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 163 records · Page 9Linked to original sources
PubMed1982

An information processing model for schizophrenia.

A disorder of information processing must be present for a person to receive the diagnosis of schizophrenia, and is present when schizophrenic symptoms occur along with other diseases. We created a model for this disorder that resolves some paradoxic findings and suggests directions for future study. Basically, schizophrenics have a deficiency in information processing that can be characterized as conscious, serial, and limited in channel capacity. In contrast, those processes that seem automatic, unconscious, parallel, and almost unlimited in capacity seem to be normal or supernormal.

Arousal↗
PubMed2003

Automatic and effortful information processing in unipolar major depression.

The present study investigated attentional dysfunction in patients with recurrent unipolar major depression in a visual search paradigm. The attentional aspects of automatic and effortful information processing were examined. The general hypothesis was that patients with unipolar major depression would have more problems with tasks that require effortful information processing than with tasks that require only automatic information processing. A task requiring effortful processing attracts attention, is more demanding, and is instruction-driven. A task that is automatically processed does not invoke attention, is less demanding, and is stimulus-driven. The results showed that the patient group needed significantly longer reaction times on the tasks requiring more effortful information processing than the control group, but there were no significant differences between groups on tasks requiring automatic information processing. Thus it seems as if the depressed patients show an impaired profile as a function of the degree of effort a task requires.

Adult↗
PubMed1990

Information-processing differences and laterality of students from different colleges and disciplines.

1023 college students were assessed for hemispheric brain dominance using the paper-and-pencil test, the Human Information Processing Survey. Analysis of scores of students majoring in Advertising, Interior Design, Music, Journalism, Art, Oral Communication, and Architecture suggested a preference for right-brain hemispheric processing, while scores of students majoring in Accounting, Management, Finance, Computer Science, Mathematics, Nursing, Funeral Service, Criminal Justice, and Elementary Education suggested a preference for left-hemispheric strategies for processing information. The differential effects of hemispheric processing in an educational system emphasizing the left-hemispheric activities of structured logic and sequential processing suggests repression of the intellectual development of those students who may be genetically favorable to right-hemispheric processing.

Adolescent↗
PubMed1987

Effects of physical conditioning on information-processing efficiency.

This study investigated changes in information-processing efficiency that occur when physical fitness improves. Information-processing variables were Sternberg's memory-scan rate, Posner's name-access time, the Cattell Culture Fair Intelligence Test, and numbers of words remembered from word lists. At present and posttest 10 to 12 wk. later, 66 adults between the ages of 18 and 48 yr. took all cognitive tests and rode a bicycle ergometer to estimate physical fitness. A 2 X 2 (improved/stable fitness groups by pretest/posttest trials) analysis of variance with repeated measures indicated that the group who improved 15% or more in physical fitness improved significantly more on the name-access time than the group whose fitness remained stable. There was a trend toward improvement in memory-scan rate and number of words remembered on the first word trial by people who became more fit. The results may have implications for assessment and training of personnel in occupations where speeded perception and responses are required.

Adolescent↗
PubMed1994

[Visual information processing in humans].

Recent advances in parallel information processing of primates and humans have been reviewed. First, I review what is known about physiology and anatomy of the primate visual pathways. Several lines of evidence suggest that the primate visual system consists of the parvocellular (P) and the magnocellular (M) pathways. M-system originates from the A retinal ganglion cells that project to the visual cortex (V1) via the magnocellular layers of the lateral geniculate nucleus (LGN). This system plays an important role for motion and stereopsis. P-system derives from the B retinal ganglion cells that project to V1 via the parvocellular layers of the LGN. This system shows selectivity for color vision and form perception. Second, I focus on the information processing of the human visual pathways. Psychophysical evidence suggests that there are also P and M systems in humans. However, there have been few electrophysiological studies which intend to separate the responses specific to P and M systems in human visual evoked potentials (VEPs). Based on the physiological distinctions between P and M systems, the use of isoluminant color patterns and apparent motion display allows us to evaluate P and M systems, respectively.

Animals↗
PubMed2004

The stage-specific effect of alcohol on human information processing.

RATIONALE: Research on the limits of information processing shows that when a dual task is performed in quick succession, performance on the second task is increasingly degraded as the temporal gap between task 1 and task 2 decreases. The carry-over effect on task 2 is assumed to occur because the central cognitive stage of processing must be completed before the processing of task 2 can begin. This creates a bottleneck when the tasks are performed in close succession, but with longer delays task 2 is no longer affected by task 1. OBJECTIVES: It was predicted that if alcohol disturbs (slows) the central stage of processing, shorter delays between task 1 and task 2 should reveal more intense disruption in the performance of task 2. METHODS: Two groups (n=16) of healthy male social drinkers performed a baseline test on a dual task. On each trial, task 1 was followed by task 2 at one of four delays (50, 200, 500, and 1100 ms). The groups then received either 0.65 g alcohol/kg or a placebo and performed the task again. RESULTS: The RT of the alcohol and placebo groups did not differ on the baseline test. In accord with the hypothesis, the alcohol group performed task 2 more slowly on the treatment test than did the placebo group at the three shortest delays (P<0.02). At the longest delay, the RT of the groups did not differ (P>0.15). CONCLUSIONS: This pattern of task 2 RTs indicates that a moderate dose of alcohol can significantly impair (slow) the central, cognitive stage of information processing.

Adult↗
PubMed1997

Towards a biomolecular computer. Information processing capabilities of biomolecular nonlinear dynamic media.

The information processing capabilities of biomolecular excitable media based on nonlinear dynamic mechanisms are discussed. Given even the simplest medium geometry, dynamics and information processing features inherent in biomolecular excitable media proves to be diverse and sophisticated. For the case of pseudo two-dimensional versions these media can be described in terms of neural networks having lateral connections. The main responses of shunting on-center off-surround feedback neural networks and pseudo two-dimensional excitable systems to the external excitations are surprisingly similar. The excitable media are capable of short-time memory, of contour enhancement and quenching or amplifying small features depending on medium state. The analogies discussed reaffirm specific neural net characteristics of excitable media and give the opportunity to estimate more accurate excitable medium characteristics.

Computers↗
PubMed1994

Automatic and controlled information processing in multiple sclerosis.

The purpose of this study was to evaluate the kind of slowing of information processing associated with multiple sclerosis and how this possible slowness is related to cognitive deterioration. We selected 45 patients with definitive multiple sclerosis diagnosis and 35 control subjects. Twenty-two patients had mild cognitive deterioration and 23 patients had preserved cognitive capacities, otherwise the groups were matched. Using computerized tests, we investigated three separate stages of information processing: automatic and controlled processing, and motor programming. The results indicate that patients with mild cognitive deterioration are slower than patients with preserved capacities or controls in every stage of processing measured in this study. Additionally, the preserved patients showed signs of mild slowing in automatic visual processing. These results show that, in multiple sclerosis patients, widespread information processing slowness is associated with multiple sclerosis-related cognitive deterioration. This study emphasizes the importance of studying subgroups rather than cognitively heterogeneous patient samples and, furthermore, the need to divide information processing into different stages is indicated.

Adult↗
PubMed2005

Information processing in brain microtubules.

Models of the mind are based on the idea that neuron microtubules can perform computation. From this point of view, information processing is the fundamental issue for understanding the brain mechanisms that produce consciousness. The cytoskeleton polymers could store and process information through their dynamic coupling mediated by mechanical energy. We analyze the problem of information transfer and storage in brain microtubules, considering them as a communication channel. We discuss the implications of assuming that consciousness is generated by the subneuronal process.

Biophysical Phenomena↗
PubMed1983

Information processing and lateralization in schizophrenia.

This experiment investigated two current approaches in the study of schizophrenic thought, information processing and hemispheric specialization. Ten paranoid and ten nonparanoid schizophrenics, ten nonschizophrenic psychiatric controls, and ten normal controls were presented three tasks tachistoscopically. The tasks, letter-naming and dot enumeration of unstructured and structured arrays, were designed to elicit left and right hemisphere functioning through automatic and controlled information-processing strategies. Hemisphere effects were significant in the letter task with the left hemisphere superior to the right for all groups. Position effects were also significant, suggesting that reading habits determine this function and the ability was shared by all psychiatric groups. The normal control group identified a significantly greater number of letters than all other groups which may suggest that the lower performance of the psychiatric groups was due to a general level of psychiatric pathology. The two dot enumeration tasks indicated that, unlike the other three groups, the nonparanoid group processed the dots using an automatic strategy but only in the left hemisphere. Right hemisphere processing was essentially the same for all groups. The left hemisphere performance of the nonparanoid replicates that of a previous study and leads us to consider the left hemisphere dysfunction as specifically related to nonparanoid schizophrenics and the dysfunction as the inability to process information in a serial manner.

Adult↗
PubMed1991

Human information processing during physical exercise.

This study was designed to investigate how conditions of physical exercise affect human information processing. Sixteen subjects performed two information processing tasks (perception and decision) during two exercise conditions (endurance vs interval protocols) and during two control conditions (rest vs minimal load protocols). The control conditions required subjects either to perform the information processing tasks under resting conditions or while pedalling a bicycle ergometer at a minimal workload. Workload during the exercise protocols consisted of a fixed percentage of the subject's maximal workload. Each 40 min protocol consisted of five consecutive stages: practice, baseline, warming-up, exercise, and cooling-down, during which heart rate and ratings of perceived exertion were determined. In the perception task subjects had to identify a briefly presented row of three letters. In the decision task subjects had to indicate which of the outer numbers in a row of three digits was the larger. Results indicated that the two control protocols did not influence cognitive task performance; however, in the exercise protocols, increments in physical workload improved performance on the decision task and reduced performance on the perception task, while decrements in physical workload reduced performance on the decision task and improved performance on the perception task. Changes in mental task performance were not evident within protocol stages; only after stage transitions did changes in mental performance occur. We discussed possible theoretical approaches to explain these results and concluded that models advanced in the context of dual-task methodology seem most promising.

Adult↗
PubMed1997

Neuropsychologic functioning in autism: profile of a complex information processing disorder.

Neurobehavioral theories of autism have hypothesized core deficits in sensory input or perception, basic attentional abilities or generalized attention to extrapersonal space, anterograde memory, auditory information processing, higher order memory abilities, conceptual reasoning abilities, executive function, control mechanisms of attention, and higher order abilities across domains. A neuropsychologic battery designed to investigate these hypotheses was administered to 33 rigorously diagnosed autistic individuals with IQ scores greater than 80, and 33 individually matched normal controls. Stepwise discriminant function was used to define the profile of neuropsychologic functioning across domains. The neuropsychologic profile in these autistic individuals was defined by impairments in skilled motor, complex memory, complex language, and reasoning domains, and by intact or superior performance in the attention, simple memory, simple language, and visual-spatial domains. This profile is not consistent with mental retardation or with a general deficit syndrome, but rather with a selective impairment in complex information processing that does not involve visual-spatial processing. This profile is not consistent with a single primary deficit, but with a multiple primary deficit model in which the deficit pattern within and across domains is reflective of the complexity of the information processing demands. This neuropsychologic profile is furthermore consistent with the neurophysiologic characterization of autism as a late information processing disorder with sparing of early information processing.

Adolescent↗
PubMed1999

The impact of ergotamine-induced headache and ergotamine withdrawal on information processing.

Ergotamine abuse and subsequent ergotamine-induced headache is a common problem in the pharmacological treatment of migraine and other headache types; often, withdrawal therapy is necessary. This study investigated whether ergotamine abuse affects information processing and whether withdrawal therapy can lead to an improvement of information processing. We designed a standardized neurophysiological retrospective (ergotamine abuse) and prospective (ergotamine withdrawal) study in a supraregional headache outpatient clinic. Seventy-one patients abusing ergotamine derivatives with subsequent daily headache were enrolled and compared to 36 migraine patients without ergotamine intake and 36 healthy subjects. Information processing was evaluated by latencies and amplitudes of visually evoked event-related potentials (ERP) before and after ergotamine withdrawal therapy. P3 latency of the ERP was significantly increased in ergotamine abuse (442 +/- 45 ms) versus migraine (415 +/- 40 ms) and healthy subjects (410 +/- 33 ms), there was no difference between ergotamine tartrate and dihydroergotamine abuse. The migraine specific loss of habituation in information processing as measured by P3 latency could not be observed in migraine patients with ergotamine abuse. After successful withdrawal therapy in 36 patients, the abnormally prolonged P3 latency was significantly shortened (452 +/- 47 ms versus 433 +/- 30 ms; P < 0.004). Our findings imply that information processing is impaired by ergotamine abuse and can be improved but not normalized after withdrawal therapy. Furthermore, our data provide strong evidence that ergotamine, besides its peripheral effects, has a central mode of action.

Adrenergic alpha-Agonists↗
PubMed1981

Impaired speed of information processing in nonmedicated schizotypal patients.

There is increasing evidence that schizophrenia is associated with an attentional or information processing deficit or both. These "early deficit" theories challenge the position that schizophrenia is primarily a disorder of thinking and higher cognitive operations. A tachistoscopic backward masking task was applied in matched groups of 20 schizophrenic, 20 schizotypal, and 20 depressive psychiatric inpatients. Resulting data are an index of visual input factors and speed of information processing. Paranoid schizophrenic and schizotypal subjects had unimpaired visual input thresholds but abnormally slow processing compared with the depressives. Since all the schizotypal subjects were nonmedicated, the data add important support to the hypothesis that impaired speed of information processing in schizophrenia spectrum disorders is due to schizophrenia per se and is not secondary to medication effects. These data also support the theoretical link between schizophrenic and schizotypal patients. The importance of the results is discussed, with emphasis on the hypothesized relationship between information processing dysfunction and symptom formation in the schizophrenias.

Adult↗
PubMed1994

The rise and fall in information-processing rates over the life span.

We surveyed studies that measured information-processing durations in groups of experimental subjects (children or elderly adults) and a group of college-aged control subjects. Some studies varied the type of processing while keeping the age of a subject group fixed. Process-durations in experimental subjects could be described by a multiplicative function of the control durations, regardless of the type of processing. Other studies varied the age of the subject groups while keeping the type of processing fixed. Process-durations declined during childhood, in a manner that could be described by a negative exponential function of age. Process-durations increased throughout middle- and old-age, in a manner that could be described by a positive exponential function of age. The sum of the two exponentials defined a U-shaped function that described process-durations over the life span. The most important studies varied both the type of processing and the age of the subject groups. An array of measurements of this kind could be described by a two-dimensional function that combined the multiplicative effect of process-duration and the exponential effects of age. The multiplicative effect of process-duration suggested that the execution of a processing sequence was conditioned by a single developmental parameter in both the experimental subject and the control subject. The exponential components determined the magnitude of the developmental parameter as the age of the subject changed. Given the global character of these effects, it seemed to us that the developmental mechanism may operate at a more elementary level than the information-processing stages conceived by cognitive theories. In a developmental framework, information processing may be reducible to a large number of small steps of a homogeneous duration or reliability, such as might be realized on a neural network. The exponential rate constants may be related to constant-probability hazards that act on one or another population of neural elements to create minute defects or incremental improvements. Their cumulative effects alter the functioning of the network over its lifetime, in a way that parallels the observed changes in process-durations.

Adolescent↗
PubMed1986

Effects of menstrual cycle on spatial information-processes.

The present study examined effects of menstrual cycle (i.e., ovulatory vs menstrual phase) on performance on spatial information-processes. Participants included 20 spontaneously cycling women (with regular 28- to 30-day menstrual cycles) who were tested on a reaction-time task developed to assess specific spatial information-processes and the Spatial Relations subtest of the PMA battery. For the spatial information-processing task, women responded faster and applied relatively less stringent criteria in the decision process during the ovulatory phase. No effects of cycle changes were found for accuracy of performance on either of the spatial tasks. It is suggested that studies examining effects of menstrual cycle on spatial ability consider an information-processing approach in measuring spatial performance and an application of signal-detection theory to separate components (strategy vs aptitude) of problem solving.

Achievement↗
PubMed1981

Early information processing deficit in schizophrenia. New findings using schizophrenic subgroups and manic control subjects.

In recent years, the idea that schizophrenia involves a primary disturbance of the higher cognitive (ie, cortical) thinking processes has been challenged by investigators who have shown that there may be a primary disturbance in schizophrenia in the early stages of information processing that occurs during the first few hundred milliseconds after the stimulus reaches the sense organs. Among the hypothesized early information processing deficits are deficiencies in iconic storage (a brief peripheral memory store) and slowness of processing from iconic storage to a more permanent memory system. Three experiments were conducted using tachistoscopically presented stimuli in order to evaluate these two stages of information processing (iconic storage and speed of processing) in schizophrenic and control subjects. Results converged in supporting the hypothesis, that independent of iconic storage and sensory registration, slow information processing is a relatively stable deficit of schizophrenic patients with a poor prognosis. The schizophrenic patients with a good prognosis had a similar deficit, which was reversible. Results are discussed as they relate to the early information processing deficit theories of schizophrenia.

Adult↗
PubMed1982

Stochastic information processing biological systems.

We propose a simple, biochemically-based model for stochastic information processing in brain, genetic, and, consequently, evolutionary modelling. The essential features of reaction-diffusion processes are realized by intrinsically stochastic probabilistic automata (Shannon and Weaver, 1948; see also Ashby, 1958, von Neumann, 1966; Burks, 1970; Paz, 1971) whose definition extends that of classical automata. (Classical automata are deterministic; earlier work on probabilistic automata focused on error correction and at least approximating deterministic behavior.) We call these probabilistic automata biochemical to emphasize the role of intrinsically stochastic process in biological information processing. Our model yields descriptions of gradualism (Conrad, 1974), learning, and apparent inefficiencies in the brain, and partially resolves the near impossibility of simultaneous point mutations (Conrad, 1972, 1978) in genetics. The genetic model implies an evolutionary dynamics of punctuated equilibria (Gould and Eldredge, 1977).

Animals↗