Neurocognitive development of flanker and Stroop interference control: A near-infrared spectroscopy study.

The abilities to resolve flanker and Stroop interference, which are primarily mediated by the prefrontal cortex (PFC), have been shown to be dissociable at the individual difference level. However, the relationship between the neurocognitive development of these two aspects of interference control remains unclear. This study examined developmental changes in inhibition performance and PFC activation during flanker and Stroop interference control using functional near-infrared spectroscopy (fNIRS). Twenty-eight healthy children and adolescents aged 7-16 years (16 males) underwent the arrow flanker and color-word matching Stroop paradigms while changes in oxyhemoglobin concentration in the PFC were monitored by fNIRS. We found developmental improvements in inhibition performance in terms of the interference scores on both the flanker and Stroop tasks. There were also developmental increases in PFC activation, particularly in the medial region, while resolving flanker and Stroop interference. Despite developmental changes in inhibition performance and medial PFC activation during both tasks, the developmental changes that we observed for these two aspects of interference control were found to be relatively independent of each other. Our findings support the heterogeneous view of interference control and suggest that the neurocognitive development of flanker and Stroop interference control is only weakly associated, if not dissociable.

Depressive and anxiety symptoms are related to decreased lateral prefrontal cortex functioning during cognitive control in older people.

Some studies have found a relationship between negative emotional symptoms and decreased lateral PFC functioning during a cognitive control task in healthy younger adults. Here, we asked whether this relationship is also present in the general older population and across different functional domains of the lateral PFC. Thirty-six older people (13 males) self-reported their recent depressive and anxiety symptoms. They also took two cognitive control tasks known to differentially engage the lateral frontoparietal network (digit n-back task) and the lateral frontotemporal network (Category Fluency Test) while hemodynamic changes in the PFC were monitored by functional near-infrared spectroscopy (fNIRS). Both depressive and anxiety symptoms were associated with decreased activation in the bilateral lateral PFC during cognitive control performance. Interestingly, these relationships were driven by the n-back task. Our findings suggest that depressive and anxiety symptoms are related to decreased lateral PFC functioning in particular domains of cognitive control among older people.

Negative mood is associated with decreased prefrontal cortex functioning during working memory in young adults.

The prefrontal-subcortical model of emotion regulation postulates that decreased prefrontal cortex (PFC) functioning may underlie the emergence of clinical affective disorders. In addition, accumulated evidence suggests that there is considerable variability in negative affect in the nonclinical population. This study examined whether negative affective symptoms were associated with decreased PFC functioning in nonclinical young adults. Forty college students aged 18-24 years (ten males) underwent an n-back paradigm (i.e., a frontal executive task) with a working memory (WM) load (i.e., 3-back) and a vigilance control condition (i.e., 0-back) while their hemodynamics changes in the lateral and medial PFC on both sides were monitored using a 16-channel functional near-infrared spectroscopy (fNIRS) system. They also filled out the Depression Anxiety Stress Scales (DASS) to estimate the levels of their negative emotions in the preceding week. Young adults exhibited an increased concentration of oxyhemoglobin and a decreased concentration of deoxyhemoglobin (i.e., activation), primarily in the lateral PFC, in response to the WM load (i.e., 3-back > 0-back). Importantly, higher DASS scores indicating higher levels of recent negative mood, especially depression and stress rather than anxiety symptoms, correlated with lower WM-related activation in the lateral PFC. Thus, recent negative mood is associated with decreased lateral PFC functioning during the executive control of WM in healthy young adults. Our findings suggest that decreased PFC functioning is also present in the nonclinical population with increased levels of negative mood and that fNIRS is a promising tool for elucidating individual differences in negative affective symptoms.

Prefrontal activation and pupil dilation during n-back task performance: A combined fNIRS and pupillometry study.

The n-back task is one of the most commonly used working memory (WM) paradigms in cognitive neuroscience. Converging evidence suggests activation in the lateral prefrontal cortex (PFC) and pupil dilation [a proxy for locus coeruleus (LC) activation] during this task. However, it remains unclear whether the lateral PFC and the LC are functionally associated during n-back task performance. This study's aim was to examine the relationship between changes in lateral PFC activity and the pupil diameter and to evaluate the effect of WM load on such relationship during the n-back task. Thirty-nine healthy young adults (10 males, 29 females) underwent a number n-back paradigm with 0- and 3-back conditions. Their prefrontal hemodynamics and changes in pupil size during task performance were simultaneously measured using a 16-channel functional near-infrared spectroscopy (fNIRS) device and a wearable eye tracker. Young adults exhibited significant activation in the bilateral lateral PFC and significant increases in pupil size when the WM load was high (i.e., 3-back) but not low (i.e., 0-back) compared with the resting period. Interestingly, significant positive correlations were found between changes in lateral PFC activity and pupil size during the 0-back task only. These correlations tended to be stronger during the 0-back than the 3-back condition. Thus, the functional relationship between the lateral PFC and the LC may vary at different load levels during the n-back task. Our findings have important implications for neuropsychiatric research and support concurrent fNIRS and pupillometric measurements for a better understanding of the mechanisms underlying WM processing.

Impaired Recognition of Negative Facial Expressions is Partly Related to Facial Perception Deficits in Adolescents with High-Functioning Autism Spectrum Disorder.

Accumulating studies have reported facial emotion recognition or facial perception impairments in autism spectrum disorder (ASD). To clarify the specificity of the emotion recognition impairment, this study examined the relationships between facial emotion recognition and facial perception abilities in ASD. Twenty-two adolescents with high-functioning ASD (20 males) and 22 typically developing (TD) adolescents (16 males) aged 11-18 years undertook a facial emotion labeling task and a facial perception test. We found that adolescents with ASD had deficits in recognizing negative facial expressions, which correlated with both facial perception deficits and severity of social impairment. In addition, the emotion recognition deficits remained after adjusting for facial perception performance. Thus, our findings suggest an emotion-specific impairment in facial emotion recognition in ASD.

Right-lateralized frontal activation underlies successful updating of verbal working memory in adolescents with high-functioning autism spectrum disorder.

Adults with autism spectrum disorder (ASD) exhibit altered frontal lobe activation during working memory (WM) processing despite relatively intact WM updating ability. To determine whether this alteration reflects compensation and is also present in adolescents, this study examined prefrontal activation during WM updating in adolescents with ASD using functional near-infrared spectroscopy. Eighteen adolescents with high-functioning ASD and 18 typically developing (TD) adolescents aged 11-18 years successfully underwent a verbal n-back paradigm with a WM (i.e., 2-back) and a control (i.e., 0-back) condition. We found that adolescents with ASD exhibit more right-lateralized prefrontal activation in response to WM load (i.e., 2-back > 0-back) compared to TD adolescents. More importantly, right-lateralized prefrontal activation was associated with better WM updating ability-specifically among adolescents with ASD. Thus, adolescents with ASD might rely on a compensatory mechanism such as the employment of a visuospatial processing style to help them update verbal WM.

Frontal lobe dysfunction underlies the differential word retrieval impairment in adolescents with high-functioning autism.

There is substantial evidence of word retrieval impairment as indicated by poor performance on the category fluency test in autism spectrum disorder (ASD). However, little is known about the neural mechanisms underlying this impairment. Functional neuroimaging studies have shown that the lateral frontal cortex plays a key role in flexible word retrieval. Thus, we examined whether individuals with ASD exhibited altered frontal processing during the category fluency test using functional near-infrared spectroscopy (fNIRS). Twenty-two adolescents with high-functioning ASD (20 males) and 22 typically developing (TD) adolescents (16 males) aged 11-18 years were recruited. All underwent a category fluency paradigm, which required production of animal or means of transportation words for 1 min each although their frontal hemodynamic changes were recorded with fNIRS. We found that adolescents with ASD produced fewer animal but not transportation words (group-by-category interaction: P = 0.003), suggesting differential word retrieval impairment. In addition, unlike TD adolescents who exhibited activation primarily in lateral frontal regions during word production, adolescents with ASD had comparable activation across lateral and medial frontal regions. More importantly, this lack of lateral-medial distinction of activation, which was associated with poor word retrieval, differed significantly between groups only in the animal category (group-by-category interaction: P = 0.018). Thus, our findings implicate frontal lobe dysfunction in the impairment of differential word retrieval in adolescents with ASD. The relatively greater involvement of the medial frontopolar cortex might reflect the use of nonspecialized brain regions to compensate for the category-dependent difficulties with word retrieval in ASD. Autism Res 2019, 12: 600-613. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Using an optical imaging tool, we found that adolescents with autism had difficulties with producing semantically related words and exhibited frontal lobe dysfunction. Nonetheless, poor word production and altered brain processing was only seen when these adolescents were asked to produce words from a category of living things but not nonliving things (i.e., animals but not means of transportation). Category-dependent word retrieval problems and frontal lobe dysfunction might be two features of this disorder.

Frontal Underactivation During Working Memory Processing in Adults With Acute Partial Sleep Deprivation: A Near-Infrared Spectroscopy Study.

Individuals with partial sleep deprivation may have working memory (WM) impairment, but the underlying neural mechanism of this phenomenon is relatively unknown. The present study examined neural processing during WM performance in individuals with and without partial sleep deprivation using near-infrared spectroscopy (NIRS). Forty college students (10 males) were equally split into Sufficient Sleep (SS) and Insufficient Sleep (IS) groups based on self-reports of previous night's sleep duration. Participants in the SS group obtained the recommended amounts of sleep according to various sleep organizations (i.e., >7.0 h), whereas those in the IS group obtained amounts of sleep no greater than the lower limit of the recommendation (i.e., ≤7.0 h). All participants underwent an n-back paradigm with a WM load (i.e., 3-back) and a control condition (i.e., 0-back) while their prefrontal hemodynamics were recorded by NIRS. The IS and SS groups performed the tasks comparably well. However, unlike the SS group, which exhibited bilateral frontal activation indicated by increased oxyhemoglobin concentration and decreased deoxyhemoglobin concentration during WM processing (i.e., 3-back > 0-back), the IS group did not exhibit such activation. In addition, levels of WM-related frontal activation, especially those on the left side, correlated with sleep duration the night before, even when habitual sleep duration was controlled for. The findings suggest the presence of frontal lobe dysfunction in the absence of evident WM difficulties in individuals with acute partial sleep deprivation. They also highlight the importance of a good night's sleep to brain health.

Risk factors and treatment of hemorrhagic cystitis in children who underwent hematopoietic stem cell transplantation.

A retrospective cohort of 163 children with 171 hematopoietic stem cell transplantation (HSCT) performed during Mar. 1992-Dec. 2005 were analyzed to evaluate the incidence, risk factors, management, and outcome of hemorrhagic cystitis (HC). Fourteen patients (8.2%) developed HC (6 boys, median age 6.6 years) at 0-166 days after HSCT (median 25 days), and lasted for 3-96 days (median 26 days). Older age at transplant (median 11.0 vs. 6.4 years, P = 0.013), allogeneic transplant (OR = 4.4, P = 0.02), cyclophosphamide-containing conditioning (OR = 4.87, P = 0.008), moderate-to-severe acute graft-versus-host disease (GVHD) (OR = 3.56, P = 0.025) and hepatic GVHD (OR = 3.62, P = 0.017) were associated with higher risks of HC in univariate but not multivariate analyses. While estrogen was ineffective in most patients, intravesical formalin, which was used in five patients, was found to be a very effective yet safe treatment for intractable HC. Patients with HC had longer hospital stay (median 175 vs. 88 days, P = 0.004). HC resolved after treatments in all cases but eight of the 14 patients subsequently died of other complications of HSCT. In conclusion, HC is a serious complication of allogeneic HSCT. Treatment with intravesical formalin appears effective and safe and can be considered early in severe HC to reduce the risk of morbidity and mortality.