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At least 487 records · Page 27Linked to original sources
PubMed2002

Age-related changes in the visual cortex.

The ability to accurately perceive the speed of moving objects is one of many visual functions that decline with age. One factor that may contribute to this is a deterioration in temporal processing speed. At present, there is a dearth of information concerning how this may occur in the central nervous system, particularly in the visual cortex. Thus, in the present study, we investigated the neural basis of speed and temporal processing in areas 17 and 18 of visual cortex in young and aged rats using either a moving bar of light or a series of flashing lights. Our results showed that the mean preferred speed of a moving bar of light was significantly reduced in aged as compared to young animals. We also found that cells recorded from young animals were able to entrain to a higher frequency of flashing light stimuli than those recorded from aged animals. In addition, we found no age-related differences between cortical fields. These results suggest an age-related difference in temporal processing speed at the level of visual cortex.

Aging↗
PubMedDate not supplied

Brief report: speed of information processing in children with insulin-dependent diabetes mellitus.

OBJECTIVE: To determine whether children with insulin-dependent diabetes mellitus (IDDM) process information more slowly than children who do not have diabetes. METHODS: We tested 31 children with early onset and longer duration of IDDM, 35 with later onset and briefer duration of IDDM, and 36 comparison children without diabetes. They were administered five tasks requiring rapid responding that assessed a range of cognitive processes. RESULTS: On most tasks, children in the three groups were quite similar in the accuracy and speed of performance. Furthermore, for children in the diabetic groups, disease-related variables were unrelated to accuracy and speed of performance. CONCLUSIONS: The results suggest that children with IDDM do not have a pervasive deficit in speed of information processing, although more circumscribed deficits in processing speed are possible.

Adolescent↗
PubMed1996

Performance differences as a function of stimulus-response compatibility with rapid serial visual presentation and spatially distributed presentation styles.

A means of presenting information temporally has been developed from the basic research on reading. Temporal displays allowed for faster processing speeds by reducing the number of saccades normally required to process spatially distributed information; however, a potential disadvantage to using temporal displays was an increased rate of error. Payne and Lang reported that a tradeoff between speed and accuracy is sometimes the result of using temporally distributed displays. As they used an alphabetic coding scheme which may not have facilitated the most optimal stimulus-response mapping, the current experiment tested the effects of a directional coding scheme on a temporally distributed display with 24 subjects. Analysis indicated the coding scheme did improve processing speed on the temporal display, but the error rate for the temporal display was higher than with the alphabetic coding scheme. Therefore, the limitation of temporal displays in a tradeoff between speed and accuracy persisted using the directional coding scheme.

Adult↗
PubMed1999

Speed of information processing as a key deficit in multiple sclerosis: implications for rehabilitation.

Speed of information processing was assessed in patients with multiple sclerosis and healthy controls using both an auditory and visual task designed to control for accuracy of performance across groups. After controlling for accuracy of performance, patients with multiple sclerosis were found to have significantly slower speed of information processing relative healthy controls, irrespective of the modality of stimulus presentation (auditory or visual). When given an adequate amount of time to process information, however, the patients performed similarly to controls. These results suggest that persons with multiple sclerosis experience deficits specifically in processing speed but not performance accuracy. Results are discussed in terms of rehabilitative guidelines for the cognitive improvement of persons with multiple sclerosis.

Adult↗
PubMed1990

Cognition in early human immunodeficiency virus infection.

Relatively little is known about cognitive changes in early human immunodeficiency virus (HIV) infection. This study examined cognitive functioning in 46 HIV-positive gay men relative to an age and education equivalent group of 13 HIV-negative gay men. The HIV-positive men were asymptomatic except for lymphadenopathy or T4 counts less than 700. The cognitive battery measured language, memory, visuospatial, information processing speeds, reasoning, attention, and psychomotor processes. The HIV-positive group was significantly slower in processing information and performed significantly less well than the HIV-negative group on certain verbal memory measures. Deviations of 1 as well as 2 SDs from the norm/control group mean on four or more tests were observed in 43% and 22% of the HIV-positive subjects, respectively, compared with 8% and none of the HIV-negative subjects, respectively. The results suggest that cognitive inefficiency occurs in a subsample of individuals during early HIV infection.

Adult↗
PubMed2004

Emotion recognition deficits in the elderly.

In two studies, healthy elderly adults were poor at recognizing certain emotions. In study one, an emotion face morphed to express a new emotion. The elderly were impaired when recognizing anger and sadness, whereas no differences were found between the two age groups in recognizing fear or happiness, or in a task requiring reasoning about non=emotion stimuli. In study two, the elderly were impaired when judging which of two faces was more angry, sad, or fearful, but they were not impaired when judging other emotions or when judging which of two beakers was more full. The elderly were also impaired when matching emotion sounds to angry, sad, and disgusted faces, but not to other emotions and not when matching non-emotion (e.g., machine) sounds to machines. Elderly deficits were independent of performance on a task requiring basic face processing (gender recognition). Overall, the results provide support for an age-related decline in the recognition of some emotions that is independent of changes in perceptual abilities, processing speed, fluid IQ, basic face processing abilities, and reasoning about non face stimuli. Recognition of emotion stimuli might be mediated by regions of the brain that are independent from those associated with a more general cognitive decline.

Adult↗
PubMed2006

Premorbid neurocognitive functioning in schizophrenia spectrum disorder.

A prospective study based on the U.S. National Collaborative Perinatal Project and using the Wechsler Intelligence Scale for Children (WISC) found lower test scores for the Coding subtest in preschizophrenic children than in their unaffected siblings. Using data on cognitive functioning in adolescence, the aim of the present prospective study was to examine whether low scores on Coding is associated with the risk of developing schizophrenia spectrum disorders. The 12 subtests of the WISC were administered to 311 children and adolescents with a mean age of 15.1 years (range: 8 to 20 years), and the diagnostic assessment (DSM-IIIR) was conducted by senior clinicians 25 years later. The group with schizophrenia spectrum disorder consisted of 84 individuals, and this group obtained significantly lower scores on Coding than nonschizophrenic controls. This difference could not be explained by differences in WISC IQ. Logistic regression analysis controlling for age at examination, gender, and social status yielded a significant, but relatively weak, association between low Coding test score and risk of schizophrenia spectrum disorder. For each unit increase in the Coding raw score, the adjusted odds ratio was 0.97 (95% CI 0.94-1.00) (p = .022), and the risk of schizophrenia spectrum disorder decreased by 3% (95% CI 6 to 0%). The Coding deficit on the WISC may indicate deficits in perceptual motor speed or in working memory processing speed in young individuals who later develop schizophrenia, schizotypal personality disorder, or other disorders within the schizophrenia spectrum.

Adolescent↗
PubMed2006

The effects of mild and severe traumatic brain injury on speed of information processing as measured by the computerized tests of information processing (CTIP).

In spite of the fact that reaction time (RT) measures are sensitive to the effects of traumatic brain injury (TBI), few RT procedures have been developed for use in standard clinical evaluations. The computerized test of information processing (CTIP) [Tombaugh, T. N., & Rees, L. (2000). Manual for the computerized tests of information processing (CTIP). Ottawa, Ont.: Carleton University] was designed to measure the degree to which TBI decreases the speed at which information is processed. The CTIP consists of three computerized programs that progressively increase the amount of information that is processed. Results of the current study demonstrated that RT increased as the difficulty of the CTIP tests increased (known as the complexity effect), and as severity of injury increased (from mild to severe TBI). The current study also demonstrated the importance of selecting a non-biased measure of variability. Overall, findings suggest that the CTIP is an easy to administer and sensitive measure of information processing speed.

Adolescent↗
PubMed1993

Speed and knowledge as determinants of adult age differences in verbal tasks.

Two studies were conducted to determine the relative importance of processing speed and knowledge as predictors of performance in simple verbal tasks within samples of young and old adults. Eight different criterion tasks were investigated, and performance on each was found to be significantly related both to speed of processing and to quantity of word knowledge. It was also discovered that although young adults were faster than old adults and that old adults were equal or superior to young adults in relevant knowledge, the same regression equations could be used to predict criterion performance in both groups. These results therefore suggest that any age-related compensation that exists in these tasks is rather weak, in the sense that speed and knowledge appear to have the same importance in young and old adults, and only the average levels of the predictors differ as a function of age.

Adult↗
PubMed1998

[A multimedia echocardiographic archive].

The widespread diffusion of echocardiography requires to rationalize clinical examination archives; the recent improvement in computer processing speed and the addition of image processing capabilities on standard personal computer by using multimedia technology provide a low-cost solution to improve video digital acquisition and base management. Furthermore, the diffusion of computer networks supports the possibility of sending images in digital format from a work station to another. In this study we describe the setting-up of a system for echocardiographic image acquisition, storage, base management and analysis based on a standard multimedia Macintosh personal computer using readily available not-dedicated software. We tested the overall efficiency of this system in terms of time required to perform hardware and software procedures, storage capacity of the archive and possibility to exchange information with other wire-linked computer work-stations or via modem. This system has proven to require an acceptable time to perform all the procedures showing a high level of connectivity with other standard personal computer work-stations; however, some limitations with regard to time required in sending via modem long movie files need to be pointed out. In conclusion, in our experience new multimedia personal computer could offer to every physician with a minimum informatic knowledge the well known advantages of digital-video, at a reasonable cost.

Archives↗