Looking at Mental Images: Eye-Tracking Mental Simulation During Retrospective Causal Judgment.

How do people evaluate causal relationships? Do they just consider what actually happened, or do they also consider what could have counterfactually happened? Using eye tracking and Gaussian process modeling, we investigated how people mentally simulated past events to judge what caused the outcomes to occur. Participants played a virtual ball-shooting game and then-while looking at a blank screen-mentally simulated (a) what actually happened, (b) what counterfactually could have happened, or (c) what caused the outcome to happen. Our findings showed that participants moved their eyes in patterns consistent with the actual or counterfactual events that they mentally simulated. When simulating what caused the outcome to occur, participants moved their eyes consistent with simulations of counterfactual possibilities. These results favor counterfactual theories of causal reasoning, demonstrate how eye movements can reflect simulation during this reasoning and provide a novel approach for investigating retrospective causal reasoning and counterfactual thinking.

Peer-Assisted Learning Is More Effective at Higher Task Complexity and Difficulty.

This paper presents two studies in which a peer-assisted learning condition was compared to an individual learning condition. The first study used the paired-associates learning task and the second study used an incrementally more complex task-the remote associate test. Participants in the peer-assisted learning condition worked in groups of four. They had to solve a given problem individually and give a first answer before being able to request to see their peers' solutions; then, a second answer was issued. After six sessions of peer-assisted practice, a final individual test was administered. Peer interaction was found to benefit learning in both studies but the benefit transferred to the final test only in the second study. Fine-grained behavioral analyses and computational modeling suggested that the benefits of peer interaction were (partially) offset by its costs, particularly increased cognitive load and error exposure. Overall, the superiority of peer-assisted learning over individual learning was more pronounced in the more complex task and for the more difficult problems in that task.

Profiling of circulating glial cells for accurate blood-based diagnosis of glial malignancies.

Here, we describe a blood test for the detection of glial malignancies (GLI-M) based on the identification of circulating glial cells (CGCs). The test is highly specific for GLI-M and can detect multiple grades (II-IV) and subtypes including gliomas, astrocytomas, oligodendrogliomas, oligoastrocytomas and glioblastomas, irrespective of gender and age. Analytical validation of the test was performed as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Real-world performance characteristics of the test were evaluated in four clinical (observational) studies. The test has high analytical sensitivity (95%), specificity (100%) and precision (coefficient of variation [CV] = 13.7% for repeatability and CV = 23.5% for within laboratory precision, both at the detection threshold) and is not prone to interference from common drugs and serum factors. The ability of the test to detect and differentiate GLI-M from non-malignant brain tumours (NBT), brain metastases from primary epithelial malignancies (EPI-M) and healthy individual donors (HD) was evaluated in four clinical cohorts. Across these clinical studies, the test showed 99.35% sensitivity (95% confidence interval [CI]: 96.44%-99.98%) and 100% specificity (95% CI: 99.37%-100%). The performance characteristics of this test support its clinical utility for diagnostic triaging of individuals presenting with intracranial space-occupying lesions (ICSOL).

Feasibility of [18F]fluoropivalate hybrid PET/MRI for imaging lower and higher grade glioma: a prospective first-in-patient pilot study.

PURPOSE: MRI and PET are used in neuro-oncology for the detection and characterisation of lesions for malignancy to target surgical biopsy and to plan surgical resections or stereotactic radiosurgery. The critical role of short-chain fatty acids (SCFAs) in brain tumour biology has come to the forefront. The non-metabolised SCFA radiotracer, [18F]fluoropivalate (FPIA), shows low background signal in most tissues except eliminating organs and has appropriate human dosimetry. Tumour uptake of the radiotracer is, however, unknown. We investigated the uptake characteristics of FPIA in this pilot PET/MRI study. METHODS: Ten adult glioma subjects were identified based on radiological features using standard-of-care MRI prior to any surgical intervention, with subsequent histopathological confirmation of glioma subtype and grade (lower-grade - LGG - and higher-grade - HGG - patients). FPIA was injected as an intravenous bolus injection (range 342-368 MBq), and dynamic PET and MRI data were acquired simultaneously over 66 min. RESULTS: All patients tolerated the PET/MRI protocol. Three patients were reclassified following resection and histology. Tumour maximum standardised uptake value (SUVmax,60) increased in the order LGG (WHO grade 2) < HGG (WHO grade 3) < HGG (WHO grade 4). The net irreversible solute transfer, Ki, and influx rate constant, K1, were significantly higher in HGG (p < 0.05). Of the MRI variables studied, DCE-MRI-derived extravascular-and-extracellular volume fraction (ve) was high in tumours of WHO grade 4 compared with other grades (p < 0.05). SLC25A20 protein expression was higher in HGG compared with LGG. CONCLUSION: Tumoural FPIA PET uptake is higher in HGG compared to LGG. This study supports further investigation of FPIA PET/MRI for brain tumour imaging in a larger patient population. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT04097535.

Effect of temperature on the post-diapause developmental rate, survival, and body mass of the solitary wasp Isodontia elegans: Implications for rearing of trap-nesting Hymenoptera.

We examined the relationship of post-diapause rearing temperature to developmental rate, survival, and adult body mass of the solitary wasp Isodontia elegans using prepupae from trap-nests. Isodontia elegans is a member of a genus often found in trap-nests in North America and Europe. Trap-nests are commonly used tools for studying cavity-nesting solitary wasps and bees. In temperate zones, progeny in nests usually overwinter as prepupae before pupating and emerging as adults. An important aspect of properly using trap-nests is determining temperatures that affect survival and health of developing offspring. After overwintering >600 cocoons containing prepupae after the summers of 2015 and 2016, we placed cocoons on a laboratory thermal gradient where offspring experienced one of 19 constant temperatures from 6 to 43 °C; emergence of adults was monitored for 100 days. Our conservative estimate for the critical thermal minimum for development is 14 °C, whereas that for the critical maximum is ∼33 °C. Prepupae transitioned to adults most rapidly at 29-33 °C, but developmental rate was lower for some progeny exposed to temperatures ≥30 °C. Offspring successfully reached the adult stage in <100 days at of temperatures of ∼19-33 °C. Adults from cocoons reared at lower temperatures weighed on average 6-10% more than expected based on their head widths, whereas those reared at higher temperatures weighed 4-10% less than expected. The difference may be due to greater rates of water loss and lipid metabolism during development at higher temperatures. Pre-overwintering cocoon mass was a significant predictor of relative adult body mass, indicating that adult health is partly related to their condition before overwintering. The trends we observed were similar to those for the bee Megachile rotundata, which we previously studied on the same gradient apparatus. However, data is needed on many other species of wasps and bees from a diversity of environments.

Diversity and distribution of orchid bees (Hymenoptera: Apidae, Euglossini) in Belize.

Background: Orchid bees are abundant and widespread in the Neotropics, where males are important pollinators of orchids they visit to collect fragrant chemicals later used to court females. Assemblages of orchid bees have been intensively surveyed in parts of Central America, but less so in Belize, where we studied them during the late-wet and early-dry seasons of 2015-2020. Methods: Using bottle-traps baited with chemicals known to attract a variety of orchid bee species, we conducted surveys at sites varying in latitude, historical annual precipitation, elevation, and the presence of nearby agricultural activities. Each sample during each survey period consisted of the same number of traps and the same set of chemical baits, their positions randomized along transects. Results: In 86 samples, we collected 24 species in four genera: Euglossa (16 species), Eulaema (3), Eufriesea (3), and Exaerete (2). During our most extensive sampling (December 2016-February 2017), species diversity was not correlated with latitude, precipitation, or elevation; species richness was correlated only with precipitation (positively). However, a canonical correspondence analysis indicated that species composition of assemblages varied across all three environmental gradients, with species like Eufriesea concava, Euglossa imperialis, and Euglossa viridissima most common in the drier north, and Euglossa ignita, Euglossa purpurea, and Eulaema meriana more so in the wetter southeast. Other species, such as Euglossa tridentata and Eulaema cingulata, were common throughout the area sampled. Mean species diversity was higher at sites with agricultural activities than at sites separated from agricultural areas. A Chao1 analysis suggests that other species should yet be found at our sites, a conclusion supported by records from adjacent countries, as well as the fact that we often added new species with repeated surveys of the same sites up through early 2020, and with the use of alternative baits. Additional species may be especially likely if sampling occurs outside of the months/seasons that we have sampled so far.

Prestimulus oscillatory brain activity interacts with evoked recurrent processing to facilitate conscious visual perception.

We investigated whether prestimulus alpha-band oscillatory activity and stimulus-elicited recurrent processing interact to facilitate conscious visual perception. Participants tried to perceive a visual stimulus that was perceptually masked through object substitution masking (OSM). We showed that attenuated prestimulus alpha power was associated with greater negative-polarity stimulus-evoked ERP activity that resembled the visual awareness negativity (VAN), previously argued to reflect recurrent processing related to conscious perception. This effect, however, was not associated with better perception. Instead, when prestimulus alpha power was elevated, a preferred prestimulus alpha phase was associated with a greater VAN-like negativity, which was then associated with better cue perception. Cue perception was worse when prestimulus alpha power was elevated but the stimulus occurred at a nonoptimal prestimulus alpha phase and the VAN-like negativity was low. Our findings suggest that prestimulus alpha activity at a specific phase enables temporally selective recurrent processing that facilitates conscious perception in OSM.

A functional neuroimaging investigation of Moral Foundations Theory.

Moral Foundations Theory (MFT) posits that the human mind contains modules (or "foundations") that are functionally specialized to moralize unique dimensions of the social world: Authority, Loyalty, Purity, Harm, Fairness, and Liberty. Despite this strong claim about cognitive architecture, it is unclear whether neural activity during moral reasoning exhibits this modular structure. Here, we use spatiotemporal partial least squares correlation (PLSC) analyses of fMRI data collected during judgments of foundation-specific violations to investigate whether MFT's cognitive modularity claim extends to the neural level. A mean-centered PLSC analysis returned two latent variables that differentiated between social norm and moral foundation violations, functionally segregated Purity, Loyalty, Physical Harm, and Fairness from the other foundations, and suggested that Authority has a different neural basis than other binding foundations. Non-rotated PLSC analyses confirmed that neural activity distinguished social norm from moral foundation violations, and distinguished individualizing and binding moral foundations if Authority is dropped from the binding foundations. Purity violations were persistently associated with amygdala activity, whereas moral foundation violations more broadly tended to engage the default network. Our results constitute partial evidence for neural modularity and motivate further research on the novel groupings identified by the PLSC analyses.

Neural differences between internal and external episodic counterfactual thoughts.

Episodic counterfactual thoughts (eCFT) consist of imagining alternative outcomes to past experiences. A common sub-class of eCFT-upward eCFT-involves imagining how past negative experiences could have been better, either because one could have done something differently (internal) or because something about the circumstances could have been different (external). Although previous neuroimaging research has shown that the brain's default mode network (DMN) supports upward eCFT, it is unclear how it is differentially recruited during internal versus external upward eCFT. We collected functional magnetic resonance imaging data while participants remembered negative autobiographical memories, generated either internal or external upward eCFT for the memory, and then rated the plausibility, perceived control and difficulty of eCFT generation. Both internal and external eCFT engaged midline regions of cingulate cortex, a central node of the DMN. Most activity differentiating eCFT, however, occurred outside the DMN. External eCFT engaged cuneus, angular gyrus and precuneus, whereas internal eCFT engaged posterior cingulate and precentral gyrus. Angular gyrus and precuneus were additionally sensitive to perceived plausibility of external eCFT, while postcentral gyrus and insula activity scaled with perceived plausibility of internal eCFT. These results highlight the key brain regions that might be involved in cases of maladaptive mental simulations. This article is part of the theme issue 'Thinking about possibilities: mechanisms, ontogeny, functions and phylogeny'.

Effects of Temperature and Wildflower Strips on Survival and Macronutrient Stores of the Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae) Under Extended Cold Storage.

Megachile rotundata (F.) is an important pollinator of alfalfa in the United States. Enhancing landscapes with wildflowers is a primary strategy for conserving pollinators and may improve the sustainability of M. rotundata. Changing cold storage temperatures from a traditionally static thermal regime (STR) to a fluctuating thermal regime (FTR) improves overwintering success and extends M. rotundata's shelf life and pollination window. Whether floral resources enhance overwintering survival and/or interact with a thermal regime are unknown. We tested the combined effects of enhancing alfalfa fields with wildflowers and thermal regime on survival and macronutrient stores under extended cold storage (i.e., beyond one season). Megachile rotundata adults were released in alfalfa plots with and without wildflower strips. Completed nests were harvested in September and stored in STR. After a year, cells were randomly assigned to remain in STR for 6 months or in FTR for a year of extended cold storage; emergence rates were observed monthly. Macronutrient levels of emerged females were assessed. FTR improved M. rotundata survival but there was no measurable effect of wildflower strips on overwintering success or nutrient stores. Timing of nest establishment emerged as a key factor: offspring produced late in the season had lower winter survival and dry body mass. Sugars and glycogen stores increased under FTR but not STR. Trehalose levels were similar across treatments. Total lipid stores depleted faster under FTR. While wildflowers did not improve M. rotundata survival, our findings provide mechanistic insight into benefits and potential costs of FTR for this important pollinator.

Inhibition of the angiotensin II type 2 receptor AT2R is a novel therapeutic strategy for glioblastoma.

Glioblastoma (GBM) is an aggressive malignant primary brain tumor with limited therapeutic options. We show that the angiotensin II (AngII) type 2 receptor (AT2R) is a therapeutic target for GBM and that AngII, endogenously produced in GBM cells, promotes proliferation through AT2R. We repurposed EMA401, an AT2R antagonist originally developed as a peripherally restricted analgesic, for GBM and showed that it inhibits the proliferation of AT2R-expressing GBM spheroids and blocks their invasiveness and angiogenic capacity. The crystal structure of AT2R bound to EMA401 was determined and revealed the receptor to be in an active-like conformation with helix-VIII blocking G-protein or ß-arrestin recruitment. The architecture and interactions of EMA401 in AT2R differ drastically from complexes of AT2R with other relevant compounds. To enhance central nervous system (CNS) penetration of EMA401, we exploited the crystal structure to design an angiopep-2-tethered EMA401 derivative, A3E. A3E exhibited enhanced CNS penetration, leading to reduced tumor volume, inhibition of proliferation, and increased levels of apoptosis in an orthotopic xenograft model of GBM.

Microscale electrophysiological functional connectivity in human cortico-basal ganglia network.

OBJECTIVE: We investigated the electrophysiological relationships in the cortico-basal ganglia network on a sub-centimeter scale to increase our understanding of neural functional relationships in Parkinson's disease (PD). METHODS: Data was intraoperatively recorded from 2 sources in the human brain-a microelectrode in the subthalamic nucleus (STN) and a micro-electrocorticography grid on the motor association cortex-during bilateral deep brain stimulation (DBS) electrode placement. STN neurons and local field potential (LFP) were defined as functionally connected when the 99.7% confidence intervals of the action potential (AP)-aligned average LFP and control did not overlap. RESULTS: APs from STN neurons were functionally connected to the STN LFP for 18/46 STN neurons. This functional connection was observed between STN neuron APs and cortical LFP for 25/46 STN neurons. The cortical patterns of electrophysiological functional connectivity differed for each neuron. CONCLUSIONS: A subset of single neurons in the STN exhibited functional connectivity with electrophysiological activity in the STN and at a distance with the motor association cortex surveyed on a sub-centimeter spatial scale. These connections show a per neuron differential topography on the cortex. SIGNIFICANCE: The cortico-basal ganglia circuit is organized on a sub-centimeter scale, and plays an important role in the mechanisms of PD and DBS.

Double Prevention, Causal Judgments, and Counterfactuals.

Mike accidentally knocked against a bottle. Seeing that the bottle was about to fall, Jack was just about to catch it when Peter accidentally knocked against him, making Jack unable to catch it. Jack did not grab the bottle, and it fell to the ground and spilled. In double-prevention cases like these, philosophers and nonphilosophers alike tend to judge that Mike knocking into the bottle caused the beer to spill and that Peter knocking into Jack did not cause the beer to spill. This difference in causal judgment is a difficult puzzle for counterfactual theories of causal judgment; if each event had not happened, the outcome would not have, yet there is a difference in people's causal judgments. In four experiments and three supplemental experiments, we confirm this difference in causal judgments. We also show that differences in people's counterfactual thinking can explain this difference in their causal judgments and that recent counterfactual models of causal judgment can account for these patterns. We discuss these results in relation to work on counterfactual thinking and causal modeling.

Arginine deprivation alters microglial polarity and synergizes with radiation to eradicate non-arginine-auxotrophic glioblastoma tumors.

New approaches for the management of glioblastoma (GBM) are an urgent and unmet clinical need. Here, we illustrate that the efficacy of radiotherapy for GBM is strikingly potentiated by concomitant therapy with the arginine-depleting agent ADI-PEG20 in a non-arginine-auxotrophic cellular background (argininosuccinate synthetase 1 positive). Moreover, this combination led to durable and complete radiological and pathological response, with extended disease-free survival in an orthotopic immune-competent model of GBM, with no significant toxicity. ADI-PEG20 not only enhanced the cellular sensitivity of argininosuccinate synthetase 1-positive GBM to ionizing radiation by elevated production of nitric oxide (˙NO) and hence generation of cytotoxic peroxynitrites, but also promoted glioma-associated macrophage/microglial infiltration into tumors and turned their classical antiinflammatory (protumor) phenotype into a proinflammatory (antitumor) phenotype. Our results provide an effective, well-tolerated, and simple strategy to improve GBM treatment that merits consideration for early evaluation in clinical trials.

Confidence and gradation in causal judgment.

When comparing the roles of the lightning strike and the dry climate in causing the forest fire, one might think that the lightning strike is more of a cause than the dry climate, or one might think that the lightning strike completely caused the fire while the dry conditions did not cause it at all. Psychologists and philosophers have long debated whether such causal judgments are graded; that is, whether people treat some causes as stronger than others. To address this debate, we first reanalyzed data from four recent studies. We found that causal judgments were actually multimodal: although most causal judgments made on a continuous scale were categorical, there was also some gradation. We then tested two competing explanations for this gradation: the confidence explanation, which states that people make graded causal judgments because they have varying degrees of belief in causal relations, and the strength explanation, which states that people make graded causal judgments because they believe that causation itself is graded. Experiment 1 tested the confidence explanation and showed that gradation in causal judgments was indeed moderated by confidence: people tended to make graded causal judgments when they were unconfident, but they tended to make more categorical causal judgments when they were confident. Experiment 2 tested the causal strength explanation and showed that although confidence still explained variation in causal judgments, it did not explain away the effects of normality, causal structure, or the number of candidate causes. Overall, we found that causal judgments were multimodal and that people make graded judgments both when they think a cause is weak and when they are uncertain about its causal role.

Transverse Pedicle Angle Is Associated With Pelvic Incidence and Increased in Lumbar Isthmic Spondylolisthesis.

STUDY DESIGN: Retrospective radiographic review. OBJECTIVES: Investigate and quantify transverse pedicle angle (TPA), the medial-to-lateral pedicle angulation, and its potential association with pelvic incidence (PI) in patients with isthmic lumbar spondylolisthesis (ISLS) and compare to those with degenerative lumbar spondylolisthesis (DSLS) and controls. METHODS: A total of 200 patients (64 ISLS, 70 DSLS, 66 control) were included. TPA was calculated at the L3-5 vertebral levels using axial computed tomography slices. PI was measured on lateral radiographs. Two independent observers completed the measurements. As a sensitivity analysis, TPA was also measured at the most cranial and caudal aspects of the L3-5 vertebral levels of a subset of participants (29 ISLS, 31 DSLS, 35 control) and the cranial to caudal change (ΔTPA) was calculated. RESULTS: TPA values (mean ± SD) at L4 and L5 for ISLS (L4: 17.3° ± 3.7°, L5: 26.0° ± 5.2°) were significantly higher than those for the DSLS (L4: 14.3° ± 3.8°, L5: 22.2° ± 5.0°) and control (L4: 14.5° ± 3.9°, L5: 20.7° ± 3.8°) groups. TPA in the DSLS group was significantly higher than controls at L5, but not L4. High PI predicted wider TPA at L5 in both DSLS and ISLS. ΔTPA (mean ± SD) increased sequentially proceeding through the L3-5 spinal levels for the ISLS (L3: 6.8° ± 4.4°, L4: 8.7° ± 5.2°, L5: 15.6° ± 9.0°), DSLS (L3: 8.2° ± 6.0°, L4: 8.3° ± 5.9°, L5: 18.3° ± 7.2°), and control (L3: 6.8° ± 4.4°, L4: 8.2° ± 4.7°, L5: 17.7° ± 7.0°) groups. CONCLUSIONS: TPA was significantly increased in ISLS compared with DSLS and controls. High PI significantly predicted high TPA at the L5 vertebral level in ISLS and DSLS. ΔTPA increased sequentially proceeding through the lumbar spine across groups.

Effects of category learning strategies on recognition memory.

Extant research has shown that previously acquired categorical knowledge affects recognition memory, and that differences in category learning strategies impact classification accuracy. However, it is unknown whether different learning strategies also have downstream effects on subsequent recognition memory. The present study investigates the effect of two unidimensional rule-based category learning strategies - learning (a) with or without explicit instruction, and (b) with or without supervision - on subsequent recognition memory. Our findings suggest that acquiring categorical knowledge increased both hits (Experiments 1 and 2) and false-alarms (Experiment 1) for category-congruent items regardless of the particular strategy employed in initially learning these categories. There were, however, small processing speed advantages during recognition memory for both explicit instruction and supervised practice relative to neither (Experiment 2). We discuss these findings in the context of how prior knowledge influences recognition memory, and in relation to similar findings showing schematic effects on episodic memory.

Tonsillar Carcinoma Spreading Metastases to Central Nervous System: Case Report and Literature Review.

We present a case report of a 51-year-old left-handed male with a background of human papillomovairus 16-positive tonsil squamous cell carcinoma presenting with tonic-clonic seizure and a radiological diagnosis of secondary metastatic deposits. These were initially treated with stereotactic radiosurgery and subsequently with surgery. Surgical resection was performed under general anesthesia with right-sided temporal and parietal approaches. Both the parietal and temporal deposits were removed, while the intraventricular mass was intentionally left to avoid postoperative deficits. Adjuvant radiotherapy and chemotherapy were administered postoperatively. The patient experienced a satisfactory recovery postoperatively and was reoperated for recurrence 4 months later. He maintained a good quality of life and an excellent performance status throughout, but unfortunately he passed away in November 2018 due to septic complications. This case history stresses the difficulty in managing squamous cell carcinomas (SCC) with brain metastatic deposits. There are no current guidelines about the management of patients presenting with such a rare condition. More data are thus desirable to better define treatment guidelines and protocols when SCC brain metastases are present.

Mortality Dynamics and Life Tables of Megachile rotundata (Hymenoptera: Megachilidae), a Pollinator Managed for Alfalfa Seed Production.

The alfalfa leafcutting bee, Megachile rotundata (F.), contributes to the pollination of more than two-thirds of alfalfa used in seed production in North America. However, losses in managed populations of more than 50% are common in the United States. Thus, understanding the causes of mortality of M. rotundata is critical to find ways to maintain and increase bee populations. Over 2 yr, we identified and quantified six mortality classes of M. rotundata, as well as estimated mortality risk using the demographic life-table model, M-DEC. Research was conducted on an alfalfa field in Toston, Montana and offspring mortality was assessed in the fall of each year. Nest shelters were manipulated for a main temperature treatment (low vs high), and nest boxes inside the shelters were manipulated for a parasitism sub-treatment (parasitism-resistant vs parasitism-enabled). Total mortality was approximately 15% for both years, but the proportion for each mortality class differed substantially. Mortality increased with increasing internal nest-tunnel temperature, and nest boxes with parasitism-enabled entry had nearly double the mortality than those with parasitism-resistant entry. Based on demographic multiple decrement life table analyses, mortality from each class was highly irreplaceable. Identifying and quantifying irreplaceable mortality classes and strategies to mitigate those causes may help producers decrease total population loss of M. rotundata before the adult stage.

Norms Affect Prospective Causal Judgments.

People more frequently select norm-violating factors, relative to norm-conforming ones, as the cause of some outcome. Until recently, this abnormal-selection effect has been studied using retrospective vignette-based paradigms. We use a novel set of video stimuli to investigate this effect for prospective causal judgments-that is, judgments about the cause of some future outcome. Four experiments show that people more frequently select norm-violating factors, relative to norm-conforming ones, as the cause of some future outcome. We show that the abnormal-selection effects are not primarily explained by the perception of agency (Experiment 4). We discuss these results in relation to recent efforts to model causal judgment.