Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Information Processing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources
PubMed1991

The effects of captopril vs atenolol on memory, information processing and mood: a double-blind crossover study.

1. Measures of memory, information processing ability, mood states and trait anxiety were estimated in a double-blind, double-dummy, randomised cross-over trial which compared the effects of atenolol (50 or 100 mg once daily) and captopril (25 or 50 mg twice daily), each taken for 6 weeks. Eighteen patients with mild to moderately severe hypertension were included. 2. There were no significant differences in systolic or diastolic blood pressure reduction between the two drugs. Pulse rate was slower after atenolol treatment (P less than 0.05). 3. Patients undertook practice on the psychological test battery prior to the treatment phases of the study in order to minimise practice effects. 4. There were no significant differences between the treatments on any of the measures of memory or information processing. 5. Patients reported feeling less anxious during treatment with atenolol (P = 0.02). 6. There were no differences between the drugs in their cognitive effects. The present study has the advantages of using an extensive battery of standard tests in a group of well-practised patients. The decreased anxiety reported with atenolol treatment may have clinical value and probably reflects the well-known effect of beta-adrenoceptor antagonist drugs on the somatic symptoms of situational anxiety.

Adult↗
PubMed2000

Information processing during sleep onset and sleep.

This Special Section examines the extent of information processing during sleep onset and sleep itself. It is generally agreed that, stimulus input is markedly inhibited during sleep, thus preventing conscious awareness of the external environment. Overt behavioural responses are rarely made within sleep. Two neurophysiological measures are therefore often used. The electrical activity of the brain (the EEG) can be employed to distinguish waking (conscious) from sleeping (unconscious) states. It is also possible to quantify the EEG prior to and following a detection (or a failure of a detection) of a stimulus. Such measures can thus be used to predict conscious awareness. A second measure that frequently has been employed is the brain's response to an external stimulus (the evoked potential). Different components of the evoked potential can be used to trace the extent of information processing during the different states of consciousness. Some are associated with a preconscious detection while others are associated with conscious awareness. Other evoked potentials may be unique to sleep.

Consciousness↗
PubMed1997

Information processing deficits of schizophrenia patients: relationship to clinical ratings, gender and medication status.

Information processing deficits were explored in a large cohort of schizophrenia patients (N = 125) and non-psychiatric subjects (N = 52). Gender, medication status and symptom factors were assessed relative to measures of performance in critical stimulus duration (CSD), visual backward masking (VBM) and auditory reaction time (RT) paradigms. Schizophrenia patients exhibited significant impairments in measures of CSD, VBM and both RT speed and RT set. Females in both groups had inflated CSDs relative to males. Female schizophrenia patients showed slower RTs and elevated RT set scores, but comparable VBM performance, when compared to males. This gender difference was not observed in the non-psychiatric subjects. To test the hypothesis that impaired performance in the VBM and RT paradigms would be related to negative symptoms and thought disorder, regression analyses were performed using factor scores derived from a factor analysis of SANS and SAPS items that generated three symptom factors: negative, disorganized, and reality distortion. Significant variance in performance on VBM and RT measures was accounted for only by the negative symptom factor. We conclude that VBM and RT assess information processing deficits in schizophrenia patients that are more related to the negative versus positive or disorganized symptoms of schizophrenia. It is possible that VBM and RT share overlapping or interacting neural substrates.

Adult↗
PubMed1990

Visual information processing in positive, mixed, and negative schizophrenic syndromes.

The purpose of this study was to determine whether schizophrenics with positive, mixed, and negative syndromes are distinguished in terms of visual stimulus registration thresholds and efficiency of information processing. Forty-five schizophrenic inpatients were classified accordingly into groups of 15 each and compared with one another and with 15 normal control subjects on a visual backward masking task. Repeated-measures analysis of variance revealed that all three schizophrenic groups were less efficient information processors than were normal subjects. Relative to the positive group, the negative group displayed significantly longer registration thresholds, fewer correct target stimulus detections, and longer time intervals to achieve their first significant improvement in performance and to first exceed chance response levels. The three syndrome groups were not significantly different in their rates of improvement over trials. Secondary correlational analyses showed that the information-processing measures were unrelated to a variety of demographic, psychiatric, and cognitive developmental variables, although shorter recognition thresholds and shorter unmasking interval scores were associated with faster psychomotor rates. Complex interrelationships were uncovered between the information-processing measures, positive and negative symptomatology, and general psychopathology. The results were interpreted as supporting the validity of the positive-negative distinction for explaining some of the heterogeneity in schizophrenia.

Adolescent↗
PubMed2004

[An event-related potential study the on information processing of binocular disparity in random-dot stereogram].

OBJECTIVE: To study the effects of discontinuous-continuous disparity gradient, uncrossed-crossed disparity and small-large disparity in random-dot stereogram (RDS) on the event-related potentials (ERPs). METHOD: Behavioral data and ERP were recorded when 16 healthy participants (8 males and 8 females) with normal depth perception were performing the task, in which the stereopsis were generated by red-blue glasses. RESULT: 1) The accuracy in discontinuous disparity gradient was higher than that in continuous disparity gradient, and the accuracy in large disparity was higher than that in small one. 2) Discontinuous disparity gradient elicited shorter N160 latency and larger N350 amplitude than continuous disparity gradient did. Compared with uncrossed disparity, crossed disparity elicited shorter N350 latency. In addition, large disparity elicited shorter N160 latency and larger P280 amplitude than small disparity did. CONCLUSION: The effect of disparity gradient on disparity information processing is significant, and the discontinuous disparity gradient has its processing advantage. Latency of N160 and amplitude of P280 is correlated with the information processing of the size of disparity. N350 component is correlated with the information processing of the uncrossed-crossed information of disparity.

Adult↗
PubMed1999

Oscillatory dynamics and information processing in olfactory systems

Oscillatory dynamics is a universal design feature of olfactory information-processing systems. Recent results in honeybees and terrestrial slugs suggest that oscillations underlie temporal patterns of olfactory interneuron responses critical for odor discrimination. Additional general design features in olfactory information-processing systems include (1) the use of central processing areas receiving direct olfactory input for odor memory storage and (2) modulation of circuit dynamics and olfactory memory function by nitric oxide. Recent results in the procerebral lobe of the terrestrial slug Limax maximus, an olfactory analyzer with oscillatory dynamics and propagating activity waves, suggest that Lucifer Yellow can be used to reveal a band-shaped group of procerebral neurons involved in the storage of an odor memory. A model has been constructed to relate wave propagation and odor memory bands in the procerebral lobe of L. maximus and to relate these findings to glomerular odor representations in arthropods and vertebrates.

Journal Article↗
PubMed1992

The analysis of distributed control and information processing in adaptive systems: a biologically motivated approach.

Biological systems have evolved hierarchical, distributed control structures that greatly enhance their adaptability. Two important determinants of biological adaptability considered here are: (i) the pattern of distribution of self-control capabilities; (ii) the degree of programmability of information processing. In this paper we model organizations as goal-oriented, adaptive systems, possessing properties similar to those of biological systems. We use the notion of implicit control (defined as the capability of self-control that is embedded in a system's own dynamics) in the analysis of the impact of specific patterns of distribution of control and information processing on the adaptability of organizations. A principle of design of organizational information systems, that captures important aspects of adaptability-preserving strategies of information processing in biological systems, is stated in terms of the implicit control concept.

Adaptation, Biological↗
PubMed1994

A cognitive-neuroscience approach for elucidation of mechanisms underlying temporal information processing.

Temporal processing of durations in the range of seconds or more is cognitively mediated, whereas processing of brief durations below 100 ms appears to be based on brain mechanisms beyond cognitive control. In a series of experiments, applying a single-behavior-multiple-brain-systems strategy, activity of various neurotransmitter systems was pharmacologically changed and effects on temporal information processing were studied. In addition, concomitant changes in different psychological functions, such as cortical arousal, speed of information processing, and memory were measured. This experimental strategy proved to be highly efficient for elucidating mechanisms underlying temporal information processing in humans. Temporal processing of durations in the range of seconds was markedly impaired by pharmacologic agents which induced deterioration of memory functions. On the other hand, temporal processing of brief durations below 100 ms was shown to be largely independent of pharmacologically induced impairment of cognitive functioning, but may rather depend on D2 receptor activity in the basal ganglia.

Administration, Oral↗
PubMed2006

Linking automatic evaluation to mood and information processing style: consequences for experienced affect, impression formation, and stereotyping.

According to the feelings-as-information account, a person's mood state signals to him or her the valence of the current environment (N. Schwarz & G. Clore, 1983). However, the ways in which the environment automatically influences mood in the first place remain to be explored. The authors propose that one mechanism by which the environment influences affect is automatic evaluation, the nonconscious evaluation of environmental stimuli as good or bad. A first experiment demonstrated that repeated brief exposure to positive or negative stimuli (which leads to automatic evaluation) induces a corresponding mood in participants. In 3 additional studies, the authors showed that automatic evaluation affects information processing style. Experiment 4 showed that participants' mood mediates the effect of valenced brief primes on information processing.

Adolescent↗
PubMed2003

Analysis of the structural bases of information processing in the basal ganglia: the spatial organization of thalamocortical projections in the dog brain.

Analysis of the architectonics of the thalamic projection systems of the caudate nucleus, putamen, and nucleus accumbens using axonal transport of retrograde markers was performed to study the morphological substrate for information processing in the striatum of the dog brain. The striatal nuclei contained areas through which segregated conduction of motor (dorsal segments of the caudate nucleus and putamen) and limbic (medial segment of the nucleus accumbens) information could occur, along with areas (ventral segments of the caudate nucleus and putamen, lateral segment of the nucleus accumbens) in which convergent conduction of functionally diverse information processed in the thalamic nuclei could occur. These data make a significant contribution to our understanding of the anatomical aspects of both the functional heterogeneity of the basal ganglia and integrative information processing occurring within them, which underlies the mechanisms organizing adaptive behavior.

Animals↗
PubMed1994

Influence of caffeine on information processing stages in well rested and fatigued subjects.

The effects of caffeine on different information processing stages were examined by using choice reaction time tasks. Independent variables were stimulus degradation, stimulus-response compatibility, time-uncertainty, state of the subject, and caffeine treatment. The task variables were assumed to affect the following processing stages; encoding, response selection and motor preparation, respectively. A 200 mg dose at the beginning of the experiment and a maintenance dose of 50 mg caffeine or lactose half-way through the session were administered to well rested and fatigued subjects, double-blind and deceptively. Behavioural measurements, event-related potentials (ERPs) and mood questionnaires were used to assess caffeine effects. The data showed that caffeine shortened reaction time. This effect showed an interaction with stimulus degradation and time uncertainty. In addition, ERP results supported the view that caffeine increases cortical arousal and perceptual sensitivity. Stimulating effects of caffeine were mainly located at input and output stages of the information processing system. Central processes were unaffected by caffeine. Fatigued subjects showed larger improvements in performance after caffeine than well-rested subjects. The results also indicated that caffeine effects were not stimulating in all subjects: 6 out of 30 subjects did not show arousing effects of caffeine.

Adolescent↗
PubMed2000

From neurophysiology to genetics: cortical information processing in migraine underlies familial influences--a novel approach.

Migraine patients show impaired cortical information processing between attacks with deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of auditory cortical evoked potentials (IDAP). This could be a genetic trait as certain genetic patterns are known for evoked potentials in healthy subjects. VEP-habituation and IDAP were studied in 40 migraine patients, i.e. pairs of 20 parents and their children. We developed a novel approach based on Monte Carlo statistics to selectively assess vertical familial influences. Both groups, parents and children, were characterized by abnormal VEP-habituation and IDAP. However, similarity between related pairs was far more pronounced than similarity between unrelated pairs. Assessed with a novel statistical approach, familial influences proved to be highly significant in determining cortical information processing in migraineurs, thus supporting the important role of genetic factors.

Adolescent↗
PubMed2001

DRD4 related to infant attention and information processing: a developmental link to ADHD?

The dopamine D4 receptor (DRD4) exon III polymorphism has generated interest because of its association with attention deficit hyperactivity disorder (ADHD), with an increased frequency of the seven-repeat allele being reported in children with ADHD. Deficits in sustained attention and information processing characterize ADHD, and individual differences in these functions are apparent from infancy. We found that in a structured play situation and on an information-processing task, 1-year-old infants with the 7-DRD4 allele showed less sustained attention and novelty preference than do infants without the 7-DRD4 allele. There was also a significant interaction between DRD4 and the serotonin transporter promoter (5-HTTLPR) gene on a measure of sustained attention. Our results provide evidence for a possible developmental link between DRD4 and ADHD via early sustained attention and information processing. It also points to the importance of considering the influence of more than one gene in studies of behavior.

Attention↗
PubMed2002

Differences in automatic social information processing between nondepressed and subclinically depressed individuals.

The present research examined individual differences in automatic social information processing. We hypothesized that because nondepressed and subclinically depressed persons have different interpersonal experiences, they may process social information in different ways. In this experiment, participants were asked to make judgments about social relationships after being reminded of a target person. They had to make these judgments under either a light or a heavy memory load. Results showed that when nondepressed participants were reminded of people with whom they had frequent pleasant interactions, they made a greater number of positive judgments about their social relationships than did subclinically depressed participants. When subclinically depressed participants were reminded of people with whom they had had frequent unpleasant interactions, they made a greater number of negative judgments about their social relationships than did their nondepressed counterparts. Moreover, performance in these experimental conditions was unaffected by memory load, suggesting that automatic thoughts about their social relationships had been evoked.

Cues↗
PubMed1997

Serotonin and human information processing: fluvoxamine can improve reaction time performance.

Fluvoxamine is a specific serotonin reuptake inhibitor. Recent evidence suggests that this antidepressive drug shortens the reaction time (RT) of healthy volunteers. The first objective of the present study was to decipher whether this effect is due to an improvement in information processing per se or to the adoption of an error-prone strategy. The second objective was to locate the effect of fluvoxamine within the series of information processing stages by means of Sternberg's additive factor method. After administration of a single oral dose of fluvoxamine (100 mg) or a placebo (randomized double-blind, cross-over design), eight healthy volunteers performed a choice RT task in which stimulus intensity, stimulus-response compatibility and response repertoire were manipulated. Fluvoxamine shortened RT without decreasing the accuracy of the responses. This demonstrates that fluvoxamine improves information processing per se. The effect of fluvoxamine was additive on RT with the respective effects of stimulus intensity and stimulus-response compatibility. This result suggests that fluvoxamine spares the processing stages of stimulus preprocessing and response selection.

Adult↗
PubMed2000

[Effect of goal setting on information processing in letter comparison tasks].

In two laboratory experiments (N1 = 84, N2 = 20) the impact of goal setting on information processing (perception) in letter-matching tasks was examined. It was expected that setting difficult goals for reaction times improves performance because identification and especially semantic classification of letters should be speeded up under goal-setting instructions. Three findings can be emphasized. (1) Current models of simultaneous letter matching are incomplete because they do not account for differences in reaction time based on alphabetic variations (lower case vs. upper case letters) within a pair of letters that are largely independent of real letter sizes. (2) In both experiments and for all types of letter pairs (AA, Aa, Ab AB), goal-setting effects are found as expected. In addition, the explanation that these effects are due to a speed-accuracy trade-off can be excluded. (3) Moreover, in some conditions goal-setting effects are also influenced by special features of letter pairs. Specifically, goal-setting effects are especially strong for letter pairs in which the right letter was enlarged and in which alphabetic differences and semantic differences within pairs call for opposite answers (Aa, AB). Based on the overall pattern of results, it is concluded that difficult goals lead to a general facilitation of processes in visual perception and, in addition, to a reduction of stimulus-induced, performance-delaying inhibition processes if linguistic information is processed predominantly in the left hemisphere.

Adult↗
PubMed2000

Shifts in information processing level: the speed theory of intelligence revisited.

A hypothesis is proposed here to reconcile the inconsistencies observed in the IQ-P3 latency relation. The hypothesis stems from the observation that task-induced increase in P3 latency correlates positively with IQ scores. It is hypothesised that: (a) there are several parallel information processing pathways of varying complexity which are associated with the generation of P3 waves of varying latencies; (b) with increasing workload, there is a shift in the 'information processing level' through progressive recruitment of more complex polysynaptic pathways with greater processing power and inhibition of the oligosynaptic pathways; (c) high-IQ subjects have a greater reserve of higher level processing pathways; (d) a given 'task-load' imposes a greater 'mental workload' in subjects with lower IQ than in those with higher IQ. According to this hypothesis, a meaningful comparison of the P3 correlates of IQ is possible only when the information processing level is pushed to its limits.

Humans↗
PubMed1975

Cardiac activity and information processing: the effects of stimulus significance, and detection and response requirements.

In two experiments, measures of heart rate and electromyographic activity were obtained from 40 male undergraduates while they performed two series of trials involving a sequential information processing task. Each trial consisted of a warning light, three successive tones, and a responded light, separated by 6-sec intervals. In Experiment 1, subjects responded only if the three tones were of different frequencies. Acclerative heart-rate responses to the last tone increased as a function of the significance of that tone. Subsequent cardiac decelerations were only observed if the subject was preparing to make a response. These results were replicated in Experiment 2, in which subjects responded only if two of the preceding tones were of the same frequency. Electromyographic activity was not significantly affected by stimulus significance or response anticipation. The data indicate that cardiac acceleration and deceleration reflect two independent psychological processes, associated with information-processing and decision-making activity on the one hand, and preparatory activity on the other.

Adolescent↗