Mikael Cavallet

High IQ May "Mask" the Diagnosis of ADHD by Compensating for Deficits in Executive Functions in Treatment-Naïve Adults With ADHD.

Objective: To evaluate and compare the performance of adults with ADHD with high and standard IQ in executive functions (EF) tasks. Method: We investigated the neuropsychological performance of 51 adults with ADHD, compared with 33 healthy controls (HC) while performing a wide battery of neuropsychological tests that measure executive functioning. Adults with clinical diagnosis of ADHD were divided into two groups according to their IQ level (IQ ≥ 110—ADHD group with more elevated IQ, and IQ < 110—ADHD group with standard IQ). Results: The ADHD group with standard IQ presented a worse executive functioning compared with the HC group in the following measures: Stroop 2 (p = .000) and 3 (p = .000), Trail Making Test (TMT) B (p = .005), Wisconsin Card-Sorting Test (WCST)—perseverative errors (p = .022) and failures to maintain set (p = .020), Continuous Performance Test (CPT)—omission errors (p = .005) and commission errors (p = .000), and Frontal Assessment Battery (FAB)—conceptualization (p = .016). The ADHD group with more elevated IQ presented only impairments in the CPT—commission errors (p = .019) when compared with the control group. Conclusion: Adults with ADHD and more elevated IQ show less evidence of executive functioning deficits compared with those with ADHD and standard IQ, suggesting that a higher degree of intellectual efficiency may compensate deficits in executive functions, leading to problems in establishing a precise clinical diagnosis.

State-dependent microstructural white matter changes in drug-naive patients with first-episode psychosis

BACKGROUNDnDiffusion tensor imaging (DTI) studies have consistently shown white matter (WM) microstructural abnormalities in schizophrenia. Whether or not such alterations could vary depending on clinical status (i.e. acute psychosis v. remission) remains to be investigated.nnnMETHODSnTwenty-five treatment-naïve first-episode psychosis (FEP) patients and 51 healthy-controls (HC) underwent MRI scanning at baseline. Twenty-one patients were re-scanned as soon as they achieved sustained remission of symptoms; 36 HC were also scanned twice. Rate-of-change maps of longitudinal DTI changes were calculated for in order to examine WM alterations associated with changes in clinical status. We conducted voxelwise analyses of fractional anisotropy (FA) and trace (TR) maps.nnnRESULTSnAt baseline, FEP presented reductions of FA in comparison with HC [p < 0.05, false-discovery rate (FDR)-corrected] affecting fronto-limbic WM and associative, projective and commissural fasciculi. After symptom remission, patients showed FA increase over time (p < 0.001, uncorrected) in some of the above WM tracts, namely the right anterior thalamic radiation, right uncinate fasciculus/inferior fronto-occipital fasciculus, and left inferior fronto-occipital fasciculus/inferior longitudinal fasciculus. We also found significant correlations between reductions in PANSS scores and FA increases over time (p < 0.05, FDR-corrected).nnnCONCLUSIONSnWM changes affecting brain tracts critical to the integration of perceptual information, cognition and emotions are detectable soon after the onset of FEP and may partially reverse in direct relation to the remission of acute psychotic symptoms. Our findings reinforce the view that WM abnormalities in brain tracts are a key neurobiological feature of acute psychotic disorders, and recovery from such WM pathology can lead to amelioration of symptoms.

Características atentivas reveladas por dicas múltiplas locais e globais

The characteristics of the attentive focus were investigated through the effect of local and global multiple cues, multiple and unitary, on the performance of a visual search task. The results show a gain in the performance of tests with valid multiple local cues; the gain is proportional to the size of the area in which the stimuli are presented. In the tests with valid local tips for the area there is a gain when the stimuli are presented in the larger area and a cost in the smaller area. Global cues do not generate a gain in tests with valid cues but are followed by a cost in tests with invalid cues. There is also a cost in tests where the attentive focus must be expanded or contracted. The results suggest that the model of multiple attentive focuses is more adequate to explain performance in tests with multiple local cues.

Distinct cognitive performance and patterns of drug use among early and late onset cocaine users

INTRODUCTIONnAdolescence is a crucial period for neurodevelopment, but few studies have investigated the impact of early cocaine use on cognitive performance and patterns of substance use.nnnMETHODSnWe evaluated 103 cocaine dependent inpatients divided in two groups: early-onset users (EOG; n=52), late-onset users (LOG; n=51), and 63 healthy controls. Neuropsychological functioning was evaluated using Digits Forward (DF) and Backward (DB), Trail Making Test (TMT), Stroop Color Word Test (SCWT), Controlled Oral Word Association Test (COWAT), Wisconsin Card Sorting Test (WCST), Rey Osterrieth Complex Figure Test (ROCFT), Frontal Assessment Battery (FAB), and Iowa Gambling Test (IGT). Use of alcohol and other drugs was assessed with the Addiction Severity Index (ASI-6).nnnRESULTSnAnalyses of covariance controlling for age, IQ and years of education showed that EOG presented worse performance in attention span (DF, p=0.020), working memory (DB, p=0.001), sustained attention (WCST, p=0.030), declarative memory (ROCFT, p=0.031) and general executive functioning (FAB, p=0.003) when compared with the control group. LOG presented impairments on divided attention (TMT, p=0.003) and general executive functioning (FAB, p=0.001) in relation to the control group. EOG presented higher use of cannabis and alcohol than LOG (p≤0.001).nnnCONCLUSIONnEarly-onset cocaine users display more pronounced neuropsychological alterations than controls, as well as a greater frequency of polydrug consumption than LOG. The prominent cognitive deficits in EOG probably reflect the deleterious interference of cocaine use with early stages of neurodevelopment. This may be related to more severe clinical characteristics of substance disorder in this subgroup, including polysubstance abuse.

Affective spatial compatibility task (AFFSCT): theory and applications

Emotional stimuli are processed very effi ciently, infl uencing physiological and behavioral responses as well as attention, perceptual processes and sensory-motor integration. In a previous work, we introduced a new paradigm, the Affective Spatial Compatibility task (AffSCt), to study whether the affective valence of the stimulus infl uences spatial compatibility effects. By using fi gures of soccer players of Favorite and Rival Teams as positive and negative valence stimuli, we found a normal Spatial Compatibility effect for the Favorite team and a reversed one for the Rival team. Here, we analyzed the time course of inhibitory and facilitatory effects of emotional valence by the Vincentization method. We found that for Favorite team, the facilitatory effect for the compatible condition, as compared to the incompatible one,

Distribution of visual attention within a cued area: evidence based on temporal order judgments

Three experiments were performed to investigate the distribution of attention across the visual field and the possibility of attentional resources to be more concentrated inside an abrupt onset frame (cue). The participants performed a temporal order judgment task of two letters presented in sequence; one letter presented inside and the other outside the frame. The results showed that the information presented inside the frame had its perceptual latency shortened in relation to the information presented outside the frame in experimental conditions where the frame orientation, the distance between the two letters and the cue onset time were manipulated. The advantage of the information presented inside the frame was attributed to the displacement of attention to the area delimited by the frame. The results contribute to the understanding of visual perception, showing that attentional resources may be redistributed inside the borders of a geometric figure.

Grey and white matter volumes either in treatment-naïve or hormone-treated transgender women: a voxel-based morphometry study

Many previous magnetic resonance imaging (MRI) studies have documented sex differences in brain morphology, but the patterns of sexual brain differences in transgender women – male sex assigned at birth – with a diagnosis of gender dysphoria (TW) have been rarely investigated to date. We acquired T1-weighted MRI data for the following four (nu2009=u200980) groups: treatment-naïve TW (TNTW), TW treated with cross-sex hormones for at least one year (TTW), cisgender men, and cisgender women (cisgender individuals as controls). Differences in whole-brain and regional white matter volume and grey matter volume (GMV) were assessed using voxel-based morphometry. We found lower global brain volumes and regional GMVs in a large portion of the posterior-superior frontal cortex in the cisgender women group than in the TTW and cisgender men groups. Additionally, both transgender groups exhibited lower bilateral insular GMVs than the cisgender women group. Our results highlight differences in the insula in both transgender groups; such differences may be characteristic of TW. Furthermore, these alterations in the insula could be related to the neural network of body perception and reflect the distress that accompanies gender dysphoria.

Influence of emotional stimulus valence on inhibitory control in adults with and without ADHD

Human behavior is influenced both by approach and avoidance automatic reactions to positive and negative stimulus, respectively, but these reactions have not been well studied in attention-deficit/hyperactivity disorder (ADHD) patients. Moreover, studies employing spatial stimulus–response compatibility tasks in ADHD and healthy control (HC) subjects are scarce and inconclusive. The present study investigated inhibitory control and emotional processing in ADHD adults with a modified stimulus–response compatibility task in which spatial and emotional features of affective stimuli had to be processed together to select the correct response. Manual responses to figures of Favorite and Rival soccer team players were measured, and compatible or incompatible responses were chosen according to the soccer team figure. Eighteen HC participants and sixteen ADHD adults performed the task. We found an ordinary spatial compatibility effect for the Favorite soccer team and a reversed one for the Rival team in the ADHD group but not in the HC group. The effects may be due to stronger approach and withdrawal reactions toward the Favorite soccer team and away from the Rival one, respectively, indicating poor inhibitory control for the ADHD group. These results show that differences between ADHD and HC subjects become prominent when response selection involves both emotional and spatial features of the stimulus.

Neurobiological support to the diagnosis of ADHD in stimulant-naïve adults: pattern recognition analyses of MRI data

In adulthood, the diagnosis of attention‐deficit/hyperactivity disorder (ADHD) has been subject of recent controversy. We searched for a neuroanatomical signature associated with ADHD spectrum symptoms in adults by applying, for the first time, machine learning‐based pattern classification methods to structural MRI and diffusion tensor imaging (DTI) data obtained from stimulant‐naïve adults with childhood‐onset ADHD and healthy controls (HC).

Tarefa de compatibilidade espacial afetiva (TCEA): teoria e aplicações

Emotional stimuli are processed very effi ciently, infl uencing physiological and behavioral responses as well as attention, perceptual processes and sensory-motor integration. In a previous work, we introduced a new paradigm, the Affective Spatial Compatibility task (AffSCt), to study whether the affective valence of the stimulus infl uences spatial compatibility effects. By using fi gures of soccer players of Favorite and Rival Teams as positive and negative valence stimuli, we found a normal Spatial Compatibility effect for the Favorite team and a reversed one for the Rival team. Here, we analyzed the time course of inhibitory and facilitatory effects of emotional valence by the Vincentization method. We found that for Favorite team, the facilitatory effect for the compatible condition, as compared to the incompatible one,