Background
The aim of this study was to determine the absolute and relative reliability of the Ruler Drop Test (RDT) for assessing dual-task, choice, and discrimination reaction time. In addition, ...the construct validity of the RDT is examined in comparison to the Deary-Liewald reaction time (DLRT).
Methods
Tests were administered by the same evaluator, one week apart. Intraclass Correlation Coefficient (ICC3.1) was used to measure relative reliability, and the standard error of measurement (SEM) and minimal detectable change (MDC95) were used to measure absolute reliability. Spearman correlation test was used to measure construct validity.
Results
The results showed that the relative reliability was good for the choice ruler drop (ICC = 0.81), moderate for the dual-task ruler drop test (ICC = 0.70) and discrimination ruler drop test (ICC = 0.72), and good for simple ruler drop test. However, the simple ruler drop test had poor reliability (ICC = 0.57). The RDT shows construct validity compared to the DLRT.
Conclusion
We conclude that the RDT is a suitable instrument for measuring dual-task, choice and discrimination reaction time. Future studies should explore the reliability of these measures in other populations.
According to the attentional resources account, mind wandering (or “task-unrelated thought”) is thought to compete with a focal task for attentional resources. Here, we tested two key predictions of ...this account: First, that mind wandering should not interfere with performance on a task that does not require attentional resources; second, that as task requirements become automatized, performance should improve and depth of mind wandering should increase. Here, we used a serial reaction time task with implicit- and explicit-learning groups to test these predictions. Providing novel evidence for the attentional resource account's first prediction, results indicated that depth of mind wandering was negatively associated with learning in the explicit, but not the implicit, group, indicating that mind wandering is associated with impaired explicit, but not implicit, learning. Corroborating the attention resource account's second prediction, we also found that, overall, performance improved while at the same time depth of mind wandering increased. From an implicit-learning perspective, these results are consistent with the claim that explicit learning is impaired under attentional load, but implicit learning is not. Data, analysis code, manuscript preparation code, and pre-print available at osf.io/qzry7/.
The design of novel carbon dots with ad hoc properties requires a comprehensive understanding of their formation mechanism, which is a complex task considering the number of variables involved, such ...as reaction time, structure of precursors or synthetic protocol employed. Herein, we systematically investigated the formation of carbon nanodots by tracking structural, chemical and photophysical features during the hydrothermal synthesis. We demonstrate that the formation of carbon nanodots consists of 4 consecutive steps: (i) aggregation of small organic molecules, (ii) formation of a dense core with an extended shell, (iii) collapse of the shell and (iv) aromatization of the core. In addition, we provide examples of routes towards tuning the core-shell design, synthesizing five novel carbon dots that all consist of an electron-dense core covered by an amine rich ligand shell.
Riemannian geometry has been successfully used in many brain-computer interface (BCI) classification problems and demonstrated superior performance. In this paper, for the first time, it is applied ...to BCI regression problems, an important category of BCI applications. More specifically, we propose a new feature extraction approach for electroencephalogram (EEG)-based BCI regression problems: a spatial filter is first used to increase the signal quality of the EEG trials and also to reduce the dimensionality of the covariance matrices, and then Riemannian tangent space features are extracted. We validate the performance of the proposed approach in reaction time estimation from EEG signals measured in a large-scale sustained-attention psychomotor vigilance task, and show that compared with the traditional powerband features, the tangent space features can reduce the root mean square estimation error by 4.30%-8.30%, and increase the estimation correlation coefficient by 6.59%-11.13%.
Laboratory measures play an important role in the study of aggression because they allow researchers to make causal inferences. However, these measures have also been criticized. In particular, the ...competitive reaction time task (CRTT) has been criticized for allowing aggression to be operationalized in multiple ways, leaving it susceptible to “p‐hacking.” This article describes the development of the CRTT and the ways in which its paradigm flexibility and analytic flexibility allows it to test a wide range of hypotheses and research questions. This flexibility gives the CRTT significant scientific utility, but as with any research paradigm, comes with the obligation that it has to be used with integrity. Although safeguards exist and there is little evidence of misuse, study preregistration can increase confidence in CRTT findings. The importance of findings such as those of Hyatt et al. (in press), which provide further evidence for the validity of the CRTT, are also noted.
Individual differences in cognitive paradigms are increasingly employed to relate cognition to brain structure, chemistry, and function. However, such efforts are often unfruitful, even with the most ...well established tasks. Here we offer an explanation for failures in the application of robust cognitive paradigms to the study of individual differences. Experimental effects become well established – and thus those tasks become popular – when between-subject variability is low. However, low between-subject variability causes low reliability for individual differences, destroying replicable correlations with other factors and potentially undermining published conclusions drawn from correlational relationships. Though these statistical issues have a long history in psychology, they are widely overlooked in cognitive psychology and neuroscience today. In three studies, we assessed test-retest reliability of seven classic tasks: Eriksen Flanker, Stroop, stop-signal, go/no-go, Posner cueing, Navon, and Spatial-Numerical Association of Response Code (SNARC). Reliabilities ranged from 0 to .82, being surprisingly low for most tasks given their common use. As we predicted, this emerged from low variance between individuals rather than high measurement variance. In other words, the very reason such tasks produce robust and easily replicable experimental effects – low between-participant variability – makes their use as correlational tools problematic. We demonstrate that taking such reliability estimates into account has the potential to qualitatively change theoretical conclusions. The implications of our findings are that well-established approaches in experimental psychology and neuropsychology may not directly translate to the study of individual differences in brain structure, chemistry, and function, and alternative metrics may be required.
When people have the chance to help others at a cost to themselves, are cooperative decisions driven by intuition or reflection? To answer this question, recent studies have tested the relationship ...between reaction times (RTs) and cooperation, reporting both positive and negative correlations. To reconcile this apparent contradiction, we argue that decision conflict (rather than the use of intuition vs. reflection) drives response times, leading to an inverted-U shaped relationship between RT and cooperation. Studies 1 through 3 show that intermediate decisions take longer than both extremely selfish and extremely cooperative decisions. Studies 4 and 5 find that the conflict between self-interested and cooperative motives explains individual differences in RTs. Manipulating conflictedness causes longer RTs and more intermediate decisions, and RTs mediate the relationship between conflict and intermediate decisions. Finally, Studies 6 and 7 demonstrate that conflict is distinct from reflection by manipulating the use of intuition (vs. reflection). Experimentally promoting reliance on intuition increases cooperation, but has no effects on decision extremity or feelings of conflictedness. In sum, we provide evidence that RTs should not be interpreted as a direct proxy for the use of intuitive or reflective processes, and dissociate the effects of conflict and reflection in social decision making.
Sequence learning underlies numerous motor, cognitive, and social skills. Previous models and empirical investigations of sequence learning in humans and non-human animals have implicated ...cortico-basal ganglia-cerebellar circuitry as well as other structures. To systematically examine the functional neuroanatomy of sequence learning in humans, we conducted a series of neuroanatomical meta-analyses. We focused on the serial reaction time (SRT) task. This task, which is the most widely used paradigm for probing sequence learning in humans, allows for the rigorous control of visual, motor, and other factors. Controlling for these factors (in sequence-random block contrasts), sequence learning yielded consistent activation only in the basal ganglia, across the striatum (anterior/mid caudate nucleus and putamen) and the globus pallidus. In contrast, when visual, motor, and other factors were not controlled for (in a global analysis with all sequence-baseline contrasts, not just sequence-random contrasts), premotor cortical and cerebellar activation were additionally observed. The study provides solid evidence that, at least as tested with the visuo-motor SRT task, sequence learning in humans relies on the basal ganglia, whereas cerebellar and premotor regions appear to contribute to aspects of the task not related to sequence learning itself. The findings have both basic research and translational implications.
•Using ALE, we synthesized the functional neuroanatomical data on sequence learning.•We focused on the widely used serial reaction time (SRT) task paradigm.•Sequence learning (sequence > random contrast) showed only basal ganglia activation.•This was found in the anterior/mid caudate and putamen, and in the globus pallidus.•Cerebellar/premotor activation was linked to other (visual/motor) SRT task factors.
Implicit learning refers to learning without conscious awareness of the content acquired. Theoretical frameworks of human cognition suggest that intuitions develop based on incomplete perceptions of ...regularity during implicit learning and, in turn, lead to the development of more explicit, consciously-accessible knowledge. Surprisingly, however, this putative information processing pathway (i.e., implicit learning ➔ intuition ➔ explicit knowledge) has yet to be empirically demonstrated. The present study investigated the relationship between implicit learning, intuitions, and explicit knowledge using a modified Serial Reaction Time Task. Results indicate that intuitions of implicitly-learned patterns emerge prior to the development of explicit knowledge. Moreover, intuition timing and accuracy were significantly associated with accuracy of explicit reports. We did not, however, find that stronger implicit learners developed more accurate intuitions. Our findings suggest a crucial role of intuition in the formation of explicit knowledge from implicit learning.
•Intuitions are temporally preceded by implicit learning.•Intuitions about learned content emerge before explicit knowledge.•Intuitions function as a basis of explicit knowledge.•Better implicit learners do not form more accurate intuitions.
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