Libet's experiment: A complex replication.

Libet's experiment is an influential classical study, which does not stop provoking heated debates. However, a full-scale replication has not been carried out to this day. Libet-style studies have usually focused on isolated ideas and concepts and never on the whole experiment in all its complexity. This paper presents detailed methodological description and results of a complex replication study. The methodology follows Libet's directions closely in most cases; when it does not, the differences are described and elaborated. The results replicate Libet's key findings, but substantial differences were found in some of the results' categories, such as the introspective reports or the number of readiness-potentials found. The discussion also addresses some current problems pertaining the methodology of the Libet-style experiments and provides some recommendations based on a detailed process evaluation.

Libet's experiment: Questioning the validity of measuring the urge to move.

The time of subjectively registered urge to move (W) constituted the central point of most Libet-style experiments. It is therefore crucial to verify the W validity. Our experiment was based on the assumption that the W time is inferred, rather than introspectively perceived. We used the rotating spot method to gather the W reports together with the reports of the subjective timing of actual movement (M). The subjects were assigned the tasks in two different orders. When measured as first in the respective session, no significant difference between W and M values was found, which suggests that uninformed subjects tend to confuse W for M reports. Moreover, we found that W values measured after the M task were significantly earlier than W values measured before M. This phenomenon suggests that the apparent difference between W and M values is in fact caused by the subjects' previous experience with M measurements.

Libet's legacy: A primer to the neuroscience of volition.

The neuroscience of volition is an emerging subfield of the brain sciences, with hundreds of papers on the role of consciousness in action formation published each year. This makes the state-of-the-art in the discipline poorly accessible to newcomers and difficult to follow even for experts in the field. Here we provide a comprehensive summary of research in this field since its inception that will be useful to both groups. We also discuss important ideas that have received little coverage in the literature so far. We systematically reviewed a set of 2220 publications, with detailed consideration of almost 500 of the most relevant papers. We provide a thorough introduction to the seminal work of Benjamin Libet from the 1960s to 1980s. We also discuss common criticisms of Libet's method, including temporal introspection, the interpretation of the assumed physiological correlates of volition, and various conceptual issues. We conclude with recent advances and potential future directions in the field, highlighting modern methodological approaches to volition, as well as important recent findings.

The process of replication target selection in psychology: what to consider?

Increased execution of replication studies contributes to the effort to restore credibility of empirical research. However, a second generation of problems arises: the number of potential replication targets is at a serious mismatch with available resources. Given limited resources, replication target selection should be well-justified, systematic and transparently communicated. At present the discussion on what to consider when selecting a replication target is limited to theoretical discussion, self-reported justifications and a few formalized suggestions. In this Registered Report, we proposed a study involving the scientific community to create a list of considerations for consultation when selecting a replication target in psychology. We employed a modified Delphi approach. First, we constructed a preliminary list of considerations. Second, we surveyed psychologists who previously selected a replication target with regards to their considerations. Third, we incorporated the results into the preliminary list of considerations and sent the updated list to a group of individuals knowledgeable about concerns regarding replication target selection. Over the course of several rounds, we established consensus regarding what to consider when selecting a replication target. The resulting checklist can be used for transparently communicating the rationale for selecting studies for replication.

Internet addiction among Czech adolescents.

Our study estimates the prevalence of Internet addiction in Czech adolescents as well as differences by gender and school type. A total of 3,950 adolescents (n = 1,940 boys, n = 2,010 girls) from 11 to 19 years of age (M = 15.73, SD = 1.99) participated in the research. They completed the Internet Addiction Test, which consists of subscales for Salience, Excessive Use, Neglect Work, Anticipation, Lack of Control, and Neglect Social Life. The results indicate that adolescent girls have higher levels of internet addiction. In boys, unlike girls, internet addiction was associated with a reduction in social relationships and interactions. Our findings show interesting differences between adolescent girls and boys and the type of school attended in the Czech population in terms of Internet addiction.

EEG data and introspective reports from the Libet׳s experiment replication.

This article provides data from a contemporary replication of Libet׳s experiment. For the methodology, results and discussion of the replication, see the article "Libet׳s Experiment: A Complex Replication" (Dominik et al., 2018). Three types of data are presented in this article: (1) introspective reports (M, W and S), (2) EMG onset times relative to a mouse click or to the target time in tasks with a movement at pre-set time and (3) relevant averaged EEG data.