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 757 records · Page 42Linked to original sources
PubMed1999

Slow information processing after very severe closed head injury: impaired access to declarative knowledge and intact application and acquisition of procedural knowledge.

As an explanation of the pattern of slow information processing after closed head injury (CHI), hypotheses of impaired access to declarative memory and intact application and acquisition of procedural memory after CHI are presented. These two hypotheses were tested by means of four cognitive reaction-time tasks, a semantic memory task, a memory comparison task, a mental rotation task and a mirror reading task. These tasks were administered on two different days to 12 survivors of a CHI tested more than 5 years after injury and a healthy control group of comparable age and education. In three tasks the difficulty of access to declarative knowledge was varied and it was expected that this would slow the CHI group more than the controls. In two tasks opportunities for procedural learning were provided by repeatedly presenting the same cognitive tasks and in one task, the difficulty of access to procedural memory was varied. It was expected that the CHI group would profit as much from this as would the control group. Both hypotheses were supported.

Adolescent↗
PubMed2000

Sequential information processing during a mental arithmetic is reflected in the time course of event-related brain potentials.

OBJECTIVE: We hypothesized that mental arithmetic is a complex of sequential information processing. In order to test the hypothesis, event-related potentials (ERPs) were measured during 3 mental tasks. METHODS: Fifteen normal human subjects performed the following tasks; (1) subjects added up every digit delivered successively on a computer display, (2) subjects counted the number of presented digits, or (3) subjects counted the number of meaningless patterns. Spatiotemporal differences between ERP waveforms under the 3 tasks were studied within the period of 1200 ms post-stimulus. RESULTS: During the adding task, N120-P180-N220 complex advanced in latency in the left frontal, central and parietal regions. P300 increased in amplitude in the frontal and temporal regions during adding and counting digits, which was specific to the digit presentation. A positive slow potential depended on the adding task and showed two spatiotemporal distributions; one was a widespread brain activity over the frontal, central, temporal and parietal regions observed within 400-820 ms, and another was a brain activity restricted to the frontal region lasting up to 1150 ms. CONCLUSIONS: The results suggest that the early portion of ERPs reflects identification of physical attributes of stimuli and numeric meaning of digits, and that the positive slow potential reflects processes associated with calculation.

Adult↗
PubMed1990

[Self-concept related information processing in relation to perceived personal ability].

Cognitive self-schemata are conceived of as being generalized representations about the self which have been derived from previous experiences and the evaluations of these experiences. Self-schemata organize and guide the processing of self-related information. An experiment investigating such processing of self-related information in relation to perceived own ability--the self-concept of ability--as a variant of cognitive self-schemata is reported. Subjects with varying levels of self-concept of ability are requested to judge ability-related adjectives with regard to the self. The results indicate that those individuals with high perceived own ability judge adjectives which are consistent with this self-perception significantly faster and more frequently as being self-descriptive than adjectives which are inconsistent with this self-perception. Individuals with low perceived own ability do not differ in response latency and percentage of words judged as being either self-descriptive or not. Overall the results confirm only the assumption that individuals with high perceived own ability--but not individuals with low perceived own ability--possess ability-consistent cognitive self-schemata.

Aptitude↗
PubMed2001

Auditory information processing in rat genotypes with different dopaminergic properties.

RATIONALE: Auditory filtering disturbances, as measured in the sensory gating and prepulse inhibition (PPI) paradigms, have been linked to aberrant auditory information processing and sensory overload in schizophrenic patients. In both paradigms, the response to the second stimulus (S2) is attenuated by an inhibitory effect of the first stimulus (S1). Dopamine (DA) agonists have been found to reduce gating of auditory evoked potentials (AEPs) and PPI in healthy human subjects and in rats. These effects have been linked to DA hyperactivity in the mesolimbic system. A non-invasive approach in studying the role of the DA system in PPI and AEP gating is to compare rat genotypes that are marked by distinct DA systems. OBJECTIVES: Several questions were asked in the present study. Are PPI and AEP gating disturbed in (a) rats that are marked by a relatively high DA reactivity of the mesolimbic system, namely apomorphine-susceptible (APO-SUS) and WAG/Rij rats or in (b) rats that are marked by a relatively high DA activity of the nigrostriatal system, namely apomorphine-unsusceptible (APO-UNSUS) and ACI rats? Moreover, is the particular DA balance (c) between the nigrostriatal and mesolimbic system related to deficits in PPI and AEP gating? METHODS: For this purpose, the above-mentioned four rat genotypes (APO-SUS, APO-UNSUS, ACI and WAG/Rij) that vary in DA balance between both systems, were compared in the AEP gating paradigm. PPI was only measured in the ACI and WAG/Rij rats, since it has already been shown in a previous study that APO-SUS rats show diminished PPI as compared to rats of the APO-UNSUS genotype. RESULTS: AEP gating of the vertex N50 was significantly reduced in WAG/Rij rats as compared to the remaining three rat genotypes (APO-SUS, APO-UNSUS and ACI). No PPI deficits were found in the ACI and WAG/Rij rats, although ACI rats had a significantly higher basal startle amplitude. CONCLUSIONS: The PPI deficit in APO-SUS and not in the other genotypes, suggests that especially a relatively high DA reactivity of the mesolimbic system, together with a relatively low activity of the nigrostriatal system, contributes to this deficit. In contrast, the N50 gating deficit in WAG/Rij rats and not in the other genotypes suggests that a relatively high DA activity of the nigrostriatal system together with a relatively high DA reactivity of the mesolimbic system is necessary for the presence of a N50 gating deficit. On the basis of these results we have concluded that both auditory filtering processes are differently regulated by DA in the nigrostriatal and mesolimbic systems.

Acoustic Stimulation↗
PubMed1988

The determinants of the non-motoric CNV in a complex, variable foreperiod, information processing paradigm.

The aim of the present study was to examine the determinants of the non-motoric CNV or E-wave elicited in a complex, variable foreperiod information processing task. Subjects were required to determine whether two sets of tones, one set presented back-to-back (S1/S2), the other separated by a variable foreperiod (S3/S4), were either matching or mismatching. Data were collected over two recording sessions; a baseline and an experimental run. The experimental session comprised three conditions; a match, a mismatch and no-response conditions. Mean amplitude and factor score comparisons showed the parietally-dominant E-wave to be dependent on the task relevance of the stimulus which it precedes. Differing midline distributions for the negative afterwave and the E-wave with increased processing requirements was taken to suggest that the two responses reflect functionally distinct phenomena.

Adult↗
PubMed1998

Kainic acid lesions in adult rats as a model of schizophrenia: changes in auditory information processing.

Previous studies have suggested that intracerebroventricular kainic acid injections alter brain anatomy and neurochemistry in a manner similar to what is observed in schizophrenic patients. Disturbances in sensory information processing are one of the major symptoms of schizophrenia. Thus, the present experiments were designed to evaluate the hypothesis that hippocampal damage, induced by administration of kainic acid, would alter the processing of auditory stimuli in a paired-click paradigm. Adult male Sprague-Dawley rats were implanted for surface recording of auditory evoked potentials. At the time of electrode implantation, the rats also received bilateral injections of either kainic acid or the vehicle solution. In vehicle-treated rats, the midlatency N40 component of the auditory evoked potential was diminished in amplitude by approximately 60% in response to the second of a pair of clicks delivered 0.5 s apart. By contrast, no reduction of the N40 wave evoked by the second click was observed in kainate-treated rats. Further, administration of haloperidol, a prototypical neuroleptic agent, did not improve this auditory processing dysfunction in kainate-treated animals. Loss of auditory filtering in the paired-click paradigm and a lack of response to haloperidol in this test are typically observed in schizophrenic humans. Thus, the present results demonstrate that kainate-lesioned rats possess a functional schizophrenia-like abnormality, further reinforcing the utility of this model system for studying the basic neurobiology of schizophrenia-induced sensory processing deficits.

Acoustic Stimulation↗
PubMed1994

On the relation between social information processing and socially competent behavior in early school-aged children.

This article tested the hypotheses that (1) children's behavioral competence is a function of patterns of social information processing; (2) processing correlates of behavior occur at each of 5 steps of processing within each of 3 social situations; (3) measures at each step uniquely increment each other in predicting behavior; (4) the relation between processing and behavior is stronger within than across domains; and (5) processing patterns are more sophisticated among older than younger children and the processing-behavior relation is stronger among older than younger children. Videorecorded stimuli were used to assess processing patterns (encoding, interpretational errors and bias, response generation, response evaluation, and enactment skill) in 3 domains (peer group entry, response to provocation, and response to authority directive) in 259 first-, second-, and third-grade boys and girls (ages 6-9 years). Ratings of behavioral competence in each domain were made by peers and teachers. Findings generally supported hypotheses, with the magnitude of relations being modest.

Age Factors↗
PubMed1990

Results of visual information processing tests in elderly people with presbycusis.

In a group of 21 elderly subjects with mild to moderate hearing loss of presbycusis type, a series of tests of visual information processing was performed. Cortical-evoked potentials were recorded in response to flash and to checker-board pattern stimulation. Further, five speech reading tests were administered. The results obtained in this group of elderly subjects were compared to those of a group of young normal-hearing subjects and those of a group of young subjects with congenital hearing impairment. The visual-evoked potentials showed significantly smaller N1P2-amplitude in elderly subjects than in the other two groups for both flash and checker-board pattern stimulation. The average latency of the P2-component was shorter than in both the other two groups in response to checker-board pattern stimulation. The elderly subjects scored significantly less well than the young normal-hearing group on all five speech reading tests. Linear regression analysis between the results of the five speech reading tests and those of the latency and amplitude measures of the evoked visual responses showed no significant correlations.

Adolescent↗
PubMed1987

Relationship between mood state and information processing of negative versus positive emotional stimuli in brain-damaged patients.

The present study investigates the relationship between affective mood state as assessed by self- and hetero-rating scales and information processing of negative versus positive emotional stimuli in unilateral brain-damaged patients. Results show a high positive correlation between depressive mood scores and rating of self-awareness. Left brain-damaged (LBD) patients do not differ significantly from right brain-damaged (RBD) patients on both rating scales. RBD patients mismatch negative emotional stimuli in the nonverbal matching task. Results are discussed with reference to interaction between expression of emotion and cognition. The selective neglect of negative information is interpreted as a more basic emotional impairment.

Adult↗
PubMed1984

The effects of cigarettes of varying yield on rapid information processing performance.

The purpose of this study was to determine the effects of four cigarettes having a range of covarying nicotine and "tar" yields on the performance of a rapid information processing task. Twenty five smokers were tested on different days with each of the cigarettes and in a non-smoking control condition. The order of testing was counterbalanced over days using a 5 x 5 Latin Square Design. Not only did smoking help to prevent the decrease in speed and accuracy which occurred over time in the non-smoking conditions, but it actually improved performance over baseline levels. Furthermore, the greatest improvements were found with the higher nicotine yielding cigarettes. These objectively measured effects of the cigarettes on performance matched the subjective evaluations of the effects of the cigarettes outside the laboratory, and are discussed in relation to other questionnaire studies and a survey of smoking at work.

Carbon Monoxide↗
PubMed1989

An additive factors analysis of the effect(s) of location cues associated with auditory stimuli on stages of information processing.

The additive factors method (AFM) was used as a tool for assessing the locus (or loci) of the detrimental effect of auditory location cues in the chain of (visual) information processing. In the first experiment the location variable was factorially combined with response specificity, which is assumed to affect the response adjustment stage. A second experiment was performed in which movement amplitude, assumed to affect the response programming stage, was manipulated in addition to the location variable and a different variety of response specificity. Finally, the location variable was combined with relative S-R frequency, which is also assumed to affect the response programming stage, in a third experiment. The results of these experiments showed additive effects of the location variable with motor variables. The remaining two experiments were designed to assess the effects of location cues on response selection. In these experiments the location variable was combined with the number of response alternatives. Response speed decreased with an increase in the number of response alternatives. However, the effects of the location variable and number of response alternatives were additive. According to the additive factor logic, then, the results of experiments 1, 2 and 3 seem to indicate that the locus of interference of the location cues is not in the later response stages of the reaction process. The results of the last two experiments were interpreted to suggest that the effects of location cues and the number of response alternatives affect either different processes within the response selection stage or affect different process stages. It was concluded that the latter alternative explains most of the data currently available and that the stimulus identification stage is the most likely candidate for the locus of the location effect.

Adolescent↗
PubMed1993

Event-related potentials in high-functioning adult autistics: linguistic and nonlinguistic visual information processing tasks.

Event-related potentials (ERPs) were recorded from high-functioning adult autistics and age- and IQ-matched normal controls during performance of two non-linguistic information processing tasks, the Continuous Performance Task (CPT) and Span of Apprehension (SPAN), and an Idiom Recognition Task (IRT) involving idiomatic, literal and nonsense phrases. The autistics exhibited behavioral deficits only when attempting to identify idiomatic phrases. The ERP correlate of that deficit was greatly reduced N400 to idioms. In addition, autistics produced larger N1 amplitudes in all tasks, and larger P3s in the IRT and CPT.

Adolescent↗
PubMed2005

Basic information processing of neurotics and stables: an experimental ERP approach to personality and distractibility.

The aim of the study was to investigate the effects of level of neuroticism on electrophysiological event-related potentials (ERPs) to different kinds of stimuli. The neuroticism items from the NEO-PI-R were administered to 168 female, right-handed undergraduates between 19 and 29 years of age. 20 highly neurotic and 22 highly stable persons underwent an ERP task that was designed to be a combination of an auditory P3a and a visual P3b oddball task. No significant differences in the P3a and P3b were detected. It is concluded that highly neurotic and highly stable persons do not differ in fast neurocognitive processing of neutral stimuli, and that cognitive differences between the groups may be located at another level in the sequence of information processing stages.

Adult↗
PubMed1999

Normalization of information processing deficits in schizophrenia with clozapine.

OBJECTIVE: The authors tested the hypothesis that the use of an atypical drug, clozapine, for patients with schizophrenia is related to less impairment in information processing deficits (assessed by prepulse inhibition of the startle response) than is the use of typical antipsychotics. METHOD: Two groups of schizophrenic patients--receiving either clozapine or a range of typical antipsychotics--were tested for prepulse inhibition (a reduction in response to a starting stimulus, if preceded briefly by a weak, nonstartling stimulus; measured at prepulse-to-pulse intervals of 30 msec, 60 msec, and 120 msec) of the acoustic startle response and compared with a group of healthy volunteers. RESULTS: Patients receiving typical antipsychotics showed less prepulse inhibition with 30-msec and 60-msec prepulse trials than did comparison subjects. Clozapine-treated patients showed normal levels of prepulse inhibition. CONCLUSIONS: Clozapine is superior to typical antipsychotics in normalizing prepulse inhibition, presumably because of its pharmacological effects on prefrontal regions of the brain or its effects on a broader range of neuroreceptors.

Acoustic Stimulation↗
PubMed1995

Information processing and concentration as a function of fitness level and exercise-induced activation to exhaustion.

To examine the effects of increasing amounts of exercise on attention and speed of information processing 20 paid male subjects were separated into groups of high and low fitness according to their VO2max values. The experiment involved an attentional task (Random Number Generation) that was given after every 10 min. of cycling at work-load resistances calculated as 40%, 50%, 60%, 70%, and 80% of individual VO2max values. An eight-choice reaction time-movement time task was given before and after exercise as well as after a 15-min. recovery period. Individuals were tested within 10 min. after exercise cessation (exhaustion) for concentration and within 15 min. for choice reaction time and movement time to assess whether fitness differentially interacted with these variables. Split-plot factorial analyses of variance suggested that the CNS appeared capable of maintaining performance after 50 min. of exhaustive exercise compared to values obtained at the preexercise condition. A 15-min. recovery period significantly impaired MT but relatively highly fit individuals did not appear to perform the choice RT and concentration tasks better than individuals low in fitness.

Adult↗
PubMed2002

Information processing in autistic children: more sequential or more simultaneous?

The objective of this study was to refine the understanding of cognitive troubles in autism and to clarify the modes of information processing mobilized by the subjects. Eight children were examined, aged 4;9-9;1, with a diagnosis of moderate autism. The Kaufman Assessment Battery for Children (K-ABC) was presented to each child. The results support an executive functioning deficit interpretation and a weak drive for central coherence in autism. Practical implications of this study in terms of follow up are also discussed.

Autistic Disorder↗
PubMed1988

[Stages of information processing and cerebral hemispheric differences in random shape recognition].

The purpose of this experiment was to investigate the differences of cerebral hemisphere function with respect to the way visual pattern information is stored in the long-term memory. The shape recognition in the left and right visual fields was measured after the subjects were trained to associate the shapes with relevant verbal labels, irrelevant verbal labels, or no verbal labels. Subjects were given a shape recognition test by the visual half-field presentation and both free- and aided-recall tests for retention of associated verbal labels. Results indicated that accuracy of recognition of shapes in the left visual field was greater than in the right visual field. Pretraining condition produced a significant main effect but no differential field effect. While irrelevant verbal labeling and observation conditions recognized the stimulus with equal reaction time in either visual field, the latency of relevant verbal labeling condition was longer in right visual field than in left visual field. These results were discussed in terms of the differences of cerebral hemisphere function in each stage of information processing.

Adult↗
PubMed2001

Information processing and insight: a process model of performance on the nine-dot and related problems.

The 9-dot problem is widely regarded as a difficult insight problem. The authors present a detailed information-processing model to explain its difficulty, based on maximization and progress-monitoring heuristics with lookahead. In Experiments 1 and 2, the model predicted performance for the 9-dot and related problems. Experiment 3 supported an extension of the model that accounts for insightful moves. Experiments 4 and 5 provided a critical test of model predictions versus those of previous accounts. On the basis of these findings, the authors claim that insight problem solving can be modeled within a means-ends analysis framework. Maximization and progress-monitoring heuristics are the source of problem difficulty, but also create the conditions necessary for insightful moves to be sought. Furthermore, they promote the discovery and retention of promising states that meet the progress-monitoring criterion and attenuate the problem space.

Adult↗