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The Trail Making Test (TMT) is one of the most popular neuropsychological tests for executive functions (EFs) assessment. It presents several strengths: it is sensitive to executive dysfunction, it is easy to understand, and has a short administration. However, it has important limitations. First, the underlying EFs articulated during the task are not well discriminated, which makes it a test with low specificity. Second, the pen-and-paper version presents one trial per condition which introduces high variability. Third, only the total time is quantified, which does not allow for a detailed analysis. Fourth, it has a fixed spatial configuration per condition. We designed a computerised version of the TMT to overcome its main limitations and evaluated it in a group of neurotypical adults. Eye and hand positions are measured with high resolution over several trials, and spatial configuration is controlled. Our results showed a very similar performance profile compared to the traditional TMT. Moreover, it revealed differences in eye movements between parts A and B. Most importantly, based on hand and eye movements, we found an internal working memory measure that showed an association to a validated working memory task. Additionally, we proposed another internal measure as a potential marker of inhibitory control. Our results showed that EFs can be studied in more detail using traditional tests combined with powerful digital setups. The cTMT showed potential use in older adult populations and patients with EFs disorders.

Objectives: To assess brain functional connectivity and variability in adults with attention deficit/hyperactivity disorder (ADHD) or euthymic bipolar disorder (BD) relative to a control (CT) group. Methods: Electroencephalography (EEG) was measured in 35 participants (BD = 11; ADHD = 9; CT = 15) during an eyes-closed 10-min rest period, and connectivity and graph theory metrics were computed. A coefficient of variation (CV) computed also the connectivity's temporal variability of EEG. Multivariate associations between functional connectivity and clinical and neuropsychological profiles were evaluated. Results: An enhancement of functional connectivity was observed in the ADHD (fronto-occipital connections) and BD (diffuse connections) groups. However, compared with CTs, intrinsic variability (CV) was enhanced in the ADHD group and reduced in the BD group. Graph theory metrics confirmed the existence of several abnormal network features in both affected groups. Significant associations of connectivity with symptoms were also observed. In the ADHD group, temporal variability of functional connections was associated with executive function and memory deficits. Depression, hyperactivity and impulsivity levels in the ADHD group were associated with abnormal intrinsic connectivity. In the BD group, levels of anxiety and depression were related to abnormal frontotemporal connectivity. Conclusions: In the ADHD group, we found that intrinsic variability was associated with deficits in cognitive performance and that connectivity abnormalities were related to ADHD symptomatology. The BD group exhibited less intrinsic variability and more diffuse long-range brain connections, and those abnormalities were related to interindividual differences in depression and anxiety. These preliminary results are relevant for neurocognitive models of abnormal brain connectivity in both disorders.

Adults with bipolar disorder (BD) have cognitive impairments that affect face processing and social cognition. However, it remains unknown whether these deficits in euthymic BD have impaired brain markers of emotional processing. We recruited twenty six participants, 13 controls subjects with an equal number of euthymic BD participants. We used an event-related potential (ERP) assessment of a dual valence task (DVT), in which faces (angry and happy), words (pleasant and unpleasant), and face-word simultaneous combinations are presented to test the effects of the stimulus type (face vs word) and valence (positive vs. negative). All participants received clinical, neuropsychological and social cognition evaluations. ERP analysis revealed that both groups showed N170 modulation of stimulus type effects (face > word). BD patients exhibited reduced and enhanced N170 to facial and semantic valence, respectively. The neural source estimation of N170 was a posterior section of the fusiform gyrus (FG), including the face fusiform area (FFA). Neural generators of N170 for faces (FG and FFA) were reduced in BD. In these patients, N170 modulation was associated with social cognition (theory of mind). This is the first report of euthymic BD exhibiting abnormal N170 emotional discrimination associated with theory of mind impairments.

Background Integration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT) called Dual Valence Association Task (DVAT) was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic). Methods Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT. Results Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT. Conclusions Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.

Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) share DSM-IV criteria in adults and cause problems in decision-making. Nevertheless, no previous report has assessed a decision-making task that includes the examination of the neural correlates of reward and gambling in adults with ADHD and those with BD. We used the Iowa gambling task (IGT), a task of rational decision-making under risk (RDMUR) and a rapid-decision gambling task (RDGT) which elicits behavioral measures as well as event-related potentials (ERPs: fERN and P3) in connection to the motivational impact of events. We did not observe between-group differences for decision-making under risk or ambiguity (RDMUR and IGT); however, there were significant differences for the ERP-assessed RDGT. Compared to controls, the ADHD group showed a pattern of impaired learning by feedback (fERN) and insensitivity to reward magnitude (P3). This ERP pattern (fERN and P3) was associated with impulsivity, hyperactivity, executive function and working memory. Compared to controls, the BD group showed fERN- and P3-enhanced responses to reward magnitude regardless of valence. This ERP pattern (fERN and P3) was associated with mood and inhibitory control. Consistent with the ERP findings, an analysis of source location revealed reduced responses of the cingulate cortex to the valence and magnitude of rewards in patients with ADHD and BD. Our data suggest that neurophysiological (ERPs) paradigms such as the RDGT are well suited to assess subclinical decision-making processes in patients with ADHD and BD as well as for linking the cingulate cortex with action monitoring systems.

During a decision-making process, the body changes. These somatic changes have been related to specific cognitive events and also have been postulated to assist decision-making indexing possible outcomes of different options. We used chess to analyze heart rate (HR) modulations on specific cognitive events. In a chess game, players have a limited time-budget to make about 40 moves (decisions) that can be objectively evaluated and retrospectively assigned to specific subjectively perceived events, such as setting a goal and the process to reach a known goal. We show that HR signals events: it predicts the conception of a plan, the concrete analysis of variations or the likelihood to blunder by fluctuations before to the move, and it reflects reactions, such as a blunder made by the opponent, by fluctuations subsequent to the move. Our data demonstrate that even if HR constitutes a relatively broad marker integrating a myriad of physiological variables, its dynamic is rich enough to reveal relevant episodes of inner thought.

The global burden of mortality and morbidity caused by traumatic brain injury (TBI) is significant, and the heterogeneity of TBI patients and the relatively small sample sizes of most current neuroimaging studies is a major challenge for scientific advances and clinical translation. The ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Adult moderate/severe TBI (AMS-TBI) working group aims to be a driving force for new discoveries in AMS-TBI by providing researchers world-wide with an effective framework and platform for large-scale cross-border collaboration and data sharing. Based on the principles of transparency, rigor, reproducibility and collaboration, we will facilitate the development and dissemination of multiscale and big data analysis pipelines for harmonized analyses in AMS-TBI using structural and functional neuroimaging in combination with non-imaging biomarkers, genetics, as well as clinical and behavioral measures. Ultimately, we will offer investigators an unprecedented opportunity to test important hypotheses about recovery and morbidity in AMS-TBI by taking advantage of our robust methods for large-scale neuroimaging data analysis. In this consensus statement we outline the working group’s short-term, intermediate, and long-term goals.

The neurobiology of reaching has been extensively studied in human and non-human primates. However, the mechanisms that allow a subject to decide-without engaging in explicit action-whether an object is reachable are not fully understood. Some studies conclude that decisions near the reach limit depend on motor simulations of the reaching movement. Others have shown that the body schema plays a role in explicit and implicit distance estimation, especially after motor practice with a tool. In this study we evaluate the causal role of multisensory body representations in the perception of reachable space. We reasoned that if body schema is used to estimate reach, an illusion of the finger size induced by proprioceptive stimulation should propagate to the perception of reaching distances. To test this hypothesis we induced a proprioceptive illusion of extension or shrinkage of the right index finger while participants judged a series of LEDs as reachable or non-reachable without actual movement. Our results show that reach distance estimation depends on the illusory perceived size of the finger: illusory elongation produced a shift of reaching distance away from the body whereas illusory shrinkage produced the opposite effect. Combining these results with previous findings, we suggest that deciding if a target is reachable requires an integration of body inputs in high order multisensory parietal areas that engage in movement simulations through connections with frontal premotor areas.

Background We extended our computerized Trail Making Test (c‐TMT) to investigate deficits in Mild Cognitive Impairment (MCI) compared to neurotypical controls. By integrating hand and eye tracking, we captured fine‐grained movement dynamics, revealing distinct trajectory alterations in MCI patients. These differences suggest potential digital biomarkers, offering a more precise assessment beyond traditional total time measurements. Methods Twenty‐nine MCI patients and 28 age‐ and education‐matched controls (with significant Mini‐Mental Test differences, p < 0.001) were enrolled at Hospital Italiano de Buenos Aires, Argentina, with informed consent. Two practice trials and 20 experimental trials (alternating TMT‐A and TMT‐B) were presented. Stimuli were displayed on a 24‐inch screen. Gaze was recorded from the right eye at 500 Hz using an EyeLink 1000 Plus. The mouse trajectory was displayed in real‐time, with feedback on the correct element selection. Results Linear Mixed Models (LMM) were applied to correct trials to estimate the main effects of subject group (MCI vs. control), trial type (TMT‐A vs. TMT‐B), and their interaction using the statsmodels library in Python. For performance metrics, LMM revealed a significant effect of subject group and trial type on the percentage of completion (PC) (SE = 0.066, p =  0.040; SE = ‐9.017, p =  1.9 × 10⁻¹⁹) and the time required to complete a trial (RT) (SE = ‐2.514, p =  0.012; SE = 7.896, p =  2.9 × 10⁻¹⁵). For eye‐tracking metrics, we found significant differences for both trial type (SE = 2.06, p =  0.002) and subject group (SE = 2.81, p =  0.023) in scanpath length (number of fixations). However, fixation duration differences were not significant (SE = 7.830, p =  0.68; SE = 12.90, p =  0.80). We also analyzed eye‐hand coordination by parsing fixations based on mouse position and time‐locking mouse and hand movements to target entry. Differences were observed by trial type but not by subject group. Conclusions Our c‐TMT version identified significant differences in scanpath length between MCI patients and controls. Hand and eye movements together allow fixation analysis to determine how increased fixations are distributed. These findings highlight the potential of this approach in Digital Neuropsychology.

We extended our computerized Trail Making Test (c-TMT) to investigate deficits in Mild Cognitive Impairment (MCI) compared to neurotypical controls. By integrating hand and eye tracking, we captured fine-grained movement dynamics, revealing distinct trajectory alterations in MCI patients. These differences suggest potential digital biomarkers, offering a more precise assessment beyond traditional total time measurements. Twenty-nine MCI patients and 28 age- and education-matched controls (with significant Mini-Mental Test differences, p < 0.001) were enrolled at Hospital Italiano de Buenos Aires, Argentina, with informed consent. Two practice trials and 20 experimental trials (alternating TMT-A and TMT-B) were presented. Stimuli were displayed on a 24-inch screen. Gaze was recorded from the right eye at 500 Hz using an EyeLink 1000 Plus. The mouse trajectory was displayed in real-time, with feedback on the correct element selection. Linear Mixed Models (LMM) were applied to correct trials to estimate the main effects of subject group (MCI vs. control), trial type (TMT-A vs. TMT-B), and their interaction using the statsmodels library in Python. For performance metrics, LMM revealed a significant effect of subject group and trial type on the percentage of completion (PC) (SE = 0.066, p =  0.040; SE = -9.017, p =  1.9 × 10⁻¹⁹) and the time required to complete a trial (RT) (SE = -2.514, p =  0.012; SE = 7.896, p =  2.9 × 10⁻¹⁵). For eye-tracking metrics, we found significant differences for both trial type (SE = 2.06, p =  0.002) and subject group (SE = 2.81, p =  0.023) in scanpath length (number of fixations). However, fixation duration differences were not significant (SE = 7.830, p =  0.68; SE = 12.90, p =  0.80). We also analyzed eye-hand coordination by parsing fixations based on mouse position and time-locking mouse and hand movements to target entry. Differences were observed by trial type but not by subject group. Our c-TMT version identified significant differences in scanpath length between MCI patients and controls. Hand and eye movements together allow fixation analysis to determine how increased fixations are distributed. These findings highlight the potential of this approach in Digital Neuropsychology.