Differences Between Consistent and Inconsistent Handedness Remain Consistently Interesting: Ten Years of Research on the Consistency of Handedness With the Edinburgh Handedness Inventory.

Almost 10 years ago Prichard et al. (2013) published a literature review on consistency of handedness. They described how consistency of handedness, typically measured by the Edinburgh Handedness Inventory (EHI), predicted outcomes in memory and decision-making paradigms better than direction of handedness. In the last 10 years, new research has extended these findings and added new theoretical perspectives. The goal of this short form review is to highlight and summarize some of these more intriguing findings and to encourage researchers in the fields of memory and decision making to incorporate handedness as a variable in future research.

Increased levels of autistic traits are associated with atypical moral judgments.

Despite evidence often showing differences between groups with Autism Spectrum Disorder (ASD) and neurotypical controls in moral judgment, the precise nature of these differences has been difficult to establish. At least two reasons for this are (1) that ASD (and its associated characteristics) is difficult to define and (2) that morality, and the inclinations that undergird it, are hard to measure empirically. These challenges have made conclusive associations between ASD and particular patterns of moral judgment hard to come by. Thus, in the current study, participants levels of a traits associated with ASD were assessed by their responses to a questionnaire (i.e., the Iowa Screener) before they made moral judgments across a set of 20 moral dilemmas that independently assess utilitarian and deontological processing. Interestingly, results indicated that increased levels of autistic traits were associated with fewer moral judgments corresponding to either moral theory; that is, higher levels of autistic traits were associated with atypical patterns of moral judgment. In addition, and consistent with some prior methods (e.g., Gaeth et al., 2016), participant scores on the Iowa Screener, as well as their self-identification, were used to categorize participants between two groups (i.e., ASD and Typical) for exploratory purposes. Taken together, this research better informs the relationship between ASD and its associated traits with moral judgment and can inform certain discrepant findings in the field. Implications and ideas for future research are discussed, such as whether traits associated with ASD might relate to alternative moral inclinations, beyond deontology and utilitarianism.

Differences in moral judgment predict behavior in a Covid triage game scenario.

Moral beliefs influence decisions across many contexts, but researchers typically test how these beliefs translate into moral judgments in hypothetical dilemmas. While this is important, in this study (N = 248), we sought to extend these findings by exploring whether moral judgment (specifically utilitarian or deontological processing) predicted behavior in a commons dilemma game against other players (programmed bots) across multiple rounds in the context of the Covid-19 pandemic. Importantly, participants had to weigh short-term needs against long-term dangers of exhausting the community pool (i.e., a tragedy of the commons). As hypothesized, increased utilitarian processing predicted reduced resource extraction from the community pool. In addition to showing that differences in moral judgment predict behavior in a game situation that simulates a somewhat ecologically valid dilemma, these results also replicate previous research connecting morality to opinions about Covid-19 vaccine requirements.

Individual differences in moral judgment predict attitudes towards mandatory vaccinations.

Skepticism about the efficacy and risks related to Covid-19 vaccinations has become a politicized issue. In response, some politicians have proposed policies (such as imposing vaccine passports) aimed at increasing public vaccination rates. The response has been mixed. In the current study (N = 266), we examined the role of conservatism and moral judgments in accounting for these differences. Results from data collected between January and March 2021 showed that increased levels of conservatism and deontological processing (i.e., having a stronger D-process) were associated with less agreement to a government-imposed Covid-19 vaccine mandate. However, participants who made utilitarian responses to traditional switch and footbridge dilemmas reported greater agreement towards the same mandate. These results are consistent with prior findings showing political divides surrounding Covid-19 and indicate that individual differences in moral judgment predict opinion about a significant and current real-world issue.

Predicting interactions in handedness research: The role of integrated versus independent dual-processes.

Over the past two decades, a new way of looking at handedness has emerged (see Prichard, E., Propper, R. E., & Christman, S. D. (2013). Degree of handedness, but not direction, is a systematic predictor of cognitive performance. Frontiers in Psychology, 4, 1-6), with an emphasis on degree (strong/consistent versus mixed/inconsistent) augmenting the traditional emphasis on direction (left versus right) of handedness. Much of this work has focused on main effects: e.g., inconsistent-handers show higher (or lower) performance than consistent-handers. However, many of these "main effects" are actually nested within higher order interactions: e.g., there are no handedness differences in a baseline/control condition, with handedness differences emerging in an experimental condition. Careful examination, though, of these interactions reveals an intriguing and predictable pattern: for integrated dual processes (e.g., episodic memory encoding versus retrieval), the interactions reflect larger effects in inconsistent-, relative to consistent-, handers. For independent, mutually exclusive dual processes (e.g., approach versus withdrawal), the interactions reflect larger effects in consistent-handers. It is argued that these patterns reflect the relative inability of (i) consistent-handers to integrate dual processes, and (ii) inconsistent-handers to keep independent dual processes separate. We also use this same theory to address higher order interactions involving changes in the experimental context as well as other individual difference factors, and make suggestions for future research.

Change detection in complex auditory scenes is predicted by auditory memory, pitch perception, and years of musical training.

Our world is a sonically busy place and we use both acoustic information and experience-based knowledge to make sense of the sounds arriving at our ears. The knowledge we gain through experience has the potential to shape what sounds are prioritized in a complex scene. There are many examples of how visual expertise influences how we perceive objects in visual scenes, but few studies examine how auditory expertise is associated with attentional biases toward familiar real-world sounds in complex scenes. In the current study, we investigated whether musical expertise is associated with the ability to detect changes to real-world sounds in complex auditory scenes, and whether any such benefit is specific to musical instrument sounds. We also examined whether change detection is better for human-generated sounds in general or only communicative human sounds. We found that musicians had less change deafness overall. All listeners were better at detecting human communicative sounds compared to human non-communicative sounds, but this benefit was driven by speech sounds and sounds that were vocally generated. Musical listening skill, speech-in-noise, and executive function abilities were used to predict rates of change deafness. Auditory memory, musical training, fine-grained pitch processing, and an interaction between training and pitch processing accounted for 45.8% of the variance in change deafness. To better understand perceptual and cognitive expertise, it may be more important to measure various auditory skills and relate them to each other, as opposed to comparing experts to non-experts.