Illusions of Force Perception: The Role of Sensori-Motor Predictions, Visual Information, and Motor Errors

2007 ◽  
Vol 97 (5) ◽  
pp. 3305-3313 ◽  
Author(s):  
Jörn Diedrichsen ◽  
Timothy Verstynen ◽  
Andrew Hon ◽  
Yi Zhang ◽  
Richard B. Ivry
Keyword(s):  
Visual Information ◽  
Efference Copy ◽  
Visual Object ◽  
Postural Response ◽  
Virtual Reality System ◽  
Force Perception ◽  
Information Signaling ◽  
Trial Basis ◽  
Fast Adaptation

Internal predictions influence the perception of force. When we support an object with one hand and lift it up with the other, we expect the force to disappear from the first, postural hand. In a virtual reality system, we violated this prediction by maintaining the force on the postural hand, whereas the object was still seen and felt to be lifted by the lifting hand. In this situation, participants perceived an illusionary increase in force on the postural hand, which was, in reality, constant. We test three possible mechanisms of how force perception may be influenced in this context. First, we showed that part of the illusion can be linked to a sensorimotor prediction—the predicted sensory consequences based on an efference copy of the lifting action. The illusion is reduced when the object is lifted by an external force. We also showed that the illusion changes on a trial-by-trial basis, paralleling the fast adaptation of the postural response. Second, motor errors that arise from a miscalibrated forward model do not contribute to the illusion; the illusion was unchanged even when we prevented motor errors by supporting the postural hand. Finally, visual information signaling the removal of the object is sufficient to elicit part of the illusion. These results argue that both sensorimotor predictions and visual object information, but not motor errors, influence force perception.

scholarly journals Inclusive digital finance: the industry of equity crowdfunding

2021 ◽  
Author(s):  
Vincenzo Butticè ◽  
Silvio Vismara
Keyword(s):  
Visual Information ◽  
Entrepreneurial Finance ◽  
Industrial Dynamics ◽  
Relevant Research ◽  
Research Directions ◽  
Entrepreneurial Ventures ◽  
Equity Crowdfunding ◽  
Recent Developments

AbstractNowadays equity crowdfunding plays an important role in the entrepreneurial finance markets. To better understand the functioning of the industry, it is important to consider the entire equity crowdfunding process and all the actors involved. Equity crowdfunding platforms match indeed the demand of capital from entrepreneurial ventures with the supply of capital by investors. This manuscript is a first step in this direction, by (1) comparing equity crowdfunding with traditional sources of entrepreneurial finance; (2) discussing the potential and the perils of equity crowdfunding for inclusivity and democratization; (3) highlighting the role of visual information in digital finance; and (4) providing first insights on the industrial dynamics in equity crowdfunding. The paper gives researchers and practitioners orientation about recent developments in equity crowdfunding literature and provides relevant research directions.

scholarly journals The process of transprofessional collaboration: how caregivers integrated the perspectives of rehabilitation through working with a physical therapist

2020 ◽  
Vol 8 (4) ◽  
pp. e000378
Author(s):  
Ryohei Goto ◽  
Junji Haruta
Keyword(s):  
Nursing Home ◽  
Action Research ◽  
Physical Therapist ◽  
Nursing Home Residents ◽  
Research Approach ◽  
Action Research Approach ◽  
Informal Interview ◽  
Trial Basis ◽  
Field Notes

ObjectivesTo clarify the process of how caregivers in a nursing home integrate the perspectives of rehabilitation into their responsibilities through working with a physical therapist.DesignThis study was conducted under an action research approach.SettingThe target facility was a nursing home located in Japan. The researcher, a physical therapist, worked at the nursing home once a week from April 2016 to March 2017. During the study period, he created field notes focused on the dialogue and action of caregivers regarding care, responses of caregivers to the physical therapist and reflections as a physical therapist. Caregivers were also given a short informal interview about their relationship with the nursing home residents. For data analysis, two researchers discussed the content based on the field notes, consolidating the findings.ParticipantsThe participants were caregivers who worked at the target facility. Thirty-eight caregivers agreed to participate. Average age was 39.6±11.1 years, 14 (37%) were male and average caregiver experience was 9.8 years.ResultsTwo cycles of action research were conducted during the study period. There were four stages in the process of how caregivers in the nursing home integrated the perspectives of rehabilitation through their work with the physical therapist. First, caregivers resisted having the rehabilitation programme carried out in the unit because they perceived that rehabilitation performed by a physical therapist was a special process and not under their responsibility. However, the caregivers were given a shared perspective on rehabilitation by the physical therapist, which helped them to understand the meaning of care to adapt the residents’ abilities to their daily life. They practised resident-centred care on a trial basis, although with a sense of conflict between their new and previous role, which emphasised the safety of residents’ lives and personhood. The caregivers increased their self-efficacy as their knowledge and skills were supplemented by the physical therapist and his approval of their attempted care. They were then able to commit to their newly conceived specialty of care as a means of supporting the lives of residents.ConclusionsThe process of working with a physical therapist led to a change in caregivers’ perception and behaviours, which occurred in four stages: resistance to incorporation, recapture of other perspectives, conflicts and trials in the role of caregiver and transformation to a resident-centred perspective.

scholarly journals Interphotoreceptor coupling: an evolutionary perspective

2021 ◽  
Author(s):  
Lorenzo Cangiano ◽  
Sabrina Asteriti
Keyword(s):  
Visual Information ◽  
Signal To Noise Ratio ◽  
Electrical Coupling ◽  
Physiological Role ◽  
Cellular Processes ◽  
Contact Points ◽  
Highly Sensitive ◽  
The Many ◽  
The Impact

AbstractIn the vertebrate retina, signals generated by cones of different spectral preference and by highly sensitive rod photoreceptors interact at various levels to extract salient visual information. The first opportunity for such interaction is offered by electrical coupling of the photoreceptors themselves, which is mediated by gap junctions located at the contact points of specialised cellular processes: synaptic terminals, telodendria and radial fins. Here, we examine the evolutionary pressures for and against interphotoreceptor coupling, which are likely to have shaped how coupling is deployed in different species. The impact of coupling on signal to noise ratio, spatial acuity, contrast sensitivity, absolute and increment threshold, retinal signal flow and colour discrimination is discussed while emphasising available data from a variety of vertebrate models spanning from lampreys to primates. We highlight the many gaps in our knowledge, persisting discrepancies in the literature, as well as some major unanswered questions on the actual extent and physiological role of cone-cone, rod-cone and rod-rod communication. Lastly, we point toward limited but intriguing evidence suggestive of the ancestral form of coupling among ciliary photoreceptors.

scholarly journals Concurrent neuroimaging and neurostimulation reveals a causal role for dlPFC in coding of task-relevant information

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jade B. Jackson ◽  
Eva Feredoes ◽  
Anina N. Rich ◽  
Michael Lindner ◽  
Alexandra Woolgar
Keyword(s):  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Relevant Information ◽  
Irrelevant Information ◽  
Visual Object ◽  
Information Coding ◽  
Frontoparietal Cortex ◽  
Dorsolateral Prefrontal ◽  
The Impact

AbstractDorsolateral prefrontal cortex (dlPFC) is proposed to drive brain-wide focus by biasing processing in favour of task-relevant information. A longstanding debate concerns whether this is achieved through enhancing processing of relevant information and/or by inhibiting irrelevant information. To address this, we applied transcranial magnetic stimulation (TMS) during fMRI, and tested for causal changes in information coding. Participants attended to one feature, whilst ignoring another feature, of a visual object. If dlPFC is necessary for facilitation, disruptive TMS should decrease coding of attended features. Conversely, if dlPFC is crucial for inhibition, TMS should increase coding of ignored features. Here, we show that TMS decreases coding of relevant information across frontoparietal cortex, and the impact is significantly stronger than any effect on irrelevant information, which is not statistically detectable. This provides causal evidence for a specific role of dlPFC in enhancing task-relevant representations and demonstrates the cognitive-neural insights possible with concurrent TMS-fMRI-MVPA.

scholarly journals How much do visual cues help listeners in perceiving accented speech?

2018 ◽  
Vol 40 (1) ◽  
pp. 93-109
Author(s):  
YI ZHENG ◽  
ARTHUR G. SAMUEL
Keyword(s):  
Visual Information ◽  
Visual Cues ◽  
Nonnative Speakers ◽  
Apparent Distance ◽  
Native English Speakers ◽  
English Speakers ◽  
Accented Speech ◽  
Compressed Speech ◽  
Degraded Speech

AbstractIt has been documented that lipreading facilitates the understanding of difficult speech, such as noisy speech and time-compressed speech. However, relatively little work has addressed the role of visual information in perceiving accented speech, another type of difficult speech. In this study, we specifically focus on accented word recognition. One hundred forty-two native English speakers made lexical decision judgments on English words or nonwords produced by speakers with Mandarin Chinese accents. The stimuli were presented as either as videos that were of a relatively far speaker or as videos in which we zoomed in on the speaker’s head. Consistent with studies of degraded speech, listeners were more accurate at recognizing accented words when they saw lip movements from the closer apparent distance. The effect of apparent distance tended to be larger under nonoptimal conditions: when stimuli were nonwords than words, and when stimuli were produced by a speaker who had a relatively strong accent. However, we did not find any influence of listeners’ prior experience with Chinese accented speech, suggesting that cross-talker generalization is limited. The current study provides practical suggestions for effective communication between native and nonnative speakers: visual information is useful, and it is more useful in some circumstances than others.

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