Fluid intelligence (Gf) involves rational thinking skills and requires the integration of information from different cortical regions to resolve novel complex problems. The effects of non-invasive brain stimulation on Gf have been studied in attempts to improve Gf, but such studies are rare and the few existing have reached conflicting conclusions. The parieto-frontal integration theory of intelligence (P-FIT) postulates that the parietal and frontal lobes play a critical role in Gf. To investigate the suggested role of parietal cortices, we applied high-definition transcranial direct current stimulation (HD-tDCS) to the left and right parietal cortices of 39 healthy adults (age 19-33 years) for 20 min in three separate sessions (left active, right active and sham). After completing the stimulation session, the participants completed a logical reasoning task based on Raven\'s Progressive Matrices during magnetoencephalography. Significant neural responses at the sensor level across all stimulation conditions were imaged using a beamformer. Whole-brain, spectrally constrained functional connectivity was then computed to examine the network-level activity. Behaviourally, we found that participants were significantly more accurate following left compared to right parietal stimulation. Regarding neural findings, we found significant HD-tDCS montage-related effects in brain networks thought to be critical for P-FIT, including parieto-occipital, fronto-occipital, fronto-parietal and occipito-cerebellar connectivity during task performance. In conclusion, our findings showed that left parietal stimulation improved abstract reasoning abilities relative to right parietal stimulation and support both P-FIT and the neural efficiency hypothesis. KEY POINTS: Abstract reasoning is a critical component of fluid intelligence and is known to be served by multispectral oscillatory activity in the fronto-parietal cortices. Recent studies have aimed to improve abstract reasoning abilities and fluid intelligence overall through behavioural training, but the results have been mixed. High-definition transcranial direct-current stimulation (HD-tDCS) applied to the parietal cortices modulated task performance and neural oscillations during abstract reasoning. Left parietal stimulation resulted in increased accuracy and decreased functional connectivity between occipital regions and frontal, parietal, and cerebellar regions. Future studies should investigate whether HD-tDCS alters abstract reasoning abilities in those who exhibit declines in performance, such as healthy ageing populations.

Fluid intelligence (Gf) involves logical reasoning and novel problem-solving abilities. Often, abstract reasoning tasks like Raven\'s progressive matrices are used to assess Gf. Prior work has shown an age-related decline in fluid intelligence capabilities, and although many studies have sought to identify the underlying mechanisms, our understanding of the critical brain regions and dynamics remains largely incomplete. In this study, we utilized magnetoencephalography (MEG) to investigate 78 individuals, ages 20-65 years, as they completed an abstract reasoning task. MEG data was co-registered with structural MRI data, transformed into the time-frequency domain, and the resulting neural oscillations were imaged using a beamformer. We found worsening behavioral performance with age, including prolonged reaction times and reduced accuracy. MEG analyses indicated robust oscillations in the theta, alpha/beta, and gamma range during the task. Whole brain correlation analyses with age revealed relationships in the theta and alpha/beta frequency bands, such that theta oscillations became stronger with increasing age in a right prefrontal region and alpha/beta oscillations became stronger with increasing age in parietal and right motor cortices. Follow-up connectivity analyses revealed increasing parieto-frontal connectivity with increasing age in the alpha/beta frequency range. Importantly, our findings are consistent with the parieto-frontal integration theory of intelligence (P-FIT). These results further suggest that as people age, there may be alterations in neural responses that are spectrally specific, such that older people exhibit stronger alpha/beta oscillations across the parieto-frontal network during abstract reasoning tasks.

This study assesses cognitive abilities through video games for entertainment (Blek, Edge, and Unpossible) that were programmed from scratch to record players\' behavior and the levels achieved in a sample without emotional problems and in one with emotional problems. The non-emotional-problem sample was recruited from three universities and two bachelor\'s degree programs. The emotional-problem sample was recruited from two outpatient centers. The participants in the emotional-problem sample completed reduced versions of the ability tests and video games, as required by their emotional problems. Three subtests of the Differential Aptitude Test that assessed abstract reasoning, visuospatial reasoning, and perceptual speed were selected as ability tests. All participants were required to complete a mental health questionnaire (PROMIS) and a brief questionnaire on their gaming habits and previous experience with the video games used. The results that were obtained showed good convergent validity of the video games as measures of cognitive abilities, and they showed that the behavior of players in the sample without emotional problems while playing predicted the level achieved in the Blek and Unpossible game fragments, but this was only true for Unpossible in the emotional-problem sample; finally, shorter versions of the Blek and Edge game fragments can be used because they maintain their good psychometric properties.

Raven\'s advanced progressive matrices (APM) comprise two types of representational codes, namely visuo-spatial and verbal-analytical, that are used to solve APM puzzles. Studies using analytical, behavioral, and imaging methods have supported the multidimensional perspectives of APM puzzles. The visuo-spatial code is expected to recruit operations more responsive to the visual perception tasks. In contrast, the verbal-analytical code is expected to use operations more responsive to the logical reasoning task and may entail different cognitive strategies. Acknowledging different representational codes used in APM puzzle-solving is critical for a better understanding of APM\'s performance and their relationship with other tasks, especially creative reasoning. We used the eye-tracking method to investigate the role of two representational codes, visuo-spatial and verbal-analytical, in strategies involved in solving APM puzzles and in generating an APM-like puzzle by using a creative-reasoning task (CRT). Participants took longer time to complete the verbal-analytical than visuo-spatial puzzles. In addition, visuo-analytical than visual-spatial puzzles showed higher progressive and regressive saccade counts, suggesting the use of more response elimination than constructive matching strategies employed while solving verbal-analytical than visuo-spatial puzzles. We observed higher CRT scores when it followed verbal-analytical (Mdn = 84) than visuo-spatial (Mdn = 73) APM puzzles, suggesting puzzle-solving specific strategies affect puzzle-creating task performance. The advantage of verbal-analytical over visuo-spatial puzzle-solving has been discussed in light of shared cognitive processing between APM puzzle-solving and APM-like puzzle-creating task performance.

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

Inflammatory processes help protect the body from potential threats such as bacterial or viral invasions. However, when such inflammatory processes become chronically engaged, synaptic impairments and neuronal cell death may occur. In particular, persistently high levels of C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) have been linked to deficits in cognition and several psychiatric disorders. Higher-order cognitive processes such as fluid intelligence (Gf) are thought to be particularly vulnerable to persistent inflammation. Herein, we investigated the relationship between elevated CRP and TNF-α and the neural oscillatory dynamics serving Gf.
Seventy adults between the ages of 20-66 years (Mean = 45.17 years, SD = 16.29, 21.4% female) completed an abstract reasoning task that probes Gf during magnetoencephalography (MEG) and provided a blood sample for inflammatory marker analysis. MEG data were imaged in the time-frequency domain, and whole-brain regressions were conducted using each individual\'s plasma CRP and TNF-α concentrations per oscillatory response, controlling for age, BMI, and education.
CRP and TNF-α levels were significantly associated with region-specific neural oscillatory responses. In particular, elevated CRP concentrations were associated with altered gamma activity in the right inferior frontal gyrus and right cerebellum. In contrast, elevated TNF-α levels scaled with alpha/beta oscillations in the left anterior cingulate and left middle temporal, and gamma activity in the left intraparietal sulcus.
Elevated inflammatory markers such as CRP and TNF-α were associated with aberrant neural oscillations in regions important for Gf. Linking inflammatory markers with regional neural oscillations may hold promise in identifying mechanisms of cognitive and psychiatric disorders.

This study was designed to determine the relationship between an observational measure of motor skills for teachers (i.e., MOQ-T), age, and some objectively assessed cognitive and motor indices. Two further goals were to examine which motor and cognitive factors predicted MOQ-T scores and to explore whether pupils with very low motor skills identified through MOQ-T also exhibited lower scores on objectively assessed motor and visuo-spatial tasks. A sample of 156 pupils aged 8.4 years-11.3 years and attending Italian primary school completed a battery of tests assessing writing speed, visuo-spatial abstract reasoning, fluency, and static balance abilities objectively assessed by measuring postural sway. Small to medium associations were found between MOQ-T scores and age, motor, and cognitive parameters, respectively. Moreover, approximately 26% of the variance in MOQ-T was predicted by sway area in the eyes-open condition, visuo-spatial fluency, and writing speed. Finally, pupils at risk of developmental coordination disorder exhibited poorer writing speed, and motor and higher-order visuo-spatial deficits. In conclusion, the synergistic use of objective measures of motor and cognitive functioning and observational screening questionnaires such as MOQ-T should be encouraged at school to identify pupils at risk of developmental coordination disorder.

OBJECTIVE: To examine the clinical utility of Wechsler Adult Intelligence Scale-IV (WAIS-IV) Matrix Reasoning in limited educated recently arrived immigrants in Denmark.
METHODS: Participants were 64 limited educated (0-9 years\' education) independently living adult immigrants primarily from Middle Eastern and Sub-Saharan African countries who completed WAIS-IV Matrix Reasoning as well as demographic, and medical questionnaires.
RESULTS: Thirty-eight participants (59%) scored more than two standard deviations below the Scandinavian mean (scaled score < 4). Performances were significantly associated with years of education but not with occupational status, years of residence in Denmark, or Danish language skills. The most common error types were repetition errors (15.84%) and incomplete correlate errors (10.47%), with a strong trend for a higher proportion of repetition errors in participants with <5 years of education.
CONCLUSIONS: The findings indicate that WAIS-IV Matrix Reasoning underestimates cognitive functioning in limited educated recently arrived immigrants, thus calling its clinical utility into question.

BACKGROUND: Distorted gambling-related cognitions are tightly related to gambling problems, and are one of the main targets of treatment for disordered gambling, but their etiology remains uncertain. Although folk wisdom and some theoretical approaches have linked them to lower domain-general reasoning abilities, evidence regarding that relationship remains unconvincing.
METHODS: In the present cross-sectional study, the relationship between probabilistic/abstract reasoning, as measured by the Berlin Numeracy Test (BNT), and the Matrices Test, respectively, and the five dimensions of the Gambling-Related Cognitions Scale (GRCS), was tested in a sample of 77 patients with gambling disorder and 58 individuals without gambling problems.
CONCLUSIONS: Neither BNT nor matrices scores were significantly related to gambling-related cognitions, according to frequentist (MANCOVA/ANCOVA) analyses, performed both considering and disregarding group (patients, non-patients) in the models. Correlation Bayesian analyses (bidirectional BF10) largely supported the null hypothesis, i.e., the absence of relationships between the measures of interest. This pattern or results reinforces the idea that distorted cognitions do not originate in a general lack of understanding of probability or low fluid intelligence, but probably result from motivated reasoning.

In this study, normative data for the age-range 18-40 years have been provided for the Verbal Judgment Test (VJT), which underpins abstract reasoning on the basis of four subtests: \"Differences\", \"Proverbs\", \"Absurdities\" and \"Classifications\". 554 participants (280 males and 274 females) were recruited and the following data were provided: means and standard deviations divided by gender, educational level (8, 13 and 18 years) and age group (18-20 years, 21-25 years, 26-30 years, 31-35 years and 36-40 years) for each subtest and the total score; percentiles for each subtest, divided by age group, and, when appropriate, educational level and/or gender; Rho correlations between age group, gender, educational level, intelligence and VJT scores. Age-, education- and gender differences were also assessed carrying out non parametric tests. Results showed that age and education positively affected performance in the subtests of Differences, Proverbs and Classifications, which are mostly based on previous knowledge, experience, and crystallized intelligence, but did not affect performance in the Absurdities subtest, which encompasses to some extent fluid intelligence. In addition, males showed higher scores than females in the subtests of Differences and Proverbs and in the total VJT, probably reflecting higher knowledge acquisition. Implications for future research are briefly discussed.