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PubMedDate not supplied

Vision, visual-information processing, and academic performance among seventh-grade schoolchildren: a more significant relationship than we thought?

OBJECTIVE: To compare visual and visual-information processing skills between children with and without mild reading and academic problems and examine the incidence of visual deficits among them. METHOD: Seventy-one seventh graders classified as proficient (n = 46) and nonproficient (n = 25) readers were compared with respect to scores on an accepted vision screening, on tests of visual-perception, visual-motor integration, and academic performance. Further, academic performance and visual-information processing were compared between children who failed and passed the vision screening. RESULTS: Visual deficits were found in 68% of the participants, and among significantly more boys than girls. Nonproficient readers had significantly poorer academic performance and vision-screening scores than the proficient readers. Participants who passed the visual screening performed significantly better in visual perception than those who failed. CONCLUSION: Visual function significantly distinguishes between children with and without mild academic problems, as well as on visual-perception scores. The high occurrence of visual deficits among participants warrants consideration of vision deficits among schoolchildren with academic performance difficulties.

Achievement↗
PubMedDate not supplied

Emotional information processing in first and recurrent major depressive episodes.

Depressive states are classically associated to increased sensitivity to negative events. However this hypersensitivity may not be stable in time, being absent in remission periods or further reinforced with recurrent depressive episodes, or may concern positive stimuli instead, e.g. in young depressive patients. To study the evolution of the processing of emotional information in depression we recorded late components of evoked potentials in first-episode and recurrent depressed patients before and after recovery. We used a visual attentional paradigm manipulating the processing of emotional information. Subjects first counted words with positive valence, and then words with negative valence from lists of usual words. The results showed that recurrent patients had increased P300 amplitudes for negative words selection only in negative words counting situation, while first-episode patients had decreased P300 amplitudes for positive words selection. After clinical improvement, the negative biases in recurrent patients group disappeared but P300 amplitudes of first-episode patients remained significantly low for positive words. First-episode depressed patients show a selective impairment for positive stimuli, with decreased response to pleasant stimuli, while recurrent depressive subjects show signs of hyperesthesia for negative stimuli. These results suggest that responses to emotional stimuli in word processing are related to the duration of the mood disorders.

Adult↗
PubMed2005

Stimulus-response compatibility and response preparation: effects on motor component of information processing for upper and lower limb responses.

The effects of stimulus-response compatibility and response preparation on the motor component of the information processing system were investigated by analyzing the fractionated reaction time for the upper and lower limbs. The reaction time was divided into two periods with respect to the onset of electromyographic activity, premotor and motor times. The response preparation was manipulated by the probability that the locations of the precue and subsequent imperative stimulus corresponded. On a stimulus-response compatible task, subjects were required to release a key on the same side as an imperative stimulus, irrespective of the precued side. On an incompatible task, subjects were required to act in the reverse manner. The upper and lower limb responses were measured during both tasks. A repeated-measures design was used with 12 male university students. Analysis of the reaction and premotor times indicated that the stimulus-response compatibility effect became larger as response preparation decreased. The analysis of motor time yielded significant interactions between stimulus-response compatibility and limb and between response preparation and limb. These findings indicated that the motor component of information processing for the lower limb response is affected by both stimulus-response compatibility and response preparation.

Adolescent↗
PubMed1991

[Paradoxical sleep and information processing: exploration by inversion of the visual field].

The purpose of this study was to test the potential relationship between REM sleep and information processing with inversion of the visual field. In the first experiment, four male subjects slept in the laboratory for two sessions of 6 consecutive nights: 2 adaptation nights, 2 nights of polysomnography, and 2 nights of dream collection. During the days preceding Nights 3, 4, 5, and 6 of each session, the subjects wore glasses which, during the second session, completely inverted (rotation of 180 degrees) their visual field. In a second experiment with four other male subjects, the order of conditions was reversed, and the experimental condition (visual inversion) was introduced a second time. When the data of the two experiments were combined, there was a significant (p less than .01) increase in the percentage of REM sleep from Nights 3 and 4 of the control condition to Nights 3 and 4 of the visual inversion condition, but there was no significant change in any of the other sleep stages. There was a significant decrease in horizontal (p less than .04) and vertical (p less than .005) REM density and in the density of vertical REM bursts (p less than .02). The increase in REM sleep supports the hypothesis that REM sleep contributes to information processing while the decrease in REM density suggests that this component of REM sleep may be involved in a homeostatic process of sensory input.

Adaptation, Physiological↗
PubMed2001

Information processing in dendrites I. Input pattern generalisation.

In this paper and its companion, we address the question as to whether there are any general principles underlying information processing in the dendritic trees of biological neurons. In order to address this question, we make two assumptions. First, the key architectural feature of dendrites responsible for many of their information processing abilities is the existence of independent sub-units performing local non-linear processing. Second, any general functional principles operate at a level of abstraction in which neurons are modelled by Boolean functions. To accommodate these assumptions, we therefore define a Boolean model neuron-the multi-cube unit (MCU)-which instantiates the notion of the discrete functional sub-unit. We then use this model unit to explore two aspects of neural functionality: generalisation (in this paper) and processing complexity (in its companion). Generalisation is dealt with from a geometric viewpoint and is quantified using a new metric-the set of order parameters. These parameters are computed for threshold logic units (TLUs), a class of random Boolean functions, and MCUs. Our interpretation of the order parameters is consistent with our knowledge of generalisation in TLUs and with the lack of generalisation in randomly chosen functions. Crucially, the order parameters for MCUs imply that these functions possess a range of generalisation behaviour. We argue that this supports the general thesis that dendrites facilitate input pattern generalisation despite any local non-linear processing within functionally isolated sub-units.

Action Potentials↗
PubMed1999

Cognitive reactivity and depressotypic information processing in children of depressed mothers.

Although high-risk research suggests that children of depressed mothers are at increased risk for psychological disorders, the mechanisms of this risk are not well understood. In the current study, the information processing of children of depressed mothers was compared with that of children whose mothers were not depressed. Half of each group received a priming induction designed to activate cognitive schemas prior to assessment. All children then completed a self-referent processing task that examined the recall of negative and positive information. Results indicate that when primed, at-risk children showed a less positive self-concept and more negative information processing than did the children in the other groups. These data may offer potential clues into the mechanisms of cognitive vulnerability in at-risk children.

Adult↗
PubMed1984

[Changes in the volume of acquired and processed information of students with regard to age].

Some aspects of the functional state of the higher nervous system and capacity for work are analyzed in the present paper, by work that is fixed in volume and duration. The capacity visual-motor analyzer, the speed, quality and accuracy of the processed information were more precisely established in 161 students from grades 9, 10 and 11, trained at 19 Unified Secondary Polytechnical School, Sofia. The table of Hartridge was used for that purpose. The results as a whole reveal a reduced volume of the acquired information as well as the accuracy of the processed information after the classes in the age groups studied, with no essential discrepancies in the indices discussed.

Adolescent↗
PubMed1997

Combining time and intensity effects in assessing operator information-processing load.

A quantitative description of the human information processor is required for predicting operator workload and performance from the simulated task time line data generated by task network models and related methods. Although many models of workload exist, few appear to be well founded in theory or to provide a satisfactory basis for a quantitative representation of operator load. Adherents of both time- and intensity-based models of operator load individually claim success for their methods, which might suggest that both factors are operating in determining operator workload and performance. This paper describes a study that explicitly investigates the relationship between a time-based factor and an intensity-based factor (amount of information to be processed) within a simulated air traffic control environment. A model is developed that posits that the load on the human information-processing system results directly from the ratio of the time necessary to process the required information to the time allowable for making a decision. This ratio, which can be identified with time pressure, determines subjective estimates of workload as well as operator performance. The model is tested against the data from the air traffic control simulation.

Adult↗
PubMed1984

Speed of information-processing and structural limitations by mentally retarded and dual-diagnosed retarded-schizophrenic persons.

Three experiments were conducted in an investigation of information-processing capabilities of mentally retarded adults, nonretarded children (mental age control), and nonretarded adults (chronological age control). In all experiments, one of two target stimuli was presented to the center and to the right or left of central fixation. Subjects were required to detect the presence of a stimulus in a yes-no forced-choice paradigm (Experiment 1), identify which of the two targets had been presented in a forced-choice discrimination paradigm (Experiment 2), or distinguish between the targets in a forced-choice discrimination task when the target was preceded by, presented stimultaneously with, or followed by a patterned noninformational masking stimulus. The findings support the theory of a structural defect in mentally retarded persons that results in slow information-processing.

Adult↗
PubMed2006

Emotional information processing in mood disorders: a review of behavioral and neuroimaging findings.

PURPOSE OF REVIEW: A relatively long history of research has shown that mood disorders are associated with abnormalities in the processing of emotional stimuli. Only the most recent studies, however, have begun to elucidate the specificity and neural basis of these abnormalities. This article reviews and discusses the results of these studies. RECENT FINDINGS: Individuals diagnosed with major depressive disorder exhibit an attentional bias toward negative emotional cues (e.g. sad faces), an attentional bias away from positive emotional cues (e.g. happy faces), and an enhanced memory for negative emotional material. Compared with healthy controls, individuals with major depressive disorder show increased neural activity in response to sad faces and diminished neural activity in response to happy faces in emotion-related brain circuits (e.g. amygdala and ventral striatum). Some of these abnormalities in the processing of emotional information persist after symptom remission and they have also been found in healthy individuals who are at heightened risk for the development of mood disorders. SUMMARY: The reviewed data show that major depressive disorder involves specific abnormalities in the cognitive and neural processing of emotional information and that these abnormalities may potentially contribute to the vulnerability for negative emotion and onset of depressive episodes.

Affect↗
PubMed2004

Accelerated age-related decline of visual information processing in first-degree relatives of persons with schizophrenia.

A recent cross-sectional study suggested that persons with schizophrenia experience an accelerated age-related decline in performance on the Span of Apprehension task, a visual information processing paradigm. However, this study was not able to determine if such decline was primarily related to genetic loading for schizophrenia, as the decline may have been related to chronic neuroleptic use or other confounds found when studying persons with schizophrenia directly. To help address this question, the current study examined healthy first-degree relatives of persons with schizophrenia over a wide age range to investigate whether such age effects may be related to genetic loading for schizophrenia. Twenty-eight healthy first-degree relatives of persons with schizophrenia (ages 21-72) and 31 healthy controls (ages 19-75) were evaluated using the Span of Apprehension task with cross-sectional methodology. Results replicated and extended the earlier report examining persons with schizophrenia, as the data indicated a statistically significant accelerated age-related decline in performance in the relatives. While the study is limited by cross-sectional methodology, it suggests a genetically driven, age-related decline in visual information processing related to schizophrenia and informs future longitudinal studies that can more definitively address such a possibility.

Adult↗
PubMed1993

Prenatal alcohol exposure and infant information processing ability.

403 black, inner-city infants born to women recruited prenatally on the basis of their alcohol consumption during pregnancy were assessed on a battery focusing on information processing and complexity of play. Prenatal alcohol exposure was not related to visual recognition memory or cross-modal transfer of information but was associated with longer fixation duration, a measure indicative of slower, less efficient information processing; lower scores on elicited play; and longer periods of toy exploration, possibly also due to slower cognitive processing. The effects on processing speed and elicited play were dose-dependent and not attributable to maternal depression, parental intellectual stimulation, other prenatal drug exposure, or postpartum maternal drinking. The processing speed deficit is consistent with deficits in older children prenatally exposed to alcohol; the present study is the first to identify slower cognitive processing in infancy and in tasks not dependent on motoric proficiency.

Adolescent↗
PubMed2003

Visual information processing under time pressure in high and low level soccer players.

The present study investigated differences in information processing rate of high and low level soccer players under three time-pressure conditions: High (0.5 sec.), Medium (1 sec.), and Low (2 sec.). No significant difference was found under Low time pressure, but under Medium time pressure the higher skilled group processed more visual information than the lower skilled group (p<.05).

Adult↗
PubMed2005

Complementary roles for the amygdala and hippocampus during different phases of appetitive information processing.

Evidence collected from rodent models of memory storage suggests that rapid forms of learning engage the involvement of multiple brain regions each of which may participate in a different component of information processing. The present study used temporary inactivation of the amygdala and hippocampus during different phases of information processing on a one-trial appetitive-conditioning task to examine how these two regions might participate in the storage of appetitive memories. Male Long Evans rats were chronically implanted into the amygdala or dorsal hippocampus and food deprived. Rats were trained on a radial maze conditioned cue preference task where training occurred in one 40-min session and testing took place 24 h later. The amygdala or hippocampus was inactivated separately with muscimol (50 ng/microl) injected immediately before or after training, or immediately before testing. Saline-injected rats displayed a conditioned preference by spending more time in the arm that previously contained food than in the arm that did not contain food. Muscimol injected into the amygdala before training or testing blocked the conditioned preference. Muscimol injected into the hippocampus immediately after training blocked the conditioned preference. These results suggest that the processing of memories may require multiple contributions from separate brain systems for at least short-term (24 h) storage. The resulting output from each system may converge on a similar downstream target to influence behavior.

Amygdala↗
PubMed2001

Spike timing, synchronization and information processing on the sensory side of the central nervous system.

To what extent is the variability of the neuronal responses compatible with the use of spike timing for sensory information processing by the central nervous system? In reviewing the state of the art of this question, I first analyze the characteristics of this variability with its three elements: synaptic noise, impact of ongoing activity and possible fluctuations in evoked responses. I then review the recent literature on the various sensory modalities: somato-sensory, olfactory, gustatory and visual and auditory processing. I emphasize that the conditions in which precise timing, at the millisecond level, is usually obtained, are conditions that usually require dynamic stimulation or sharp changes in the stimuli. By contrast, situations in which stimulation not belonging to the temporal domain is temporally encoded lead to much coarser temporal coding; although in both cases, neural networks transmit the signals with similarly high precision. Synchronization among neurons is an important tool in information processing in both cases but again seems to act either at millisecond or tens of millisecond levels. Information theory applied to both situations confirms that the average rate of information transmission is much higher in dynamic than in static situations. These facts suggest that channels of precise temporal encoding may exist in the brain but imply populations of neurons working in a yet to be discovered way.

Animals↗
PubMed2003

Kuffler's inhibitory surround, the function of the inner plexiform layer and an information processing unit in the retina. Neural interaction at the nanometer level.

Comparing Kuffler's recordings of ganglion cell discharges and bipolar cell responses to the same stimuli, deduced on the basis of a knowledge of synaptic connections between the neurons, revealed that the bipolar cell signals had not been modified by synaptic interaction in the inner plexiform layer. This layer therefore receives bipolar cell signals generated by groups of bipolar cells within the center of ganglion cell receptive fields, sorts and distributes the signals to a (compared to the number of photoreceptors and bipolar cells), small number of ganglion cells in such a way that the retinal image can be reconstructed in the visual center by reversing the fusion. Transmission between photoreceptor and bipolar cell is controlled by an information processing circuit receiving information from one photoreceptor, from the large horizontal cell network, formed by synaptic connections between the large horizontal cell processes, from cone networks formed by the cone processes connecting cones and from one small horizontal cell. Interaction between input neurons shapes the input to the bipolar cell. The interaction establishes a gate like control of transmission at the bipolar cell synapse and maintains bipolar cell threshold at a constant level, two features that prevent noise in the output signal. The output is generated by simultaneous input from all input neurons at the bipolar cell synapse, a multiinput synapse. Bipolar cell response is therefore based on perfect timing of fusion of information and of the neural interaction preceding fusion. Proper timing is secured by the dimensions of the components of the circuit measuring in the nanometer range. The volume of the information processing circuit is only 0.3 cubic micrometer, which is less than one two hundredth the volume of the soma of a bipolar cell. Extension of the study of the nervous system to the nanometer level opens a new field of research by making it possible to analyze how information contributed by the sense organs is processed in the nervous system to regulate body functions.

Animals↗
PubMed1997

Information processing through the first year of life: a longitudinal study using the visual expectation paradigm.

This Monograph uses a developmental function approach to describe age-related change and individual differences in infant information processing during the first year of life. The Visual Expectation Paradigm (VExP) is used to measure speed of information processing, response variability, and expectancy formation. Eye-movement reaction times and anticipatory saccades were gathered from 13 infants assessed monthly from 2 to 9 months and then again at 12 months. Analysis of response patterns demonstrated the applicability of the paradigm throughout the age range studied. Converging operations strongly indicate that the traditional estimate of the minimum time required for infants to initiate a saccade to a peripheral stimulus may be as much as 100 milliseconds (ms) too long. Moreover, the newly estimated minimum of 133 ms does not appear to change during the 2-12-month period. Reanalysis of the present data and past research reveals that the new, shorter minimum reaction time is unlikely to affect findings based on mean reaction time. However, using the traditional minimum reaction time will inflate estimates of percentage anticipation, especially in infants older than 5 months. Group and individual growth curves are described through quantitative models of four variables: reaction time, standard deviation of reaction time, percentage anticipation, and anticipation latency. Developmental change in reaction time was best described by an asymptotic exponential function, and evidence for a local asymptote during infancy is presented. Variability in reaction time was found to decline with age, independent of mean reaction time, and was best described by a polynomial function with linear and quadratic terms. Anticipation showed little lawful change during any portion of the age span, but latency to anticipate declined linearly throughout the first year. Stability of individual differences was strong between consecutive assessments of mean reaction time. For nonconsecutive assessments, stability was found only for the 6-12-month period. Month-to-month stability was inconsistent for reaction-time variability and weak for both anticipation measures. Analyses of individual differences in growth curves were carried out using random regressions for the polynomial models. The only significant individual difference (in growth curves) was found for reaction-time variability. Parameter estimates from the exponential models for reaction time suggested two or three developmental patterns with different exponential trajectories. This finding indicates that the strong form of the exponential growth hypothesis, which states that processing speed develops at the same rate for all individuals, does not hold for the first year of life. In the concluding chapter, Grice's Variable Criterion Model (Grice, 1968) is used to integrate three key findings: regular age changes in mean reaction time and variability but no age change in the minimum reaction time. It is argued that the rate of growth of sensory-detection information is developmentally constant during much of the first year but that age changes occur in the level and spread of the distribution of response threshold values. The unique strengths of the paradigm are discussed, and future directions are suggested for further developing the paradigm itself and for using it as a tool to study broad issues in infant cognition.

Eye Movements↗
PubMed2000

Modulation of induced gamma band activity in the human EEG by attention and visual information processing.

Here we present a series of four studies aimed to investigate the link between induced gamma band activity in the human EEG and visual information processing. We demonstrated and validated the modulation of spectral gamma band power by spatial selective visual attention. When subjects attended to a certain stimulus, spectral power was increased as compared to when the same stimulus was ignored. In addition, we showed a shift in spectral gamma band power increase to the contralateral hemisphere when subjects shifted their attention to one visual hemifield. The following study investigated induced gamma band activity and the perception of a Gestalt. Ambiguous rotating figures were used to operationalize the law of good figure (gute Gestalt). We found increased gamma band power at posterior electrode sites when subjects perceived an object. In the last experiment we demonstrated a differential hemispheric gamma band activation when subjects were confronted with emotional pictures. Results of the present experiments in combination with other studies presented in this volume are supportive for the notion that induced gamma band activity in the human EEG is closely related to visual information processing and attentional perceptual mechanisms.

Attention↗