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Results for “Processing Speed”

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PubMed1997

Memory and speed: their role in the relation of infant information processing to later IQ.

This study examined the extent to which memory and processing speed accounted for relations we had found earlier between infant information processing and childhood IQ. The measures of speed and memory were obtained when the children were 11 years of age using paper-and-pencil tasks and an extensive battery of computer-administered tasks. The relations of 7 months visual recognition memory and 1 year cross-modal transfer to 11 year IQ were both substantially reduced with statistical control of factors derived from these measures. These results suggest that speed and memory underlie some of the infant-childhood continuities in cognition. Path and structural equation modeling indicated that the significant pathways from 7 month visual recognition memory to 11 year IQ were both direct and indirect, the indirect paths going through memory and speed.

Age Factors↗

PubMed2003

Effects of age and speed of processing on rCBF correlates of syntactic processing in sentence comprehension.

Positron emission tomography (PET) was used to determine the effect of age on regional cerebral blood flow (rCBF) during syntactic processing in sentence comprehension. PET activity associated with making plausibility judgments about syntactically more complex subject object (SO) sentences (e.g., The juice that the child spilled stained the rug) was compared to that associated with making judgments about synonymous syntactically simpler object subject (OS) sentences (e.g., The child spilled the juice that stained the rug). In the first study, 13 elderly (70-80-year-old) subjects showed increased rCBF in the left inferior parietal lobe. This result contrasted with previous studies, which have shown activation in Broca's area in this task in young subjects. Elderly subjects were noted to have longer reaction times than young subjects previously tested. A second study found that young subjects whose reaction times were as long as those of the elderly subjects tested in Experiment 1 activated left superior parietal, and not left inferior frontal, structures. A third experiment found that elderly subjects with reaction times as fast as previously tested young subjects activated left inferior frontal structures. The results suggest that the speed of syntactic processing, but not age per se is related to the neural location where one aspect of syntactic processing is carried out.

Adult↗

PubMed1991

Temporal segmentation of response speed in depression: neuro-electrophysiological approaches.

1. Depressive psychomotor retardation, as observed by delayed reaction times (RT), may be related to a slowing in information processing speed. 2. Two separate studies compared indices of information processing speed in depressed patients and non-clinical controls by segmenting behavioral RT with brain event-related potentials (ERPs) and electromyographic (EMG) responses. 3. In Study I, slower behavioral RTs in depression were concomitant with slower central processing times (CPT) but not motor execution times (MET). 4. In Study II, P165, a putative early cognitive ERP related to 'stimulus evaluation time', was found to be slower but within normal range in depressed patients.

Acoustic Stimulation↗

PubMed1991

High-speed memory scanning in Parkinson's disease: adverse effects of levodopa.

High-speed memory scanning as assessed by the Sternberg paradigm was studied in 12 nondemented patients with fluctuating Parkinson's disease and 13 age-matched healthy controls. Patients were first assessed before taking their morning dose of levodopa ("off") and again after that dose had produced full clinical effect ("on") after that dose had produced full clinical effect ("on"). Although motor components of the measured choice reaction time were slower in patients when off than in control subjects, memory scanning speed was not different. After levodopa (on), patients' motor time normalized, but cognitive processing speed became significantly slower when compared with previous performance in the off condition and with controls. Contrary to previous concepts of bradyphrenia in patients with Parkinson's disease, these results indicate that dopaminergic stimulation can reduce cognitive processing speed.

Frontal Lobe↗

PubMed1988

Slowed information processing in multiple sclerosis.

Sixteen patients with a definitive diagnosis of multiple sclerosis (MS) and an equal number of matched controls were administered tests of memory and information processing speed. Results indicated a significant long-term verbal memory impairment in patients with MS, with spared short-term memory and memory scanning. Speed of information processing was evaluated with the Paced Auditory Serial Addition Test. The results for the two highest rates of presentation revealed significantly impaired processing in the MS group. Performance at the higher rates and retrieval of information from long-term memory were significantly correlated. These results suggest that slowed information processing is a deficit that contributes to long-term memory impairment in patients with MS.

Adult↗

PubMed1995

Decline in working memory associated with HIV infection. HNRC Group.

HIV infection has been associated with decline in a number of cognitive functions that are components of 'working memory'. Thus, tests of working memory that require the interaction of these components may be particularly sensitive to cognitive dysfunction that arises from HIV infection. To assess this possibility, working memory was examined in 147 HIV-seropositive (HIV+) and 38 HIV-seronegative (HIV-) males using the Reading Span Test and the Digit Span subtest from the Wechsler Memory Scale-Revised (WMS-R). Speed of information processing, a component of some working memory tasks, was assessed with a version of the Sternberg Memory Scanning task. Results indicated that symptomatic HIV+ subjects were impaired relative to HIV- control subjects on the Reading Span and Digit Span tests. Asymptomatic and mildly symptomatic HIV+ groups exhibited a trend toward impairment on these tests, and on the whole, a greater proportion of HIV+ subjects than HIV- subjects were impaired. The groups did not differ significantly in information processing speed. These results indicate that deficits in working memory are apparent in at least a subset of HIV-infected individuals. These deficits are most apparent in symptomatic HIV+ individuals, but the decline may begin during the asymptomatic phase of infection.

Adult↗

PubMed2000

Attentional function in secondary school students receiving isoniazid prophylaxis for tuberculosis infection.

Reports have suggested that isoniazid treatment may be associated with poor concentration and subtle reduction in memory. This study examines attentional function and processing speed in a group of 25 adolescents who received isoniazid prophylaxis for at least 6 months. As adolescents often face major educational assessment milestones, such cognitive side effects may have important implications. Participants were assessed before treatment, 1 month into treatment and at least 1 week after treatment cessation. Measures included the Paced Auditory Serial Addition Test and subtests of the appropriate Wechsler scale sensitive to attention and speed of information processing. Isoniazid does not appear to cause significant adverse effects on attentional function in adolescents.

Adolescent↗

PubMed1988

Evaluation of a remedial programme for attentional deficits following closed-head injury.

Although the frequency and implications of disorders of attention in head-injured subjects have been recognised in recent years, there have been few carefully controlled attempts to evaluate remedial interventions. The present study employed a multiple baseline across subjects design to evaluate a computer-mediated programme for the remediation of deficits in speed of information processing in 10 severely head-injured subjects, aged 17-38 years. Following a baseline period, the effectiveness of computer training alone was compared with that combined with therapist feedback and reinforcement in separate training phases, each lasting 3 weeks. The final phase involved a return to baseline conditions. Dependent measures of attention, taken across all phases, included psychometric measures of processing speed, a rating scale completed by the patient's Occupational Therapist, and a video of the patient working in therapy. Results suggested that, once spontaneous recovery and practice effect were controlled, the patients showed little response to the interventions in terms of the dependent measures used.

Adolescent↗

PubMed2001

Cognitive effects in dichotic speech testing in elderly persons.

OBJECTIVE: To study the effect of chronologic age on central auditory functions using dichotic speech tests and to study whether and how the age effect in dichotic listening is related to cognitive ability. DESIGN: Dichotic speech tests and cognitive tests were performed on 30 bilaterally hearing-impaired subjects, with a pure-tone average better than 50 dB HL. They were between 42 and 84 yr of age and were divided into an older and a younger group comprising 15 subjects each. The dichotic test material were digits, low-redundancy sentences and consonant-vowel syllables. The subjects reported stimuli heard in both ears (free report) or in one ear (directed report to left or right ear). The cognitive test battery comprised tests focusing on short-term memory, verbal information-processing speed and phonologic processing. RESULTS: A decreased overall performance in all dichotic speech tests was observed in the older group. In the syllable test the older subjects showed poorer results when focusing on the stimuli heard in the left ear, as compared with when focusing on stimuli heard in the right ear, whereas the younger group showed almost equal results for left- and right ear-focusing conditions. An age effect was also seen in reaction times recorded in the cognitive tests and in the scores of the reading span test. These cognitive parameters correlate with the results of the dichotic test when focusing to the left, but not when focusing to the right in the directed report condition. In the free report condition the overall performance showed a high correlation with cognitive test parameters. CONCLUSIONS: Effects of chronologic age in dichotic speech tests in the elderly have been verified. The degree of effect is dependent on test material, way of reporting and focusing condition. The different listening tasks in dichotic tests put different demands on cognitive ability shown by a varying degree of correlations between cognitive function and dichotic test parameters. Also, the results indicate a strong connection between age-related cognitive decline in the elderly and problems to perceive stimuli presented to the left ear.

Adult↗

PubMed1998

Is nondipping in 24 h ambulatory blood pressure related to cognitive dysfunction?

OBJECTIVE: Associations between the outcome of 24 h ambulatory monitoring and cognitive performance were studied in order to evaluate the potential relevance of ambulant blood pressure status to brain function. It was hypothesized that a small daytime-night-time difference in mean blood pressure (nondipping) is associated with reduced cognitive performance, in line with studies in hypertensive subjects that have reported associations between nondipping and target-organ damage. METHODS: The study followed a cross-sectional design and was part of a larger research programme on determinants of cognitive aging (Maastricht Aging Study, MAAS). A group of 115 community residents aged 28-82 years was recruited from a general practice population and screened for cardiovascular events and medication use. All underwent 24 h blood pressure monitoring. Cognitive performance was measured with tests of verbal memory, attention, simple speed and information processing speed. RESULTS: Mean daytime or night-time levels of both systolic and diastolic blood pressure were unrelated to cognitive outcome, when age, sex and educational level were controlled for. Differences between mean daytime and night-time blood pressure (based on both narrow and wide measurement intervals for day and night-time periods) were positively associated with memory function (5-9% of additional variance explained) and one sporadic positive association was found on the sensorimotor speed score (4%). Nondippers (n=15) showed lower levels of both memory and sensorimotor speed scores. CONCLUSIONS: Ambulatory blood pressure status was not associated with cognitive performance. A reduced nocturnal blood pressure drop was associated with quite specific cognitive deficits, but the underlying mechanism remains to be determined.

Adult↗

PubMedDate not supplied

Toward understanding age-related memory loss in late adulthood.

BACKGROUND: While laboratory tests indicate that older adults typically perform more poorly than do younger adults on many types of memory tasks, the question arises as to whether, or to what extent, it is valid to attribute these differences to ageing per se or to some variable or class of variables that intervene between age and remembering. OBJECTIVE: The purpose of this review is to present three current views that might explain the relationship between age and remembering. They can be construed as variants on resource theories and include: the processing speed hypothesis, the executive function hypothesis, and the common cause hypothesis. METHODS: The review samples results pertinent to these hypotheses that derive from behavioural research. Studies involving various imaging techniques were considered beyond the scope of the review. RESULTS: The balance of research strongly implicates reductions in the speed of information processing as a fundamental contributor to normal age-related memory loss. Nonetheless there are circumstances where other mechanisms, such as working memory, executive function, and sensory processes, are important. CONCLUSION: Despite the phenomenological and empirical reality of age-related memory loss and the breadth of attempts to explain it, much work remains to be done to understand why it occurs. Contemporary debates about the nature and means of identifying shared and unique effects promise to shape future directions for research on memory aging.

Adult↗

PubMed2002

Factor structure of MicroCog in a clinical sample.

Two factor solutions adequately describe the MicroCog performance data of a clinical sample of substance abusers. Information Processing Speed and Information Processing Accuracy factors seem to explain the Short Form and Standard Form scores of a clinical sample as they do for the normative sample. Clinicians need to be aware that the factor scores do not allow for unambiguous interpretation, but may be more meaningful than independent domain scores.

Cognition Disorders↗

PubMed1993

Memory in patients with cerebellar degeneration.

Eleven patients with relatively selective cerebellar degeneration and 11 normal control subjects underwent a comprehensive neurologic and neuropsychological examination. The neuropsychological tests assessed general intellectual ability, different aspects of memory (effortful, automatic, and implicit memory processes), speed of information processing, and verbal fluency (using both category and letter fluency tasks). The results indicated that cerebellar patients were significantly impaired only on tasks requiring the use of executive functions, such as the initiation/perseveration subtest of the Mattis Dementia Rating Scale or the fluency tests, and on memory measures requiring greater processing effort. They performed normally on automatic and implicit measures of memory. Performance on the effortful memory and executive measures was not associated with neurologic variables or mood state. After controlling for the initiation/perseveration deficit, the effortful memory scores of the cerebellar patients were no longer different from those of controls. The present study suggests that memory in patients with relatively pure cerebellar dysfunction is only partially compromised and that the impairment is secondary to a deficit in executive functions.

Adult↗

PubMed1999

Relationship between choice reaction time and the Tower of Hanoi test.

The aim of this study was to examine a possible relation between the speed of information processing, as measured by simple and choice visual RT, and problem-solving, as measured by the Tower of Hanoi test. For 20 normal teenagers, performing all tests, significant correlations were found between choice RT and both measures of performance on the Tower of Hanoi, number of disk moves, and time taken to complete the task. Simple RT was correlated with Completion time but not with the number of moves, while the reverse pattern was discerned for decision time. Choice movement time was also associated with both measures, but simple movement time was not. These results are consistent with the hypothesis of a common neurobiological basis to information-processing speed and executive functions.

Adolescent↗

PubMed1987

E-speed dental films processed with rapid chemistry: a comparison with D-speed film.

Image quality of E-speed film processed in four rapid chemistry solutions was evaluated and compared to that of D-speed film. One-hundred-twenty films (60 E-speed and 60 D-speed) were exposed with the use of a quality-control phantom and processed in four different rapid solutions. The images were evaluated for speed, contrast, fog and base, resolution, and granularity, and the useful lifetime of the solutions was determined. E-speed film processed with rapid chemistry produced images equal in quality to D-speed film in the range tested (70 to 90 kVp). Fog and base levels of E-speed film were greater than those of D-speed film. The resolution and granularity of the images were equal and were judged adequate in both film types, regardless of the chemistry used. Rapid processing solutions were found to have a 10% to 15% shorter useful lifetime with E-speed film than with D-speed film. The processing of E-speed film in rapid chemistry is recommended for emergency care and endodontics.

Densitometry↗

PubMed1996

Attention deficits and dual task demands after mild traumatic brain injury.

Attention deficits are a prominent aspect of cognitive dysfunction after mild traumatic brain injury (MTBI). Patients frequently complain of distractibility and difficulty attending to more than one thing at a time, and several neuropsychological studies have found evidence for a specific attention deficit without general neuropsychological impairment. The present study examined the nature of attentional disturbance after MTBI using an extended version of the 2 and 7 Test, which introduced two conditions reflecting patients' subjective complaints: the ability to perform with background 'noise', and while simultaneously attending to a secondary task. The dual task demands produced a significant slowing in processing speed for both the MTBI patients and control subjects. However, the relative decline in processing speed appeared much greater for the patients with MTBI, and they differed from control subjects only in this condition. The results are consistent with findings that patients with MTBI exhibit relatively subtle cognitive deficits which are apparent primarily under conditions which require effortful or controlled cognitive processing and exceed their available cognitive resources. Thus, the attentional deficits apparent during dual task demands may represent decreased cognitive, and perhaps neural, efficiency which reflects MTBI patients' subjective complaints and functional impairments.

Adult↗

PubMed2026

Beyond Glycaemia: Fear of Hypoglycaemia, Cognition and Functional Mobility After Advanced Hybrid Closed-Loop Therapy in Older Adults With Type 1 Diabetes: A Prespecified Secondary Analysis of a Randomised, Single-Centre Study.

BACKGROUND: Evidence on psychological, cognitive and functional outcomes of advanced diabetes technologies in older adults with long-standing type 1 diabetes (T1D) remains limited. We evaluated whether initiation of advanced hybrid closed-loop (AHCL) therapy was associated with changes in fear of hypoglycaemia, diabetes distress, psychological well-being, cognition, frailty-related measures and mobility-related function in adults aged ≥ 65 years with T1D. METHODS: This prespecified, exploratory secondary analysis was conducted within a single-centre, open-label, randomised, controlled, parallel-group trial including adults aged ≥ 65 years with long-standing T1D. Participants were randomly assigned (1:1) to initiate AHCL therapy using the MiniMed 780G system or to continue standard diabetes treatment. The secondary outcomes included WHO-5, the 17-item Diabetes Distress Scale (DDS), Hypoglycemia Fear Survey-II (HFS-II), Montreal Cognitive Assessment, Digit Symbol Substitution Test, Fried frailty phenotype and performance-based functional measures. No formal sample-size calculation was performed for these secondary outcomes. RESULTS: Thirty-one participants were randomised and 29 completed 12 months of follow-up and were included in the treatment-effect analyses. In the baseline-adjusted primary analysis, AHCL therapy was associated with a lower HFS-II score than standard treatment (adjusted mean difference -18.9; 95% CI: -32.4 to -5.4; nominal p = 0.008), although this finding did not remain statistically significant after Holm correction (adjusted p = 0.104) or in an exploratory model additionally adjusted for sex (difference -13.6; 95% CI: -32.2 to 5.0; p = 0.145). Diabetes distress, psychological well-being, global cognition and processing speed did not differ between groups. In sex-adjusted sensitivity analyses, the between-group differences remained statistically significant for 6-min walk distance (92.6 m; 95% CI: 36.8 to 148.3; p = 0.002) and Timed Up and Go performance (-2.27 s; 95% CI: -4.28 to -0.27; p = 0.028), but not for gait speed (0.27 m/s; 95% CI: -0.05 to 0.59; p = 0.099). At 12 months, 12 of 14 AHCL participants were robust and 2 were pre-frail; in the control group, 11 of 15 were robust and 4 were pre-frail. No participant was classified as frail at follow-up. CONCLUSIONS: In this small, selected cohort, AHCL therapy was associated with a nominally lower fear-of-hypoglycaemia score and better performance on selected mobility-related tests over 12 months. The fear-of-hypoglycaemia finding did not remain statistically significant after correction for multiple comparisons or additional adjustment for sex. Six-minute walk distance and Timed Up and Go remained statistically significant in the exploratory sex-adjusted sensitivity analyses, whereas the gait-speed difference did not. No measurable between-group deterioration in global cognition or processing speed was observed. These exploratory findings require confirmation in larger studies with balanced representation by sex and direct measurement of physical activity. These findings also support a person-centred clinical message: older age alone should not be regarded as a barrier to AHCL when treatment is introduced with individualised education and appropriate ongoing support.

Humans↗

PubMed1998

Neural dynamics of motion processing and speed discrimination.

A neural network model of visual motion perception and speed discrimination is presented. The model shows how a distributed population code of speed tuning, that realizes a size-speed correlation, can be derived from the simplest mechanisms whereby activations of multiple spatially short-range filters of different size are transformed into speed-turned cell responses. These mechanisms use transient cell responses to moving stimuli, output thresholds that covary with filter size, and competition. These mechanisms are proposed to occur in the V1-->MT cortical processing stream. The model reproduces empirically derived speed discrimination curves and simulates data showing how visual speed perception and discrimination can be affected by stimulus contrast, duration, dot density and spatial frequency. Model motion mechanisms are analogous to mechanisms that have been used to model 3-D form and figure-ground perception. The model forms the front end of a larger motion processing system that has been used to simulate how global motion capture occurs, and how spatial attention is drawn to moving forms. It provides a computational foundation for an emerging neural theory of 3-D form and motion perception.

Form Perception↗