SEARCH · PubMed Health

Results for “processing speed”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources

PubMed2006

Information processing in patients with intracranial tumours: A preliminary evaluation of the clinical utility of inspection time.

Psychomotor slowing is a common feature in many patients with intracranial tumours. We therefore performed a preliminary study to determine if inspection time, a measure of the efficiency of the brain's information processing, was impaired in patients with intracranial tumours. Inspection time, and some other neuropsychological and functional tests, were compared in 23 people with intracranial tumours and 24 spinal surgery controls prior to surgery. Groups were matched for sex, age and education. Inspection time scores were poorer in the brain tumour group (p < 0.003) and the effect size was moderate (eta2 = 0.197). The brain tumour group also had lower scores on the Boston Aphasia Severity Rating Scale, more anxiety on the Hospital Anxiety Depression Scales, but better Karnovsky Performance scores. Other cognitive and functional tests showed no significant differences between the groups, although group sizes were small. There were no significant changes in inspection time after spinal surgery; however, after intracranial tumour surgery, approximately 30% of patients showed no change, 30% deteriorated and 40% improved. This preliminary study suggests that recording inspection time, in a neuro-oncological setting, may prove informative and practically useful in assessing non-motor processing speed in people with brain tumours.

Brain Neoplasms↗

PubMed2005

Prefrontal lesions and attentional skills in childhood.

Despite the potential impact on development, few studies have examined the influence of prefrontal lesions occurring prior to maturation of the central nervous system. This study investigates the effect of prefrontal lesions in general, as well as the impact of lesion laterality, with respect to attentional abilities. The sample comprised 36 children with prefrontal lesions and 40 healthy controls. Attentional function was assessed across four domains: selective, shifting and divided attention, and processing speed. Group mean performances for children with prefrontal lesions indicated global attentional deficits, with greatest difficulties for "higher-order" skills including shifting and divided attention. Children with left prefrontal lesions performed similarly to controls, with a specific deficit characterized by difficulties with on-line processing of auditory-verbal information. Right prefrontaj lesions were primarily associated with impairments in day-to-day executive functions, including reduced monitoring, poor shifting attention and disinhibition. Children with bilateral prefrontal lesions performed worse than controls on tasks requiring greater cognitive resources. These results provide evidence of the important role played by prefrontal cortex in the development of attentional skills, and the particular role of the right prefrontal cortex. The pattern of attention deficits observed following early prefrontal lesions suggests some lateralization of function within the frontal lobes, even during childhood.

Adolescent↗

PubMed2001

Depression in multiple sclerosis: relationship to planning ability.

Recent research has demonstrated deficits on effortful executive tasks involving planning in multiple sclerosis (MS) patients. Given the high prevalence of depression in MS and the commonly reported link between depression and performance on executive tasks, planning impairments in MS may be associated with depression. We compared the performance of depressed and nondepressed MS patients on a planning task (Tower of London-TOL) to evaluate this hypothesis. Compared with nondepressed MS patients, depressed MS patients made significantly (p < .05) more moves and took more time per trial on the TOL. A follow-up regression analysis was conducted that included the TOL and speeded attentional/working memory task indices found to be associated with depression in MS from the authors' prior reports. This analysis revealed that 25% of the variance in depression scores was predicted by the most sensitive speeded attentional/working memory task. Furthermore, this variance overlapped completely with variance predicted by the TOL-time/trial index. The only clearly nonspeeded task index, TOL-moves per trial, was associated with unique variance (8%) in predicting MS depression scores. These results suggest that slowed information processing speed and, secondarily, deficient nonspeeded central executive skill, may be core to the cognitive deficits characteristic of depressed MS patients.

Adult↗

PubMed1998

Relation of task switching to speed, age, and fluid intelligence.

Two studies were conducted to investigate whether a meaningful task-switching construct could be identified and, if so, to determine how it was related to measures of higher order cognition and to adult age. Both studies revealed that measures of task switching were moderately correlated across different combinations of tasks and that a switching construct could be distinguished from a construct reflecting processing speed. The results of the 2nd study revealed that although the task-switching construct was related to age and to measures of episodic memory, inductive reasoning, and spatial visualization, most of the relations between the switching construct and both age and other measures of cognition were shared with other variables.

Adolescent↗

PubMed2005

Aging and longitudinal change in perceptual-motor skill acquisition in healthy adults.

Knowledge about aging of perceptual-motor skills is based almost exclusively on cross-sectional studies. We examined age-related changes in the retention of mirror-tracing skills in healthy adults who practiced for 3 separate days at baseline and retrained 5 years later at follow-up. Overall, the speed and accuracy of an acquired skill were partially retained after a 5-year interim, although the same asymptote was reached. Analyses with individual learning curves indicated that the effects of age on mirror-tracing speed were greater at longitudinal follow-up than at baseline, with older adults requiring more training to reach asymptote. Thus, although the long-term retention of acquired skills declines with age, older adults still retain the ability to learn the skill. Moreover, those who maintained a processing speed comparable with that of the younger participants evidenced no age-related performance decrements on the mirror-drawing task.

Adult↗

PubMed2004

Transformations in the couplings among intellectual abilities and constituent cognitive processes across the life span.

Two-component theories of intellectual development over the life span postulate that fluid abilities develop earlier during child development and decline earlier during aging than crystallized abilities do, and that fluid abilities support or constrain the acquisition and expression of crystallized abilities. Thus, maturation and senescence compress the structure of intelligence by imposing age-specific constraints upon its constituent processes. Hence, the couplings among different intellectual abilities and cognitive processes are expected to be strong in childhood and old age. Findings from a population-based study of 291 individuals aged 6 to 89 years support these predictions. Furthermore, processing robustness, a frequently overlooked aspect of processing, predicted fluid intelligence beyond processing speed in old age but not in childhood, suggesting that the causes of more compressed functional organization of intelligence differ between maturation and senescence. Research on developmental changes in functional brain circuitry may profit from explicitly recognizing transformations in the organization of intellectual abilities and their underlying cognitive processes across the life span.

Adolescent↗

PubMed2005

Reward-based decision-making and aging.

Healthy aging is associated with a number of neuroanatomical and neurobiological alterations that result in various cognitive changes. Both, the dopaminergic as well as the serotonergic system are subject to change during aging. Receptor loss and severe structural changes in PFC and striatum have been reported. Aging is associated with a progressive decline in several cognitive functions, such as episodic memory, working memory, and processing speed. Furthermore, it is associated with deficits in tasks requiring adaptation to external feedback of right or wrong, or task-switching. Here, we develop the hypothesis that this loss of behavioral flexibility is caused by structural and functional alterations of the reward system leading to impairments in reward processing, learning stimulus reinforcement associations, and reward-based decision-making. We review (a) data on neural correlates and substrates of reward processing in young healthy animals and humans, (b) evidence for age related functional and structural alterations of the reward system, and (c) behavioral and neuroimaging data of age effects on reward-based decision-making processes. Implications for neuroeconomics and neurodegenerative diseases are discussed.

Aging↗

PubMed2006

White matter growth as a mechanism of cognitive development in children.

We examined the functional role of white matter growth in cognitive development. Specifically, we used hierarchical regression analyses to test the unique contributions of age versus white matter integrity in accounting for the development of information processing speed. Diffusion tensor imaging was acquired for 17 children and adolescents (age range 6-17 years), with apparent diffusion coefficient (ADC) and fractional anisotropy (FA) calculated for 10 anatomically defined fiber pathways and 12 regions of hemispheric white matter. Measures of speeded visual-spatial searching, rapid picture naming, reaction time in a sustained attention task, and intelligence were administered. Age-related increases were evident across tasks, as well as for white matter integrity in hemispheric white matter. ADC was related to few measures. FA within multiple hemispheric compartments predicted rapid picture naming and standard error of reaction time in sustained attention, though it did not contribute significantly to the models after controlling for age. Independent of intelligence, visual-spatial searching was related to FA in a number of hemispheric regions. A novel finding was that only right frontal-parietal regions contributed uniquely beyond the effect of age in accounting for performance: age did not contribute to visual-spatial searching when FA within these regions was first included in the models. Considering we found that both FA in right frontal-parietal regions and speed of visual-spatial searching increased with age, our findings are consistent with the growth of regional white matter organization as playing an important role in increased speed of visual searching with age.

Adolescent↗

PubMed2002

Tissue plasminogen activator administration does not result in clinically relevant neuropsychological dysfunction in patients with myocardial ischemia.

BACKGROUND: Recent evidence from animal models has demonstrated that tPA can be neurotoxic to the hippocampus and cerebellum. Since tPA is used in patients with myocardial infarction and has been approved for the treatment of acute ischemic stroke, we carried out a pilot study to investigate whether its administration could result in any clinically relevant neuropsychological dysfunction, with particular attention to those structures most involved in the animal model. PATIENT AND METHODS: Patients with acute myocardial infarction (AMI) who were subjected to thrombolysis with r-tPA and without evidence of prior or concomitant neurological-neuropsychological damage, were eligible. Controls consisted of patients with AMI not candidate for thrombolysis or patients with severe angina admitted to the intensive care unit. A detailed neurological and neuropsychological evaluation was performed, which included mood, visual and verbal memory, psychomotor speed processing and motor dexterity and visuomotor sequence learning. RESULTS: Ten patients and 13 controls were included. No significant differences between both groups were found, although all the subjects performed in the lower limits of the normal range on the Purdue pegboard test (motor dexterity) and digit-symbol test (psychomotor speed). There was no evidence of depression, as assessed by the Hamilton scale, that could have interfered with performance. Declarative memory (Rey auditory-verbal learning test) as well as visual memory (Rey-Osterrieth figure copy) and visuomotor sequence learning (serial reaction time task) were normal, without between-group differences. CONCLUSIONS: tPA administration at the usual doses did not result in detectable neuropsychological abnormalities in patients with myocardial ischemia.

Adult↗

PubMed2006

Construct validity of the Bender-Gestalt II: comparison with Wechsler Intelligence Scale for Children-III.

This study investigated the relationships of visuomotor constructs as measured by the Bender-Gestalt II with the subtests of the WISC-III. A factor analysis included the standardized Copy and Recall scores of the Bender-Gestalt II and subtest scores of the WISC-III. The Copy score was predicted to load on measures of visual and spatial thinking and the Recall score on a short-term memory factor. The results of a principal components analysis suggest a four-factor solution with the Bender-Gestalt II Copy score loading on a visual and spatial thinking factor primarily with WISC-III Perceptual Organization subtests. The Recall score loaded on a visual and spatial thinking factor as well as a short-term memory factor with the WISC-III Digit Span subtest. The results suggest the Bender-Gestalt II Copy subtest shared commonality with the visual and spatial tasks given the similarity in the visuomotor demands of each test and was less influenced by processing speed or cultural knowledge than other tests on the visual and spatial thinking factor. Also, results suggest Bender-Gestalt II Recall measures elements of both visual and spatial thinking as well as aspects of short-term memory and memory retrieval. Clinical guidelines for co-administration and underlying processing demands are discussed.

Adolescent↗

PubMed2004

The relation of hydration status to cognitive performance in healthy older adults.

Little is known about the relation of hydration status to cognitive performance in older adults, who may be more vulnerable to poor hydration and cognitive impairment. We examined whether hydration status was related to cognitive functioning in 28 healthy community-dwelling older adults. Hierarchical regression models demonstrated that lower hydration status was related to slowed psychomotor processing speed and poorer attention/memory performance, after controlling for demographic variables and blood pressure.

Aged↗

PubMed2005

Odor identification and decline in different cognitive domains in old age.

The authors examined the association of odor identification with rate of decline in different cognitive systems. Participants are 481 older persons from the Rush Memory and Aging Project. At baseline, the Brief Smell Identification Test was administered. At annual intervals for up to 3 years, a battery of 19 cognitive tests was administered from which previously established composite measures of 5 cognitive domains were derived. In mixed-effects models adjusted for age, sex, and education, lower odor identification score was associated with lower function at baseline in each cognitive domain. Lower score was also associated with more rapid decline in perceptual speed (estimate=0.015, SE=0.006, p=0.013) and episodic memory (estimate=0.012, SE=0.006, p=0.030) but not with rate of decline in semantic memory, working memory, or visuospatial ability. Thus, on average, a person with a low odor identification score (6, 10th percentile) declined more than twice as rapidly in perceptual speed and episodic memory as a person with a high score (11, 90th percentile). Results were unchanged in subsequent analyses that controlled for cigarette smoking or clinically diagnosed stroke. The results indicate that impaired odor identification in old age is associated with impaired global cognition and more rapid decline in perceptual processing speed and episodic memory.

Aged↗

PubMed2005

Ligase detection reaction/hybridization assays using three-dimensional microfluidic networks for the detection of low-abundant DNA point mutations.

We have fabricated a flow-through biochip assembly that consisted of two different microchips: (1) a polycarbonate (PC) chip for performing an allele-specific ligation detection reaction (LDR) and (2) a poly(methyl methacrylate) (PMMA) chip for the detection of the LDR products using an universal array platform. The operation of the device was demonstrated by detecting low-abundant DNA mutations in gene fragments (K-ras) that carry point mutations with high diagnostic value for colorectal cancers. The PC microchip was used for the LDR in a continuous-flow format, in which two primers (discriminating primer that carried the complement base to the mutation being interrogated and a common primer) that flanked the point mutation and were ligated only when the particular mutation was present in the genomic DNA. The miniaturized reactor architecture allowed enhanced reaction speed due to its high surface-to-volume ratio and efficient thermal management capabilities. A PMMA chip was employed as the microarray device, where zip code sequences (24-mers), which were complementary to sequences present on the target, were microprinted into fluidic channels embossed into the PMMA substrate. Microfluidic addressing of the array reduced the hybridization time significantly through enhanced mass transport to the surface-tethered zip code probes. The two microchips were assembled as a single integrated unit with a novel interconnect concept to produce the flow-through microfluidic biochip. A microgasket, fabricated from an elastomer poly(dimethylsiloxane) with a total volume of the interconnecting assembly of <200 nL, was used as the interconnect between the two chips to produce the three-dimensional microfluidic network. We successfully demonstrated the ability to detect one mutant DNA in 100 normal sequences with the biochip assembly. The LDR/hybridization assay using the assembly performed the entire assay at a relatively fast processing speed: 6.5 min for on-chip LDR, 10 min for washing, and 2.6 min for fluorescence scanning (total processing time 19.1 min) and could screen multiple mutations simultaneously.

Base Sequence↗

PubMedDate not supplied

[Aging effects on lexical access. The tip-of-the-tongue phenomenon on proper names].

INTRODUCTION: The tip-of-the-tongue (TOT) phenomenon is one of the most frequent complaints in aging, especially with reference to the proper names retrieval. Previous experimental studies focussed on comparing extreme age groups and they used strategic search paradigms that impede the processing knowledge. AIMS: To analyze TOT frequency and resolution in the normal process of aging. SUBJECTS AND METHODS: 140 participants aged from 19 to 82 performed an experiment of production of famous people' names from their definitions, and 36 participants aged from 20 to 80 performed other similar experiment from pictures. Data were analyzed using a linear general model with vocabulary level and processing speed as covariables. RESULTS: Adults aged from 50 produced more TOTs than young adults and the TOTs' increase was higher in adults from 70 years independently of their vocabulary level. Older adults resolved fewer TOTs than young adults but phonological priming improved TOTs resolution. CONCLUSION: Aging weakens activation in the proper names retrieval process but phonological priming increases the activation and improves lexical access.

Acoustic Stimulation↗

PubMed1998

An automated hydrodynamic process for controlled, unbiased DNA shearing.

An automated, inexpensive, easy-to-use, and reproducible technique for controlled, random DNA fragmentation has been developed. The technique is based on point-sink hydrodynamics that result when a DNA sample is forced through a small hole by a syringe pump. Commercially available components are used to reduce the cost and complexity of the instrument. The design is optimized to reduce the volume of sample required and to speed processing time. Shearing of the samples can be completely automated by computer control. Ninety percent of sheared DNA fragments fall within a twofold size distribution that is highly reproducible. Three parameters are critical: the flow geometry, the flow rate, and a minimum number of iterations. Shearing is reproducible over a wide range of temperatures, DNA concentrations, and initial DNA size. The cloning efficiency of the sheared DNA is very good even without end repair, the distribution of assembled sequences is random, and there is no sequence bias at the ends of sheared fragments that have been cloned. The instrument, called the Point-sink Shearer (PtS), has already been exported successfully to many other laboratories.

Automation↗

PubMed1999

Processing lexically embedded spoken words.

A large number of multisyllabic words contain syllables that are themselves words. Previous research using cross-modal priming and word-spotting tasks suggests that embedded words may be activated when the carrier word is heard. To determine the effects of an embedded word on processing of the larger word, processing times for matched pairs of bisyllabic words were examined to contrast the effects of the presence or absence of embedded words in both 1st- and 2nd-syllable positions. Results from auditory lexical decision and single-word shadowing demonstrate that the presence of an embedded word in the 1st-syllable position speeds processing times for the carrier word. The presence of an embedded word in the 2nd syllable has no demonstrable effect.

Adult↗

PubMed2003

Sensorimotor slowing with ageing is mediated by a functional dysregulation of motor-generation processes: evidence from high-resolution event-related potentials.

The objective of the present study was to identify the origin(s) of ageing-related behavioural slowing in sensorimotor tasks. For this aim, event-related potentials (ERPs) were analysed at 64 electrodes to evaluate the strength and timing of different stages of information processing in the brain. Electrophysiological indices of stimulus processing, sensorimotor integration/response selection and motor-related processing were used to compare the processing speed of young (n = 13, mean age = 22.5 years) and older adults (n = 14, mean age = 58.3 years) in simple- and choice-reaction tasks presented in two modalities, auditory and visual. The behavioural results showed significant ageing-related slowing, but only in the choice-reaction task. The quantification of separate central processing stages, in combination with advanced ERP methodology, helped to reveal that this slowing did not originate from the early processes of stimulus processing and response selection. Instead, it was produced by slower activation patterns over the contralateral motor cortex underlying response generation. It is concluded that ageing is accompanied by a functional dysregulation of motor cortex excitability during sensorimotor processing, with this deficit becoming progressively evident with greater task complexity.

Acoustic Stimulation↗

PubMed1992

Cognitive impairment following closed head injury.

Cognitive impairments are usually the most disabling sequelae of CHI. The earliest stage of recovery from moderate to severe closed head injury is a period of PTA that typically includes memory loss for events preceding and surrounding the injury and memory loss for events occurring since the injury. Following resolution of PTA, deficits may be present in a number of cognitive domains. Memory and attention/information processing speed and efficiency are typically the cognitive domains most severely affected by head injury. Intellectual, language, and perceptual skills tend to be relatively preserved. Neurologic variables such as pupillary reactivity and worst GCS score are prognostic of cognitive impairment at 1 to 2 years postinjury. Following mild head injury, impairments of memory and information processing may be apparent within the first week of recovery. These deficits usually resolve in 1 to 3 months, although chronic complaints persist in a minority of individuals. The long-term cognitive effects of CHI are typically more severe for younger children than older children. Neuropsychologic assessment provides an objective way to measure the presence and severity of cognitive impairment.

Adult↗