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PubMed2002

Synchronization and information processing by an on-off coupling.

This paper proposes an on-off coupling process for chaos synchronization and information processing. An in depth analysis for the net effect of a conventional coupling is performed. The stability of the process is studied. We show that the proposed controlled coupling process can locally minimize the smoothness and the fidelity of dynamical data. A digital filter expression for the on-off coupling process is derived and a connection is made to the Hanning filter. The utility and robustness of the proposed approach is demonstrated by chaos synchronization in Duffing oscillators, the spatiotemporal synchronization of noisy nonlinear oscillators, the estimation of the trend of a time series, and restoration of the contaminated solution of the nonlinear Schrödinger equation.

Journal Article↗
PubMed1996

[ERP study of information processing disturbance on schizophrenia--from aspects of automatic processing and controlled processing].

We studied the relationship between automatic processing and controlled processing in schizophrenic disorder and examined the changes of the relationship through various clinical courses of the illness using event related potentials (ERPs). Thirty schizophrenic patients were classified into two groups according to ERP variations; group-A consisted of schizophrenics who showed higher mismatch negativity (MMN) amplitudes and lower P300 amplitudes than group-B patients. After pharmacological treatment, MMN amplitudes decreased and P300 increased in group-A patients. On the other hand, MMN amplitudes increased, but no significant changes in P300 amplitudes were recognized in group-B patients. MMN amplitudes had a negative correlation with the extent of dilatation of the left Sylvian fissure and the bilateral lateral ventricles on CT scans. From these results, it is suggested that automatic processing and controlled processing complement each other in information processing of schizophrenics. In group-A, higher MMN amplitudes suggested plasticity of processing dysfunction, which showed good social adjustment after pharmacological treatment. In group-B, more severe vulnerability to the disorder was suggested from lower MMN amplitudes, which showed poor social adjustment after the treatment.

Adult↗
PubMed2005

Information processing flow and neural activations in the dorsolateral prefrontal cortex in the Stroop task in schizophrenic patients. A spatially filtered MEG analysis with high temporal and spatial resolution.

Using a spatially filtered magnetoencephalography analysis (synthetic aperture magnetometry), we estimated neural activations in the Stroop task in nearly real time for schizophrenic patients with/without auditory hallucinations and for normal control subjects. In addition, auditory hallucinations were examined through the information processing flow of the brain neural network, including the frontal regions. One hundred unaveraged magnetoencephalography signals during the incongruent stimulus responses were analyzed with a time window of 200 ms in steps of 50 ms. In the 25-60-Hz band, cortical regions that showed significant current source density changes were examined for each time window. The three groups showed significantly decreased current source density, corresponding to neural activation, with temporal overlap along the fundamental cognitive information processing flow: sensory input system, executive control system, motor output system. Transient neural activations in the dorsolateral prefrontal cortex were bilateral with left-side dominancy for normal controls, left-lateralized for nonhallucinators and right-lateralized for hallucinators. Our results suggest that the dysfunction in the left dorsolateral prefrontal cortex was related to auditory hallucinations, while the information processing flow was unaffected in the schizophrenic subjects in the Stroop task.

Adolescent↗
PubMedDate not supplied

[Altered visual information processing in anorectic girls--the study on potentials related to the test of attention].

AIM: Combined biological and psychological basis of anorexia nervosa, related to increased self-control, low self-esteem and peculiar motivation, makes a synthetic approach still hard to achieve. The presented study assessed cognitive functions in anorectic patients with respect to both neuropsychological (test of attention) and biological (electrophysiology of information processing) approaches, and their reciprocal interrelations as well. METHODS: Eleven adolescent anorectic females and 10 control subjects performed the Continuous Attention Test CAT. Parameters of potentials elicited by the visual CAT items were referred to the CAT results. RESULTS: The anorectic girls were more accurate during CAT performance, revealing a lower index of errors, especially of commissions. On the other hand, they revealed a lower amplitude of the P2 component (correlated with index of commissions) and shortened latency of the frontal N2 component (correlated with a lower index of errors). The groups differed in relations between psychometric and biological parameters referring to the earlier stages of information processing. In the control group, high index of detections was correlated to right-sided P1 and P2 components. In the patient group, correlations linked a lowered index of commissions with right-sided N1 and bilateral P2 amplitudes. CONCLUSIONS: Increased self-control in anorexia nervosa, reflected by lower frequency of needless reactions, is related to alterations in biological visual information processing yet on its early, preconscious stage.

Adolescent↗
PubMed1994

Cognitive functioning and information processing of adult mentally retarded men with fragile-X syndrome.

The present study describes cognitive skills and information processing strategies of mentally retarded fra(X) men. Fifty-eight fra(X) positive and 58 fra(X) negative adults, matched on sex, chronological age, length of institutionalisation, general cognitive level, and living conditions, were evaluated with the Bayley or McCarthy Scales of Mental Abilities. Mental ages were mostly situated in the severe mental handicap category and were found to be negatively influenced by chronological age. A relative strength in perceptual performance and non-verbal reasoning and a deficit in sequential information processing turned out to be typical of all mentally retarded subjects, irrespective of fra(X) or control status. Fra(X) adults could be significantly differentiated from control persons on the ground of a higher level of acquired knowledge because of better vocabulary and verbal-expressive skills. On the other hand, they were less able to imitate non-verbal patterns, had more difficulty with visual-motor integration and co-ordination, and applied less efficient general mental processing skills in solving new problems. The memory profile of fra(X) adults was strongly determined by the meaning and the complexity of the information that has to be reproduced. In this article the profile of cognitive strengths and weaknesses in the fra(X) group will be discussed and some general advice for training is suggested.

Adult↗
PubMed1985

The time course of information-processing deficits in schizophrenia.

A visual backward masking task was used to specify the time course of the information-processing dysfunction in 19 schizophrenic patients and 15 matched control patients using novel interstimulus intervals. The authors found that the information-processing deficit in schizophrenic subjects occurred at interstimulus intervals of greater than 60 msec and less than 500 msec. These data are compared with the results of evoked-potential and other psychophysiological studies. The visual-processing impairment is specific and time-linked rather than a reflection of the effects of gross psychopathology or medication in schizophrenic individuals.

Adult↗
PubMed2006

[Progress and prospects of research on information processing techniques for intelligent diagnosis of traditional Chinese medicine].

Information processing for intelligent diagnosis of traditional Chinese medicine (TCM), an important part of the modernization of Chinese medicine, attracts world wide attention from the science circle. This article presents a systematic introduction to the development of information technology, especially the processing of pulse and tongue images and systems of computer-aided Chinese medical diagnosis. Furthermore, it points out four essential areas of future research, including epistemic logic system of syndrome differentiation, system construction technology, data miming technology and information acquisition and analysis in TCM diagnosis.

Diagnosis, Computer-Assisted↗
PubMed1994

Age, information processing speed, and intelligence.

Two parallel, but independent, literatures have grown out of observations that individual differences in information processing speed, as expressed in performance on choice reaction time (C RT) tasks, modestly correlate with individual differences in age and IQ test performance. These associations have prompted theories that individual differences in information processing speed functionally determine individual differences in performance of all cognitive skills by people of different general intellectual ability (Eysenck, 1986; Jensen, 1985) or age (Salthouse, 1982, 1985). The experiments on which this literature has been based suffer from methodological weaknesses, such that comparisons have only been made very early in practice and have only concerned mean latencies for correct responses. An experiment compared 90 volunteers aged from 50 through 79 years who were grouped in terms of their performance on the AH 4 (Heim, 1968) IQ test. It explored the joint and independent effects of individual differences in age and in IQ test score and the effects of practice on mean latencies (C RTs) on the shapes of distributions of correct and incorrect responses and on the limiting speeds with which accurate responses can be made (speed/error trade-off functions). We suggest that a plausible explanation for the results is that individual differences in age and in general ability influence C RTs mainly because they affect the efficiency with which responses can be controlled to maximize speed while maintaining accuracy.

Age Factors↗
PubMed1996

Predicting age-related differences in visual information processing using a two-stage queuing model.

Recent work on age-related differences in some types of visual information processing has qualitatively stated that younger adults are able to develop parallel processing capability, while older adults remain serial processors. A mathematical model based on queuing theory was used to quantitatively predict and parameterize age-related differences in the perceptual encoding and central decision-making aspects of a multiple-frame search task. Statistical results indicated main effects for frame duration, display load, age group, and session of practice. Comparison of the full model and a restricted model indicated an efficient contribution of the encoding speed parameter. The best-fitting parameter set indicated that (1) younger participants processed task information with a two-channel parallel system, while older participants were serial processors; and (2) perceptual encoding had a large impact on age-related differences in task performance. Results are discussed with implications for human factors design principles.

Adult↗
PubMedDate not supplied

Information processing deficits in children with attention-deficit/hyperactivity disorder, inattentive type, and children with reading disability.

We examined the information processing capabilities of children diagnosed with the inattentive subtype of attention-deficit/hyperactivity disorder (ADHD) who had been characterized as having a sluggish cognitive tempo. Children referred for school-related problems (n = 81) and nonreferred community controls (n = 149) participated. Of the referred children, 24 met criteria for ADHD, 42 met criteria for reading disability (RD), and 9 of these were comorbid for RD and ADHD. Children with ADHD differed from those without ADHD on a visual search task but not on an auditory processing task; the reverse was true for children with RD. Decomposition of the visual search task into component operations demonstrated that children in the ADHD group had a slow processing rate that was not attributable to inattention. The children with ADHD were not globally poor at information processing or inattentive, but they demonstrated diminished speed of visual processing.

Attention Deficit Disorder with Hyperactivity↗
PubMedDate not supplied

Effects of information processing demands on slow negative shift latencies and N100 amplitude in selective and divided attention.

The influence of information processing demands on auditory event-related potentials (ERPs) in selective and divided attention was examined by varying the stimulation rate and target difficulty in a two-channel discrimination task. Subjects were required to detect targets in either one or both ears (channels) in a series of tones presented randomly to both ears. The amplitude of the N100 component (latency 80-140 msec) of the ERP to all stimuli in an attended channel was greater if attention was focused on that channel that if it was directed to the opposite channel. N100 amplitude was also reduced in divided attention compared to focused attention. In general, these effects were obtained only if the stimulation rate was high and/or targets were difficult to detect. However, these effects of attention modulated an underlying slow negative shift (SNS) rather than N100 directly. The onset and peak latencies of the SNS were strongly dependent on the processing demands of the task. The results show that the temporal relationship of the SNS to the N100 component is the principal factor responsible for variations in the effects of attention on the ERP with changes in information processing demands. The relationship between these ERP components and resource allocation theories of attention is discussed.

Adolescent↗
PubMed2006

Heroin addicts show impairment of information processing at the iconic level.

Heroin addicts (n = 100) and healthy controls (n = 100) were examined for their information processing ability at iconic (100 ms, 125 ms) as well as relatively deeper (250 ms, 500 ms) levels. Subjects were asked to identify briefly exposed photographs of familiar objects through an electronic tachistoscope. Addicts showed significant impairment of visual information processing at iconic but not at deeper levels.

Adult↗
PubMed2005

Dopamine receptor (DRD2) genotype-dependent effects of nicotine on attention and distraction during rapid visual information processing.

The effects of nicotine, distractor type, and dopamine type-2 receptor (DRD2) genotype on rapid visual information processing (RVIP) task performance were assessed in habitual smokers. Four RVIP tasks differed in terms of distractor location (central vs. peripheral) and distractor type (numeric vs. emotional). Each participant performed each of the tasks on two different days, once while wearing an active nicotine patch and once while wearing a placebo patch. Overall, the nicotine patch produced more accurate detection of and faster reaction times to target sequences; however, these effects varied with distractor type and genotype. Nicotine speeded reaction time more with left-visual-field (LVF) than right-visual-field (RVF) emotional distractors but speeded reaction time more with RVF than LVF numeric distractors, especially when the distractor digit matched the target sequence in terms of numeric oddness or evenness. Nicotine tended to facilitate performance more in individuals with at least one A1 allele than in homozygous A2A2 individuals, especially with numeric distractors presented to the left hemisphere. Nicotine tended to reduce distraction by negative stimuli more than other types of stimuli. Few gender differences were observed. The overall pattern of results was consistent with the view that nicotine modulates selective attention or subsequent information processing in a manner that depends partly on the emotional versus numeric nature of task distractors, DRD2 genotype, and the brain hemisphere that initially processes the distractors (visual field of distractor).

Adolescent↗
PubMed1979

Information processing in a binary classification task.

Three choice-reaction time studies were conducted to investigate whether information processing is exhaustive or self-terminating, serial or parallel, and N-dependent or N-independent. A total of 54 subjects were required to make key-pressing responses to one, two, or three digits presented in a circular display; one key was pressed if the display contained one or more target digits and another key was pressed if the display contained only nontarget digits. The first two studies utilized within-subjects designs in which the displays were constructed from only one target and one nontarget item (Study 1) or from three target and seven nontarget items (Study 2). The third study used a between-subjects design in which different groups of subjects responded to one-, two-, or three-element displays. In general, the results indicate that CRTs increased as the total number of display elements increased and decreased as the number of target elements (or the ratio of target to nontarget items) increased for a given display size. When only target elements were presented, CRT was independent of the number of elements displayed, and when only one target was presented, CRT increased as total number of elements increased. Theses combined results are interpreted as support for the inference that information processing in visual search tasks tends to be self-terminating, serial, and N-dependent (of limited capacity).

Adult↗
PubMed2002

Effects of risperidone on information processing and attention in first-episode schizophrenia.

Risperidone appears to have a beneficial effect in several areas of cognitive function in schizophrenic patients. In previous studies, however, the clinical characteristics of the subjects differed between studies, and were heterogeneous even in single study. Most of the subjects were previously exposed to different kinds of neuroleptics and some of them were treatment-resistant. The aim of this study is to evaluate the effect of risperidone on attention and information processing in a homogeneous subgroup of schizophrenic patients, i.e. drug-naïve first-episode inpatients. In the patient group (n=17), cognitive tests and clinical assessments were performed before and after 8 weeks of risperidone treatment. The same cognitive tests were administered to the control group (n=24). The delay between test and retest was 8 weeks. Before treatment, the patient group performed significantly worse than control group on the tests measuring continuous attention, vigilance, and the speed of information processing. After treatment (the average dose of risperidone was 7.3mg/day), in spite of significant improvement of the clinical symptoms, the patients did not show any significant improvement or worsening in most of the items of these tests. The control group did not show any practice effect. These results suggest that first-episode schizophrenic patients have deficits in sustained attention and vigilance to visual stimuli, as well as the speed of information processing to visual and auditory stimuli, and these deficits are unrelated to clinical symptoms and remain stable during the early phase of treatment. This study did not receive pharmaceutical company financial support.

Adolescent↗
PubMed1978

[Automated information processing of systolic time intervals].

The revalorization of the systolic time intervals in clincial and experimental cardiology is described on the basis of informations from literature and own experiences. Concerning the method of work the systolic time intervals have reached a limit which can be overcome only be automatized information processing. It is reported on principles and problems of the automatized information processing of systolic time intervals and an own development is described (HTME 101).

Electrocardiography↗
PubMed1982

The effectiveness of visual information processing training with hispanic children.

The purpose of this study was to determine whether one kind of visual information processing training improves performance on visual tasks and on academic achievement. One hundred fifty-three kindergarten, first- and second-grade Hispanic children who were poor visual processors were randomly assigned to either a training, a contrast, or a control group. The training group received tutoring in visual-information processing for approximately seven weeks while the contrast group was given small group instruction with regular curriculum materials. At the conclusion of the training all Ss were administered several visual tasks and achievement measures. Results indicated that only the tutored children performed significantly better than the other children on the Bender Gestalt test and that the attained visual motor integrative skills were maintained over a period of time. However, training in visual processing skills did not increase performance on academic tasks or on a task of basic concepts.

Achievement↗
PubMed2005

Enhanced and diminished visuo-spatial information processing in autism depends on stimulus complexity.

Visuo-perceptual processing in autism is characterized by intact or enhanced performance on static spatial tasks and inferior performance on dynamic tasks, suggesting a deficit of dorsal visual stream processing in autism. However, previous findings by Bertone et al. indicate that neuro-integrative mechanisms used to detect complex motion, rather than motion perception per se, may be impaired in autism. We present here the first demonstration of concurrent enhanced and decreased performance in autism on the same visuo-spatial static task, wherein the only factor dichotomizing performance was the neural complexity required to discriminate grating orientation. The ability of persons with autism was found to be superior for identifying the orientation of simple, luminance-defined (or first-order) gratings but inferior for complex, texture-defined (or second-order) gratings. Using a flicker contrast sensitivity task, we demonstrated that this finding is probably not due to abnormal information processing at a sub-cortical level (magnocellular and parvocellular functioning). Together, these findings are interpreted as a clear indication of altered low-level perceptual information processing in autism, and confirm that the deficits and assets observed in autistic visual perception are contingent on the complexity of the neural network required to process a given type of visual stimulus. We suggest that atypical neural connectivity, resulting in enhanced lateral inhibition, may account for both enhanced and decreased low-level information processing in autism.

Adolescent↗