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 253 records · Page 14Linked to original sources

PubMed2005

Stability and predictability of the classification of mild cognitive impairment as assessed by episodic memory test performance over time.

This study aimed to address the criteria and the stability of the classification of MCI. The Foresight Challenge cohort of 157 community-dwelling volunteers was assessed on 3 visits at 2-year intervals with episodic, semantic and working memory tests. Subjective memory complaints were assessed with the CAMDEX. Of the cohort, 2% had dementia and 31% were classified with MCI at visit 3, 43% with stable impairment from Time 1. Thirteen percent of those with objective memory impairment at Time 1 or 2 improved to control status by Time 3. Episodic memory tests were predictive for MCI at all timepoints, as were tests for praxis and Graded Naming, while at Time 3 spatial span lost predictive value, but processing speed became predictive. Decline in processing speed was seen in control and MCI groups, while memory performance and MMSE decline occurred only in the MCI group. The use of combined memory test scores gave better sensitivity to MCI than single tests. Subjective memory complaints were positive for 79% of the MCI group and 62.5% of controls. These findings would suggest consideration of modification of current MCI criteria.

Aged↗

PubMed2006

Visual attention capacity after right hemisphere lesions.

Recently there has been a growing interest in visual short-term memory (VSTM) including the neural basis of the function. Processing speed, another main aspect of visual attention capacity, has received less investigation. For both cognitive functions human lesion studies are sparse. We used a whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared statistically to lesion location and size measured by MRI. Visual processing speed was impaired in the contralesional hemifield for most patients, but typically preserved ipsilesionally, even after large cortico-subcortical lesions. When bilateral deficits in processing speed occurred, they were related to damage in the right middle frontal gyrus or leukoaraiosis. The storage capacity of VSTM was also normal for most patients, but deficits were found after severe leukoaraiosis or large strokes extending deep into white matter. Thus, the study demonstrated the importance of white-matter connectivity for both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention.

Adult↗

PubMed2006

Smoking and cognitive change from age 11 to 66 years: a confirmatory investigation.

Previously we reported that smoking is associated with a small relative decline in cognition from childhood to old age. In this study we perform confirmatory analyses on a further wave of data collected from 298 of the participants, all with age 11 IQ scores, at age 66years, 2years after the original observations. Non-smokers scored a mean 4.9 memory test and 2.6 information processing speed test points and ex-smokers 3.5 memory test and 1.9 information processing speed test points higher than current smokers respectively over the two waves of testing, equivalent to 4-8% of mean test scores, adjusted for the effects of childhood IQ. Across tests a 100l/min higher Peak Expiratory Flow Rate was associated with a 3-4% higher test score at ages 64 and 66years. These data confirm the adverse effect of smoking on information processing speed, and provide new evidence for a similar adverse effect on memory for people in their mid-sixties.

Aged↗

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↗

PubMed2004

Impairments of attention following treatment with cranial irradiation and chemotherapy in children.

Neurobehavioral impairments are frequently reported following treatment for childhood cancers, with cranial irradiation (CRT). This study investigated attention and information processing skills, predicting that these skills would be impaired due to the vulnerability of cerebral white matter in early childhood. Three treatment groups were studied: (i) CRT+chemotherapy (n = 35); (ii) chemotherapy alone (n = 19); (iii) healthy children (n = 35). All children were aged 9 to 16 years at time of assessment, with no pre-diagnosis history of neurologic, developmental, or psychiatric disorder. Children were administered a series of task measuring processing speed and sustained, selective, and shifting attention. For children treated with CRT + chemo, results identified residual deficits in processing speed for complex tasks, selective and shifting attention. In contrast, processing speed was intact for simple tasks, and there was no clear evidence of deterioration in performance over time, as might be expected in the presence of a sustained attention deficit. Children treated with chemotherapy alone demonstrated generally intact attentional skills. However, this group did record an increasing number of attentional lapses over time on tasks tapping sustained attention skills.

Adolescent↗

PubMed1999

[Fast visual categorization and speed of processing in migraine].

It has been suggested that the visual cortex of migraine sufferers is hypersensitive. To test this hypothesis, we compared the speed of visual processing in eight migraine patients (including three with aura) and nine controls performing two categorisation tasks of different complexity. In the complex task developed by Thorpe et al. (1996), subjects had to detect the presence of animals in briefly presented photographs (20 ms). The speed of visual processing was measured by the latency of the differential cerebral activity that appears around 150 ms between target and non-target trials. In the simple task, subjects performed a square/circle categorisation. All subjects were faster (445 ms/497 ms) with a higher rate of success (97%/91%) in the simple task. But in both tasks, the behavioural performance and the associated evoked potentials did not show any difference suggesting a cortical hypersensitivity in migraine sufferers.

Adolescent↗

PubMed1997

Predicting episodic memory performance of very old men and women: contributions from age, depression, activity, cognitive ability, and speed.

Regression models were developed to explain age-related and total variance in memory and to determine the independent contribution from general processing speed, having taken into account cognitive and noncognitive individual differences. Episodic memory was assessed for 3 tasks in a population-based sample of 951 adults comprising 515 men and 436 women (aged 70-96, M = 77.6, SD = 5.5). Correlations between age and memory accounted for 6%-9% of the variance. Hierarchical multiple regressions showed a reduction in this age-related variance by up to 94%, after entering gender, depression, health, cognitive status, activities, and speed. General processing speed was the major mediator of age-related variance in memory. Although both the age-related variance and the speed-related variance in memory were significantly reduced by prior entry of other individual differences variables for all 3 tasks, speed remained a significant mediator of remembering, and negligible differences in the residual age-related variance were observed by inclusion of other background variables.

Activities of Daily Living↗

PubMed2003

Speed of processing of the visual-orthographic and auditory-phonological systems in adult dyslexics: the contribution of "asynchrony" to word recognition deficits.

This study investigated whether "asynchrony" in speed of processing (SOP) between the visual-orthographic and auditory-phonological modalities contributes to word recognition deficits among adult dyslexics. Male university students with a history of diagnosed dyslexia were compared to age-matched normal readers on a variety of experimental measures while event-related potentials and reaction time data were collected. Measures were designed to evaluate auditory and visual processing for non-linguistic (tones and shapes) and linguistic (phonemes and graphemes) low-level stimuli as well as higher-level orthographic and phonological processing (in a lexical decision task). Data indicated that adult dyslexic readers had significantly slower reaction times and longer P300 latencies than control readers in most of the experimental tasks and delayed P200 latencies for the lexical decision task. Moreover, adult dyslexics revealed a systematic SOP gap in P300 latency between the auditory/phonological and visual/orthographic processing measures. Our data support and extend previous work that found SOP asynchrony to be an underlying factor of childhood dyslexia. The present data suggests, however, that among adult dyslexics the between modalities asynchrony occurs at later processing stages than in children.

Adult↗

PubMed2003

Infant visual recognition memory: independent contributions of speed and attention.

Relations between infant visual recognition memory and later cognition have fueled interest in identifying the underlying cognitive components of this important infant ability. The present large-scale study examined three promising factors in this regard--processing speed, short-term memory capacity, and attention. Two of these factors, attention and processing speed (but, surprisingly, not short-term memory capacity), were related to visual recognition memory: Infants who showed better attention (shorter looks and more shifts) and faster processing had better recognition memory. The contributions of attention and processing speed were independent of one another and were similar at all ages studied--5, 7, and 12 months. Taken together, attention and speed accounted for 6%-9% of the variance in visual recognition memory, leaving a considerable, but not unexpected, portion of the variance unexplained.

Attention↗

PubMed2005

Speed, speed variability, and accuracy of information processing in 5 to 6-year-old children at risk of ADHD.

The early assessment of Attention-Deficit/Hyperactivity Disorder (ADHD) children has mainly focused on the behavioral, social, and pre-academic impairments. This study examined whether 5 to 6-year-old children at risk of ADHD are characterized by information-processing deficits. By screening 1317 children in Southern Limburg (the Netherlands) with the Child Behavior Checklist, 363 were selected and underwent a computerized examination. Eighteen months later, standardized psychiatric information was obtained. Thirty-three ADHD children were compared with 75 borderline ADHD children, 122 pathological controls, and 133 healthy controls. ADHD and borderline ADHD children were slower and more variable in their processing speed on all tasks than children with no or other pathology. These differences were most pronounced for the divided and focused attention tasks. Furthermore, one measure of a state regulation deficit discriminated between groups. With regard to accuracy, only the proportion of misses on a go-no-go task was higher in the ADHD group than in the other groups. Evidence was found that ADHD is better seen as a continuum rather than a discrete category. Already at a young age, children at risk of ADHD show specific information-processing deficits. Deficits in time perception and/or energetic state control in children with ADHD may possibly account for subnormal task performance.

Attention↗

PubMed2005

Cortical volume and speed-of-processing are complementary in prediction of performance intelligence.

The rationale for the present study was to investigate the relationship between cortical volume, the latency of the ERP component P3a (as a measure of speed-of-processing), and performance intelligence (not adjusted for age differences). Seventy-one participants aged 20-88 years underwent a visual 3-stimuli oddball ERP task, an MRI-scan, and intelligence testing. P3a latency and cortical volume shared 9% variance (p<.05) and both were significantly related to performance intelligence (R2=.26 and .40, respectively). The amount of explained variance increased significantly (to R2=.51) when both measures were used as simultaneous predictors. When a path diagram was constructed including age as an exogenous variable, P3a latency and cortical volume both significantly predicted performance intelligence, but were no longer related to one another. The main conclusion from the study is that speed and size are complementary in prediction of performance intelligence, and the theoretical implications are discussed.

Adult↗

PubMed2006

Cognitive impairment and decline in different MS subtypes.

This paper presents results of two studies conducted to investigate cognition in different MS subtypes. First, the results of a study that has previously been published will be discussed. This was a cross-sectional study with 108 relapsing-remitting (RR), 71 secondary progressive (SP), 55 primary progressive (PP) MS patients, and 67 healthy controls [S.C.J. Huijbregts, N.F. Kalkers, L.M.J. de Sonneville, V. de Groot, I.E.W. Reuling, C.H. Polman, Differences in cognitive impairment of relapsing-remitting, secondary and primary progressive MS. Neurology 63 (2004) 335-339]. The second study involved a follow-up assessment after 2 years and included 30 SPMS patients, 25 PPMS patients, and 33 controls. The Brief Repeatable Battery of Neuropsychological Tests (BRB-N) was used for all cognitive assessments. All patient groups demonstrated cognitive deficits compared to healthy controls. RRMS patients were less affected compared to patients with progressive MS subtypes on the Paced Auditory Serial Addition Task (PASAT) and the Symbol Digit Modalities Test (SDMT). These differences were attenuated after control for physical disability level as measured by the Expanded Disability Status Scale. RRMS and SPMS patients were more severely impaired than PPMS patients on the 10/36 Spatial Recall Task and Word List Generation. Results of the follow-up study indicated that both progressive MS subtypes showed a lack of improvement compared to controls on the PASAT and the SDMT, but not on the other tasks of the BRB-N, indicating that performance on tasks requiring multiple abilities concurrently, i.e. visuo-spatial ability and processing speed (SDMT) or working memory and processing speed (PASAT), is most likely to decline across time.

Auditory Perception↗

PubMed2004

Performance discrepancies on the California Verbal Learning Test-Children's Version (CVLT-C) in children with traumatic brain injury.

One hundred sixty-seven children with traumatic brain injury (TBI), selected from an 8-year series of consecutive referrals to a Midwestern rehabilitation hospital, completed the California Verbal Learning Test-Children's Version (CVLT-C) and the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) within 1 year after injury. A large proactive interference (PI) effect, defined as performance on the second list that was at least 1.5 standard deviations below that on the 1st one, was statistically significantly more common in this clinical sample (21%) than in the CVLT-C standardization sample (11%). Other performance discrepancies, including retroactive interference, rapid forgetting, and retrieval problems, occurred at approximately the same rate in the clinical and standardization samples. Children with anterior cerebral lesions were about 3 times less likely to have a large PI effect than children without such lesions, but the former group performed worse on the first CVLT-C list. The impact of pediatric TBI on a wide range of CVLT-C quantitative variables was mediated by speed of information processing, as assessed by the WISC-III Processing Speed factor index. It is concluded that failure to release from PI is somewhat common, although certainly not universal, in children with TBI. Unlike with adults, anterior cerebral lesions are not associated selectively with an increased risk for PI after pediatric TBI but rather with a reduced efficiency of allocation of cognitive resources. Deficits in speed of information processing appear to be primarily responsible for the learning deficits on the CVLT-C after pediatric TBI.

Adolescent↗

PubMed1986

The effects of stimulant drugs on information processing in elderly adults.

The effects of stimulant drug on information processing in elderly adults was studied. In Experiment 1, the effect of methylphenidate (MP) was examined in 8 young and 8 elderly women using a task (SERS) in which stimulus and response complexities were varied. MP speeded processing in the young but not in the elderly women. A second experiment was then conducted to isolate the age-stimulant effects. In Experiment 2, the effects of MP and 10 mg of d-amphetamine (DAMP) were studied in 12 young and 12 elderly men on different types of information processing. Stimulants changed performance on a continuous performance task in both groups. Both stimulants speeded processing on SERS in young, but not in elderly men. MP, however, speeded processing in both groups on a response processing task. The findings suggest that stimulants act on response processing and there appear to be several such processes. Some of these stages decline with age whereas others do not.

Adult↗

PubMed1985

Speed of processing in normal aging: effects of speech rate, linguistic structure, and processing time.

Young and elderly adults heard three types of speech materials varying in both length and degree of semantic and syntactic constraints. Time compression was used to vary speech rates systematically to test a speed of processing hypothesis as one explanation of performance deficits associated with normal aging. In addition to segment length effects, the elderly participants showed significantly steeper rates of performance decline with increasing speech rate, with slope constants dependent on the structural constraints of the speech materials. The results are discussed in terms of processing rate hypotheses and context utilization.

Adolescent↗

PubMed2001

A limit to the speed of processing in ultra-rapid visual categorization of novel natural scenes.

The processing required to decide whether a briefly flashed natural scene contains an animal can be achieved in 150 msec (Thorpe, Fize, & Marlot, 1996). Here we report that extensive training with a subset of photographs over a 3-week period failed to increase the speed of the processing underlying such Rapid Visual Categorizations: Completely novel scenes could be categorized just as fast as highly familiar ones. Such data imply that the visual system processes new stimuli at a speed and with a number of stages that cannot be compressed. This rapid processing mode was seen with a wide range of visual complex images, challenging the idea that short reaction times can only be seen with simple visual stimuli and implying that highly automatic feed-forward mechanisms underlie a far greater proportion of the sophisticated image analysis needed for everyday vision than is generally assumed.

Adult↗

PubMed2002

Diagnostic utility of attention measures in postconcussion syndrome.

Neuropsychological evaluation may be of particular relevance in the detection of subtle cognitive impairments after mild traumatic brain injury (MTBI), including the subgroup of MTBI patients with a persistent postconcussion syndrome (PCS). Attention measures may be the most sensitive indicators of dysfunction associated with MTBI; however, previous studies have typically relied on the analysis of overall group differences, which may not reflect the diagnostic accuracy of attention measures when applied to individuals with MTBI. In the present study, subjects with persistent symptoms at least 3 months following a mild traumatic brain injury were compared with a sample of community living, normal control subjects in order to evaluate the sensitivity, specificity, and diagnostic accuracy of attention measures. Patients with PCS, screened with conservative inclusion and exclusion criteria, and a matched normal control group were administered six clinical tests of attention: Digit Span, Trail Making Test, Part A and Part B, Stroop Color-Word Test, Continuous Performance Test of Attention (CPTA), Paced Auditory Serial Addition Test (PASAT), and Ruff 2 & 7 Selective Attention Test. Consistent with prior research, these measures exhibited a wide range of sensitivity and specificity to possible cognitive impairment among patients. Attention measures may be the most sensitive indicators of dysfunction associated with PCS. Measures with high specificity (e.g., Stroop Color, and 2 & 7 Processing Speed) were shown to have strong positive predictive value, while measures with high sensitivity (e.g., CPTA) demonstrated strong negative predictive value for diagnosing PCS. Examination of the Odds Ratios indicated that measures assessing processing speed had a reliable, positive association with PCS, while measures without a processing speed component did not. Implications for making informed clinical decisions are discussed.

Acoustic Stimulation↗

PubMed2000

High "intelligence," low "IQ"? Speed of processing and measured IQ in children with autism.

The uneven profile of performance on standard assessments of intelligence and the high incidence of savant skills have prompted interest in the nature of intelligence in autism. The present paper reports the first group study of speed of processing in children with autism (IQ 1 SD below average) using an inspection time task. The children with autism showed inspection times as fast as an age-matched group of young normally developing children (IQ 1 SD above average). They were also significantly faster than mentally handicapped children without autism of the same age, even when these groups were pairwise matched on Wechsler IQ. To the extent that IT tasks tap individual differences in basic processing efficiency, children with autism in this study appear to have preserved information processing capacity despite poor measured IQ. These findings have implications for the role of general and specific cognitive systems in knowledge and skill acquisition: far from showing that children with autism are unimpaired, we suggest that our data may demonstrate the vital role of social insight in the development of manifest "intelligence."

Adolescent↗