The role of expertise in the aesthetic evaluation of mathematical equations.

There is a notion that mathematical equations can be considered aesthetic objects. However, whereas some aesthetic experiences are triggered primarily by the sensory properties of objects, for mathematical equations aesthetic judgments extend beyond their sensory qualities and are also informed by semantics and knowledge. Therefore, to the extent that expertise in mathematics represents the accumulation of domain knowledge, it should influence aesthetic judgments of equations. In a between-groups study design involving university students who majored in mathematics (i.e., experts) or not (i.e., laypeople), we found support for the hypothesis that mathematics majors exhibit more agreement in their aesthetic judgments of equations-reflecting a greater degree of shared variance driven by formal training in the domain. Furthermore, their judgments were driven more strongly by familiarity and meaning than was the case for laypeople. These results suggest that expertise via advanced training in mathematics alters (and sharpens) aesthetic judgments of mathematical equations.

Effects of testosterone administration on fMRI responses to executive function, aggressive behavior, and emotion processing tasks during severe exercise- and diet-induced energy deficit.

BACKGROUND: Clinical administration of testosterone is widely used due to a variety of claimed physical and cognitive benefits. Testosterone administration is associated with enhanced brain and cognitive function, as well as mood, in energy-balanced males, although such relationships are controversial. However, the effects of testosterone administration on the brains of energy-deficient males, whose testosterone concentrations are likely to be well below normal, have not been investigated. METHODS: This study collected functional magnetic resonance imaging (fMRI) data from 50 non-obese young men before (PRE) and shortly after (POST) 28 days of severe exercise-and-diet-induced energy deficit during which testosterone (200 mg testosterone enanthate per week in sesame oil, TEST) or placebo (sesame seed oil only, PLA) were administered. Scans were also collected after a post-energy-deficit weight regain period (REC). Participants completed five fMRI tasks that assessed aspects of: 1) executive function (Attention Network Task or ANT; Multi-Source Interference Task or MSIT; AXE Continuous Processing Task or AXCPT); 2) aggressive behavior (Provoked Aggression Task or AGG); and 3) latent emotion processing (Emotional Face Processing or EMO). RESULTS: Changes over time in task-related fMRI activation in a priori defined task-critical brain regions during performance of 2 out of 5 tasks were significantly different between TEST and PLA, with TEST showing greater levels of activation during ANT in the right anterior cingulate gyrus at POST and during MSIT in several brain regions at REC. Changes over time in objective task performance were not statistically significant; testosterone-treated volunteers had greater self-reported anger during AGG at POST. CONCLUSIONS: Testosterone administration can alter some aspects of brain function during severe energy deficit and increase levels of anger.

Can a fast thinker be a good thinker? The neural correlates of base-rate neglect measured using a two-response paradigm.

Traditionally, it has been assumed that logical thinking requires deliberation. However, people can also make logical responses quickly, exhibiting logical intuitions. We examined the neural correlates of logical intuitions by administering base rate problems during fMRI scanning using a two-response paradigm where participants first responded quickly and then reflectively to problems that did or did not pit a normative response against an intuitively-cued stereotypical response (i.e., conflict vs. non-conflict problems). As predicted, participants were less likely to make judgments in accordance with base rates on conflict problems. Critically, in only 4% of cases did longer deliberation change an initially biased response to a normatively correct response. The fMRI data revealed that intuitively-made initial biased judgments nevertheless activate regions typically involved in cognitive control, executive functions and attention, including anterior, inferior, middle and superior frontal cortex, suggesting that even when errors are made, there might be very early awareness of conflict.

The role of working memory capacity in evaluative judgments of liking and beauty.

Judgments of liking and beauty appear to be expressions of a common hedonic state, but they differ in how they engage cognitive processes. We hypothesised that beauty judgments place greater demands on limited executive resources than judgments of liking. We tested this hypothesis by asking two groups of participants to judge works of visual art for their beauty or liking while having to remember the location of 1, 3, or 5 dots in a 4 by 4 matrix. We also examined the effect of individual differences in working memory capacity. Our results show that holding information about the location of the dots in working memory delayed judgments of beauty but not of liking. Also, the greater participants' working memory capacity, the faster they completed the working memory task when judging liking, but not when judging beauty. Our study provides evidence that judging beauty draws more on working memory resources than judging liking.

The relationship between methods of scoring the alternate uses task and the neural correlates of divergent thinking: Evidence from voxel-based morphometry.

Divergent thinking tests have been used extensively in neuroscientific studies of creativity. However, output from tests of divergent thinking can be scored in different ways, and those scores can influence assessments of divergent thinking performance and its relationship with brain activation. Here we sought to investigate the relationship between various methods of scoring the Alternate Uses Task (AUT)-a well-known test of divergent thinking-and regional grey matter volume (GMV) using voxel-based morphometry (VBM). We assessed AUT performance based on (a) traditional approaches that involve scoring participants' output on fluency, flexibility, originality, and elaboration, (b) a subjective approach that involves scoring output directly on "snapshot" creativity, and (c) the definitional approach that involves scoring output separately on novelty and usefulness-the two criteria deemed necessary and jointly sufficient to categorize an idea as creative. Correcting for age, sex, intracranial volume, verbal IQ and working memory capacity, we found negative correlations between regional GMV in the left inferior temporal gyrus (ITG) and novelty and usefulness scores, but no correlation involving other scoring approaches. As part of the brain's core semantic system, this region is involved in concept retrieval and integration. We discuss the implications of these findings for our understanding of the neural bases of divergent thinking, and how ITG could be related to the generation of novel and useful responses.

The Reflective Mind: Examining Individual Differences in Susceptibility to Base Rate Neglect with fMRI.

Performance on heuristics and bias tasks has been shown to be susceptible to bias. In turn, susceptibility to bias varies as a function of individual differences in cognitive abilities (e.g., intelligence) and thinking styles (e.g., propensity for reflection). Using a classic task (i.e., lawyer-engineer problem), we conducted two experiments to examine the differential contributions of cognitive abilities versus thinking styles to performance. The results of Experiment 1 demonstrated that the Cognitive Reflection Test (CRT)-a well-established measure of reflective thinking-predicted performance on conflict problems (where base rates and intuition point in opposite directions), whereas STM predicted performance on nonconflict problems. Experiment 2 conducted in the fMRI scanner replicated this behavioral dissociation and enabled us to probe their neural correlates. As predicted, conflict problems were associated with greater activation in the ACC-a key region for conflict detection-even in cases when participants responded stereotypically. In participants with higher CRT scores, conflict problems were associated with greater activation in the posterior cingulate cortex (PCC), and activation in PCC covaried in relation to CRT scores during conflict problems. Also, CRT scores predicted activation in PCC in conflict problems (over and above nonconflict problems). Our results suggest that individual differences in reflective thinking as measured by CRT are related to brain activation in PCC-a region involved in regulating attention between external and internal foci. We discuss the implications of our findings in terms of PCC's possible involvement in switching from intuitive to analytic mode of thought.

Structural correlates of Openness and Intellect: Implications for the contribution of personality to creativity.

Openness/Intellect (i.e., openness to experience) is the Big Five personality factor most consistently associated with individual differences in creativity. Recent psychometric evidence has demonstrated that this factor consists of two distinct aspects-Intellect and Openness. Whereas Intellect reflects perceived intelligence and intellectual engagement, Openness reflects engagement with fantasy, perception, and aesthetics. We investigated the extent to which Openness and Intellect are associated with variations in brain structure as measured by cortical thickness, area, and volume (N = 185). Our results demonstrated that Openness was correlated inversely with cortical thickness and volume in left middle frontal gyrus (BA 6), middle temporal gyrus (MTG, BA 21), and superior temporal gyrus (BA 41), and exclusively with cortical thickness in left inferior parietal lobule (BA 40), right inferior frontal gyrus (IFG, BA 45), and MTG (BA 37). When age and sex were statistically controlled for, the inverse correlations between Openness and cortical thickness remained statistically significant for all regions except left MTG, whereas the correlations involving cortical volume remained statistically significant only for left middle frontal gyrus. There was no statistically significant correlation between Openness and cortical area, and no statistically significant correlation between Intellect and cortical thickness, area, or volume. Our results demonstrate that individual differences in Openness are correlated with variation in brain structure-particularly as indexed by cortical thickness. Given the involvement of the above regions in processes related to memory and cognitive control, we discuss the implications of our findings for the possible contribution of personality to creative cognition.

An improved model to predict performance under mental fatigue.

Fatigue has become an increasing problem in our modern society. Using MATLAB as a generic modelling tool, a fatigue model was developed based on an existing one and compared with a commercial fatigue software for prediction of cognitive performance under total and partial sleep deprivation. The flexibility of our fatigue model allowed additions of new algorithms and mechanisms for non-sleep factors and countermeasures and thus improved model predictions and usability for both civilian and military applications. This was demonstrated by model simulations of various scenarios and comparison with experimental studies. Our future work will be focused on model validation and integration with other modelling tools. Practitioner Summary: Mental fatigue affects health, safety and quality of life in our modern society. In this paper, we reported a cognitive fatigue model based on existing models with newly incorporated components taking both the operator's state of alertness and task demand into account. The model provided the additional capability for prediction of cognitive performance in scenarios involving pharmaceutical countermeasures, different task demands and shift work.

Buildings, Beauty, and the Brain: A Neuroscience of Architectural Experience.

A burgeoning interest in the intersection of neuroscience and architecture promises to offer biologically inspired insights into the design of spaces. The goal of such interdisciplinary approaches to architecture is to motivate construction of environments that would contribute to peoples' flourishing in behavior, health, and well-being. We suggest that this nascent field of neuroarchitecture is at a pivotal point in which neuroscience and architecture are poised to extend to a neuroscience of architecture. In such a research program, architectural experiences themselves are the target of neuroscientific inquiry. Here, we draw lessons from recent developments in neuroaesthetics to suggest how neuroarchitecture might mature into an experimental science. We review the extant literature and offer an initial framework from which to contextualize such research. Finally, we outline theoretical and technical challenges that lie ahead.

Psychological models of art reception must be empirically grounded.

We commend Menninghaus et al. for tackling the role of negative emotions in art reception. However, their model suffers from shortcomings that reduce its applicability to empirical studies of the arts: poor use of evidence, lack of integration with other models, and limited derivation of testable hypotheses. We argue that theories about art experiences should be based on empirical evidence.

Performance Evaluation of a Salivary Amylase Biosensor for Stress Assessment in Military Field Research.

BACKGROUND: A convenient biosensor for real-time measurement of biomarkers for in-field psychophysiological stress research and military operations is desirable. We evaluated a hand-held device for measuring salivary amylase as a stress marker in medical technicians undergoing combat casualty care training using two different modalities in operating room and field settings. METHODS: Salivary amylase activity was measured by two biosensor methods: directly sampling saliva with a test strip placed under the tongue or pipetting a fixed volume of precollected saliva onto the test strip, followed by analyzing the sample on the strip using a biosensor. The two methods were compared for their accuracy and sensitivity to detect the stress response using an enzyme assay method as a standard. RESULTS: The measurements from the under-the-tongue method were not as consistent with those from the standard assay method as the values obtained from the pipetting method. The under-the-tongue method did not detect any significant increase in the amylase activity due to stress in the operating room (P > 0.1), in contrast to the significant increases observed using the pipetting method and assay method with a significance level less than 0.05 and 0.1, respectively. Furthermore, the under-the-tongue method showed no increased amylase activity in the field testing, while both the pipetting method and assay method showed increased amylase activity in the same group (P < 0.1). CONCLUSION: The accuracy and consistency of the biosensors need to be improved when used to directly measure salivary amylase activity under the tongue for stress assessment in military medical training.

Impact of contour on aesthetic judgments and approach-avoidance decisions in architecture.

On average, we urban dwellers spend about 90% of our time indoors, and share the intuition that the physical features of the places we live and work in influence how we feel and act. However, there is surprisingly little research on how architecture impacts behavior, much less on how it influences brain function. To begin closing this gap, we conducted a functional magnetic resonance imaging study to examine how systematic variation in contour impacts aesthetic judgments and approach-avoidance decisions, outcome measures of interest to both architects and users of spaces alike. As predicted, participants were more likely to judge spaces as beautiful if they were curvilinear than rectilinear. Neuroanatomically, when contemplating beauty, curvilinear contour activated the anterior cingulate cortex exclusively, a region strongly responsive to the reward properties and emotional salience of objects. Complementing this finding, pleasantness--the valence dimension of the affect circumplex--accounted for nearly 60% of the variance in beauty ratings. Furthermore, activation in a distributed brain network known to underlie the aesthetic evaluation of different types of visual stimuli covaried with beauty ratings. In contrast, contour did not affect approach-avoidance decisions, although curvilinear spaces activated the visual cortex. The results suggest that the well-established effect of contour on aesthetic preference can be extended to architecture. Furthermore, the combination of our behavioral and neural evidence underscores the role of emotion in our preference for curvilinear objects in this domain.

Return-to-work challenges following a work-related mild TBI: The injured worker perspective.

PRIMARY OBJECTIVE: To explore how individuals with work-related mild traumatic brain injury (wrMTBI) experience return-to-work (RTW) processes when returning to the workplace where the injury occurred. DESIGN: RTW experiences were explored using in-depth interviews and an inductive analytic approach. Qualitative analysis guided by the research question moved through phases of line-by-line and thematic coding through which categories and the interaction between categories emerged. PARTICIPANTS: Twelve workers diagnosed with a wrMTBI reported on their RTW experiences following wrMTBIs that occurred 3-5 years prior to the time of the interview. MAIN OUTCOMES AND RESULTS: Participants perceived employer and workers' compensation factors as profoundly influencing their RTW experiences. Participants consistently reported that employers and workers' compensation representatives had an inadequate understanding of wrMTBI sequelae. Six of 12 participants were re-injured following their wrMTBI, with three of these injuries occurring at work. CONCLUSION: Employers, co-workers and workers' compensation representatives should be aware of wrMTBI sequelae so injured workers can receive appropriate supports and both stigmatization and re-injury can be mitigated. Greater attention to the structural and social elements of workplace and compensation environments could inform strategies to break down barriers to successful return-to-work following a wrMTBI.

Neural correlates of viewing paintings: evidence from a quantitative meta-analysis of functional magnetic resonance imaging data.

Many studies involving functional magnetic resonance imaging (fMRI) have exposed participants to paintings under varying task demands. To isolate neural systems that are activated reliably across fMRI studies in response to viewing paintings regardless of variation in task demands, a quantitative meta-analysis of fifteen experiments using the activation likelihood estimation (ALE) method was conducted. As predicted, viewing paintings was correlated with activation in a distributed system including the occipital lobes, temporal lobe structures in the ventral stream involved in object (fusiform gyrus) and scene (parahippocampal gyrus) perception, and the anterior insula-a key structure in experience of emotion. In addition, we also observed activation in the posterior cingulate cortex bilaterally-part of the brain's default network. These results suggest that viewing paintings engages not only systems involved in visual representation and object recognition, but also structures underlying emotions and internalized cognitions.

Effects of testosterone enanthate on aggression, risk-taking, competition, mood, and other cognitive domains during 28 days of severe energy deprivation.

RATIONALE: Behavioral effects of testosterone depend on dose, acute versus sustained formulation, duration of administration, personality, genetics, and endogenous levels of testosterone. There are also considerable differences between effects of endogenous and exogenous testosterone. OBJECTIVES: This study was the secondary behavioral arm of a registered clinical trial designed to determine if testosterone protects against loss of lean body mass and lower-body muscle function induced by a severe energy deficit typical of sustained military operations. METHODS: Behavioral effects of repeated doses of testosterone on healthy young men whose testosterone was reduced by severe energy deficit were examined. This was a double-blind, placebo-controlled, between-group study. Effects of four weekly intramuscular injections of testosterone enanthate (200 mg/week, N = 24) or matching placebo (N = 26) were evaluated. Determination of sample size was based on changes in lean body mass. Tasks assessing aggression, risk-taking, competition, social cognition, vigilance, memory, executive function, and mood were repeatedly administered. RESULTS: During a period of artificially induced, low testosterone levels, consistent behavioral effects of administration of exogenous testosterone were not observed. CONCLUSIONS: Exogeneous testosterone enanthate (200 mg/week) during severe energy restriction did not reliably alter the measures of cognition. Study limitations include the relatively small sample size compared to many studies of acute testosterone administration. The findings are specific to healthy males experiencing severe energy deficit and should not be generalized to effects of other doses, formulations, or acute administration of endogenous testosterone or studies conducted with larger samples using tests of cognitive function designed to detect specific effects of testosterone.

Psychological and neural responses to art embody viewer and artwork histories.

The research programs of empirical aesthetics and neuroaesthetics have reflected deep concerns about viewers' sensitivities to artworks' historical contexts by investigating the impact of two factors on art perception: viewers' developmental (and educational) histories and the contextual histories of artworks. These considerations are consistent with data demonstrating that art perception is underwritten by dynamically reconfigured and evolutionarily adapted neural and psychological mechanisms.

Negative valence can evoke a liberal response bias in syllogistic reasoning.

Recently, studies have demonstrated that negative valence reduces the magnitude of the belief-bias effect in syllogistic reasoning. This effect has been localized in the reasoning stage, in the form of increased deliberation on trials where validity and conclusion believability are incongruent. Here, using signal detection theory, we show that the attenuation of belief bias observed when valence was negative can also be evoked by a liberal response bias at the decision stage. Indeed, when valence was negative participants adopted a more liberal criterion for judging syllogisms as "valid," and were overconfident in their judgments. They also displayed less sensitivity in distinguishing between valid and invalid syllogisms. Our findings dovetail with recent evidence from memory research suggesting that negative valence can evoke a liberal response bias without improving performance. Our novel contribution is the demonstration that the attenuating effect of negative valence on belief bias can take multiples routes--by influencing the decision stage as was the case here, the reasoning stage as has been demonstrated elsewhere, and potentially both stages.

Effect of exogenous testosterone in the context of energy deficit on risky choice: Behavioural and neural evidence from males.

Previous research has shown greater risk aversion when people make choices about lives than cash. We tested the hypothesis that compared to placebo, exogenous testosterone administration would lead to riskier choices about cash than lives, given testosterone's association with financial risk-taking and reward sensitivity. A double-blind, placebo-controlled, randomized trial was conducted to test this hypothesis (Clinical Trials Registry: NCT02734238, www.clinicaltrials.gov). We collected functional magnetic resonance imaging (fMRI) data from 50 non-obese males before and shortly after 28 days of severe exercise-and-diet-induced energy deficit, during which testosterone (200 mg testosterone enanthate per week in sesame oil) or placebo (sesame seed oil only) was administered. Because we expected circulating testosterone levels to be reduced due to severe energy deficit, testosterone administration served a restorative function to mitigate the impact of energy deficit on testosterone levels. The fMRI task involved making choices under uncertainty for lives and cash. We also manipulated whether the outcomes were presented as gains or losses. Consistent with prospect theory, we observed the reflection effect such that participants were more risk averse when outcomes were presented as gains than losses. Brain activation in the thalamus covaried with individual differences in exhibiting the reflection effect. Testosterone did not impact choice, but it increased sensitivity to negative feedback following risky choices. These results suggest that exogenous testosterone administration in the context of energy deficit can impact some aspects of risky choice, and that individual differences in the reflection effect engage a brain structure involved in processing emotion, reward and risk.

The brain under cognitive workload: Neural networks underlying multitasking performance in the multi-attribute task battery.

Multitasking is a common requirement in many occupations. Considerable research has demonstrated that performance declines as a result of multitasking, and that it engages multiple brain regions. Despite growing evidence suggesting that brain regions operate as networks, minimal research has investigated the cognitive brain networks implicated in multitasking. The Multi-Attribute Task Battery II (MATB) is a common method for assessing multitasking ability that simulates a pilot's operational environment inside an aircraft cockpit. The aim of the present study was to examine multitasking performance on the MATB, and the associated neural patterns underlying performance with functional magnetic resonance imaging (fMRI). Twenty-four participants completed the MATB in the fMRI scanner. Participants completed four runs of the MATB in a 2 (Task: multitasking vs. single tasking) × 2 (Difficulty: hard vs. easy) design. MATB performance was measured as a function of accuracy. We analyzed the fMRI brain scans using both static and dynamic functional connectivity to determine whether there were differences in the connectivity patterns associated with each of the four conditions. A significant interaction between Task and Difficulty was observed such that multitasking performance accuracy, which was derived from the average across tasks, was lower than single tasking in the hard, but not easy, condition. The fMRI data revealed that static and dynamic functional connectivity between the default mode and dorsal attention networks was stronger during multitasking relative to single tasking. The static functional connectivity between the default mode and left frontoparietal networks, along with the dynamic functional connectivity between the dorsal attention and left frontoparietal networks, were both more anti-correlated during multitasking relative to single tasking. Taken together, the static and dynamic functional connectivity analyses provide complementary information to reveal the interactions among cognitive networks that support multitasking performance. Targeting these networks may offer a path to enhance multitasking ability through the application of neurostimulation and neuroenhancement techniques.

Repeated Occupational Exposure to Low-level Blast in the Canadian Armed Forces: Effects on Hearing, Balance, and Ataxia.

INTRODUCTION: Recently, there has been increasing concern about the adverse health effects of long-term occupational exposure to low-level blast in military personnel. Occupational blast exposure occurs routinely in garrison through use of armaments and controlled blast detonations. In the current study, we focused on a population of breaching instructors and range staff. Breaching is a tactical technique that is used to gain entry into closed spaces, often through the use of explosives. MATERIALS AND METHODS: Initial measurements of blast overpressure collected during breaching courses found that up to 10% of the blasts for range staff and up to 32% of the blasts for instructors exceeded the recommended 3 psi exposure limit. Using a cross-sectional design, we used tests of balance, ataxia, and hearing to compare a sample of breachers (n = 19) to age-and sex-matched military controls (n = 19). RESULTS: There were no significant differences between the two groups on the balance and ataxia tests, although the average scores of both groups were lower than would be expected in a normative population. The prevalence of hearing loss was low in the breacher group (4 of 19), and hearing thresholds were not significantly different from the controls. However, the prevalence of self-reported tinnitus was significantly higher in the breacher group (12 of 19) compared with the controls (4 of 19), and all breachers who were identified as having hearing loss also reported tinnitus. CONCLUSIONS: Our results suggest that basic tests of balance, ataxia, and hearing on their own were not sensitive to the effects of long-term occupational exposure to low-level blast. Some of the blast exposure levels exceeded limits, and there was a significant association of exposure with tinnitus. Future studies should supplement with additional information including exposure history and functional hearing assessments. These findings should be considered in the design of future acute and longitudinal studies of low-level blast exposure.