Interindividual Differences Research Articles

A fast differential network with adaptive reference sample for gaze estimation

Most non-invasive gaze estimation methods do not consider the inter-individual differences in anatomical structure, but directly regress the gaze direction from the appearance image information, which limits the accuracy of individual-independent gaze estimation networks. In addition, existing gaze estimation methods tend to consider only how to improve the model’s generalization performance, ignoring the crucial issue of efficiency, which leads to bulky models that are difficult to deploy and have questionable cost-effectiveness in practical use. This paper makes the following contributions: (1) A differential network for gaze estimation using adaptive reference samples is proposed, which can adaptively select reference samples based on scene and individual characteristics. (2) The knowledge distillation is used to transfer the knowledge structure of robust teacher networks into lightweight networks so that our networks can execute quickly and at low computational cost, dramatically increasing the prospect and value of applying gaze estimation. (3) Integrating the above innovations, a novel fast differential neural network (Diff-Net) named FDAR-Net is constructed and achieved excellent results on MPIIGaze, UTMultiview and EyeDiap.

Menstrual cycle related depressive symptoms and their diurnal fluctuations – an ambulatory assessment study

Abstract Background Reproductive mood disorders indicate that within-person variation in depressive symptoms across the menstrual cycle can be related to ovarian hormone changes. Until now, such cycle-related symptom changes have been measured once daily, even though depression research indicates systematic diurnal changes in symptoms. Further, previous research often focused on aggregated depression scores. This study examined whether three daily assessments of depressive symptoms follow similar trajectories across the menstrual cycle and investigated within-person cyclical fluctuation of all individual symptoms and the aggregated score. Methods 77 naturally-cycling participants (35 with and 42 without depressive disorder) provided three daily ratings of depressive symptoms across one menstrual cycle to evaluate individual and summarized symptoms. Results Reliability estimates (w) of the three diurnal measurements ranged from 0.56 to 0.78. Cyclicity showed statistically significant interindividual differences for all symptoms, and individual symptoms differed significantly from each other in their magnitude of cyclicity. Limitations Only one menstrual cycle was assessed to reduce participant burden. Further, ovulation testing dates were based on self-reported cycle lengths, and only LH (luteinizing hormone) peaks were tested without subsequent progesterone rises. Conclusions The results highlight the need for a symptom-specific approach to assess individual variance in cyclicity of depressive symptoms. Reliability for one daily assessment can be improved by using the afternoon value, a sum score for depressiveness, or multiple items per symptom. Furthermore, this study emphasizes, that depressive symptoms can systematically change across the menstrual cycle, and it is, therefore, important to include it in depression research. Exploring female-specific risk factors of depression will enable the development of person-tailored treatments. Trial registration The study was preregistered at ClinicalTrials.gov (NCT04086316) with the first registration on 27/08/2019.

Magnetic nanoradiotracers for targeted neutrophil detection in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a severe disease characterized by elevated blood pressure in the pulmonary artery that can ultimately damage the right ventricle of the heart. PAH is pathophysiologically heterogeneous, which makes early diagnosis and treatment difficult. Inflammation is thought to be an important factor in the development and progression of this disease and may explain some of the observed interindividual differences. In the context of both acute and chronic inflammation, neutrophil recruitment to the lung has been suggested as a potential biomarker for studying PAH progression. However, there are currently no specific probes for its non-invasive in vivo detection. The imaging-based gold standard for assessing inflammation is [18F] fluorodeoxyglucose (18F-FDG), which is not cell specific. This highlights the urgent need for more specific molecular probes to support personalized medicine. This study investigated the potential of magnetic nanoradiotracers based on ultrasmall iron oxide nanoparticles, functionalized with N-cinnamoyl-F-(D)L-F-(D)L-F peptide, to detect increased neutrophil infiltration in vivo in different PAH animal models via positron emission tomography. These nanoprobes target formyl peptide receptor 1, which is abundantly expressed in the cell membrane of neutrophils. To assess the benefit of these nanoprobes, their biodistribution was first assessed via magnetic resonance imaging and histology. Then, their lung uptake was compared by positron emission tomography with that of 18F-FDG in two types of PAH animal models with different profiles of inflammation and neutrophil infiltration: monocrotaline and double-hit Sugen-chronic hypoxia PAH rat models. Our targeted magnetic nanoradiotracer detected an increase in pulmonary neutrophil infiltration in both PAH models and distinguished between them, which was not possible with 18F-FDG PET. This study underscores the importance of targeted imaging in providing an individualized and longitudinal evaluation of heterogeneous and multifactorial diseases such as PAH. The use of targeted multimodal nanoprobes, for magnetic resonance/positron emission tomography imaging has the potential to facilitate the diagnosis and monitoring of diseases, as well as the development of novel therapies.

PharmFreq: a comprehensive atlas of ethnogeographic allelic variation in clinically important pharmacogenes.

Genetic polymorphisms in drug metabolizing enzymes, drug transporters as well as in genes encoding the human major histocompatibility complex contribute to inter-individual differences in drug efficacy and safety. The extent, pattern and complexity of such pharmacogenetic variation differ drastically across human populations. Here, we present PharmFreq, a global repository of pharmacogenetic frequency information that aggregates frequency data of 658 allelic variants from over 10 million individuals collected from>1200 studies across 144 countries. Most investigations were conducted in East Asian and European populations, accounting for 29.4 and 26.6% of all studies, respectively. We find that the number of studies per country and aggregated cohort size correlated significantly with population size (R=0.55, P=3*10-9) and country gross domestic product (R=0.43, P=2*10-6) with overall population coverage varying between 5% in Estonia to<0.001% in many countries in Sub-Saharan Africa and Asia. All frequency data are openly accessible via a web-based interactive dashboard at pharmfreq.com that facilitates the exploration, visualization and analysis of country- and population-specific data and their inferred phenotypic consequences. PharmFreq thus presents a comprehensive, freely available resource for pharmacogenetic variant frequencies that can inform about ethnogeographic pharmacogenomic diversity and reveal important inequities that help to focus future research efforts into underrepresented populations.

Associating EEG functional networks and the effect of sleep deprivation as measured using psychomotor vigilance tests.

People are routinely forced to undertake cognitive challenges under the effect of sleep deprivation, due to professional and social obligations forcing them to ignore their circadian clock. However, low intra-individual and high inter-individual differences in behavioural outcomes are known to occur when people are sleep deprived, leading to the conclusion that trait-like differences to sleep deprivation could explain the differing levels of resilience. Within this study we consider if trait-like resilience to sleep deprivation, measured using psychomotor vigilance tests over a 40h protocol, could be associated with graph metrics (mean node strength, clustering coefficient, characteristic path length and stability) calculated from EEG functional networks acquired when participants ([Formula: see text]) are well rested (baseline). Furthermore, we investigated how stability (the consistency of a participant's functional network over time measured using 2-D correlation) changed over the constant routine. We showed evidence of strong significant correlations between high mean node strength, low characteristic path length and high stability at baseline with a general resilience to extended sleep deprivation, although the same features lead to vulnerability during the period of natural sleep onset, highlighting non-uniform correlations over time. We also show significant differences in the levels of stability between resilient and vulnerable groups.

Changes in Cardiorespiratory Fitness Following Exercise Training Prescribed Relative to Traditional Intensity Anchors and Physiological Thresholds: A Systematic Review with Meta-analysis of Individual Participant Data.

It is unknown whether there are differences in maximal oxygen uptake ( O2max) response when prescribing intensity relative to traditional (TRAD) anchors or to physiological thresholds (THR). The present meta-analysis sought to compare: (a) mean change in O2max, (b) proportion of individuals increasing O2max beyond a minimum important difference (MID) and (c) response variability in O2max between TRAD and THR. Electronic databases were searched, yielding data for 1544 individuals from 42 studies. Two datasets were created, comprising studies with a control group ('controlled' studies), and without a control group ('non-controlled' studies). A Bayesian approach with multi-level distributional models was used to separately analyse O2max change scores from the two datasets and inferences were made using Bayes factors (BF). The MID was predefined as one metabolic equivalent (MET; 3.5 mLkg-1min-1). In controlled studies, mean O2max change was greater in the THR group compared with TRAD (4.1 versus 1.8 mLkg-1min-1, BF > 100), with 64% of individuals in the THR group experiencing an increase in O2max > MID, compared with 16% of individuals taking part in TRAD. Evidence indicated no difference in standard deviation of change between THR and TRAD (1.5 versus 1.7 mLkg-1min-1, BF = 0.55), and greater variation in exercise groups relative to non-exercising controls (1.9 versus 1.3 mLkg-1min-1, BF = 12.4). In non-controlled studies, mean O2max change was greater in the THR group versus the TRAD group (4.4 versus 3.4 mLkg-1min-1, BF = 35.1), with no difference in standard deviation of change (3.0 versus 3.2 mLkg-1min-1, BF = 0.41). Prescribing exercise intensity using THR approaches elicited superior mean changes in O2max and increased the likelihood of increasing O2max beyond the MID compared with TRAD. Researchers designing future exercise training studies should thus consider the use of THR approaches to prescribe exercise intensity where possible. Analysis comparing interventions with controls suggested the existence of intervention response heterogeneity; however, evidence was not obtained for a difference in response variability between THR and TRAD. Future primary research should be conducted with adequate power to investigate the scope of inter-individual differences in O2max trainability, and if meaningful, the causative factors.

The effects of embedded quizzes on self‐regulated processes and learning performance during a multimedia lesson

AbstractBackgroundPrevious research has demonstrated that quizzing can improve self‐regulation processes and learning performances. However, it remains unclear whether quizzes in multimedia material bring similar benefits, and whether interindividual differences such as working memory capacity (WMC) modulate quizzing effects.AimsThis study aimed to examine the effects of embedded quizzes (multiple quizzes within the learning sequence) with feedback during a multimedia learning sequence on self‐regulated processing (monitoring and control) and learning performances on repeated (material already tested) and new (untested) questions, and possible WMC moderation on performances.Sample and MethodsParticipants were 59 students who learned a multimedia neuroscience course module in either a no‐quiz or embedded quizzes condition. With regard to self‐regulated processing, control was assessed with eye‐tracking measures (fixation durations and transitions between texts and illustrations), and monitoring by comparing self‐reported judgements of learning with actual performances (calibration). At the end, students' WMC was measured, and learning performances were assessed with repeated and new questions.ResultsQuizzing improved learning performances on repeated and new questions, and enhanced monitoring (better calibration). Students with low WMC benefited more from quizzing for new questions than those with high WMC. However, contrary to our hypothesis, the embedded quizzes group allocated less time to the learning than the no‐quiz group.ConclusionsEmbedded quizzes are relevant tools to help students recalibrate their monitoring process and foster more effective self‐regulated learning. Results confirm that the use of quizzes can be recommended to improve the learning of multimedia material, especially among students with low WMC.

Job satisfaction declines before retirement in Germany.

Job satisfaction has been found to increase with age. However, we still have a very limited understanding of how job satisfaction changes as people approach retirement. This is important as the years before retirement present specific challenges for older workers. We employed a time-to-retirement approach to investigate (i) mean levels of change in job satisfaction in the decade before retirement, and (ii) social inequalities and interindividual differences in change in pre-retirement job satisfaction. Data were drawn from the German Socioeconomic Panel Study (n = 2595). Latent growth curve modeling revealed that job satisfaction declined slightly as people approached retirement, with steeper declines in the very last years before retirement. However, the mean-level decline was very small. Education, age, health, region, marital status, and historical time, but not gender or caregiving mattered for level and change in job satisfaction before retirement. The findings demonstrate the importance of taking a time-to-retirement approach when examining experiences of older workers.

On the Epistemic Roles of the Individualized Niche Concept in Ecology, Behavioral Biology, and Evolutionary Biology

Abstract We characterize four fruitful and underappreciated epistemic roles played by the concept of an individualized niche in contemporary biology, utilizing results of a qualitative empirical study conducted within an interdisciplinary biological research center. We argue that the individualized niche concept (1) shapes the research agenda of the center, (2) facilitates explaining core phenomena related to interindividual differences, (3) helps with managing individual-level causal complexity, and (4) promotes integrating local knowledge from ecology, evolutionary biology, behavioral biology, and other biological fields. We thereby also challenge arguments that the niche concept is superfluous in ecology.

Pharmacogenomics of Lipid-Lowering Therapies in Obese Individuals with Dyslipidemia

Dyslipidemia is a key contributor to cardiovascular diseases, especially in obese individuals, where lipid metabolism is frequently impaired. Lipid-lowering therapies, such as statins, fibrates, and PCSK9 inhibitors, are commonly prescribed to manage dyslipidemia, but their efficacy and adverse effect profiles vary significantly across individuals. Pharmacogenomics, the study of how genetic variations influence drug response, has emerged as a powerful tool in predicting these inter-individual differences and optimizing treatment regimens. In obese individuals, genetic polymorphisms in genes involved in lipid metabolism, such as SLCO1B1, CYP3A4, APOE, and LDLR, have been linked to variable responses to lipid-lowering drugs. This review explores the impact of pharmacogenomics on lipid-lowering therapies in obese individuals with dyslipidemia, emphasizing the potential of personalized medicine in improving therapeutic outcomes. By understanding genetic influences on drug efficacy and safety, clinicians can tailor treatments to individual patients, thereby reducing adverse effects and improving lipid control. We also highlight current challenges in translating pharmacogenomic findings into clinical practice and discuss the future directions of this emerging field. Keywords: Pharmacogenomics, Lipid-Lowering Therapies, Dyslipidemia, Obesity, Statins, Fibrates, PCSK9 Inhibitors

EXPRESS: ALTERCENTRISM IN PERSPECTIVE-TAKING: THE ROLE OF HUMANIZATION IN EMBODYING THE AGENT'S POINT OF VIEW.

We investigated the role of humanization in Visual Perspective-Taking (VPT) by testing whether and how agent's human-likeness and attractiveness ('hedonic quality') interact with social cues (action and eye gaze) in influencing the participants' disposition to embody another's perspective. In a VPT task, participants viewed scenes displaying an actor (human or robotic) grasping, gazing (or both) a target object, or adopting a still posture, and were required to judge the left/right location of the target, without receiving any instruction on the perspective to be assumed. Across two studies we selected human and robotic agents to use as actors in the VPT task. Results consistently demonstrated that participants could be effectively clustered by a data-driven method into two perspective-taking styles, depending on the presence of a systematic tendency to locate the target object in the VPT scenarios from own (egocentric) or the actor's (altercentric) point of view. The human vs. non-human nature of the agent seemed able to affect the participants' egocentric or altercentric tendency whereas both the agent's hedonic quality and social cues were not able to influence this propensity. Identifying the factors influencing altercentrism during human-robot interactions can be essential for developing artificial agents favouring user's acceptance and willingness to interact. In this respect, considering differences among individuals in their propensity to take another's point of view may be of central importance. Clustering approaches can represent a useful means to capture interindividual differences in this central aspect of human social cognition.

Interindividual Differences in Higher and Lower-Order Object-Related Cognition: The Role of Inner Speech

The capacity to experience inner speech has been hypothesized to impact cognitive functions like object recognition, abstract thought, and metacognition. However, little is known about how individual differences in the propensity to experience inner speech affect these functions, a relevant topic to address given the wide variation in this trait within the general population. Here, we contribute novel evidence addressing this gap and provide a new tool to measure these individual differences in German-speaking participants. In a first study, we validate the IRQ-G, a German version of the Internal Representations Questionnaire (Roebuck &amp; Lupyan, 2020), offering scales that index the capacity to manipulate visual representations (Representational Manipulation), and the tendencies to experience thoughts in the form of visual and verbal information (Visual Imagery and Internal Verbalization, respectively). In a second study, we observe that participants with higher Internal Verbalization scores respond faster in a word-picture verification task where they match words to images but are more slowed by increases in semantic similarity between the items, relative to those with lower scores. We interpret this as a reflection of more categorical representations being cued in those with more language-reliant thinking during object recognition. In a third study, we present exploratory evidence based on a complex categorization task that more Internal Verbalization relates to slower determinations of response confidence when participants group images that rarely occur in the same context. We additionally offer exploratory evidence that condensed forms of inner speech hamper object recognition but aid abstract thought. Together, our studies highlight the complex and diverse effects of individual differences in inner speech tendencies on noncommunicative cognitive functions and broaden the methodological toolkit of researchers pursuing this line of inquiry in the German-speaking world.

Cognitive Engagement and Subjective Well-Being in Adults: Exploring the Role of Domain-Specific Need for Cognition

Need for Cognition (NFC) is an investment trait reflecting interindividual differences in intrinsically motivated engagement in cognitive endeavors. While other motivational constructs like the ability self-concept are typically conceptualized domain-specific, NFC was initially conceived to describe domain-general behavior. Building on a previous study reporting the relevance of domain-specific aspects of NFC in the school context, we investigated the domain-specificity of NFC in predicting various aspects of subjective well-being across three samples with N = 1074 participants and subsamples of students and professionals ranging from n = 140 to n = 346. Our findings reveal positive associations of both domain-general and domain-specific NFC with positive affect, life satisfaction, and job- and study-related satisfaction. In part, domain-specific NFC was more strongly related to domain-specific life satisfaction compared to domain-general NFC. Additionally, we found evidence for small incremental values of domain-specific NFC over and above domain-general NFC in predicting subjective well-being. Confirming previous research, self-control and the emotion regulation strategy reappraisal partially mediated the prediction of well-being by NFC. Our results indicate that additionally considering NFC as domain-specific can meaningfully complement the domain-general conceptualization.

Predation Risk Experienced by Tadpoles Shapes Personalities Before but Not After Metamorphosis.

Consistent inter-individual differences in behaviour, that is, personalities, can emerge as a result of inter-individual differences in ontogenetic experience, and predation risk is a potent one. As personalities develop over lifetime, however, they may also be broken by ontogenetic transitions of the individual. Here we first tested the hypothesis that consistent inter-individual differences in larval behaviour arise under predation challenge, and are entangled with differences in body size. We then tested the hypothesis that adult behavioural type is related to body size rather than to larval behavioural phenotype. To test these hypotheses, we performed a longitudinal study following the development of about 50 moor frogs, Rana arvalis. We manipulated their larval and current environment, and recorded their behaviours repeatedly, under control conditions, invertebrate predators' chemical cues or in live predator presence. Partially in line with our predictions, the ontogenetic experience of predator presence led to personality emergence in tadpoles, yet their behaviour was not explained by their body size. This pattern was lost over metamorphosis. According to predictions, pre-adult moor frog behaviour was affected by their body size-time to exit shelter was shorter in larger frogs-but neither by their behaviour as tadpoles nor by their larval environment, that is, tadpole predator-exposure experience. Our results show that individual behavioural tendencies can be well decoupled between prior and post metamorphosis, which adds to the growing empirical evidence supporting adaptive decoupling hypothesis.

Novel Regulatory Mechanisms for Expression of Drug Metabolism-related Factors

Interindividual differences in the expression and activity of drug-metabolizing enzymes, including cytochrome P450, UDP-glucuronosyltransferase, and esterases, cause variability of therapeutic effectiveness and side effects during drug treatment. Conventional research has focused on transcriptional regulation by transcription factors and nuclear receptors such as aryl hydrocarbon receptor, pregnane X receptor (PXR), constitutive androstane receptor, and hepatocyte nuclear factor 4α, as the major mechanisms causing the differences in the expression of drug-metabolizing enzymes. Recently, we have revealed that adenosine-to-inosine RNA editing and methylation of adenosine at the N6 position on RNA, two major types of posttranscriptional modification, play a pivotal role in the regulation of drug metabolism. In addition, switch/sucrose non-fermentable complex, a chromatin remodeler, is required for PXR-mediated transcriptional regulation of drug-metabolizing enzymes. This review article introduces the significance of these epitranscriptomic and epigenetic regulations as factors in determining drug metabolism potency. Further research on this link is expected to lead to a deeper understanding of interindividual differences in the therapeutic effectiveness and side effects of medicines.

Assessing Individual Sensitivity to the Thermal Grill Illusion: A Two-Dimensional Adaptive Psychophysical Approach

In the thermal grill illusion (TGI), the spatial alternation of non-noxious warm and cool temperatures elicits burning sensations that resemble the presence of noxious stimuli. Previous research has largely relied on the use of specific temperature values (i.e., 20°C and 40°C) to study this phenomenon in both healthy individuals and patient populations. However, this methodology fails to account for inter-individual differences in thermal sensitivity, limiting the precision with which TGI responses can be evaluated across diverse populations. To address this gap, we created a Two-Dimensional Thermal Grill Calibration (2D-TGC) protocol, enabling an efficient and precise estimation of the combinations of warm and cool temperatures needed to elicit burning sensations tailored to each individual. By applying the 2D-TGC protocol in 43 healthy participants, we demonstrated key findings: (1) The TGI can be thresholded using an adaptive psychophysical method. (2) Multiple combinations of warm and cool temperatures can elicit this phenomenon. (3) The protocol facilitated the identification of temperature combinations that elicit TGI with varying levels of probability, intensity, and perceived quality ranging from freezing cold to burning hot. (4) TGI responsivity can be quantified as a continuous variable, moving beyond the conventional classification of individuals as responders vs. non-responders based on arbitrary temperature values in the innocuous temperature range. The 2D-TGC offers a comprehensive approach to investigate the TGI across populations with altered thermal sensitivity, and can be integrated with other methods (e.g., neuroimaging) to elucidate the mechanisms responsible for perceptual illusions in the thermo-nociceptive system. PerspectiveThis study reveals that the Thermal Grill Illusion can be accurately measured using psychophysical methods. The innovative Two-Dimensional Thermal Grill Calibration protocol allows for personalized temperature assessments, enhancing our understanding of thermal sensitivity variations and perceptual illusions in the thermo-nociceptive system across different populations.

Don't forget the dams! Dairy cows' responses to two separation methods after 3 months of cow-calf contact

Weaning and separation remain among some of the biggest challenges for cow-calf contact systems, making the development of practical and low stress separation methods mandatory for future success of these systems. This study aimed to compare behavioral and physiological responses of dairy cows to separation from their calves after 3 mo of full-time contact with either the 2-step method (NF, 2 wks full-time contact while calves wore a nose flap, 1 wk fence-line contact before total separation, n = 18) or by gradual reduction of contact time between cow and calf (GR, 1 wk half day contact, 1 wk morning contact, 1 wk fence-line contact before total separation, n = 18). Vocalizations and searching behavior were observed on 4 d/wk from 1 wk before separation until 1 wk after total separation. During the same period, lying behavior and rumination time was automatically assessed via accelerometers and pressure sensors. Fecal and blood samples were collected twice/wk from day -1 till +23 relative to separation start for analysis of fecal cortisol metabolites and the immune response. Milk yield in the parlor was continuously recorded. Statistical analysis was conducted using linear mixed effects models. We found no difference between the 2 separation methods in any of the examined behavioral and physiological response variables. However, a significant increase in vocalizations and searching behavior compared with baseline was present with both methods. Further, there was a transient increase in physiological distress markers and a short-lived retention of milk yield at initiation of treatments, indicating that both methods induced distress for the cows. Descriptively, there were large inter-individual differences between cows as well as a different temporal distribution in occurrence of behavioral responses, as GR cows vocalized most frequently during the week with fence-line contact and after total separation from the calf, while NF cows reacted strongest during the 2 wks while calves wore the nose flap. Milk yield was higher in NF than GR cows during the 2 wks while GR calves had time-restricted access to their dams and NF calves were prevented from suckling, but showed no difference afterward anymore. However, similar evening milk yields of GR cows in the weeks with half day and morning contact, indicated that the weekly reductions in contact time worked in a rather stepwise than gradual manner, which warrants further improvement of the GR method. Taken together, results showed that cows experienced distress during separation with the GR method, when implemented over 3 wks in 3 steps, as well as with the NF method, but differences between individuals were considerable.

Intracranial voltage profiles from untangled human deep sources reveal multisource composition and source allocation bias.

Intracranial potentials are used as functional biomarkers of neural networks. As potentials spread away from the source populations, they become mixed in the recordings. In humans, interindividual differences in the gyral architecture of the cortex pose an additional challenge, as functional areas vary in location and extent. We used source separation techniques to disentangle mixing potentials obtained by exploratory deep arrays implanted in epileptic patients of either sex to gain access to the number, location, relative contribution and dynamics of co-active sources. The unique spatial profiles of separated generators made it possible to discern dozens of independent cortical areas for each patient, whose stability maintained even during seizure, enabling the follow up of activity for days and across states. Through matching these profiles to MRI, we associated each with limited portions of sulci and gyri, and determined the local or remote origin of the corresponding sources. We also plotted source-specific 3D coverage across arrays. In average, individual recording sites are contributed to by 3-5 local and distant generators from areas up to several centimeters apart. During seizure, 13-85 % of generators were involved, and a few appeared anew. Significant bias in location assignment using raw potentials is revealed, including numerous false positives when determining the site of origin of a seizure. This is not amended by bipolar montage, which introduce additional errors of its own. In this way, source disentangling reveals the multisource nature and far intracranial spread of potentials in humans, while efficiently addressing patient-specific anatomofunctional cortical divergence.Significance Statement Field potentials are used to better localize zones showing normal and pathological activity. However, as potentials spread throughout the brain volume, they mix with others and make their place of origin uncertain, even when recorded intracranially. We used advanced algorithms to disentangle the activity of each these zones by their unique spatial profiles, which allowed us to determine the 3D outline of normal and epileptic areas and follow their activity for days. Dozens of independent sources per patient can be explored and precisely located. The findings show that standard stereoEEG recordings are contributed by 3-5 populations, which after separation will help to plan clinical intervention to break epileptic networks by more accurately marking epileptic foci and avoiding false positives.

Integration across biophysical scales identifies molecular and cellular correlates of person-to-person variability in human brain connectivity

Brain connectivity arises from interactions across biophysical scales, ranging from molecular to cellular to anatomical to network level. To date, there has been little progress toward integrated analysis across these scales. To bridge this gap, from a unique cohort of 98 individuals, we collected antemortem neuroimaging and genetic data, as well as postmortem dendritic spine morphometric, proteomic and gene expression data from the superior frontal and inferior temporal gyri. Through the integration of the molecular and dendritic spine morphology data, we identified hundreds of proteins that explain interindividual differences in functional connectivity and structural covariation. These proteins are enriched for synaptic structures and functions, energy metabolism and RNA processing. By integrating data at the genetic, molecular, subcellular and tissue levels, we link specific biochemical changes at synapses to connectivity between brain regions. These results demonstrate the feasibility of integrating data from vastly different biophysical scales to provide a more comprehensive understanding of brain connectivity.

Verbal and visual short-term memory predict performance in a multiplication production task: Evidence from a Malaysian sample.

Arithmetic requires the use of multiple cognitive processes, such as short-term memory (STM). However, findings on the association between STM and simple multiplication solving are mixed, potentially due to large interindividual differences in multiplication proficiency within and between samples. The present study aims to explore further the relationship between visual and verbal STM and simple multiplication solving with a large Malaysian sample (N = 230). Adults (age = 17-42) completed an online production-based multiplication-solving task, STM measures (verbal and visuospatial STM tasks), and a demographic survey. A mixed-model analysis found that verbal STM and visual STM predict multiplication performance, with lower span participants having longer reaction times during multiplication solving. Interestingly, we also observed the relationship between verbal STM and multiplication was moderated by interference, the impact of verbal STM was stronger in high-interference problems, while the visual STM-multiplication relation was moderated by problem size, high visual span participants took more advantage of their visual STM when presented with large size problems. Thus, our findings show that both verbal and visual STM in interaction with problem properties predict simple multiplication solving in adults. Hypotheses on the concrete mechanisms involved in these relationships are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).