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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↗
PubMed2004

Dynamic control and information processing in chemical reaction systems by tuning self-organization behavior.

Specific external control of chemical reaction systems and both dynamic control and signal processing as central functions in biochemical reaction systems are important issues of modern nonlinear science. For example nonlinear input-output behavior and its regulation are crucial for the maintainance of the life process that requires extensive communication between cells and their environment. An important question is how the dynamical behavior of biochemical systems is controlled and how they process information transmitted by incoming signals. But also from a general point of view external forcing of complex chemical reaction processes is important in many application areas ranging from chemical engineering to biomedicine. In order to study such control issues numerically, here, we choose a well characterized chemical system, the CO oxidation on Pt(110), which is interesting per se as an externally forced chemical oscillator model. We show numerically that tuning of temporal self-organization by input signals in this simple nonlinear chemical reaction exhibiting oscillatory behavior can in principle be exploited for both specific external control of dynamical system behavior and processing of complex information.

Biochemistry↗
PubMed1997

Evidence for a specific information processing deficit in monkeys with lesions of the septo-hippocampal system.

Monkeys with dysfunction of the septo-hippocampal system induced by excitotoxic lesion of the CA1 region of the hippocampus, or the septal/diagonal band area (which sends cholinergic projections to the hippocampus via the fornix), or with fornix transection were impaired on conditional learning tasks (when X choose A not B, when Y choose B not A) when trials with these different contingencies were presented in pseudorandom order but they were not impaired on learning this type of task if, prior to learning with trials in the pseudorandom order, the two types of trial had been presented in a fixed number of alternating batches of each type of trial. These results suggest that the septo-hippocampal system is required to process information in a particular type of way rather than to process a particular type of information and supports the view that the amnesia which results from medial temporal lobe damage in humans comprises an impairment of encoding information into long-term memory.

Amnesia↗
PubMed1983

Schizophrenia: a neurophysiological evaluation of abnormal information processing.

Evoked potential indices of an early and late stage of attentional processing were recorded from schizophrenic and normal subjects during dichotic listening tasks. Despite slow and inaccurate detections, the schizophrenic subjects were able to focus selectively to different ears but only at a fast stimulation rate, showing integrity of the early selective stage. They showed an abnormal late stage, indicating inefficiency in processing information from detected targets. Marked deficits at a slow stimulation rate and during divided attention suggest that the schizophrenic attention disorder is one of control and maintenance of a selective processing strategy rather than of general slowness or absence of selectivity.

Attention↗
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↗
PubMed2002

Naive causal understanding of valenced behaviors and its implications for social information processing.

People bring to bear on their understanding of others' behaviors naive theories of the causes of valenced behaviors. Generally, positive behaviors are understood to be caused by social demands, whereas negative behaviors are understood to be caused by people's dispositions. Various research findings are reviewed in support of the idea that people possess such naive theories. The analysis is extended to establish how these sense-making tendencies affect the manner in which people approach and process information about others. A second set of studies is reviewed in support of these implications for person perception. Comparisons to other models of social inference are considered, implications of the frame-work are examined, and the framework is situated within a general model of the attribution process.

Behavior↗
PubMed1997

A left temporal lobe impairment of auditory information processing in schizophrenia: an event-related potential study.

A measure of auditory prepulse inhibition (PPI) is the reduction of the scalp-recorded P1 event-related potential (ERP) after a sound that is preceded by 100-300 ms by a click as prepulse. This measure of sensory gating was adapted to study the effect of a prepulse on processing tones that were part of a 'go no-go' discrimination. ERPs were recorded at right and left, frontal and temporal sites in groups of patients with schizophrenia (SCH) or obsessive compulsive disorder (OCD) and healthy controls (CON). A prepulse 100 ms but not 500 ms before either tone reduced the P1 ERP amplitude in healthy and OCD subjects but not SCH patients. At frontal and temporal recording sites the P1 amplitude was similar bilaterally in controls but showed a right temporal shift in the SCH patients. If the tone was the 'no-go' tone, the prepulse reduced the N1 amplitude in both the CON and SCH groups. The N1 was similar, bilaterally in controls but again showed a right temporal shift in the SCH group. These results show a reduction of a PPI-like effect on early processing (P1) that is more marked in the left hemisphere of SCH patients and may affect channel selection for processing information (N1) about task-relevant sounds.

Acoustic Stimulation↗
PubMed1995

Social information processing in compliance situations by mothers of behavior-problem boys.

This investigation examined differences between mothers of behavior-problem boys (MBP; n = 20) and mothers of average boys (MAB; n = 20) in processing information in compliance situations (mean ages; mothers = 30 years, children = 8 years). Mothers responded to videorecorded stimuli of child behavior cues. Compliant and oppositional stimuli were clear regarding whether the child was going to obey the mother; however, bargaining and complaining were ambiguous. MBPs made greater attributions of defiant intent toward the child and experienced more anger than did MABs in ambiguous stimulus situations. MBPs also expected more resistance from the child and experienced more anxiety than did MABs, in all stimulus situations (ambiguous and clear). Differences between group mean processing scores were greater under conditions of stimulus ambiguity than under conditions of stimulus clarity. Findings are discussed in terms of the interface of mother-child relationship history and the child's current behavioral cues.

Child↗
PubMed2001

Information processing of visually-induced apparent self motion in the cortex of humans: analysis with magnetoencephalography.

The cortical site which processes information on whole-body linear displacement is unknown. In this study, neuromagnetic responses to a visually-induced linear vection were recorded in 5 healthy, right-handed, adult subjects using a 122-channel whole cortex neuromagnetometer. We presented expanding rectangles on the screen which came into view one after another and accelerated in expanding speed at random cycle, giving the subjects the sensation of linear self motion (linear vection) through an illusory tunnel with occasional acceleration. Clear responses of magnetic fields related to the accelerative event were obtained in both hemispheres around the parietal and temporal regions. The dipole sources of the component were estimated in the cortex around the superior temporal sulcus, insula and medial superior temporal area. Some parts of these regions may have been comprised in the vestibular cortex, suggesting that it processes the sensation of linear self motion and plays an important role in space perception.

Adult↗
PubMed1983

Carbon monoxide exposure and information processing during perceptual-motor performance.

This study examined the influence of exposure to ambient carbon monoxide resulting in final carboxyhemoglobin (COHb) levels of approximately 5.0% on the ability to process information during motor performance. Subjects (n = 16) performed a primary reciprocal tapping task and a secondary digit manipulation task singly and/or concurrently during 2.5 h exposure to room air (0 ppm CO) or 100 ppm CO. Five levels of tapping difficulty and two levels of digit manipulation were employed. Tapping performance was unaffected when COHb levels were as high as 5%. However, at this level of COHb it was noted that CO exposure interacted with task difficulty of both tasks to influence reaction time on the digit manipulation task. It was concluded that motor performance was not influenced by exposure to CO leading to COHb concentrations of 5%. Task difficulty was a significant factor mediating behavioral effects of CO exposure.

Adult↗
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↗
PubMed1984

The hippocampus, context, and information processing.

Two experiments are described in which groups of rats with bilateral hippocampal lesions, cortical lesions, and operated controls are compared on tests of discrimination learning, retention, and reversal learning. Experiment 1 examined the effects of varying prior training and context on new learning. Experiment 2 used a transfer paradigm to compare extent of original learning by hippocampal and control groups in a discrimination task involving multiple discriminanada . The major findings were that rats with hippocampal damage were less efficient at processing information and were more constrained by contextual influences than control rats.

Animals↗
PubMed1996

Alpha frequency, reaction time, and the speed of processing information.

Several experiments indicate that alpha frequency is significantly correlated with the speed of information processing, as measured by reaction times. These data imply that alpha frequency is a timing mechanism for cognitive processes. However, this interpretation contradicts the well-accepted view that there is no single alpha rhythm, but instead an entire population of different alpha oscillations. We present arguments and report data in the attempt to demonstrate that this paradox can be resolved if different states of alpha oscillations are distinguished. The results of the present study show that during a state of desynchronization, task-related shifts in alpha frequency are not "real" because they are not related to reaction times. Instead, they most likely reflect power changes in different frequency bands.

Adult↗
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↗
PubMed1996

Information processing during general anesthesia: evidence for unconscious memory.

Memory for words presented during general anesthesia was studied in two experiments. In Experiment 1, surgical patients (n = 80) undergoing elective procedures under general anesthesia were presented shortly before and during surgery with words via headphones. At the earliest convenient time after surgery (within 5 h) and 24 h later, memory was tested by asking patients to complete auditorily presented word stems with the first word that came to mind and to leave out words they remembered having heard earlier (exclusion task). Moreover, patients were requested to perform a "yes/no" forced-choice recognition task to assess recognition memory for both the pre- and intraoperative words. Memory for the material presented during anesthesia was demonstrated immediately after surgery and 24 h later by means of both tasks. In a second similar experiment (n = 80), the results were replicated. These findings show that anesthetized patients can process information that was presented intraoperatively.

Adolescent↗