Ivo Todorov

Questioning Anecdotal Beliefs and Scientific Findings: A Reply to Strayer, Medeiros-Ward, and Watson (2013)

Questioning Anecdotal Beliefs and Scientific Findings : A Reply to Strayer, Medeiros-Ward, and Watson (2013)

Hepatitis C Among Injecting Drug Users Is Two Times Higher in Stockholm, Sweden than in Rotterdam, the Netherlands

This study assessed risk behavior and preventive measures for hepatitis C among injecting drug users in Rotterdam, the Netherlands (452 participants, 2002–2003) and Stockholm, Sweden (310 participants, 2004–2006), two cities with contrasting drug policies. Uni- and multivariate logistic regression models were used. We found that the prevalence of hepatitis C was almost two times higher in participants from Stockholm than in participants from Rotterdam, even after adjustment for sex sharing paraphernalia (adjusted relative risk: 1.92, 95% confidence interval: 1.60–2.29). Follow-up comparative studies are needed to determine if policies with structured health programs can decrease transmission of hepatitis C.

Study for now, but judge for later : Delayed judgments of learning promote long term retention

Delayed judgments of learning (JOL) are assumed to be based on covert retrieval attempts. A common finding is that testing memory during learning improves later retention (i.e., the testing effect), and even more so than an equivalent amount of study, but only after a longer retention interval. To test the assertion that also delayed JOLs improve memory, the participants either studied Swahili-Swedish word pairs four times, or they both studied (two times) and performed delayed JOLs (two times) alternately. Final cued recall test were given after either five minutes or one week. Results showed a reliable learning-group by retention-interval interaction, with less forgetting in the group that alternated between studying and making JOLs. The results are discussed in relation to the self-fulfilling prophecy account of Spellman and Bjork (1992), and in terms of study advice, the results further underscore the importance of delaying JOLs when studying and evaluating ones ongoing learning.

Deadlines in space: Selective effects of coordinate spatial processing in multitasking

Many everyday activities require coordination and monitoring of multiple deadlines. One way to handle these temporal demands might be to represent future goals and deadlines as a pattern of spatial relations. We examined the hypothesis that spatial ability, in addition to executive functioning, contributes to individual differences in multitasking. In two studies, participants completed a multitasking session in which they monitored four digital clocks running at different rates. In Study 1, we found that individual differences in spatial ability and executive functions were independent predictors of multiple-task performance. In Study 2, we found that individual differences in specific spatial abilities were selectively related to multiple-task performance, as only coordinate spatial processing, but not categorical, predicted multitasking, even beyond executive functioning and numeracy. In both studies, males outperformed females in spatial ability and multitasking and in Study 2 these sex differences generalized to a simulation of everyday multitasking. Menstrual changes moderated the effects on multitasking, in that sex differences in coordinate spatial processing and multitasking were observed between males and females in the luteal phase of the menstrual cycle, but not between males and females at menses. Overall, these findings suggest that multiple-task performance reflects independent contributions of spatial ability and executive functioning. Furthermore, our results support the distinction of categorical versus coordinate spatial processing, and suggest that these two basic relational processes are selectively affected by female sex hormones and differentially effective in transforming and handling temporal patterns as spatial relations in the context of multitasking.

Time takes space: selective effects of multitasking on concurrent spatial processing

Many everyday activities require coordination and monitoring of complex relations of future goals and deadlines. Cognitive offloading may provide an efficient strategy for reducing control demands by representing future goals and deadlines as a pattern of spatial relations. We tested the hypothesis that multiple-task monitoring involves time-to-space transformational processes, and that these spatial effects are selective with greater demands on coordinate (metric) than categorical (nonmetric) spatial relation processing. Participants completed a multitasking session in which they monitored four series of deadlines, running on different time scales, while making concurrent coordinate or categorical spatial judgments. We expected and found that multitasking taxes concurrent coordinate, but not categorical, spatial processing. Furthermore, males showed a better multitasking performance than females. These findings provide novel experimental evidence for the hypothesis that efficient multitasking involves metric relational processing.

Spatial offloading in multiple task monitoring

ABSTRACT Coordinating multiple tasks requires a high degree of cognitive control, and individuals with limited executive functions often show difficulties in everyday multitasking. We tested the hypothesis that demands on executive control can be alleviated by internally representing the temporal pattern of goals and deadlines as spatial relations. In two experiments, participants completed a multitasking session by monitoring deadlines of four clocks running at different rates, along with separate tasks of executive functioning and spatial ability. In Experiment 1, individual and gender-related differences in spatial ability (mental rotation) predicted multitasking performance, beyond the contributions of both the updating and inhibition components of executive functioning, and even when spatial cues were eliminated from the layout of the monitoring task. Experiment 2 extended these findings by showing that concurrent spatial load impaired task monitoring accuracy, and that these detrimental effects were accentuated when spatial abilities were compromized due to fluctuation in female sex hormones. These findings suggest that multiple task monitoring involves working memory-related functions, but that these cognitive control demands can be offloaded by relying on spatial relation processes.