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This triple-arm, double-blind, randomized clinical trial investigated the effect of multisession prefrontal transcranial direct current stimulation (tDCS) on social functioning in individuals with autism spectrum disorder (ASD). A total of 105 individuals (age 14-21 years) diagnosed with ASD were randomized into the active-tDCS, sham-tDCS, and waitlist control groups. The experimental group received 20 min of 1.5 mA tDCS stimulation (cathode: F3; anode: Fp2) for 10 days with concurrent computerized cognitive remediation training. Changes in overall social functioning, social communication, and restricted, repetitive behaviors (RRB) were measured by the Social Responsiveness Scale-2nd edition (SRS-2). Two-level hierarchical linear mixed-model analysis showed significant group*time interactions for SRS-2 total [F(2, 107.09) = 7.82; p = 0.001] and RRB [F(2, 90.26) = 5.62; p = 0.005] T-scores. When compared with the waitlist control group, the changes in scores were only significant in active-tDCS (SRS-2 total T-score p < 0.001, d = 0.61; SRS-2 RRB T-score p = 0.002, d = 0.88), but not sham-tDCS (SRS-2 total T-score p < 0.12, d = 0.30; SRS-2 RRB T-score p = 0.54, d = 0.17) group. Multiple sessions of prefrontal tDCS coupled with cognitive training is a safe and effective treatment for improving social functioning in people with ASD. Trial Registration: ClinicalTrials.gov (ID: NCT03814083; URL: https://clinicaltrials.gov/ct2/show/NCT03814083).

Background: Alzheimer's disease has become increasingly prevalent among the older population, leading to significant social and economic burdens. Transcranial photobiomodulation (tPBM) has shown promise as a cognitive intervention for enhancing cognitive efficiency in healthy older adults, and individuals with mild cognitive impairment and Alzheimer's disease. However, determining the optimal tPBM dosage is crucial for ensuring effective and efficient intervention. Objective: This study aimed to compare the effects of different dosages in a single tPBM session on cognitive efficiency in healthy older adults. Methods: In this randomized controlled trial, 88 healthy older participants were assigned to either a single dose (irradiance = 30 mW/cm2, fluence = 10.8 J/cm2; n = 44) or a double dose (irradiance = 30 mW/cm2, fluence = 21.6 J/cm2; n = 44) tPBM session. Cognitive efficiency was assessed using functional near-infrared spectroscopy during a visual working memory span task. Results: The single dose group exhibited significantly greater cognitive efficiency enhancement, indicated by a more pronounced reduction in oxygenated hemoglobin during a challenging task level (span level 9) (p = 0.021, d = 0.50), and better working memory task performance (p = 0.045, d = 0.31). Furthermore, participants with better visuospatial abilities demonstrated greater improvement after a single dose (r = –0.42, p = 0.004). In contrast, participants with varying cognitive function did not exhibit additional benefits from a double dose (r = –0.22–0.15, p = 0.16–0.95). Conclusions: These findings suggest that higher tPBM dosages may not necessarily result in superior cognitive improvement in older adults. [ABSTRACT FROM AUTHOR]

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.

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., Author(s): Michael K. Yeung [sup.1] [sup.2] , Tsz L. Lee [sup.2] , Agnes S. Chan [sup.2] [sup.3] Author Affiliations: (1) grid.14709.3b, 0000 0004 1936 8649, Department of Neurology and Neurosurgery, [...]

Previous studies have shown that children with autism spectrum disorders (ASDs) have impaired executive function, disordered neural connectivity, and abnormal immunologic function. The present study examined whether these abnormalities were associated. Seventeen high-functioning (HFA) and 17 low-functioning (LFA) children with ASD, aged 8-17 years, participated voluntarily in the study. The two groups of children were compared on their general intelligence in terms of IQ; executive function as measured by the Hong Kong List Learning Test, D2 Test of Concentration, Five Point Test, Children's Color Trail Test, Tower of California Test, and Go/No-Go task; a non-executive task as measured by the Picture Completion Task; neural connectivity as measured by theta coherence in the anterior and posterior regions; and immunologic function as measured by the level of circulating CD3+ CD8+ suppressor/cytotoxic T lymphocytes in a blood sample. Results on executive function showed that LFA children performed significantly poorer than HFA children as shown on their lower Executive Composite as well as individual executive function scores. However, there was no group difference on the Picture Completion Task. Results on neural connectivity showed that LFA children demonstrated a different pattern of electroencephalography (EEG) coherence from HFA children as shown in the significantly elevated theta coherence in the anterior network, as well as at the left "intra-hemispheric" (LA-LP) and right-to-left "inter-hemisphere" (RA-LP) connections of LFA children. In immunologic function, results showed that LFA children had significantly elevated level of suppressor/cytotoxic T lymphocytes (CD3+ CD8+) (p less than 0.05). In addition, the executive dysfunction, disordered neural connectivity, and abnormal immunologic function were found to be associated. These results provided some initial evidence to support the notion that immunologic factors are associated with neuronal damage, measureable by EEG coherence and manifested as executive dysfunctions. (Contains 5 tables and 2 figures.)

Inhibition of return (IOR) occurs when a target is preceded by an irrelevant stimulus (cue) at the same location: Target detection is slowed, relative to uncued locations. In the present study, we used relatively complex displays to examine the effect of repetition of nonspatial attributes. For both color and shape, attribute repetition produced a robust inhibitory effect that followed a time course similar to that for location-based IOR. However, the effect only occurred when the target shared both the feature (i.e., color or shape) and location with the cue; this constraint implicates a primary role for location. The data are consistent with the idea that the system integrates consecutive stimuli into a single object file when attributes repeat, hindering detection of the second stimulus. The results are also consistent with an interpretation of IOR as a form of habituation, with greater habituation occurring with increasing featural overlap of a repeated stimulus. Critically, both of these interpretations bring the IOR effect within more general approaches to attention and perception, rather than requiring a specialized process with a limited function. In this view, there is no process specifically designed to inhibit return, suggesting that IOR may be the wrong framing of inhibitory repetition effects. Instead, we suggest that repetition of stimulus properties can interfere with the ability to focus attention on the aspects of a complex display that are needed to detect the occurrence of the target stimulus; this is a failure of activation, not an inhibition of processing. (Contains 2 footnotes and 6 figures.)

The present study examined the memory performance and cortical connectivity of children with ASD, and investigated whether the memory deficits exhibited by these children were associated with the cortical connectivity. Twenty-one children with ASD and 21 children with normal development (NC), aged 5-14 years, participated in the study. Each child was administered a neuropsychological battery that included the Test of Non-verbal Intelligence (TONI-III), Digit Span test (DS), Rey-Osterrieth Complex Figure Test (Rey-O), and Hong Kong List Learning Test (HKLLT); and an EEG recording session when performing the visual encoding Object Recognition (OR) task. Six neuropsychological measures from the test battery and six EEG coherence measures in the theta band were compared between the children with ASD and normal children. Results indicated that children with ASD performed at comparable levels with normal children in the DS and Rey-O, but were significantly poorer in HKLLT and OR. They also exhibited significantly elevated long-range coherences in the fronto-posterior connections involving the left hemisphere (left anterior-left posterior; left anterior-right posterior). Pearson correlation showed significant negative associations between the anterior-posterior EEG coherences and memory performance. (Contains 2 figures and 4 tables.)

Previous studies showed that the anterior cingulate cortex (ACC) is activated when individuals engage in attention and inhibitory control tasks. The present study examined whether ACC activity is associated with behavioral performance of the two tasks. Twenty normal and 20 children with autism spectrum disorders (ASDs) were subjected to neuropsychological assessments on attention and inhibitory control, as well as electroencephalography recording. Children with ASD performed significantly worse than normal children on attention tasks as shown in their poorer performance on the Digit Span test, the greater number of Omission Errors on both the Continuous Performance Test II and the Go/No-Go tasks. They also performed significantly worse than normal children on inhibitory control tasks as shown by the greater number of False Alarms on the Object Recognition and Hong Kong List Learning Test. Their ACC activities, as indicated by relative theta power, were found to be significantly lower than those of normal controls during performance of the Go/No-Go task. Depressed ACC activities were further found to be significantly associated with poorer performance in attention and inhibition. Clinical implications on the use of theta activities in the ACC as an indicator to monitor intervention progress in children with ASD were discussed. (Contains 3 figures and 4 tables.)

The present study examined the verbal memory profile and its relation to organizational strategies in high-functioning (Hi-AUT) and low-functioning (Lo-AUT) children with autism. Twenty-two Hi-AUT and 16 Lo-AUT, and 22 age-, gender- and handedness-matched normal children (NC) were required to remember a list of semantically related words for immediate and delayed recall and recognition. All autistic children showed impaired free recall, a reduced discrimination score and an elevated false alarm rate at recognition. While Hi-AUT children showed encoding and retrieval deficit, Lo-AUT children demonstrated more severe encoding problem and an additional retention difficulty. Lo-AUT, but not the Hi-AUT, children showed impaired semantic clustering. The recall performance in autistic children was not as strongly correlated with semantic clustering as in NC. The dual deficits of encoding and retrieval in autistic children, regardless of functioning level, implicate a frontal-lobe problem commonly observed in autism. The additional retention difficulty shown by low-functioning autistic children may be suggestive of pathological temporal-lobe involvement. The present findings may provide insights into future exploration of memory intervention for autistic children. (Contains 3 figures and 2 tables.)

Language impairment is a primary characteristic of children with autism; however, findings on the language deficits of these children have been inconclusive, and even less is known about the language profiles of Chinese-speaking children with autism. The present study examined the verbal expression-comprehension abilities of 46 Chinese children at ages 5 to 6. The children with autism were further classified into high- or low-functioning groups based on their nonverbal intelligence. Results showed that 63% of the children with autism demonstrated language impairment. Specifically, 42% were impaired in both verbal expression and comprehension abilities, and 21% demonstrated impaired expression skills. General intelligence did not seem to explain this heterogeneity, as variability was also observed among the high-functioning children with autism. The results also suggested that a test of expressive language is more sensitive than a test of comprehension in differentiating Chinese children with autism from their age-matched counterparts at early childhood.