern recognition technology for pilots’ posture information and environmental information. Human tactile sensing is limited, however, through control of the spatial distribution and vibration intensity of each contact in the tactile stimulation array, the accuracy, convenience, and comfort of the tactile device can be comprehensively improved. Moreover, the recognition rate of most current flight posture information methods is low. In this paper, the principle of vibration haptic coding is optimized. A combined coding scheme of “vibration [Formula: see text] sequence” is used to recognize pilot’s flight posture. A novel triangular coding scheme is proposed for the first time. Compared to other commonly used coding schemes such as “needle scheme“ and “rectangle scheme”, experimental results show that the triangular coding scheme is 1.5% more accuracy with response time reduced by nearly 1.25s in recognition pilots’ flight posture information.

scholarly journals Affordance matching predictively shapes the perceptual representation of others’ ongoing actions.

2018 ◽  
Author(s):  
Katrina L McDonough ◽  
Marcello Costantini ◽  
Matthew Hudson ◽  
Patric Bach
Keyword(s):  
Precision Grip ◽  
Predictive Processing ◽  
Small Object ◽  
Perceptual Representation ◽  
Hand Grip ◽  
System P ◽  
Perceptual Shift ◽  
On Line ◽  
High Level ◽  
First Time

Recent predictive processing models argue that action understanding is a predictive process, in which goal inferences are constantly tested by comparing predictions of forthcoming behaviour against the actual perceptual input. In a recent series of studies, we showed that these predictions can be visible as a subtle shift in perceptual action judgments towards these inferred goals. Here we test whether this perceptual shift occurs even when goals are not explicitly given but have to be derived implicitly from the unfolding action kinematics. In two experiments, participants watched an actor reach towards a large object and a small object forming either a whole hand power grip or a precision grip. During its course, the hand suddenly disappeared, and participants made perceptual judgments about the last seen position on a touch screen. As predicted, judgments were consistently biased towards apparent action targets, such that power grips were perceived closer to large objects and precision grips closer to small objects, even if the actual kinematics were the same. Strikingly, perceptual shifts were independent of participants’ explicit goal judgments, and were of equal size when action goals were explicitly judged in each trial (Experiment 1) or not judged (Experiment 2). Moreover, across trials and across participants, explicit goal judgments and perceptual shifts were uncorrelated. This provides evidence, for the first time, that people make on-line adjustments of predicted actions based on the match between hand grip and object goals, distorting the perceptual representation of the action. These distortions may not reflect high-level goal assumptions, but emerge from relatively low-level processing of kinematic features within the perceptual system.

scholarly journals Evidence of salt rich Jurassic extension in the Tethyan-Pyrenean linkage zone. Pre-orogenic inheritance in the Corbières-Languedoc Transfer Zone (Corbières Arc, France)

2021 ◽  
Author(s):  
Antoine Crémades ◽  
Mary Ford ◽  
Julien Charreau
Keyword(s):  
Field Study ◽  
Strong Interaction ◽  
Salt Tectonics ◽  
Southwestern Part ◽  
Stratigraphic Architecture ◽  
Crustal Structures ◽  
Wilson Cycle ◽  
First Time ◽  
Transfer Zone

A detailed field study of Jurassic tectono-stratigraphic architecture of the southwestern part of the Corbières-Languedoc Transfer Zone (CTZT) in the French Pyrenees demonstrates for the first time 3D variations in thickness and stratigraphic geometries on near-orthogonal syn-sedimentary structures linked to Jurassic extension with salt. Some of these structures were previously interpreted as compressional and Pyrenean in origin (Late Santonian-Eocene). Our study instead shows that these are extensional salt- related structures that were reactivated during Pyrenean compression and again during Oligo-Miocene extension. We propose that the structures evolved through a strong interaction between inherited crustal structures of the same orientation, and salt tectonics. Strong segmentation of the CLTZ supra-salt cover by oblique structures, is inherited from Jurassic and is linked to interaction between basement EW structures of the Pyrenean rift domain and NE-SW structures of the European Tethyan margin. We distinguish NE-SW trending stuctures (Cévenoles) as extensional forced folds and NE-SW trending salt ridges that developed above basement cutting faults NE-SW oriented. Salt ridges delimited the future NE-SW trending orogenic domains (retro-foreland, Frontal, Main Nappe). N110 trending Pyrenean structures are represented by the Treilles Fault, a major syn sedimentary fault that roots into Keuper evaporites. This study shows that the Corbières is a key area to better understand Pyreneo-provençal evolution along its whole Wilson cycle (rift to rift) and to better understand the processes that govern the formation of a salt-rich rift transfer zone in a strongly pre-structured crust, its positive inversion and the role of salt tectonics in different deformation phases.

scholarly journals Effect of Rapidly Rising Proton?Proton Total Cross Sections on Idealized Extensive Air Showers

1972 ◽  
Vol 25 (6) ◽  
pp. 679
Author(s):  
JA Campbell
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Strong Interaction ◽  
Extensive Air Showers ◽  
Proton Scattering ◽  
Air Showers ◽  
Proton Proton ◽  
Total Cross Sections ◽  
First Time

A simulation of extensive air showers above 1013 eV in which proton?proton scattering takes place partly through a medium-strong interaction is reported. In previous papers the simulation has been shown to be in fair agreement with observational data. The present version includes for the first time the assumption that the total cross section for proton-proton scattering increases with energy, as concluded in a recent paper by Yodh, Pal, and Trefil. The effect of the assumption is to make a noticeably better agreement between the simulation and the data.

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