The impact of MRI scanner environment on perceptual decision-making

Despite the widespread use of functional magnetic resonance imaging (fMRI), few studies have addressed scanner effects on performance. The studies that have examined this question show a wide variety of results. In this article we report analyses of three experiments in which participants performed a perceptual decision-making task both in a traditional setting as well as inside an MRI scanner. The results consistently show that response times increase inside the scanner. Error rates also increase, but to a lesser extent. To reveal the underlying mechanisms that drive the behavioral changes when performing a task inside the MRI scanner, the data were analyzed using the linear ballistic accumulator model of decision-making. These analyses show that, in the scanner, participants exhibit a slow down of the motor component of the response and have less attentional focus on the task. However, the balance between focus and motor slowing depends on the specific task requirements.     

Neural mechanisms of sensitivity to peer information in young adult cannabis users

Though social influence is a critical factor in the initiation and maintenance of marijuana use, the neural correlates of influence in those who use marijuana are unknown. In this study, marijuana-using young adults (MJ; n = 20) and controls (CON; n = 23) performed a decision-making task in which they made a perceptual choice after viewing the choices of unknown peers via photographs, while they underwent functional magnetic resonance imaging scans. The MJ and CON groups did not show differences in the overall number of choices that agreed with versus opposed group influence, but only the MJ group showed reaction time slowing when deciding against group choices. Longer reaction times were associated with greater activation of frontal regions. The MJ goup, compared to CON, showed significantly greater activation in the caudate when presented with peer information. Across groups, caudate activation was associated with self-reported susceptibility to influence. These findings indicate that young adults who use MJ may exhibit increased effort when confronted with opposing peer influence, as well as exhibit greater responsivity of the caudate to social information. These results not only better define the neural basis of social decisions, but also suggest that marijuana use is associated with exaggerated neural activity during decision making that involves social information.     

Sensitivity in detecting facial displays of emotion: Impact of maternal depression and oxytocin receptor genotype

The current study examined sensitivity in detecting emotional faces among children of depressed and non-depressed mothers. A second goal was to examine the potential moderating role of the oxytocin receptor gene (OXTR rs53576), which has been linked to emotion recognition in the past. Participants included 247 children (ages 8–14). Children completed a forced choice emotion identification task. Maternal history of major depressive disorder during children's lives was associated with children's sensitivity in detecting emotional faces among children homozygous for the OXTR rs53576 G allele, but not among carriers of the A allele. Among G homozygotes, children of depressed mothers exhibited increased sensitivity in detecting sad faces, and reduced sensitivity in detecting happiness, compared to children of non-depressed mothers.     

Differences in emotion modulation using cognitive reappraisal in individuals with and without suicidal ideation: An ERP study

Difficulties in emotion regulation have been associated with increased suicidal thoughts and behaviours. The majority of studies have examined self-reported use of emotion regulation strategies. In contrast, the current study focused on a direct measure of individuals’ ability to use a specific emotion regulation strategy, cognitive reappraisal, using the late positive potential (LPP), an event-related potential component that reflects attention to emotional stimuli. Specifically, the cognitive reappraisal ability of 33 undergraduate students was assessed via an image-viewing task during which the participants had to passively view, increase or reduce their emotions in response to looking at neutral, positive or dysphoric images. We found that participants with a history of suicidal ideation (SI) had significantly higher LPP when asked to reduce negative emotion in response to dysphoric images, compared to individuals with no history of SI. These findings suggest that difficulties with using cognitive reappraisal, specifically to decrease negative affect, might be linked to suicide risk.     

Language statistics explain the spatial–numerical association of response codes

The spatial–numerical association of response codes (SNARC) has shown that parity judgments with participants’ left hands yield faster response times (RTs) for smaller numbers than for larger numbers, with the opposite result for right-hand responses. These findings have been explained by participants perceptually simulating magnitude on a mental number line. In three RT experiments, we showed that the SNARC effect can also be explained by language statistics. Participants made parity judgments of number words (Exp. 1) and Arabic numerals (Exp. 2). Linguistic frequencies of the number words and numbers mirrored the SNARC effect, explaining aspects of processing that a perceptual simulation account could not. In Experiment 3, we investigated whether high- and low-frequency nonnumerical words would also elicit a SNARC-like effect. Again, RTs were faster for high-frequency words for left-hand responses, with the opposite result for right-hand responses. These results demonstrate that what has only been attributed to perceptual simulation should also be attributed to language statistics.     

How crucial is the response format for the testing effect?

Combining study and test trials during learning is more beneficial for long-term retention than repeated study without testing (i.e., the testing effect). Less is known about the relative efficacy of different response formats during testing. We tested the hypothesis that overt testing (typing responses on a keyboard) during a practice phase benefits later memory more than covert testing (only pressing a button to indicate successful retrieval). In Experiment 1, three groups learned 40 word pairs either by repeatedly studying them, by studying and overtly testing them, or by studying and covertly testing them. In Experiment 2, only the two testing conditions were manipulated in a within-subjects design. In both experiments, participants received cued recall tests after a short (~19 min) and a long (1 week) retention interval. In Experiment 1, all groups performed equally well at the short retention interval. The overt testing group reliably outperformed the repeated study group after 1 week, whereas the covert testing group performed insignificantly different from both these groups. Hence, the testing effect was demonstrated for overt, but failed to show for covert testing. In Experiment 2, overtly tested items were better and more quickly retrieved than those covertly tested. Further, this does not seem to be due to any differences in retrieval effort during learning. To conclude, overt testing was more beneficial for later retention than covert testing, but the effect size was small. Possible explanations are discussed.     

“A new and modern golden age of Jewish culture”: shaping the cultural politics of transnational Jewish antifascism

The Holocaust and a worldwide Jewish enthusiasm and support for the Red Army’s defeat of the German Army on the Eastern Front led to a greater sense of international Jewish consciousness and solidarity often tied to an antifascist politics. Utilizing a transnational lens, I explore how Jewish antifascists of the immediate post-war period proffered a novel cultural politics as a means of addressing ongoing international issues of post-Holocaust Jewish survival in a dangerous and politically uncertain modernity. I examine three Jewish left magazines of the late 1940s that were involved in a loose international antifascist progressive Jewish network and ideological framework. These magazines Jewish Life (USA), New Life (UK) and Unity (Australia) represented similar antifascist politics and cultural outlooks in the USA, Britain and Australia, respectively. They have received little sustained scholarly attention previously. I analyse their vision of diverse multilingual Jewish cultures which were to be promoted and developed in any country where Jews lived and in whatever language they spoke. Their cultural vision represented antifascist values against bourgeois or nationalist Jewish culture and broadly reflected a pro-Soviet, progressive and Jewish internationalist, Popular Front politics and worldview.     

Monitor yourself! Deficient error-related brain activity predicts real-life self-control failures

Despite their immense relevance, the neurocognitive mechanisms underlying real-life self-control failures (SCFs) are insufficiently understood. Whereas previous studies have shown that SCFs were associated with decreased activity in the right inferior frontal gyrus (rIFG; a region involved in cognitive control), here we consider the possibility that the reduced implementation of cognitive control in individuals with low self-control may be due to impaired performance monitoring. Following a brain-as-predictor approach, we combined experience sampling of daily SCFs with functional magnetic resonance imaging (fMRI) in a Stroop task. In our sample of 118 participants, proneness to SCF was reliably predicted by low error-related activation of a performance-monitoring network (comprising anterior mid-cingulate cortex, presupplementary motor area, and anterior insula), low posterror rIFG activation, and reduced posterror slowing. Remarkably, these neural and behavioral measures predicted variability in SCFs beyond what was predicted by self-reported trait self-control. These results suggest that real-life SCFs may result from deficient performance monitoring, leading to reduced recruitment of cognitive control after responses that conflict with superordinate goals.     

A Modal Sortal Logic

An intensional semantic system for languages containing, in their logical syntax, sortal quantifiers, sortal identities, (second-order) quantifiers over sortals and the necessity operator is constructed. This semantics provides non-standard assignments to predicate expressions, which diverge in kind from the entities assigned to sortal terms by the same semantic system. The nature of the entities assigned to predicate expressions shows, at the same time, that there is an internal semantic connection between those expressions and sortal terms. A formal logical system is formulated that is proved to be absolutely consistent, sound and complete with respect to the intensional semantic system.     

Coh-metrix: analysis of text on cohesion and language.

Advances in computational linguistics and discourse processing have made it possible to automate many language- and text-processing mechanisms. We have developed a computer tool called Coh-Metrix, which analyzes texts on over 200 measures of cohesion, language, and readability. Its modules use lexicons, part-of-speech classifiers, syntactic parsers, templates, corpora, latent semantic analysis, and other components that are widely used in computational linguistics. After the user enters an English text, CohMetrix returns measures requested by the user. In addition, a facility allows the user to store the results of these analyses in data files (such as Text, Excel, and SPSS). Standard text readability formulas scale texts on difficulty by relying on word length and sentence length, whereas Coh-Metrix is sensitive to cohesion relations, world knowledge, and language and discourse characteristics.