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 829 records · Page 46Linked to original sources
PubMed2002

On optimality in auditory information processing.

We study limits for the detection and estimation of weak sinusoidal signals in the primary part of the mammalian auditory system using a stochastic Fitzhugh-Nagumo model and an action-recovery model for synaptic depression. Our overall model covers the chain from a hair cell to a point just after the synaptic connection with a cell in the cochlear nucleus. The information processing performance of the system is evaluated using so-called phi-divergences from statistics that quantify "dissimilarity" between probability measures and are intimately related to a number of fundamental limits in statistics and information theory (IT). We show that there exists a set of parameters that can optimize several important phi-divergences simultaneously and that this set corresponds to a constant quiescent firing rate (QFR) of the spiral ganglion neuron. The optimal value of the QFR is frequency dependent but is essentially independent of the amplitude of the signal (for small amplitudes). Consequently, optimal processing according to several standard IT criteria can be accomplished for this model if and only if the parameters are "tuned" to values that correspond to one and the same QFR. This offers a new explanation for the QFR and can provide new insight into the role played by several other parameters of the peripheral auditory system.

Animals↗
PubMed1995

Event-related potentials and information processing in infants with and without Down syndrome.

Event-related brain potentials (ERPs) were recorded from 6-month-old infants with and without Down syndrome presented with a visual recognition memory task. The ERP morphology was the same for both groups. The chronometry of information processing by infants with Down syndrome was similar to or faster than that of the infants without Down syndrome, depending on ERP component. The amplitude differences between groups may implicate frontal attentional processes in Down syndrome as opposed to more posterior processes. Infants with Down syndrome had an amplitude decrement in Nc over the central but not frontal cortex. The infants with Down syndrome also had similar visual fixation. Infants may have more subtle differences than those found in older individuals with Down syndrome.

Arousal↗
PubMed1991

Parallel Visual Information Processing Test. An experimental assessment of alexithymia.

A novel clinical and experimental situation has been created, based on the psychopathological concepts of 'pensée opératoire' and alexithymia and the contribution of recent trends in cognitive science as to the dual skills of the brain hemispheres: the Parallel Visual Information Processing Test. This test was validated in more than 100 subjects, and revealed that holistic visual attention is reduced during logical task performance; this impairment appeared to be typical of patients with poor fantasizing ability and operative behavior. Such findings are consistent with some authors' theory according to which there is a functional commissurotomy in alexithymic and psychosomatic patients.

Adolescent↗
PubMed1992

Influences of witnessed affect on information processing in children.

Children between the ages of 5 and 10 years watched a videotape of a child having a routine medical exam. Embedded within the scenes were systematic variations of depicted facial affect shown by doctor and child. Measures were taken of autonomic reactions and information-processing errors in response to positive, neutral, and negative affective cues. For 5-6-year-olds, processing errors were greatest in the negative affect condition. Additionally, peak increases in heart rate (HR) and skin conductance level (SCL) were demonstrated by 5-6-year-olds in response to negative affect shown by the witnessed child; increases in HR were in turn predictive of processing errors. Older children (9-10 years) showed trends reflecting reduced processing errors in response to witnessed negative affect. It was suggested that younger children respond to salient threat cues with a "defensive" response pattern that is relatively adaptive at younger but not older ages.

Affect↗
PubMed2006

Neuropsychologic functioning in children with autism: further evidence for disordered complex information-processing.

A wide range of abilities was assessed in 56 high-functioning children with autism and 56 age- and IQ-matched controls. Stepwise discriminant analyses produced good group discrimination for sensory-perceptual, motor, complex language, and complex memory domains but lower agreement for the reasoning domain than previously obtained for adults. Group discrimination did not occur for attention, simple language, simple memory, and visuospatial domains. Findings provide additional support for a complex information-processing model for autism, previously based on adult data, demonstrating a pattern across domains of selective impairments on measures with high demands for integration of information and sparing when demands were low. Children as compared to adults with autism exhibited more prominent sensory-perceptual symptoms and less pronounced reasoning deficits reflecting brain maturation.

Adolescent↗
PubMed2000

The chronometry of single neuron activity: testing discrete and continuous models of information processing.

The authors propose to study information transmission by comparing the effects of experimental factors on reaction time (RT) with the latency of the changes in activity of single-neurons. An experiment was conducted in which a monkey (Macaca mulatta) performed a tactilo-manual 2-choice RT task and the compatibility of the stimulus-response mapping was manipulated. Task-related neurons were recorded in the monkey's primary somesthetic and motor cortices. The changes in activity of 105 of these neurons were classified either as sensory-like or as motor-like. The sensory-like changes occurred before the motor-like ones. The stimulus-response mapping exerted its entire effect on the RT after the sensory-like changes and before the motor-like ones. These findings suggest that the information was transmitted discretely from the processes affected by the mapping to the processes implemented by the motor-like changes.

Animals↗
PubMedDate not supplied

Temporal limitations of information processing in global and local attention: the effect of information content.

PURPOSE: The refractory period during which detection or identification of a probe is degraded, following the successful visual identification of a target, is referred to as the attentional blink (AB). Previous work in this laboratory using global/local letter forms has shown that the degree of complexity of information influences the length of time between successful visual identifications, as does the attentional modality required of the subject. In the standard rapid serial visual presentation (RSVP) task, a gap following the first target is reported to destroy the AB. The current study examines the effect on the AB duration of inserting a gap in the stream of local orthographic information while not interrupting the stream of global information. It was hypothesized that masking of the local elements of the item immediately following the target (the +1 item) would lead to a decreased AB duration for local identification. METHODS: Twenty-one adult participants, experienced in the experimental paradigm, viewed sequences of compound letter stimuli and were required to identify a global or local red letter (target) and detect the presence of a global or local X (probe) in the sequence following. RESULTS: In one-half of the trials the local letter identity of the +1 global/local form was obscured, leaving only a global form. Neither the attentional condition nor local +1 masking significantly influenced the slope of recovery from the AB. Furthermore, no difference was observed in the AB duration for global or local probe detection between control and crystallized trials. CONCLUSIONS: The results suggest that the visual image of the item is accepted nto VSTM and processed for target candidature.

Adult↗
PubMed1984

Event-related potential concomitants of information processing dysfunction in schizophrenic children.

ERPs were recorded from 10 schizophrenic and 13 normal children during the performance of the Span of Apprehension task (Span). This task involves the discrimination of a randomly placed target letter among distractors, and it has been shown to discriminate between normal and schizophrenic individuals. The EEG was recorded at 7 scalp loci, and ERPs were averaged over a 1500 msec interval initiated by a warning tone which preceded the visual Span stimuli by 500 msec. Stimulus arrays were grouped into 4 levels of difficulty. The data from both subject groups were combined in a single principal components analysis (separate PCAs exhibited few differences between groups) generating 8 rotated factors which were readily interpreted in terms of conventional ERP components. Factor scores for the two groups were examined using Analysis of Variance. The schizophrenic children produced a small CNV which was slow to develop and resolve as well as diminished amplitudes for the N1, P3 and slow wave components. This suggests that these children are impaired in their ability to regulate processes involved in the mobilization and direction of attention and the discrimination of target stimuli. Significantly, the schizophrenic children did not show progressive increases in N1 and SW amplitudes in response to increases in information processing demand (array difficulty) as was the case in the normal children. ERP components of the schizophrenic children were most aberrant at frontal leads, but midline and lateralized deficits were also seen at vertex and posterior recording sites.

Adolescent↗
PubMed1977

Reading disability: an information-processing analysis.

In a task designed to separate perceptual processes from memory, 12-year-old children with reading disabilities showed no perceptual deficits as compared to their peers. However, they exhibited major deficiencies in memory skills for both labelable and nonlabelable visual information. Reading-disabled children in this age group appear to suffer from a basic information-processing deficiency.

Child↗
PubMed1985

Schizotaxia, information processing and the MMPI 2-7-8 code type.

The relationship between the 2-7-8 MMPI code type and schizotaxia was investigated. College students whose Minnesota Multiphasic Personality Inventory profiles revealed a 2-7-8 code were compared to an elevation-free group on a visual information-processing task. The 2-7-8 group exhibited a processing deficiency similar to that previously found for schizophrenics and in-patient schizotypal personalities, supporting the construct validity of the 2-7-8 code as a measure of schizotaxia.

Female↗
PubMed2004

Relationship between information processing speed in temporal lobe epilepsy and white matter volume.

Abnormalities in white matter have been linked to processing speed impairment in clinical populations (e.g., multiple sclerosis, closed head injury). Recent studies indicate the presence of significant reduction in cerebral white matter volume in some patients with chronic temporal lobe epilepsy (TLE). The objective of this study was to examine the relationship between white matter volume and processing speed and performance efficiency on the Sternberg Memory Scanning Test (SMST). The study groups included TLE subjects with white matter volume reduction (n=13), TLE subjects with normal white matter volume (n=14), and healthy controls (n=18). The groups did not differ in total cerebral gray matter volume. Compared with the controls, the reduced white matter volume TLE group exhibited a significantly steeper slope on the SMST. This was characterized by a disproportionate increase in reaction time with increased processing demands (set size), particularly for negative probe trials. In contrast, no significant differences on the SMST were evident between controls and the normal white matter volume TLE group. These findings suggest the presence of information processing speed and efficiency impairment in TLE and its relationship with white matter volume integrity.

Adolescent↗
PubMed1991

Terminal chaos for information processing in neurodynamics.

New nonlinear phenomenon-terminal chaos caused by failure of the Lipschitz condition at equilibrium points of dynamical systems is introduced. It is shown that terminal chaos has a well organized probabilistic structure which can be predicted and controlled. This gives an opportunity to exploit this phenomenon for information processing. It appears that chaotic states of neurons activity are associated with higher level of cognitive processes such as generalization and abstraction.

Animals↗
PubMed2005

Accessory stimulation in the time course of visuomotor information processing: stimulus intensity effects on reaction time and response force.

A series of three visual choice-reaction time experiments were performed to systematically investigate the effects of accessory auditory stimulation on response time (RT) and response force (RF). In Experiment 1, the effect of accessory auditory stimulation on early visual information processing was investigated. Experiments 2 and 3 were designed to examine the effects of accessory intensity on RT and RF across the entire time course of sensorimotor processing. Accessory stimulation accelerated response speed only when presented within 100 ms after onset of the visual response signal. An enhancing effect of accessory stimulation on RF, however, was found as late as 220 ms after onset of the response signal. These findings support the notion that response speed and response dynamics represent functionally independent sensorimotor phenomena.

Female↗
PubMed2003

Stochastic cascade processes as a model of multi-stage concurrent information processing.

McClelland's (Psychol. Rev. 86 (1979) 287) influential cascade model of reaction time (RT) is often seen as an important explicitly formulated alternative to strictly serial models because some of its basic notions fit in with known characteristics of neural activation processes. A disadvantage is that it is an essentially deterministic model to which noise is added by across-trials parameter variability that is unrelated to the concept of cascaded activation propagation per se. We propose and analyze a general stochastic cascade model based on neural counting processes; within this framework we present a new process-oriented interpretation of McClelland's cascade activation equation. We then theoretically explain and numerically explore conditions under which the stochastic cascade model predicts additive vs. interactive mean RT effects, and compare them to known properties of McClelland's model. Some of these properties remain valid even within a stochastic neural counting formulation, while others reflect assumptions which are essentially unrelated to the concept of cascaded activation.

Brain↗
PubMed2006

Dual-task information processing in schizotypal personality disorder: evidence of impaired processing capacity.

Working memory theories heavily rely on the concept of processing resources and the their efficient deployment. Some recent work with schizophrenia-spectrum patients has suggested that many associated cognitive impairments may be reduced to deficits in working memory, possibly related to reductions in information-processing capacity resources. In this study, 38 patients with schizotypal personality disorder (SPD), 22 patients with other personality disorders, and 14 healthy comparison participants performed a dual-task processing assessment that was designed specifically for use in this type of study. Participants recalled lists of digits at their predetermined maximum digit span and performed box-checking tests, first alone and then in a dual-task format. Instructions included equal prioritization of both tasks. SPD patients had significantly shorter digit spans, and they also showed more deterioration on both tasks. Performance operating characteristics curves indicated that SPD patients' reduced performance was not due to abnormal resource allocation strategies leading to strategic failures. The authors discuss the implications of these processing capacity limitations for understanding both the signature of cognitive impairment within the schizophrenia spectrum and general abnormalities in working memory.

Adult↗
PubMed2006

Lack of acknowledgment of fruit and vegetable recommendations among nonadherent individuals: associations with information processing and cancer cognitions.

Inadequate consumption of fruits and vegetables is regarded as an important behavioral risk factor for multiple types of cancer. Nevertheless, adherence with the National Cancer Institute (NCI) guidelines to eat between five and nine servings of fruits and vegetables per day is remarkably low. The current study explored the extent to which nonadherent respondents in a national survey (N = 5,625) listed fruit and vegetable consumption as a method by which to decrease their own or others' cancer risk. We sought to determine whether respondents who listed fruit and vegetable consumption as a method by which to decrease their own or others' cancer risk (hereafter referred to as "listers") differed from respondents who did not list fruit and vegetable consumption as a method by which to decrease their own or others' cancer risk (hereafter referred to as) "nonlisters" on measures of information processing and cancer cognitions. Nonlisters were more likely than listers to seek out cancer information but less likely to trust the information. The two groups did not differ in the amount of attention they paid to such information. Listers had lower absolute risk perceptions than nonlisters, but listers and nonlisters did not differ on measures of relative breast and colon cancer risk perceptions and worry for cancer in general. Female listers did perceive themselves to be at less relative risk for breast cancer than nonlisters. Respondents were more likely to list fruit and vegetable consumption as a cancer-risk reduction strategy for others than for themselves, suggesting a "double standard" in their beliefs. These findings suggest that communications designed to promote fruit and vegetable consumption need to account for biases in how nonadherent individuals respond to these communications.

Cognition↗
PubMed2003

Robust quantum information processing with techniques from liquid-state NMR.

While nuclear-magnetic-resonance (NMR) techniques are unlikely to lead to a large-scale quantum computer, they are well suited to investigating basic phenomena and developing new techniques. Indeed, it is likely that many existing NMR techniques will find uses in quantum information processing. Here I describe how the composite-rotation (composite-pulse) method can be used to develop quantum logic gates which are robust against systematic errors.

Journal Article↗