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PubMed1995

Information processing during cardiac surgery: an event related potential study.

The aim of this study was to investigate whether information processing persists during general anesthesia, and if so, to determine the relationship between the degree of cognitive processing measured during anesthesia and the presence or absence of intraoperative memories measured after anesthesia. Subjects were 12 patients, undergoing cardiac surgery with propofol/alfentanil anesthesia. During several periods of the operation, event related potentials (ERPs) to frequent and infrequent tones of different pitch were analyzed. After the operation, a word recognition task with ERP recording was administered to determine whether intraoperatively presented words would elicit a (covert) recognition reaction in the brain. ERP wave forms could be obtained during the intraoperative recording periods but differed substantially from those in the awake state. The presence of ERP components up to 500 msec after stimulus presentation suggests that auditory information processing continued during anesthesia up to a certain level of cognition. Intraoperative ERPs to frequent and infrequent tones were not different from each other implying that differences in pitch could not be detected. The postoperative results demonstrated evidence for intraoperative memories in 3 patients. For 2 of these 3 patients, low propofol levels as well as reliable ERPs with large amplitudes were found close to the moment of information presentation. The results emphasize the importance of combining intra- and postoperative measurements and suggest that late ERP components might be used as indicators of an increased risk of auditory perception.

Acoustic Stimulation↗
PubMed1998

Medical information processing: an interactive course for the Internet.

Medical students in Germany have to study the basics of medical information processing within a special curriculum which is part of the ecological course. This curriculum offers an introduction to principles of medical informatics. Starting with a conventional textbook, a computer-based training (CBT) program has been developed using the technologies of the internet and the World Wide Web (WWW). Features of the program include a well structured presentation of the information within the software and a high degree of interactivity. Early experiences suggest that this program enhances the learning in the domain of medical information processing. The program may be viewed via the URL: htfp.//www.med-rz.uni-sb.de/med_fak/imbei/pro jekt.

Education, Medical↗
PubMed2002

Automatic and controlled verbal-information processing in patients with frontal lobe lesions.

The selectivity of frontal lobe lesion effects in the domains of verbal-information processing has not been well established. The authors hypothesized that capacity-limited controlled processing would be more impaired than automatic processing in frontal lobe patients (FLPs). Fifteen FLPs were compared with 2 matched control groups: 14 posterior-lesion patients and 15 normal controls. Both behavioral and event-related brain potential (ERP) measures were collected. Results suggest that both automatic and controlled processing were affected by frontal lobe lesions. ERP results indicated that the main dificulty for the FLPs was in the perceptual stage of information processing. This rather unexpected result may be explained by a basic difficulty of FLPs in attending to a new stimulus in order to process it.

Adult↗
PubMed1985

Relation of neuroleptic dose and tardive dyskinesia to attention, information-processing, and psychophysiology in medicated schizophrenics.

Relationships of neuroleptic dosage and tardive dyskinesia with measures of attentional, information-processing, and psychophysiological dysfunctions in medicated chronic schizophrenics were explored by correlational and stepwise multiple-regression analysis. High neuroleptic dosage was found to be associated with increased reaction time, reduced span of apprehension, low basal skin conductance level, and reduced skin conductance reactivity. Severe abnormal involuntary movements were associated with increased eye-tracking dysfunction, increased scanning eye-movement rate, increased reaction time, and reduced skin conductance reactivity. These findings led to the hypothesis that neuroleptic dosage and tardive dyskinesia may be sources of error variance in the measurement of attentional, information-processing, and psychophysiological functions in schizophrenics.

Adolescent↗
PubMed1997

Mild head injury and speed of information processing: a prospective study of professional rugby league players.

The sensitivity of several short tests of speed of information processing to the effects of mild head injury in rugby league football was investigated. The measures used were the Symbol Digit Modalities Test, the Digit Symbol Substitution Test, and the Speed of Comprehension Test. Two studies were conducted, the first to examine the effect of practice, the second to determine sensitivity to cognitive impairment immediately following injury. The first study established alternate form equivalence and demonstrated that performance on the Speed of Comprehension and Digit Symbol Substitution tests improved with practice, whereas the Symbol Digit Modalities test remained stable. A second study of 10 players who subsequently sustained mild head injuries showed that measures of speed of information processing were sensitive to impairment in the postacute phase, whereas an untimed task of word recognition (Spot-the-Word) was not. Speed of Comprehension was more sensitive to postinjury impairment than either the Digit Symbol Substitution or Symbol Digit Modalities tests. A repeated baseline assessment before injury using the higher score to reflect a player's potential, allowed measurement of impaired performance on sensitive tests.

Acute Disease↗
PubMed2006

Early visual information processing deficit in depression with and without Borderline Personality Disorder.

Backward masking is a measure of early visual information processing usually abnormal in psychotic disorders. Previous studies of subjects with Borderline Personality Disorder have been inconsistent regarding their impairment or lack of impairment on backward masking. We examined visual backward masking performance in samples of unmedicated depressed patients with (n=12) and without (n=16) Borderline Personality Disorder, and healthy volunteers (n=18). Accuracy was poorer in depressed BPD patients, relative to both non-BPD depressed and healthy comparison subjects. As in previous studies, no differences in accuracy were found between non-BPD depressed patients and healthy comparison subjects. Differences in BPD subjects' accuracy were most evident at the fastest ISI and were not attributable to intercurrent psychotic symptoms. Beyond these group differences, accuracy at faster ISI's correlated with self-ratings of impulsiveness in all patients, and may be a general correlate of this trait. Poor early information processing appears to be a feature of Borderline Personality Disorder, and may play a role in the impulsive behavior that is characteristic of the disorder.

Adult↗
PubMed2004

Quantum information processing by NMR using a 5-qubit system formed by dipolar coupled spins in an oriented molecule.

Quantum information processing by NMR with small number of qubits is well established. Scaling to higher number of qubits is hindered by two major requirements (i) mutual coupling among qubits and (ii) qubit addressability. It has been demonstrated that mutual coupling can be increased by using residual dipolar couplings among spins by orienting the spin system in a liquid crystalline matrix. In such a case, the heteronuclear spins are weakly coupled, but the homonuclear spins often become strongly coupled. In such circumstances, the strongly coupled spins, which yield second order spectra, can no longer be individually treated as qubits. However, it has been demonstrated elsewhere, that the 2(N) energy levels of a strongly coupled N spin-1/2 system can be treated as an N-qubit system. For this purpose the various transitions have to be identified to well defined energy levels. This paper consists of two parts. In the first part, the energy level diagram of a heteronuclear 5-spin system is obtained by using a newly developed heteronuclear z-cosy (HET-Z-COSY) experiment. In the second part, implementation of logic gates, preparation of pseudopure states, creation of entanglement, and entanglement transfer is demonstrated, validating the use of such systems for quantum information processing.

Journal Article↗
PubMed2004

Auditory information processing is altered in novelty stress conditions: first session effects in auditory-evoked potentials.

Novelty conditions may elicit stress responses. First session effects are systematic changes in physiological parameters, resulting from the interference of physiological processes with novelty stress. Along with endocrinological changes, these stress responses may be accompanied by alterations of sensory and attentional processes. The present study examines the impact of novelty conditions on event-related potential indicators of auditory information processing and on cortisol. Twenty-two healthy subjects participated in a series of experimental sessions. Auditory-evoked potentials were recorded, and the plasma cortisol levels were determined. The first session causes an activation of the hypothalamo-hypopituitary-adrenal axis. The auditory-evoked potentials show an additional slow negative potential component in the novelty condition. This potential component is maximal at fronto-central electrode sites and reaches its peak at about 240 ms after stimulus onset. Similarities with the processing negativity suggest alterations in attention-related auditory information-processing in the novelty condition encountered in the first session.

Acoustic Stimulation↗
PubMed1988

Information processing, critical flicker fusion threshold and benzodiazepines: results and speculations.

There is evidence to suggest that the rate of information processing, as measured by the critical flicker fusion threshold (CFFT), is slower following some benzodiazepines than others. Changes in CFFT brought about by benzodiazepine administration are usually, but not always, correlated with changes in other measures of cognitive performance and memory. However, the drug-induced changes in information processing and memory cannot be fully explained by simple postulates regarding alterations in the overall level of CNS arousal. Results from a series of studies of the effect of benzodiazepines on measures of CFFT and memory will be reviewed and the utility of CFFT in evaluating the amnesic or mnemonic potential of CNS-active drugs will be assessed.

Anti-Anxiety Agents↗
PubMedDate not supplied

Information processing of trauma.

This article presents a neuropsychosocial model to explain a victimization experience. It surveys the relation of sensation, perception, and cognition as a systematic way to provide a framework for studying human behavior and to describe human response to traumatic events. This framework is an information processing approach. The goal of information processing investigations is to identify how incoming external stimuli or intentionally engendered stimuli enter the central nervous system and eventuate in some kind of final response.

Arousal↗
PubMed1993

The 'oddball CNV' as an indicator of different information processing in patients with panic disorders.

In previous studies we found an inverse relationship between CNV amplitude and the probability of the occurrence of the warning stimulus (S1) in a cued reaction time task. The aim of the present study was to investigate this 'oddball effect' on CNV amplitude (Oddball CNV) in patients with anxiety disorders, since this effect describes the influence of event probability on reactive as well as proactive components of information processing. Patients suffering from panic disorders with or without agoraphobia and controls participated in a choice reaction time experiment. The subjects' task was to respond to flashes (S2s), cued 4 s in advance in random order by one of two easily distinguishable acoustic stimuli (S1a, S1b). In condition 1 the probability of S1a and S1b was 0.2 and 0.8, respectively, and in condition 2 0.5 for both S1s. The DC-EEG was recorded from F3, F4, C3, Cz, C4 and P3, linked mastoids as the reference. The data obtained confirm the oddball effect on the CNV amplitude, show clear deviations of patients in this effect, and also indicate remarkable differences in CNV shape between patients and controls. These observations are discussed as differences in information processing and information utilization.

Adult↗
PubMed2006

Effects of risperidone on auditory information processing in neuroleptic-naive patients with schizophrenia spectrum disorders.

Early effects of risperidone (2.5 +/- 1 mg/day) on auditory information processing were investigated in 9 neuroleptic naive patients with schizophrenia spectrum disorders and 9 healthy controls by using event-related potentials (ERPs). ERPs were elicited during active auditory "oddball" paradigm and were recorded before and after two weeks of treatment. Baseline P3 latencies were significantly delayed in patient group. Risperidone treatment did not change P3 amplitudes and latencies. However, P2 amplitudes were reduced in parallel with the clinical improvement measured by Positive and Negative Syndrome Scale (PANSS). Although risperidone did not change neural bases of active attention after two weeks of treatment, the reduction of P2 amplitude suggests that risperidone may affect auditory information processing in patients with schizophrenia spectrum disorders who never have been exposed to antipsychotic treatment.

Adolescent↗
PubMed1985

Information processing abilities and performance on two perceptual-motor tasks.

The purpose of this study was to investigate whether the hypothesized information-processing mechanisms, thought to be reflected by the slope and intercept of the regression of choice reaction time on stimulus information or information transmitted could account for performance on two novel laboratory tasks. In addition, analyses were performed to determine whether these theorized mechanisms represent stable within individual abilities or task specific capabilities. Analysis indicated that the slopes obtained from two different choice reaction time paradigms were unrelated while intercepts were moderately correlated. Examination of the pattern of zero-order correlations further showed that regression components were not meaningfully related to performance on either novel task, suggesting that knowledge of information-processing mechanisms, as assessed in choice RT paradigms, did not enhance the understanding of performance in more complex tasks.

Adolescent↗
PubMed2005

An information-processing model of three cortical regions: evidence in episodic memory retrieval.

ACT-R (Anderson, J.R., et al., 2003. An information-processing model of the BOLD response in symbol manipulation tasks. Psychon. Bull. Rev. 10, 241-261) relates the inferior dorso-lateral prefrontal cortex to a retrieval buffer that holds information retrieved from memory and the posterior parietal cortex to an imaginal buffer that holds problem representations. Because the number of changes in a problem representation is not necessarily correlated with retrieval difficulties, it is possible to dissociate prefrontal-parietal activations. In two fMRI experiments, we examined this dissociation using the fan effect paradigm. Experiment 1 compared a recognition task, in which representation requirement remains the same regardless of retrieval difficulty, with a recall task, in which both representation and retrieval loads increase with retrieval difficulty. In the recognition task, the prefrontal activation revealed a fan effect but not the parietal activation. In the recall task, both regions revealed fan effects. In Experiment 2, we compared visually presented stimuli and aurally presented stimuli using the recognition task. While only the prefrontal region revealed the fan effect, the activation patterns in the prefrontal and the parietal region did not differ by stimulus presentation modality. In general, these results provide support for the prefrontal-parietal dissociation in terms of retrieval and representation and the modality-independent nature of the information processed by these regions. Using ACT-R, we also provide computational models that explain patterns of fMRI responses in these two areas during recognition and recall.

Adolescent↗
PubMed2006

Targeting information-processing deficit in schizophrenia: a novel approach to psychotherapeutic drug discovery.

Current observations indicate that dysfunction of neuronal circuitry dynamics contributes to the abnormal information processing in the brain in schizophrenia. It is presumed that disrupted auditory gating, abnormal P300-evoked potentials and deficits in mismatch negativity in schizophrenic patients indicate impaired processing of information. Recently, abnormalities in neuronal synchrony and oscillatory activity have been postulated as the mechanisms that underlie the distorted perception and cognitive dysfunction associated with schizophrenia. These novel observations might reveal the pathophysiology of the disorder, and indicate potential targets for antipsychotic drug therapy. Neuronal circuitry dynamics, such as network oscillations and sensory-gating processes, are conserved phylogenetically, which provides excellent opportunities for designing translational biomarkers. Whether preclinical, experimental compounds that impact on network oscillations and sensory processing (such as agonists and modulators of alpha7 nicotinic acetylcholine receptors) elicit the same neurophysiological events in schizophrenic patients and, subsequently, improve perception and cognitive functions will be determined when these drug candidates are available clinically.

Animals↗
PubMed2003

Spectral dynamics of electroencephalographic activity during auditory information processing.

Dynamics of electroencephalographic (EEG) activity during auditory information processing were evaluated in response to changes in stimulus complexity, stimulus discriminability and attention using the oddball paradigm. In comparison to pre-stimulus baseline conditions, auditory stimulation synchronized EEG activity in delta, theta and alpha frequency bands. Event-related synchronization (ERS) effects were greatest at approximately 3 Hz (theta frequency band), and their magnitude depended on stimulus and task demands. Event-related desynchronization (ERD) of EEG activity was observed in the beta frequency band. This effect was greatest at approximately 21 Hz but occurred only for easily discriminable stimuli in attention-related target conditions. Because active discrimination tasks also required a button-press response with the right hand, ERDs involved more complex responses that may be related to a combination of perceptual, motor and cognitive processes. These results demonstrate that oddball and attention-related EEG responses to auditory stimulation could be characterized in the frequency domain. The specific design and analysis features described herein may prove useful since they provide a simple index of the brain's response to stimulation while at the same time provide powerful information not contained in typical time domain analysis.

Adult↗
PubMed1999

Attention and information processing efficiency in patients with Chronic Fatigue Syndrome.

In this study a battery of attentional tests and a verbal memory task were administered to outpatients with Chronic Fatigue Syndrome (CFS) in order to evaluate aspects of attention that have not been explored in this group to date. In addition, this study was designed to further examine memory function and to extend the few reports investigating the rate of cognitive processing independent of motor speed and the possibility of a modality-specific impairment of information processing. Twenty-nine patients with CFS and 22 healthy controls matched for age, gender, intelligence, and education were included in this study. The results show that patients with CFS do not seem to be impaired for modification of phasic arousal level, nor for visual selective attention requiring shifting of attention in the visuospatial field. The results further support the presence of reduced information processing speed and efficiency, and strengthen the evidence of a global non-modality-specific attentional dysfunction in patients with CFS. In this study the poor performance of patients with CFS on recall of verbal information was due to poor initial storage rather than to a retrieval failure.

Adult↗
PubMed1984

How information processing mode could affect prostaglandin E1 metabolism and lung inactivation: relevance of hemispheric specialization, neurotransmitter asymmetry and brain reactivity.

Due to asymmetry of brain neurotransmitters and differential hemispheric information processing modes, it is suggested that the excessive use of one information processing mode could engender a state of brain reactivity whose neurochemical correlates would be either a rise in melatonin or beta-endorphin in systemic circulation. Since melatonin and beta-endorphin have opposite effects on lung-mediated regulation of prostaglandins, it is further suggested that the pulmonary inactivation of prostaglandin E1 would either be increased or inhibited. Low levels of PGE1 would engender high levels of PGE2 whose effects would explain the findings in schizophrenics of: 'reducing' pattern of visual evoked response, cerebral atrophy, and viral and autoimmune phenomena. The primacy of the disordered cognitive style in leading up to the immunological, biochemical and neuropathological processes is stressed. Implications of this model for understanding depression, anxiety and phobic disorders, autism, attention deficit disorder, obesity, alcoholism, smoking, drug addiction, sexual deviations, and certain psychosomatic and psychophysiological disorders are suggested.

Alprostadil↗