Eye-movement Patterns of Chinese Children with Developmental Dyslexia during the Stroop Test.

OBJECTIVE: To compare the eye-movement patterns of Chinese children with developmental dyslexia (DD children) with those of non-dyslexic children as they perform the Stroop Color and Word Test (SCWT), and to explore the relationship between their eye-movement patterns and interference effect. METHODS: An EyeLink II was used to record the eye-movement parameters of 32 DD children and 37 non-dyslexic children as they performed the SCWT. The independent samples t-test and repeated measures were used to analyze behavioral and eye-movement parameters. RESULTS: Compared to the control group, Chinese DD children presented lower accuracy (F = 8.488), slower response time (F = 25.306), and larger interference effect (t = 2.29); Chinese DD children also exhibited lower frequency of fixations (F = 6.069), greater numbers of saccades (F = 7.914) and fixations (F = 5.272), and shorter mean saccade distance (F = 4.03). All behavioral and eye-movement parameters differed significantly among the three tasks in the SCWT. There was significant interaction between groups and tasks in accuracy (F = 5.844), and marginally significant interaction in response time (F = 3.040). Chinese DD children tended to have lower accuracy and longer response time than the control group in the 'color-word naming' task. CONCLUSION: Compared to non-dyslexic children, Chinese DD children are subject to a stronger interference effect. When performing the SCWT, Chinese DD children exhibit abnormal eye-movement patterns, namely shorter mean saccade distance, lower frequency of fixations, and more fixations and saccades. These abnormal eye movements may be relatively stable oculomotor patterns of DD children performing visual processing, and not influenced by impaired interference effect.

[Analysis of the complete mitochondrial genome sequence of Larus brunnicephalus (Aves, Laridae)].

The complete sequence of mitochondrial genome of Larus brunnicephalus was determined using long PCR and conserved primers walking approaches. The results showed that the entire mitochondrial genome of L. brunnicephalus is 16,769 bp in length, which has been deposited in GenBank with the accession number JX155863. The mitochondrial genomic organization and gene order of L. brunnicephalus were consistent with that of Gallus gallus, which contains 13 protein coding genes (PCGs), 22 tRNA, 2 rRNA, and a control region. Except for COI gene using GTG and ND3 gene with ATT as the initiation codon, all other 11 PCGs of the mtDNA in L. brunnicephalus started with the typical ATG codon. AGG, TAG, TAA, or AGA were used in 11 PCGs as usual termination codons, except for COIII and ND4 genes with incomplete termination codon (T). The secondary structures of 22 tRNAs were predicted and it is found that the tRNASer (AGN) lacks DHU arm and tRNAPhe contains the fourth types of permutation in the TψC arm. It is predicted that the secondary structures of 12S rRNA and 16S rRNA include 4 structural domains with 47 helics and 6 domains with 60 helics, respectively. F-box, E-box, D-box, C-box, B-box, Bird similarity-box, and CSB-boxes (1-3), which were found in the control regions of other bird species were also present in L. brunnicephalus. The sequence in the starting regions of H-strand replication (OH) and the bidirectional light and heavy-strand transcription promoters (LSP/HSP) in the control region were also predicted. Result of phylogeny analysis supports that L. brunnicephalus should be categorized into the Masked gulls species.

Characterization of the complete mitogenomes of Baillon's Crake Porzana pusilla and phylogenetic analysis.

The complete mitochondrial genome of the Baillon's Crake Porzana pusilla (Gruiformes: Rallidae) are sequenced and annotated, which contained 37 typical genes. The length of the complete mitochondrial genome is 16,966 bp (GenBank No. MW043485), with As, Ts, Cs, Gs, and AT content of the mitochondrial genome is 32.1, 23.2, 30.9, 13.8, and 55.3%, respectively. All protein-coding genes started with ATN except COX1 and ND5, which start with GTG, and all protein-coding genes end with a complete triplet codon (TAA, AGG, AGA, and TAG), except COX3, which ends with an incomplete T. The ND3 gene of P. pusilla with an extra C nucleotide in 174 site. Phylogenetic analysis revealed that the new sequenced species of P. pusilla was closer to the clade of Porzana fusca and Porzana paykullii, and all three Porzana are clustered into one branch.

The first mitogenome of Lesser Whitethroat, Sylvia curruca blythi Ticehurst & Whistler, 1933 (Passeriformes: Sylviidae) and its phylogenetic implications for the genus Sylvia.

The complete mitogenome of the Lesser Whitethroat, Sylvia curruca blythi Ticehurst & Whistler, 1933 was determined, which belongs to Sylviidae, Passeriformes. The mitogenome had a length of 17,959 bp and consisted of 37 genes including 13 PCGs, 2 ribosomal RNAs (rRNA) genes, and 22 transfer RNAs (tRNA) genes. In addition, two control regions (CRs) were also existed in the mitogenome, with Sylvioidea typcial gene arrangement of cytb-trnT-CR1-trnP-nad6-trnE-CR2-trnF-rrnS. Phylogenetic analysis using 37 mitochondrial genes of 17 related species revealed that S. c. blythi had a closer relationship with S. crassirostris, and the monophyly of Sylvia was also recovered. The mitogenome data of S. c. blythi would provide useful resources for further studying the evolution of Sylvia and the subspecies taxonomic revision of S. curruca intraspecific.

Characterization of the mitogenomes for two sympatric breeding species in Recurvirostridae (Charadriiformes) and their phylogenetic implications.

Recurvirostridae is a family of Charadriiformes that displays an amazing amount of characterization at evolutionary level. The mitogenomes of Himantopus himantopus and Recurvirostra avosetta are 17,378 bp and 16,856 bp in size, respectively. Both two mitogenomes reveal the same gene order and genomic organization to that of typical avian mtDNA. The first conserved block with two interrupted poly-C and four long terminal repeats with 140 bp are present in H. himantopus control region. Phylogenetic analysis indicated that Recurvirostridae (H. himantopus and R. avosetta) has the closest relationship with Haematopodidae. We supported that Stercorariidea is a sister group to (Alcidae (Laridae, Sternidae)), and suggested that the status of Larus vegae should be further investigated.

The mitogenomes of Gelochelidon nilotica and Sterna hirundo (Charadriiformes, Sternidae) and their phylogenetic implications.

Gelochelidon nilotica and Sterna hirundo are two sympatric breeding species. The mitogenomes of G. nilotica and S. hirundo are 16,748 bp and 16,707 bp in size. Both two mitogenomes reveal the same gene order and genomic organization to that of typical avian mtDNA. The first conserved blocks with a interrupted poly-C are present in the two species control regions, but not existed in S. albifrons. Seventeen and 11 simple sequence repeats are found in G. nilotica and S. hirundo, respectively. Phylogenetic analysis indicated that Sternidae has the closest relationship with Laridae. We supported that Stercorariidea is a sister group to (Alcidae (Laridae, Sternidae)), G. nilotica is genetically most related to S. hirundo (all belonged to Black cap species), but distant with S. albifrons (White blaze species) in kinship, and suggested that the status of Larus vegae should be further investigated.

Complete mitochondrial genome of Relict Gull, Larus relictus (Charadriiformes: Laridae).

The complete mitochondrial genome sequence of Larus relictus was 16,586-bp long, containing 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and a control region. Most PCGs begin with the typical ATN start codon with the exception of COI and ND5 genes, which use GTG as the initiation codon. Stop codons AGG, TAG, TAA and AGA are present in the PCGs; exceptions are COIII and ND4, which possess incomplete termination codons (T), and ND3, in which one extra C nucleotide is found. Secondary structure prediction of the 22 tRNA genes revealed the absence of the DHU arm in tRNA(Ser)((AGN)). Seven conserved sequence box elements, as well as the origin of H-strand replication (OH) and bidirectional light- and heavy-strand transcription promoters (LSP/HSP), are found in control region.

Sequencing complete mitochondrial genome of Lanius sphenocercus sphenocercus (Passeriformes: Laniidae) using Illunima HiSeq 2500.

Using an Illumina platform, we sequenced the complete mitochondrial genome of Lanius sphenocercus sphenocercus to an average coverage of 1669.5×. We performed a de novo assembly using SOAPdenovo2 and obtained the total mitogenome with 16,833 bp in length. Most PCGs begin with the typical ATG start codon with the exception of COI gene, which use GTG as the initiation codon. Stop codons AGG, TAG, TAA, and AGA are present in the PCGs; exceptions are COII, COIII and ND4, which possess incomplete termination codons (T). But, the function of COII with incomplete stop codon T should be further investigated. The phylogeny revealed that genetic distance of Laniidae and Corvidae was closer than other species. Compared to other three shrike species, L. s. sphenocercus occupy a separate status in the genus Lanius.

Structural characteristics of the Relict Gull (Larus relictus) mitochondrial DNA control region and its comparison to other Laridae.

The structure of the mitochondrial DNA control region in the Relict Gull (Larus relictus) was predicted and compared with data from the National Center for Biotechnology Information (NCBI) on five other gulls. The results showed that the control regions of the six gulls comprise three domains. Sequences of CSB-1-like (domain I) and CSB-1 (domain III) in L. relictus have the highest similarity with those in the other five gulls. The insertion fragments are located in downstream domain I of L. ridibundus, L. brunnicephalus, and L. saundersi. Seven conserved sequence boxes (additional box, F-box, E-box, D-box, C-box, bird-similarity-box, and B-box) are located in domain II in all six gulls. It is suggested that the CSB-2/3 sequence, the origin of H-strand replication, and bidirectional light- and heavy-strand transcription promoters in domain III of L. relictus have some distinguishing features to those of other gulls. Some repeat units are contained in the 3' end of the control region in the five gulls; however, no repeat units are found in the sequence CAAACAACAAA in L. relictus. The distribution of nucleotide diversity analysis will provide the useful information on the selected DNA fragment within the control region for genetic analyses among gulls.

Preliminary study of genetic diversity and population structure of the Relict Gull Larus relictus (Charadriiformes Laridae) using mitochondrial and nuclear genes.

The genetic diversity and the population history of the Relict Gull (Larus relictus) were studied based on the sequences of two mitochondrial genes (Cyt b and ND2) and one nuclear gene (the third intron of the Z-linked muscle-specific kinase gene [MUSK]) from 47 individuals. The results showed that the population expresses very low genetic diversity while lacking large geographical population. Demographic history analysis suggested that population expansion might have been recent and that the average estimated expansion time of L. relictus is from 0.09 to 0.23 Ma BP. Whether the other three breeding subpopulations are involved in the Ordos breeding subpopulation, require further study with more effective molecular markers. The species is threatened by habitat loss and fragmentation, and actions to protect it are suggested to improve the population fragmentation of breeding.

Neuropsychological characteristics of selective attention in children with nonverbal learning disabilities.

BACKGROUND: Children with nonverbal learning disabilities (NLD) usually manifest defective attention function. This study sought to investigate the neuropsychological characteristics of selective attention, such as attention control, working memory, and attention persistence of the frontal lobe in children with NLD. METHODS: Using the auditory detection test (ADT), Wisconsin card sorting test (WCST), and C-WISC, 27 children with NLD and 33 normal children in the control group were tested, and the results of C-WISC subtests were analyzed with factor analysis. RESULTS: Compared with the control group, the correct response rate in the auditory detection test in the NLD group was much lower (P < 0.01), and the number of incorrect responses was much higher (P < 0.01); NLD children also scored lower in WCST categories achieved (CA) and perseverative errors (PE) (P < 0.05). Factor analysis showed that perceptual organization (PO) related to visual space and freedom from distractibility (FD) relating to attention persistence in the NLD group were obviously lower than in the control group (P < 0.01). CONCLUSIONS: Children with NLD have attention control disorder and working memory disorder mainly in the frontal lobe. We believe that the disorder is particularly prominent in the right frontal lobe.

Eye-movement study during visual search in Chinese children with developmental dyslexia.

BACKGROUND: Developmental dyslexia (DD) is a disorder in which children with normal intelligence and sensory abilities show learning deficits in reading. Abnormal eye movements have been found in DD. However, eye-movement abnormalities during visual search among Chinese children with DD remain unknown. We aimed to identify the eyemovement characteristics and search efficiency of Chinese children with DD during visual search for targets of different conceptual categories, under same-category conditions. METHODS: We compared 32 Chinese dyslexic children and 39 non-dyslexic children in visual search tasks, which were assessed using EyeLink II High-Speed Eye Tracker (SR Research Ltd., Canada). Letters, single Chinese characters, digits, Chinese phrases, figures and facial expressions were used as stimuli. Targets were similar to distractors in meaning, phonology and/or shape. RESULTS: A main effect of task on visual search scores and all eye-movement parameters were found. Search scores, average saccade amplitude and saccade distance were significantly smaller in the DD group than in the controls. An interaction between group and task was found for pupil diameter. CONCLUSIONS: Unlike normal readers, children with DD had a reduction in the visual attention span and search accuracy. Besides, children with DD could not increase their mental workload with increase in task difficulty. The conceptual category of the stimulus materials significantly impacts search speed, accuracy and eye-movement parameters.

Regional cerebral blood flow in children with autism spectrum disorders: a quantitative 99mTc-ECD brain SPECT study with statistical parametric mapping evaluation.

BACKGROUND: Autism spectrum disorders (ASD), which include autism, asperger syndrome (AS) and pervasive developmental disorder-not otherwise specified (PDD-NOS), are devastating neurodevelopmental disorders of childhood resulting in deficits in social interaction, repetitive patterns of behaviors, and restricted interests and activities. Single photon emission computed tomography (SPECT) is a common technique used to measure regional cerebral blood flow (rCBF). Several studies have measured rCBF in children with ASD using SPECT, however, findings are discordant. In addition, the majority of subjects used in these studies were autistic. In this study, we aimed to investigate changes in rCBF in children with ASD using SPECT. METHODS: A Technetium-99m-ethyl cysteinate dimmer (99m)Tc-ECD) brain SPECT study was performed on an ASD group consisting of 23 children (3 girls and 20 boys; mean age (7.2 ± 3.0) years) who were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria and an age-matched control group with 8 children (1 girl and 7 boys, mean age (5.5 ± 2.4) years). Image data were evaluated with Statistical Parametric Mapping, 5th version (SPM5). A Student's t test for unpaired data was used to compare rCBF and asymmetry in the autism and corresponding control group. The covariance analysis, taking age as covariance, was performed between the ASD and control group. RESULTS: There was a significant reduction in rCBF in the bilateral frontal lobe (frontal poles, arcula frontal gyrus) and the bilateral basal ganglia in the autism group, and a reduction in the bilateral frontal, temporal, parietal, legumina nucleus and cerebellum in the AS group compared to the control. In addition, asymmetry of hemispheric hypoperfusion in the ASD group was observed. Inner-group comparison analysis revealed that rCBF decreased significantly in the bilateral frontal lobe (42.7%), basal nucleus (24.9%) and temporal lobe (22.8%) in the autism group, and in the bilateral cerebellum (22.8%), basal nucleus (19.3%) and right thalamencephalon (16.6%) in the AS group (P < 0.05). CONCLUSIONS: The decrease in rCBF in ASD is a global event, which involves the bilateral frontal, temporal, limbic system and basal ganglias. Asymmetry of hemispheric hypoperfusion was more obvious in the AS group than the autism group, which indicates a different neurobiological mechanism from that of autism.

Picture perception in Chinese dyslexic children: an eye-movement study.

BACKGROUND: Currently, whether or not there is visuospatial impairments in Chinese dyslexic children is still a matter of discussion. The relatively recent application of an eye-tracking paradigm may offer an opportunity to address this issue. In China, in comparison with reading studies, there have not been nearly as many eye movement studies dealing with nonreading tasks such as picture identification and whether Chinese children with dyslexia have a picture processing deficit is not clear. The purposes of the present study were to determine whether or not there is visuospatial impairments in Chinese dyslexic children. Moreover, we attempted to discuss whether or not the abnormal eye movement pattern that dyslexic subjects show during reading of text appropriate for their age is a consequence of their linguistic difficulties. METHODS: An eye-link II High-Speed Eye Tracker was used to track the series of eye-movement of 19 Chinese dyslexic children and 19 Chinese normal children. All of the subjects were presented with three pictures for this eye-tracking task and 6 relative eye-movement parameters, first fixation duration, average fixation duration, average saccade amplitude, mean saccade distance, fixation frequency and saccade frequency were recorded for analysis. RESULTS: Analyzing the relative parameter among three pictures, except for the fixation frequency and the saccade frequency, other eye-movement parameters were significantly different among the three pictures (P<0.05). Among the three pictures, the first fixation duration was longer, and the average fixation duration, the average saccade amplitude and the mean saccade distance were shorter from picture 2 to picture 3. Comparing all eye-movement parameter between the two groups, the scores of average saccade amplitude (P=0.017) and the mean saccade distance (P=0.02) were less in the dyslexia group than in the normal group (P<0.05), other parameters were the same in the two different groups (P>0.05). CONCLUSIONS: The characteristics of the pictures can significantly influence the visuospatial cognitive processing capability of the Chinese children. There is a detectable disability for the Chinese dyslexic children in the visuospatial cognitive processing: their saccade amplitude and mean saccade distance are shorter, which may be interpreted as specific for their reading disability.

[Neuropsychological characteristics of selective attention in children with nonverbal learning disabilities].

OBJECTIVE: To investigate the neuropsychological characteristics of selective attention such as attention control, working memory and attention persistence of frontal lobe in children with nonverbal learning disabilities (NLD). METHODS: With Auditory Detection Test (ADT), Wisconsin Card Sorting Test (WCST) and C-WISC, 14 children with NLD and 23 controls were tested and the results of sub-tests of C-WISC were analyzed with factor analysis. ADT was mainly applied to test the ability of auditory discernment and the function of dominance lateralization in the cerebra; WCST was employed to test the function of working memory which was based on the frontal lobe, and, C-WISC, to test the intelligent structure and characteristics. RESULTS: Compared with control group, the correct response rate of ADT in NLD group was much lower (P < 0.01), and the number of incorrect response was much larger (P < 0.01). Children with NLD had deficits of auditory selective attention. Moreover, the number of categories achieved (CA) and perseverative error (PE) of WCST were much lower (P < 0.05), which indicated that children with NLD had the disorders of selective attention and performance function. Factor analysis showed that perceptual organization (PO) related to visual space and freedom from distractibility (FD) related to attention persistence in NLD group were obviously lower than those in control group (P < 0.01, P < 0.05). These findings further supported the above-mentioned results. CONCLUSIONS: Children with NLD had attention control disorder and working memory disorder mainly in frontal lobe; we suppose that the disorder in right frontal lobe was distinctive.