Neural responses to gaming content on social media in young adults.

Excessive gaming can impair both mental and physical health, drawing widespread public and clinical attention, especially among young generations. People are now more exposed to gaming-related content on social media than before, and this exposure may have a significant impact on their behavior. However, the neural mechanisms underlying this effect remain unexplored. Using functional magnetic resonance imaging (fMRI), this study aimed to investigate the neural activity induced by gaming-related content on social media among young adults casually playing online games. While being assessed by fMRI, the participants watched gaming-related videos and neutral (nongaming) videos on social media. The gaming-related cues significantly activated several brain areas, including the medial prefrontal cortex, posterior cingulate cortex, hippocampus, thalamus, superior/middle temporal gyrus, precuneus and occipital regions, compared with the neutral cues. Additionally, the participants' gaming desire levels positively correlated with a gaming-related cue-induced activation in the left orbitofrontal cortex and the right superior temporal gyrus. These findings extend previous studies on gaming cues and provide useful information to elucidate the effects of gaming-related content on social media in young adults. Continued research using real-world gaming cues may help improve our understanding of promoting gaming habits and provide support to individuals vulnerable to gaming addiction.

Overlapping yet dissociable contributions of superiority illusion features to Ponzo illusion strength and metacognitive performance.

Humans are typically inept at evaluating their abilities and predispositions. People dismiss such a lack of metacognitive insight into their capacities while even enhancing (albeit illusorily) self-evaluation such that they should have more desirable traits than an average peer. This superiority illusion helps maintain a healthy mental state. However, the scope and range of its influence on broader human behavior, especially perceptual tasks, remain elusive. As belief shapes the way people perceive and recognize, the illusory self-superiority belief potentially regulates our perceptual and metacognitive performance. In this study, we used hierarchical Bayesian estimation and machine learning of signal detection theoretic measures to understand how the superiority illusion influences visual perception and metacognition for the Ponzo illusion. Our results demonstrated that the superiority illusion correlated with the Ponzo illusion magnitude and metacognitive performance. Next, we combined principal component analysis and cross-validated regularized regression (relaxed elastic net) to identify which superiority components contributed to the correlations. We revealed that the "extraversion" superiority dimension tapped into the Ponzo illusion magnitude and metacognitive ability. In contrast, the "honesty-humility" and "neuroticism" dimensions only predicted Ponzo illusion magnitude and metacognitive ability, respectively. These results suggest common and distinct influences of superiority features on perceptual sensitivity and metacognition. Our findings contribute to the accumulating body of evidence indicating that the leverage of superiority illusion is far-reaching, even to visual perception.

Explicit and implicit effects of gaming content on social media on the behavior of young adults.

Excessive gameplay can have negative effects on both mental and physical health, especially among young people. Nowadays, social media platforms are bombarding users with gaming-related content daily. Understanding the effect of this content on people's behavior is essential to gain insight into problematic gaming habits. However, this issue is yet to be studied extensively. In this study, we examined how gaming-related content on social media affects young adults explicitly and implicitly. We studied 25 healthy young adults (average age 21.5 ± 2.2) who played online games casually and asked them to report their gaming desire. We also conducted an implicit association test (IAT) to measure their implicit attitudes toward gaming-related content. We also investigated the relationship between these measures and various psychological factors, such as personality traits, self-efficacy, impulsiveness, and cognitive flexibility. The results revealed that participants had a higher explicit gaming desire when exposed to gaming-related cues on social media than neutral cues. They also had a robust positive implicit attitude toward gaming-related content on social media. Explicit gaming desire was positively correlated with neuroticism levels. Furthermore, the IAT effect was negatively correlated with self-efficacy and cognitive flexibility levels. However, there were no significant correlations between explicit gaming desire/IAT effect and impulsiveness levels. These findings suggest that gaming-related content on social media can affect young adults' behavior both explicitly and implicitly, highlighting the need for further research to prevent gaming addiction in vulnerable individuals.

Association between enhanced carbonyl stress and decreased apparent axonal density in schizophrenia by multimodal white matter imaging.

Carbonyl stress is a condition featuring increased rich reactive carbonyl compounds, which facilitate the formation of advanced glycation end products including pentosidine. We previously reported the relationship between enhanced carbonyl stress and disrupted white matter integrity in schizophrenia, although which microstructural component is disrupted remained unclear. In this study, 32 patients with schizophrenia (SCZ) and 45 age- and gender-matched healthy volunteers (HC) were recruited. We obtained blood samples for carbonyl stress markers (plasma pentosidine and serum pyridoxal) and multi-modal magnetic resonance imaging measures of white matter microstructures including apparent axonal density (intra-cellular volume fraction (ICVF)) and orientation (orientation dispersion index (ODI)), and inflammation (free water (FW)). In SCZ, the plasma pentosidine level was significantly increased. Group comparison revealed that mean white matter values were decreased for ICVF, and increased for FW. We found a significant negative correlation between the plasma pentosidine level and mean ICVF values in SCZ, and a significant negative correlation between the serum pyridoxal level and mean ODI value in HC, regardless of age. Our results suggest an association between enhanced carbonyl stress and axonal abnormality in SCZ.

People have modest, not good, insight into their face recognition ability: a comparison between self-report questionnaires.

Whether people have insight into their face recognition ability has been intensely debated in recent studies using self-report measures. Although some studies showed people's good insight, other studies found the opposite. The discrepancy might be caused by the difference in the questionnaire used and/or the bias induced using an extreme group such as suspected prosopagnosics. To resolve this issue, we examined the relationship between the two representative self-report face recognition questionnaires (Survey, N = 855) and then the extent to which the questionnaires differ in their relationship with face recognition performance (Experiment, N = 180) in normal populations, which do not include predetermined extreme groups. We found a very strong correlation (r = 0.82), a dominant principal component (explains > 90% of the variance), and comparable reliability between the questionnaires. Although these results suggest a strong common factor underlying them, the residual variance is not negligible (33%). Indeed, the follow-up experiment showed that both questionnaires have significant but moderate correlations with actual face recognition performance, and that the correlation was stronger for the Kennerknecht's questionnaire (r = - 0.38) than for the PI20 (r = - 0.23). These findings not only suggest people's modest insight into their face recognition ability, but also urge researchers and clinicians to carefully assess whether a questionnaire is suitable for estimating an individual's face recognition ability.

Myelin Measurement: Comparison Between Simultaneous Tissue Relaxometry, Magnetization Transfer Saturation Index, and T1w/T2w Ratio Methods.

Magnetization transfer (MT) imaging has been widely used for estimating myelin content in the brain. Recently, two other approaches, namely simultaneous tissue relaxometry of R1 and R2 relaxation rates and proton density (SyMRI) and the ratio of T1-weighted to T2-weighted images (T1w/T2w ratio), were also proposed as methods for measuring myelin. SyMRI and MT imaging have been reported to correlate well with actual myelin by histology. However, for T1w/T2w ratio, such evidence is limited. In 20 healthy adults, we examined the correlation between these three methods, using MT saturation index (MTsat) for MT imaging. After calibration, white matter (WM) to gray matter (GM) contrast was the highest for SyMRI among these three metrics. Even though SyMRI and MTsat showed strong correlation in the WM (r = 0.72), only weak correlation was found between T1w/T2w and SyMRI (r = 0.45) or MTsat (r = 0.38) (correlation coefficients significantly different from each other, with p values < 0.001). In subcortical and cortical GM, these measurements showed moderate to strong correlations to each other (r = 0.54 to 0.78). In conclusion, the high correlation between SyMRI and MTsat indicates that both methods are similarly suited to measure myelin in the WM, whereas T1w/T2w ratio may be less optimal.

Color harmony represented by activity in the medial orbitofrontal cortex and amygdala.

Observing paired colors with a different hue (in terms of chroma and lightness) engenders pleasantness from such harmonious combinations; however, negative reactions can emerge from disharmonious combinations. Currently, neural mechanisms underlying the esthetic and emotional aspects of color perception remain unknown. The current study reports evidence regarding the neural correlates of color harmony and disharmony. Functional magnetic resonance imaging was used to assess brain regions activated by harmonious or disharmonious color combinations in comparison to other stimuli. Results showed that the left medial orbitofrontal cortex (mOFC) and left amygdala were activated when participants observed harmonious and disharmonious stimuli, respectively. Taken together, these findings suggest that color disharmony may depend on stimulus properties and more automatic neural processes mediated by the amygdala, whereas color harmony is harder to discriminate based on color characteristics and is reflected by the esthetic value represented in the mOFC. This study has a limitation that we could not exclude the effect of preference for color combination, which has a strong positive correlation with color harmony.

Dissociable cortical pathways for qualitative and quantitative mechanisms in the face inversion effect.

Humans' ability to recognize objects is remarkably robust across a variety of views unless faces are presented upside-down. Whether this face inversion effect (FIE) results from qualitative (distinct mechanisms) or quantitative processing differences (a matter of degree within common mechanisms) between upright and inverted faces has been intensely debated. Studies have focused on preferential responses to faces in face-specific brain areas, although face recognition also involves nonpreferential responses in non-face-specific brain areas. By using dynamic causal modeling with Bayesian model selection, here we show that dissociable cortical pathways are responsible for qualitative and quantitative mechanisms in the FIE in the distributed network for face recognition. When faces were upright, the early visual cortex (VC) and occipital and fusiform face areas (OFA, FFA) suppressed couplings to the lateral occipital cortex (LO), a primary locus of object processing. In contrast, they did not inhibit the LO when faces were inverted but increased couplings to the intraparietal sulcus, which has been associated with visual working memory. Furthermore, we found that upright and inverted face processing together involved the face network consisting of the VC, OFA, FFA, and inferior frontal gyrus. Specifically, modulatory connectivity within the common pathways (VC-OFA), implicated in the parts-based processing of faces, strongly correlated with behavioral FIE performance. The orientation-dependent dynamic reorganization of effective connectivity indicates that the FIE is mediated by both qualitative and quantitative differences in upright and inverted face processing, helping to resolve a central debate over the mechanisms of the FIE.

Age and individual differences in visual working memory deficit induced by overload.

Many studies on working memory have assumed that one can determine an individual's fixed memory capacity. In the current study, we took an individual differences approach to investigate whether visual working memory (VWM) capacity was stable irrespective of the number of to-be-remembered objects and participant age. Younger and older adults performed a change detection task using several objects defined by color. Results showed wide variability in VWM capacity across memory set sizes, age, and individuals. A marked decrease in the number of objects held in VWM was observed in both younger and older adults with low memory capacity, but not among high-capacity individuals, when set size went well beyond the limits of VWM capacity. In addition, a decrease in the number of objects held in VWM was alleviated among low-capacity younger adults by increasing VWM encoding time; however, increasing encoding time did not benefit low-capacity older adults. These findings suggest that low-capacity individuals are likely to show decreases in VWM capacity induced by overload, and aging exacerbates this deficit such that it cannot be recovered by simply increasing encoding time. Overall, our findings challenge the prevailing assumption that VWM capacity is fixed and stable, encouraging a revision to the strict view that VWM capacity is constrained by a fixed number of distinct "slots" in which high-resolution object representations are stored.

Individual differences in autistic traits predict the perception of direct gaze for males, but not for females.

Despite the emphasis of autism spectrum disorders as a continuum of atypical social behaviors and the sexual heterogeneity of phenotypic manifestations, whether gaze processing constitutes an autistic endophenotype in both sexes remains unclear. Using the Autism-Spectrum Quotient and a psychophysical approach in a normal population (N = 128), here we demonstrated that individual differences in autistic traits predicted direct-gaze perception for males, but not for females. Our findings suggest that direct-gaze perception may not constitute an autistic endophenotype in both sexes, and highlight the importance of sex differences when considering relationships between autistic traits and behaviors.

Differential roles for parietal and occipital cortices in visual working memory.

Visual working memory (VWM) is known as a highly capacity-limited cognitive system that can hold 3-4 items. Recent studies have demonstrated that activity in the intraparietal sulcus (IPS) and occipital cortices correlates with the number of representations held in VWM. However, differences among those regions are poorly understood, particularly when task-irrelevant items are to be ignored. The present fMRI-based study investigated whether memory load-sensitive regions such as the IPS and occipital cortices respond differently to task-relevant information. Using a change detection task in which participants are required to remember pre-specified targets, here we show that while the IPS exhibited comparable responses to both targets and distractors, the dorsal occipital cortex manifested significantly weaker responses to an array containing distractors than to an array containing only targets, despite that the number of objects presented was the same for the two arrays. These results suggest that parietal and occipital cortices engage differently in distractor processing and that the dorsal occipital, rather than parietal, activity appears to reflect output of stimulus filtering and selection based on behavioral relevance.

Differential contributions of the intraparietal sulcus and the inferior parietal lobe to attentional blink: evidence from transcranial magnetic stimulation.

When two targets (T1 and T2) are to be identified in rapid serial visual presentation, the response to T1 induces impairment of T2 report if T2 appears within 500 msec after T1 (attentional blink: AB). AB is thought to reflect temporal limitations of attention which affect target perception. Recent research suggests that the intraparietal sulcus (IPS) contributes to an attentional set associated with task goals, whereas the inferior parietal lobe (IPL) is associated with the disengagement and reorienting of attention to a relevant stimulus presented outside the current focus of attention. We investigated respective involvement of the IPS and the IPL in AB using transcranial magnetic stimulation (TMS). The results of Experiment 1 showed that the magnitude of AB deficit decreased TMS disrupted activity of the IPS after T1 onset. In addition, an increased AB deficit occurred when TMS was delivered over the IPS or IPL after T2 onset. In Experiment 2, where participants were instructed to ignore T1, they showed an AB-like T2 deficit only when TMS was delivered to the IPS after a T2 onset. Findings are discussed in terms of hypotheses about the respective roles of the IPS, in realizing an attentional set, and the IPL, in contributing to a disengagement of attention (from T1 to T2) during an AB period.

Task-irrelevant memory load induces inattentional blindness without temporo-parietal suppression.

We often fail to consciously detect an unexpected object when we are engaged in an attention-demanding task (inattentional blindness). The inattentional blindness which is induced by visual short-term memory (VSTM) load has been proposed to result from a suppression of temporo-parietal junction (TPJ) activity that involves stimulus-driven attention. However, the fact that, inversely proportional to TPJ activity, intraparietal sulcus (IPS) activity correlates with VSTM load renders questionable the account of inattentional blindness based only on TPJ activity. Here, we investigated whether the TPJ is solely responsible for inattentional blindness by decoupling IPS and TPJ responses to VSTM load and then using the same manipulation to test the behavioral inattentional blindness performance. Experiment 1 showed that TPJ activity was not suppressed by task-irrelevant load while the IPS responded to both task-relevant and task-irrelevant load. Although the TPJ account of inattentional blindness predicts that the degree of inattentional blindness should track TPJ activity, we found in Experiment 2 that inattentional blindness was induced not only by task-relevant load but also by task-irrelevant load, showing inconsistency between the extent of inattentional blindness and TPJ response. These findings suggest that inattentional blindness can be induced without suppression of TPJ activity and seem to offer the possibility that the IPS contributes to conscious perception.

Implied motion because of instability in Hokusai Manga activates the human motion-sensitive extrastriate visual cortex: an fMRI study of the impact of visual art.

The recent development of cognitive neuroscience has invited inference about the neurosensory events underlying the experience of visual arts involving implied motion. We report functional magnetic resonance imaging study demonstrating activation of the human extrastriate motion-sensitive cortex by static images showing implied motion because of instability. We used static line-drawing cartoons of humans by Hokusai Katsushika (called 'Hokusai Manga'), an outstanding Japanese cartoonist as well as famous Ukiyoe artist. We found 'Hokusai Manga' with implied motion by depicting human bodies that are engaged in challenging tonic posture significantly activated the motion-sensitive visual cortex including MT+ in the human extrastriate cortex, while an illustration that does not imply motion, for either humans or objects, did not activate these areas under the same tasks. We conclude that motion-sensitive extrastriate cortex would be a critical region for perception of implied motion in instability.

Repetitive transcranial magnetic stimulation of human MT+ reduces apparent motion perception.

We investigated the effects of repetitive transcranial magnetic stimulation (rTMS) over the human cerebral cortex on apparent motion perception. Previous studies have shown that human extrastriate visual area MT+ (V5) processes not only real but also apparent motion. However, the functional relevance of MT+ on long-range apparent motion perception remains unclear. Here, we show direct evidence for the involvement of MT+ in apparent motion perception using rTMS, which is known to temporarily inhibit a localized region in the cerebral cortex. The results showed that apparent motion perception decreased after applying rTMS over MT+, but not after applying rTMS over the control region (inferior temporal gyrus). The decrease in performance caused by applying rTMS to MT+ suggests that MT+ is a causally responsible region for apparent motion perception, and thus, further supports the idea that MT+ plays a major role in the perception of motion.