Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Visual event-related potentials were recorded from five male autistics and five matched controls. Sensory effects were investigated by having subjects passively view flashes of three different but equiprobable intensities (augmenting/reducing paradigm). Cognitive effects were examined by having subjects count infrequent, target, flashes of one intensity embedded within a series of frequent, nontarget, flashes of a different intensity (oddball paradigm). In the augmenting/reducing paradigm, the sensory N100 wave of autistic but not controls showed a significant increase in amplitude (augmenting) as flash intensity increased. The cognitive P300 wave of autistics did not differ from controls in the oddball paradigm. Unlike controls, autistics had an equally large P300 in the no-task augmenting/reducing paradigm. It is concluded that autistics may experience a degree of stimulus overload in the visual modality.
J Autism Dev Disord 1987 Jun
PMID:Visual augmenting/reducing and P300 in autistic children. 361 Sep 97

Cognitive functioning in autistic subjects was investigated by employing ERP recordings. The sample included four autistic patients, with five normal subjects and four Down's syndrome patients serving as the two control groups. The P300 component was investigated under three different experimental conditions, that is; "No-task," "Counting," and "Keypress." Two out of four autistic subjects were able to perform the required task under the Counting condition. However, none of them were able to complete the task for the Key-press condition. Autistic subjects demonstrated a lower amplitude of the P300 component under the No-task condition as compared to the other two groups. It was speculated that the autistic, as opposed to the other two groups, had some cognitive difficulties in the "active stimulus evaluating process."
J Autism Dev Disord 1983 Mar
PMID:P300 and stimulus evaluation process in autistic subjects. 622 29

Averaged evoked potentials (EPs) to clicks, random pitch changes (signals), and random deletions of stimuli within a regular train of tones were examined in five autistic and five normal children. Brainstem auditory EPs were abnormal in one of the autistic patients. The early cortical EP components P60 and N100 showed no differences across groups, whereas the P200 component of the cortical responses to clicks, as well as the late positive component (P300) to the pitch changes and deleted stimuli, were significantly smaller in the autistic subjects as a group. Furthermore, when P200 and P300 amplitudes were averaged across conditions for the individual subjects, these components were smaller in every autistic subject than in any of the normal subjects. These results are consistent with the view that there are auditory defects in autism that may sometimes involve lower levels of neural transmission as manifested by abnormalities in the brainstem and auditory EP, but are more consistently manifest in higher aspects of processing that involve the registration and storage of stimulus information. It is suggested that the severe language disorder in childhood autism may be secondary to the basic deficits in higher auditory processing.
 ...
PMID:An electrophysiologic indication of auditory processing defects in autism. 693 52

The auditory P300 response and smooth pursuit eye tracking were recorded from a group of 23 male adult subjects who had been diagnosed in childhood as having schizoid personality. No differences were found in these physiological measures between the study group, their matched controls of other child psychiatric patients, and a group of population controls. The essentially negative findings are discussed in the light of abnormalities of these psychophysiological responses previously found in schizophrenic patients, in some of their biological relatives, and in other groups of psychiatric patients, including autistic children and adults with a diagnosis of borderline and schizotypal personality disorder. Results suggest that "schizoid" children, despite their high scores on a measure of schizotypy, do not have schizophrenia spectrum disorder or that schizotypy is a heterogeneous condition.
J Autism Dev Disord 1994 Aug
PMID:"Schizoid" personality in childhood: auditory P300 and eye tracking responses at follow-up in adult life. 796 32

The involvement of the C.N.S. in dysmorphic syndromes is very frequent; therefore a systematic analysis of the functions of the nervous system is important in the clinical definition of these syndromes. Besides the morphological aspects, studied by magnetic resonance imaging, investigations should be carried out in the neuroelectrophysiological and neuropsychological fields. For the former, the following examinations are proposed: EEG in wakefulness and sleep, multimodal evoked potentials (VEP, BAEP, SEP), cortical magnetic stimulation and P300 (P3). For the neuropsychological field, a general intelligence test appropriate to the mental age of the subject (the Wechsler, Terman-Merrill, or Brunet-Lezine scale) and, whenever possible, the following complementary tests: Raven's Progressive Matrices, Bender's and Santucci's graphic tests, go-no go, Goodenough draw-a-person, reading and writing tests, Langeot's scale for development of the logical thinking, sorting test and verbal and spatial memory tests. In some cases, the behaviour should be defined, through Conner's scale for attention deficit-hyperactivity disorders, the Autism Diagnostic Interview, the Adaptive Behaviour Scale and the Brief Psychiatric Rating Scale.
 ...
PMID:[The analysis of nervous system functions in dysmorphic syndromes]. 841 91

Autism is a syndrome with multiple etiologies, as is made clear both by the evidence of neurobiological research and by the catalog of disorders that present with autistic behaviors. What remains unclear are the specific neuropathological mechanisms that produce autistic behaviors; for example, is there a common neuroanatomic pathology for all cases of autism, or can autistic behaviors emerge from different pathological sequences within the brain? Although it is premature to generalize, neuropathological studies appear to have identified common abnormalities in the cerebellum and limbic system of at least five autistic subjects. These subjects, with variable levels of mental retardation, demonstrated marked Purkinje cell loss in the cerebellar hemispheres, together with retained fetal neuronal circuitry in cerebellar nuclei and increased neuronal packing in specific regions of the limbic system, amygdala, and hippocampus. The architecture of the cerebral cortex was not affected. Although our knowledge of brain functioning is incomplete, alterations of the kind noted in the cerebellum and limbic system could reasonably produce autistic behaviors. For more detail, readers are directed to a review of cerebellar contributions to higher functions by Schmahmann (1991). Neuroimaging studies allow less resolution of brain structure than do neuroanatomic studies, and the reported findings from neuroimaging are somewhat contradictory. However, a number of investigators have reported structural abnormalities in ventricle size and cerebral hemispheric asymmetry using CT. MRI, which offers greater resolution, has uncovered some consistent findings, along with a variety of nonspecific abnormalities. Common abnormalities include reduced volume of cerebellar hemispheres and vermal lobules--findings not inconsistent with the above-mentioned neuropathological defects. It is also interesting to note that individuals with fragile X syndrome have similar cerebellar findings. PET and NMR studies of autism are at a preliminary stage, but these methodologies allow insight into the functioning of the brain, rather than simply brain anatomy. Recent PET studies indicating decreased association between paired regions of the brains of autistic subjects are of interest, particularly if they can be confirmed and refined by additional studies. Neurophysiological studies also offer insight into brain function, but are subject to numerous methodological criticisms. Nevertheless, recent reports of diminished P300 waves and absent NC components in autistic subjects seem to indicate fundamental defects in attention and secondary processing, which could help explain the self-stimulatory behaviors often seen in autism. The disturbances in brain development associated with autism can be produced in a number of ways, and at different times during development of the nervous system.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:The neurobiology and genetics of infantile autism. 846 65

Facial expression of emotion is a key mechanism of non-verbal social communication in humans. Deficits in processing of facial emotion have been implicated in psychiatric disorders characterized by abnormal social behavior, such as autism and schizophrenia. Identification of genetically transmitted variability in the neural substrates of facial processing can elucidate the pathways mediating genetic influences on social behavior and provide useful endophenotypes for psychiatric genetic research. This study examined event-related brain potentials (ERPs) evoked by changes in facial expression in adolescent twins (age 12, 47 monozygotic and 51 dizygotic pairs). Facial images with happy, fearful, and neutral expressions were administered in a continuous mode, such that different expressions of the same face instantaneously replaced each other. This experimental design allowed us to isolate responses elicited by changes in emotional expression that were not confounded with responses elicited by image onset. Changes of emotional expression elicited a N240 wave with a right temporoparietal maximum and a P300 wave with a centropariatal midline maximum. Genetic analyses using a model fitting approach showed that a substantial proportion of the observed individual variation in these ERP responses can be attributed to genetic factors (36-64% for N250 and 42-62% for P300 components, respectively). This study provides the first evidence for heritability of neuroelectric indicators of face processing and suggests that ERP components sensitive to emotional expressions can potentially serve as endophenotypes for psychpathology characterized by abnormalities in social cognition and behavior.
 ...
PMID:Heritability of individual differences in cortical processing of facial affect. 2012 3

Individuals with high-functioning autism often display deficits in social interactions and high-level cognitive functions. Such deficits may be influenced by poor ability to process feedback and rewards. The feedback-related negativity (FRN) is an event-related potential (ERP) that is more negative following losses than gains. We examined FRN amplitude in 25 individuals with Autism Spectrum Disorder (ASD) and 25 age- and IQ-matched typically developing control participants who completed a guessing task with monetary loss/gain feedback. Both groups demonstrated a robust FRN that was more negative to loss trials than gain trials; however, groups did not differ in FRN amplitude as a function of gain or loss trials. N1 and P300 amplitudes did not differentiate groups. FRN amplitude was positively correlated with age in individuals with ASD, but not measures of intelligence, anxiety, behavioral inhibition, or autism severity. Given previous findings of reduced-amplitude error-related negativity (ERN) in ASD, we propose that individuals with ASD may process external, concrete, feedback similar to typically developing individuals, but have difficulty with internal, more abstract, regulation of performance.
 ...
PMID:Feedback and reward processing in high-functioning autism. 2112 21

Stathmin 1 (STMN1) is a neuronal growth associated protein (NGAP) that is involved in microtubule dynamics and plays an important role in neurite outgrowth and synaptic plasticity. It is highly expressed in the amygdala, but also in different areas of the neocortex including the frontal lobe. Based on previous findings regarding an impact of STMN1 on fear processing, the present study aimed at extending the evidence concerning its functional role to include the domain of executive (frontal lobe) functions. To this end, a group of 59 healthy volunteers stratified for the single-nucleotide polymorphism rs182455 of the STMN1 gene was examined by means of three experimental paradigms probing different aspects of cognitive-affective functioning. Event-related potential measures of cognitive response control, emotional interference processing, and action monitoring were analyzed. STMN1 genotype significantly affected the NoGo-anteriorization (NGA)-a neurophysiological marker of cognitive response control associated with medial prefrontal cortex activation-as well as the modulation of the P300 by the valence of emotional Stroop stimuli. In both cases, carriers of the rs182455 C-allele showed altered cognitive-affective processing; effects appeared to be more pronounced in females. Our findings indicate a functional impact of STMN1 on cognitive and affective control processes, thereby complementing previous evidence on its role in fear processing. Based on these results, an influence of STMN1 should be considered in studies aiming at the etiopathogenesis of a broad range of neuropsychiatric disorders with dysfunctional networking, including neurodegenerative disorders as well as schizophrenia, autism spectrum disorders, anxiety disorders, depression, and ADHD.
 ...
PMID:Influence of a genetic variant of the neuronal growth associated protein Stathmin 1 on cognitive and affective control processes: an event-related potential study. 2143 38

This study examines the link between children's repetitive, ritualistic, behavior and cortical brain activity. Twelve typically developing children between the ages of 6 and 12 years were administered two visual P300, oddball tasks with a 32-electrode electroencephalogram (EEG) system. One of the oddball tasks was specifically designed to reflect sensitivity to asymmetry, a phenomenon common in children and in a variety of disorders involving compulsive behavior. Parents completed the Childhood Routines Inventory. Children's repetitive, compulsive-like behaviors were strongly associated with faster processing of an asymmetrical target stimulus, even when accounting for their P300 latencies on a control task. The research punctuates the continuity between observed brain-behavior links in clinical disorders such as OCD and autism spectrum disorders, and normative variants of repetitive behavior.
 ...
PMID:Cortical activity and children's rituals, habits and other repetitive behavior: a visual P300 study. 2165 17


1 2 3 Next >>