RESUMO
How and when motor intentions form has long been controversial. In particular, the extent to which motor preparation and action-related processes produce a conscious experience of intention remains unknown. Here, we used a brain-computer interface (BCI) while participants performed a self-paced movement task to trigger cues upon the detection of a readiness potential (a well-characterized brain signal that precedes movement) or in its absence. The BCI-triggered cues instructed participants either to move or not to move. Following this instruction, participants reported whether they felt they were about to move at the time the cue was presented. Participants were more likely to report an intention (i) when the cue was triggered by the presence of a readiness potential than when the same cue was triggered by its absence, and (ii) when they had just made an action than when they had not. We further describe a time-dependent integration of these two factors: the probability of reporting an intention was maximal when cues were triggered in the presence of a readiness potential, and when participants also executed an action shortly afterwards. Our results provide a first systematic investigation of how prospective and retrospective components are integrated in forming a conscious intention to move.
Assuntos
Conscientização , Intenção , Encéfalo , Sinais (Psicologia) , Humanos , Movimento , VoliçãoRESUMO
The idea that human agents voluntarily control their actions, including their spontaneous movements, strongly implies an anticipatory awareness of action. That is, agents should be aware they are about to act before actually executing a movement. Previous research has identified neural signals that could underpin prospective conscious access to motor preparation, including the readiness potential and the beta-band event-related desynchronization. In this study, we ran two experiments to test whether these two neural precursors of action also tracka subjective feeling of readiness. In Experiment 1, we combined a self-paced action task with an intention-probing design where participants gave binary responses to indicate whether they felt they had been about to move when a probe was presented. In Experiment 2, participants reported their feeling of readiness on a graded scale. We found that the feeling of readiness reliably correlates with the beta-band amplitude, but not with the readiness potential.
RESUMO
The ability to build and expertly manipulate manual tools sets humans apart from other animals. Watching images of manual tools has been shown to elicit a distinct pattern of neural activity in a network of parietal areas, assumingly because tools entail a potential for action-a unique feature related to their functional use and not shared with other manipulable objects. However, a question has been raised whether this selectivity reflects a processing of low-level visual properties-such as elongated shape that is idiosyncratic to most tool-objects-rather than action-specific features. To address this question, we created and behaviourally validated a stimulus set that dissociates objects that are manipulable and nonmanipulable, as well as objects with different degrees of body extension property (tools and non-tools), while controlling for object shape and low-level image properties. We tested the encoding of action-related features by investigating neural representations in two parietal regions of interest (intraparietal sulcus and superior parietal lobule) using functional MRI. Univariate differences between tools and non-tools were not observed when controlling for visual properties, but strong evidence for the action account was nevertheless revealed when using a multivariate approach. Overall, this study provides further evidence that the representational content in the dorsal visual stream reflects encoding of action-specific properties.
Assuntos
Mapeamento Encefálico , Lobo Parietal , Humanos , Imageamento por Ressonância Magnética , Lobo Parietal/diagnóstico por imagem , Reconhecimento Visual de ModelosRESUMO
As the development of the Internet and social media has led to pervasive data collection and usage practices, consumers' privacy concerns have increasingly grown stronger. While previous research has investigated consumer valuation of personal data and privacy, only few studies have investigated valuation of different privacy aspects (e.g., third party sharing). Addressing this research gap in the literature, the present study explores Internet users' valuations of three different privacy aspects on a social networking service (i.e., Facebook), which are commonly captured in privacy policies (i.e., data collection, data control, and third party sharing). A total of 350 participants will be recruited for an experimental online study. The experimental design will consecutively contrast a conventional, free-of-charge version of Facebook with four hypothetical, privacy-enhanced premium versions of the same service. The privacy-enhanced premium versions will offer (1) restricted data collection on side of the company; (2) enhanced data control for users; and (3) no third party sharing, respectively. A fourth premium version offers full protection of all three privacy aspects. Participants' valuation of the privacy aspects captured in the premium versions will be quantified measuring willingness-to-pay. Additionally, a psychological test battery will be employed to examine the psychological mechanisms (e.g., privacy concerns, trust, and risk perceptions) underlying the valuation of privacy. Overall, this study will offer insights into valuation of different privacy aspects, thus providing valuable suggestions for economically sustainable privacy enhancements and alternative business models that are beneficial to consumers, businesses, practitioners, and policymakers, alike.