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At least 19 recordsLinked to original sources
PubMed1991

[Psychophysiologic chronometry: detection of facilitating and inhibiting processes in information processing using electroencephalographic and electromyographic data].

The objective of the present research was to tally the potential usefulness of psychophysiological measures in the systematic analysis of human information processing. Different context conditions were established in two cued choice-reaction time experiments. The context could either facilitate or inhibit the processing of an imperative stimulus. Event-related brain potentials (EEG-ERP) and event-related electromyograms (EMG-ERP) were recorded and from these biosignals latencies and duration times for different aspects of stimulus evaluation and movement execution were derived. The EEG-ERP provided measures for the time of primary stimulus categorization (N2), the time necessary to test actual stimulus information against stimulus expectancies (P3b), and the time necessary to check the decision about the stimulus-response mapping (pSW). From the EMG-ERP, processing times were derived which are related to the initiation of a motor program and to distinct sections of the movement trajectory. Results show that these latency measures react differently to different context manipulations. EEG-ERP measures, for example, reflected differences during stimulus evaluation which were not detectable in response- or EMG-derived movement times. The parallel analysis of EEG-ERPs and EMG-ERPs allowed delineation of processing modules which are responsible for particular context-dependent facilitation and inhibition effects. Moreover, the data revealed substantial overlap of evaluation times and movement times. This finding seems to be more compatible with a parallel processing model than with a strictly sequential model.

Adult↗
PubMed1989

A study suggesting two kinds of information processing of the sexual response.

Genital and subjective sexual arousal in response to sexual imagery was studied. In a previous study subjects who were encouraged to process information on sexual stimuli and sexual responses were more sexually aroused than subjects encouraged to process information on sexual stimuli only. In the present study, the reverse effect was found in subjects who had received further verbal training to differentially process information on sexual stimuli or responses. This suggests two different kinds of processing information on sexual responses. They may result from simple encouragement or verbal training to process sexual information.

Adult↗
PubMed1990

Effects of closed-head injury on attentional processes: an information-processing stage analysis.

The present study, based on Sternberg's (1969) additive-factor method, examined attentional processes in terms of four information-processing stages (feature extraction, identification, response selection, and motor adjustment). Four task variables were used to operationally define the stages (signal quality, signal similarity, signal-response compatibility, and foreperiod uncertainty). In two studies, a visuo-spatial reaction-time task was undertaken by a group of university subjects (Experiment 1) and by three groups of closed-head-injured patients (severe short-term, severe long-term, and mild short-term) and their corresponding matched controls (Experiment 2). The results indicated that both patients and normals exhibited a similar mode of linear information processing. In addition, it was found that the severe short-term group was impaired on the response-selection stage and response selection stage; the severe long-term group was impaired only on the response-selection; and no evidence of impairment was found for the mild short-term patients. The implications of these findings with reference to the study of attentional processes in closed-head injured patients and to neuropsychological assessment and rehabilitation are discussed.

Adolescent↗
PubMed1987

Metabolic control and auditory information processing at altered glucose levels in insulin-dependent diabetes.

Previous work with a visual reaction time (RT) paradigm showed rate of mental processing to be slowed during a state of brain energy depletion (i.e., hypoglycemia). The present study employed an analog auditory RT paradigm to determine if modality differences in processing information might occur in response to glucose alteration. A balanced crossover design was used in which men with insulin-dependent diabetes completed RT tasks of increasing complexity at each of the following glucose levels: hypoglycemia (60 mg/dL), normoglycemia/control (110 mg/dL), and hyperglycemia (300 mg/dL). Results revealed two performance groups. A convergent group displayed slower RT responding during hypoglycemia, consistent with the visual RT pattern of results. A divergent group displayed better responding on one RT measure during hypoglycemia, and generally poorer responding on all RT measures during the other glucose conditions. Subjects in the divergent group maintained more stringent metabolic control and tended to have experienced more episodes of hypoglycemic unconsciousness. The present results provide the first evidence that more stringent metabolic control may be related to generally slower rates of processing auditory information. Possible explanations for these findings include hypotheses of immutable structual derangement, state-dependent performance effects, and a U-shaped response curve.

Adult↗
PubMed1987

Information processing in rapid eye movement sleep. Possible neurophysiological, neuropsychological, and clinical correlates.

Studies on cerebral hemispheric specialization suggest that the right and left hemispheres process information in different and sometimes conflicting ways. Rapid eye movement (REM) and non-REM sleep may reflect relatively greater activation or efficiency of the right and left hemispheres, respectively. Much of the mentation in wakefulness is dominated by the left hemisphere and its heavy language orientation. Modern theories of dreaming suggest that new solutions or adaptations to existing problems (i.e., new attitudes) may be enhanced by REM sleep and reflected in dreams. This report reviews experimental and clinical evidence to find neurophysiological, neuropsychological, and clinical support for the view that information is processed during REM sleep through increased activation, efficiency, and/or relative functional isolation of the right hemisphere.

Adult↗
PubMedDate not supplied

[The effect of coupled cardiovascular and respiratory afferent signals on the central processes of human information processing].

On the basis of contemporary knowledge on close functional connections between respiratory and cardiovascular afferents a computerized experimental device was developed by means of which central information processing can be studied in dependence on respiration phase and the level of baroreceptor activity. In all the examined parameters (time of motor reaction of two hands, latency of eye-lid reflex) the greatest changes were observed at maximum baroreceptor activity. These changes were clearly distinguished by direction during the phases of inhalation and exhalation. Such effect is probably based on the fact that the influence of cardiovascular afferents on the level of central activity is modulated in respiration rhythm through the mechanism of breath "gating" of postsynaptic STN structures.

Acoustic Stimulation↗
PubMed1991

[How people process increasing amounts of information as trials go on: reduction of the trade-off between memory and information-processing in the mental resources].

In solving problems in which the amount of memory required increases during the course of solution the subjects would select such strategies as to cope with the deterioration of performance due to the trade-off between the memory load and the information-processing efficiency. To test the above hypothesis 58 graduates and undergraduates were asked to solve a number-guessing problem. In Experiment I, the subjects' responses were categorized and two different information-processing strategies were extracted; the condensation-of-information strategy and the partiality-decision strategy. These strategies were coded as flow charts. In Experiment II, to clarify the relation between processing and memory strategies, memory load was varied by giving the subjects different amount of cues for the solution. Results suggested that the subjects coped flexibly with the demand of situation by adaptive usage of two-layer solving strategies corresponding to the amount of memory load; one was a memory strategy and the other was a processing strategy.

Adaptation, Psychological↗
PubMed1985

Information processing deficits in Parkinson's disease during movement.

The capacity to process information during movement selection and execution was studied in Parkinsonian patients and controls in a task involving movement of a hand-held stylus between two targets whose size and separation could be systematicaly varied. Movement time and accuracy were evaluated when the size and required accuracy of movements were changed to modify movement difficulty. Movement time and inaccuracy of patients with Parkinson's disease were exaggerated by increasing target separation so as to increase movement extent (target size held constant) or by decreasing target size (target separation held constant). The fact that these changes in task difficulty caused greater deterioration of performance for patients than for controls is consistent with previous studies indicating that Parkinsonian patients have deficits in executing high-velocity movements. These data also show that performance deficits by Parkinsonian patients can be brought out by increasing movement difficulty through requiring increased movement accuracy. These findings are interpreted in relation to the relative contribution of deficits in movement execution vs motor programming in the motor disorders of Parkinson's disease.

Aged↗
PubMed1976

Asymmetry of information processing in hallucinators and nonhallucinators.

In previous work we had developed evidence suggesting that hallucinating schizophrenics differ from nonhallucinators in the pattern of errors made in a shadowing task. Non hallucinators appeared to be less willing to guess when they were unsure. The errors of the hallucinators seemed more semantically elaborate. The experiment had not been designed to study these factors and the current experiment was conducted using a technique reported by Pisoni et al. These workers had studied normal Ss in an immediate recall task, using semantically well integrated (SWI) or poorly integrated (SPI) sentences. Pisoni et al. had shown that right ear presentation produced more accurate recall of SWI as compared to SPI sentences, whereas left ear presentation failed to discriminate these sentences. Utilizing the methods of Pisoni et al., we replicated their findings in a normal control group. The results from our hallucinating and nonhallucinating groups were different from each other, the nonhallucinators being less accurate, discriminating semantic integration level on left rather than right ear input, and making more fragmented errors. Little support could be found for attributing this pattern of performance to nonspecific aspects of the procedures. It appears that the nonhallucinators process information differently from hallucinators. These differences may reflect alterations in language development. It is speculated that such differences might be consistent with interference with the development of brain asymmetry.

Age Factors↗
PubMed1988

Information processed by dorsal horn spinocerebellar tract neurones in the cat.

1. A group of spinocerebellar tract neurones located in the dorsal horn of the mid-lumbar segments of the spinal cord but outside of Clarke's column have been investigated by intracellular and extracellular recording from their somata. The existence of these neurones has been demonstrated previously using anatomical methods, but their properties have not been investigated in detail. In contrast to the cells of Clarke's column, these neurones were found to process information from both exteroceptors and proprioceptors. 2. All of the investigated neurones were powerfully excited following stimulation of muscle nerves at strengths sufficient to activate group II afferents while there was no evidence for actions from group I afferents onto any of them. Most were excited by group II afferents from many different nerves, including those from muscles acting on different joints. The latencies and properties of the excitatory postsynaptic potentials (EPSPs) suggest that at least a large proportion of them were monosynaptically evoked. 3. All of the neurones were powerfully excited following electrical stimulation of cutaneous afferents. The most potent effects were evoked from the saphenous and sural nerves which innervate the skin of the leg and thigh. In many cases these EPSPs had latencies indicative of a monosynaptic connection. The superficial peroneal and tibial nerves which innervate the skin of the foot evoked EPSPs which were usually smaller and of longer latency. 4. Responses to adequate stimulation of cutaneous afferents were examined in twenty extracellularly recorded neurones. All but one of them could be discharged by weak mechanical stimulation of the skin over the proximal part of the leg and thigh. None were activated from the skin of the foot. 5. Some of the neurones were influenced by stimulation of the posterior knee joint or interosseous nerves. These actions were relatively weak, however, suggesting that the powerful effects seen on stimulation of muscle nerves were unlikely to have been mediated by articular or Pacinian afferents which contaminate them. 6. Excitation from group II afferents was sometimes followed by inhibition (in 27% of the neurones). In almost all cases the inhibitory postsynaptic potentials (IPSPs) were evoked from the same nerves which evoked EPSPs. The minimal latencies of the IPSPs were approximately 1.0 ms longer than those of the EPSPs, suggesting that they were evoked disynaptically. 7. The possibility that these neurones provide information regarding limb position is discussed.

Action Potentials↗
PubMed1989

Informational processing of complex sound. I: Intensity discrimination.

This paper reports on some initial experiments using the sample discrimination paradigm to investigate normal-hearing listeners' ability to process information in complex, nonspeech sounds. An important feature of the sample discrimination experiment is that the value of the difference to be discriminated randomly varies from trial to trial. It is this variation that yields potential information. In the present study, listeners heard a pair of multitone complexes (or sequences) on each trial. The individual levels of the tones were drawn from two normal distributions differing only in mean. The listener's task was to identify the sound having the higher mean tone level. For an ideal observer in these experiments, performance in d' grows as the square root n, where n is the number of tones. Obtained d' grew more nearly as the cube root of n regardless of whether the tones were played sequentially or simultaneously or whether they were increased in number from high frequencies to low or from low frequencies to high. A preliminary model is proposed in which discrimination performance depends predominantly on the information content of the sounds and is largely independent of the physical dimensions along which the sounds vary. Information content is defined in terms of the variance of the underlying stimulus distributions and a stimulus equivocation factor that is derived from the data. Based on this model, transmitted information is estimated to be between 1.0 and 2.6 bits.

Acoustic Stimulation↗
PubMed1990

Informational processing of complex sound. II. Cross-dimensional analysis.

A series of experiments investigated listeners' ability simultaneously to process information across different acoustic dimensions. On each trial, the listener heard a pair of brief n-tone sequences (n = 1 to 12). The frequency, intensity, and duration of each tone in the sequence varied randomly from trial to trial. On average, the values of these three parameters were greater for one sequence, the target, than the other, the nontarget. The listener's task was to identify the target on each trial. For an ideal observer in this task, d' performance grows as the square root n. Obtained d' grew at a rate slightly less than the square root of n. Close to cube root of n growth was observed when the average difference occurred in only one of the three tone parameter values within a block of trials. Although performance fell short of ideal, optimum weights were consistently given to each tone and each parameter. The results are consistent with a model in which performance depends predominantly on the information content of the sounds regardless of how the information is "packaged" in the stimulus. Transmitted information is estimated to be 0.9-2.0 bits within a single acoustic dimension, 2.1-3.0 bits when distributed across dimensions.

Adult↗
PubMed1975

Information processing immunogenetic analysis. IV. Information amount and predictive power of different immunogenetic models.

Principles of information theory are imposed on immunogenetic information processing, whereby the 'information amount', simplicity, 'redundancy' and 'predicatability' of different encodings, models, theories or mappings can be objectively compared. As an example, the experimental observables emanating from the Rh system at its 10 reagent-8 haplotype level is shown to obtain an information amount of 140,120 and 78 bits when interpreted (encoded according to a simple-complex, complex-simple and complex-complex theory, model or program, respectively. The 'predictive' or 'accomodating' power of the simple-complex and complex-simple theories is shown to be 134, respectively 366 bits for a given set of experimental observables emanating from a S3 universe.

Computers↗
PubMed1991

[Changes in the rate and accuracy of information processing in the computer training of upper-grade pupils].

The basic activity of the student during the "computer training process" is the introduction and processing of information. In the dialogue regime of work, between student and computer, the velocity and accuracy of the information processing take important place. In this aspect, special attention is given to the changes in the indicated indices during the computer lesson, computer plays and the traditional training. Studies are carried out on 30 students from classes X and XI, educated in vocational school "V. Levski", the town of Pravets. For the purpose is used electron determinator with test programme, containing consecutively exposure to 50 visual stimulators in red, blue, green, yellow and white colours at 1,2 s/speed. The results as a whole show that the most favourable results concerning the computer plays, very likely could be explained with the diversion effect and the positive motivation adjustment to the activity performed. By means of dispersion analysis is established, that only the type of activity has an essential effect on the velocity and accuracy of the information processing.

Bulgaria↗
PubMed1985

The effect of methylphenidate on information processing.

Models of information processing currently popular in cognitive psychology divide the reaction process into a series of discrete separable stages. The distinction between one stage and another is verified by the additive factors method (AFM) as defined by Sternberg (1969). Task factors that do not interact with each other are inferred to affect different stages. The distinction between stimulus evaluation stages and response selection stages has been supported by brain event related potential (ERP) studies. The latency of the P300 component of the ERP is sensitive to changes in stimulus complexity but not to to changes in response complexity. The focus of this research is to determine the effects of stimulant drugs on stages of information processing using both reaction time (RT) and P300 latency within an AFM framework. Four doses of methylphenidate (MP) were used in a within-subjects design to examine the effects of MP on stimulus and response processing. We found that MP speeds RT, and that this effect does not interact with the effect of stimulus complexity on RT. MP dose interacts with response complexity, the dose for optimal speeding varying with the level of complexity. The latency of P300 is increased by stimulus complexity, and not by response complexity, nor is it affected by MP. These results show that the stimulant drug acts on processes involved in response selection, rather than in stimulus evaluation. Individual differences in drug response are dose dependent, but also point to an effect on response processing.

Adult↗
PubMed1987

The effects of selective inattention upon the electrodermal orienting reflex: a test of information-processing theory.

Information-processing theories of the orienting reflex (OR) predict that disruptions of attention which impede the registration of a stimulus in memory should retard habituation of the OR. Studies examining effects of selective inattention upon rate of habituation of skin conductance responses (SCRs) to concurrently presented stimuli have yielded inconsistent results. We employed a dichotic vigilance task calling for selective attention to either male-voice or female-voice words. Comparisons between previously attended versus nonattended stimuli were subsequently conducted for habituation of SCR, as well as for a direct measure of recognition memory. Although there were unequivocal differences in long-term memory between attended and non-attended material, there was no clear evidence for corresponding differences in either initial magnitude or rate of habituation of SCR. These data, which replicated results from an earlier study, failed to demonstrate an effect of memory on the OR as predicted by information-processing theories.

Attention↗