Chunking in task sequences modulates task inhibition

In a study of the formation of representations of task sequences and its influence on task inhibition, participants first performed tasks in a predictable sequence (e.g., ABACBC) and then performed the tasks in a random sequence. Half of the participants were explicitly instructed about the predictable sequence, whereas the other participants did not receive these instructions. Task-sequence learning was inferred from shorter reaction times (RTs) in predictable relative to random sequences. Persisting inhibition of competing tasks was indicated by increased RTs in n- 2 task repetitions (e.g., ABA) compared with n- 2 nonrepetitions (e.g., CBA). The results show task-sequence learning for both groups. However, task inhibition was reduced in predictable relative to random sequences among instructed-learning participants who formed an explicit representation of the task sequence, whereas sequence learning and task inhibition were independent in the noninstructed group. We hypothesize that the explicit instructions led to chunking of the task sequence, and that n- 2 repetitions served as chunk points (ABA-CBC), so that within-chunk facilitation modulated the inhibition effect.     

A common representational system governed by Weber's law: nonverbal numerical similarity judgments in 6-year-olds and rhesus macaques

This study compared nonverbal numerical processing in 6-year-olds with that in nonhuman animals using a numerical bisection task. In the study, 16 children were trained on a delayed match-to-sample paradigm to match exemplars of two anchor numerosities. Children were then required to indicate whether a sample intermediate to the anchor values was closer to the small anchor value or the large anchor value. For two sets of anchor values with the same ratio, the probability of choosing the larger anchor value increased systematically with sample number, and the psychometric functions superimposed when plotted on a logarithmic scale. The psychometric functions produced by the children also superimposed with the psychometric functions produced by rhesus monkeys in an analogous previous experiment. These examples of superimposition demonstrate that nonverbal number representations, even in children who have acquired the verbal counting system, are modulated by Weber's law.     

The MMPI-2 Restructured Clinical Scales: a paradigmatic shift in scale development

Tellegen et al. (2003) proposed fundamental changes in MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) scale development by discarding empirical scale development in favor of construct validation via Jackson's (1970) sequential system of scale development. As a result of their efforts, a general distress factor (Demoralization) was identified and 8 Restructured Clinical (RC) Scales were developed. Using 7,330 clinical cases from Caldwell's (1997) data set, in this study, we sought to cross-validate the MMPI-2 RC Scales. Scale homogeneity was confirmed with high alpha coefficients and interitem correlations in the expected range. We also achieved a major objective of reducing interscale correlations. In replicating Tellegen et al.'s principal components analysis, we achieved a high concordance for 6 of the 8 RC Scales. We critically examine these results in light of Jackson's construct validation. We discuss the clinical usefulness of the MMPI-2 RC Scales within the context of current and future research.     

Development and Initial Validation of an Implicit Measure of Religiousness‐Spirituality

An implicit measure of religiousness‐spirituality (RS) was constructed and used in two studies. In Study 1, undergraduates completed a Religiousness‐Spirituality Implicit Association Test (RS‐IAT) and several self‐report measures of RS and related constructs (e.g., religious fundamentalism, authoritarianism). Informants rated the participants’ RS. The RS‐IAT was internally consistent. Implicit RS correlated positively with self‐reported RS, spiritual transcendence, spiritual experiences, religious fundamentalism, and intrinsic religiousness. Informant ratings correlated positively with participants’ self‐reported religiousness but not implicit RS. In Study 2, implicit RS accounted for unique variability in self‐reported attitudes toward gay men and lesbian women when controlling for self‐reported religiousness and right‐wing authoritarianism. These findings demonstrate that an implicit measure of trait RS explains some variability in attitudes that self‐report measures do not. An implicit measure of RS could advance the scientific study of religion beyond what is known from self‐report measures.     

Gradual growth versus shape invariance in perceptual decision making

A dominant theme in modeling human perceptual judgments is that sensory neural activity is summed or integrated until a critical bound is reached. Such models predict that, in general, the shape of response time distributions change across conditions, although in practice, this shape change may be subtle. An alternative view is that response time distributions are shape invariant across conditions or groups. Shape invariance is predicted by some race models in which the first of several parallel fibers to communicate the signal determines the response. We competitively assess a specific gradual growth model, the one-bound diffusion model, against a natural shape-invariant competitor: shape invariance in an inverse Gaussian distribution. Assessment of subtle shape change versus shape invariance of response time distributions is aided by a Bayesian approach that allows the pooling of information across multiple participants. We find, conditional on reasonable distributional assumptions, subtle shape changes in response time that are highly concordant with a simple diffusion gradual growth model and discordant with shape invariance.     

Crossmodal action selection: Evidence from dual-task compatibility

Response-related mechanisms of multitasking were studied by analyzing simultaneous processing of responses in different modalities (i.e., crossmodal action). Participants responded to a single auditory stimulus with a saccade, a manual response (single-task conditions), or both (dual-task condition). We used a spatially incompatible stimulus-response mapping for one task, but not for the other. Critically, inverting these mappings varied temporal task overlap in dual-task conditions while keeping spatial incompatibility across responses constant. Unlike previous paradigms, temporal task overlap was manipulated without utilizing sequential stimulus presentation, which might induce strategic serial processing. The results revealed dual-task costs, but these were not affected by an increase of temporal task overlap. This finding is evidence for parallel response selection in multitasking. We propose that crossmodal action is processed by a central mapping-selection mechanism in working memory and that the dual-task costs are mainly caused by mapping-related crosstalk.     

Lateralisation of diffuse positive and negative affect: Ascribing valence to ambiguous stimuli

The available evidence regarding the lateralisation of affect is rather divergent. Interestingly, the common procedure in previous research on affective lateralisation has been to measure hemispheric dominance following exposure to concrete affective stimuli. Therefore, prior research seems to tap primarily into the lateralisation of specific approach–avoidance motivations rather than diffuse affective states. The present research adopted an alternative methodological approach that excluded approach–avoidance motivations and merely studied the lateralised nature of diffuse affect. Participants evaluated ambiguous stimuli presented in either the right or left visual field. Results showed that stimuli presented in the left visual field were significantly more often ascribed a positive meaning compared to information in the right visual field. The present findings are compatible with related lateralised processes and underscore the necessity of distinguishing between specific motivations and diffuse affect.     

Mental rotation of letters,pictures, and three-dimensional objects in German dyslexic children

This study examines mental rotation ability in children with developmental dyslexia. Prior investigations have yielded equivocal results that might be due to differences in stimulus material and testing formats employed. Whereas some investigators found dyslexic readers to be impaired in mental rotation, others did not report any performance differences or even superior spatial performance for dyslexia. Here, we report a comparison of mental rotation for letters, three-dimensional figures sensu Shepard and Metzler, and colored pictures of animals or humans in second-grade German dyslexic readers. Findings indicate that dyslexic readers are impaired in mental rotation for all three kinds of stimuli. Effects of general intelligence were controlled. Furthermore, dyslexic children were deficient in other spatial abilities like identifying letters or forms among distracters. These results are discussed with respect to the hypotheses of a developmental dysfunction of the parietal cortex or a subtle anomaly in cerebellar function in dyslexic readers.     

How many notions of necessity?

Evans distinguishes between superficial necessity and deep necessity in his analysis of the contingent a priori. The distinction between these two notions of necessity is formalized by Davies and Humberstone through the addition of the operator Fixedly to Actuality Modal Logic (AML, S5A), where deep necessity is represented by the combination Fixedly Actually. Wehmeier’s Subjunctive Modal Logic (SML) provides an extension of the expressive capacity of ordinary modal predicate logic alternative to AML. I add Fixedly to SML and show that in the system SML with Fixedly the distinction between deep and superficial necessity disappears. I conclude that the existence of the distinction between deep and superficial necessity, as well as the existence of the contingent a priori, cannot be asserted independently of the choice of background logic.