Computerized Test Of Information Processing Research Articles

Exploring bradyphrenia in Huntington’s disease using the computerized test of information processing (CTiP)

BackgroundBradyphrenia, best thought of as the mental equivalent of bradykinesia, has been described in several disorders of the brain including Parkinson’s disease and schizophrenia; however, little is known about this phenomenon in Huntington’s Disease (HD). ObjectiveThe aim of this study was to investigate the presence of bradyphrenia in HD using the Computerized Test of Information Processing (CTiP), an easy to administer and objective task that assesses cognitive processing speed with increasing task complexity. MethodsThis study included 211 participants: Huntington’s Disease Integrated Staging System (HD-ISS) Stage 0 [n = 28], Stage 1 [n = 30], Stage 2 [n = 48] and Stage 3 [n = 48], and healthy controls (HC) [n = 57]. The CTiP incorporates three subtests: Simple Reaction Time (SRT), which assesses baseline motor function; Choice Reaction Time (CRT), with an added decisional component; and Semantic Search Reaction Time (SSRT), with an added conceptual component. SRT scores were subtracted from CRT and SSRT scores to establish a motor-corrected measure of central conduction time, which was used to operationalize bradyphrenia. ResultsHD-ISS and HC within-group reaction times differed significantly when comparing motor-corrected CRT vs SSRT (all ps < 0.0001). Furthermore, the magnitude of these differences increased with HD disease stage (p < 0.0001). An ROC analysis determined that motor-corrected within-subject differences significantly distinguished Stage 2 + 3 from Stage 0 + 1 (AUC = 0.72, p < 0.0001). ConclusionsWe report evidence of bradyphrenia in HD that increases with disease progression. This processing deficit, which can be quantified using the CTiP, has the potential to greatly impact HD daily life and warrants additional research.

Central Cognitive Processing Speed Is an Early Marker of Huntington's Disease Onset.

Several studies have suggested that cognitive processing speed may be useful for assessing early cognitive change in premanifest Huntington's disease (HD); however, current measures lack the ability to control for the effects of motor dysfunction commonly found in HD. The Computerized Test of Information Processing (CTiP) is a rapidly administered computerized tool that allows for the examination of central cognitive processing speed by using motor-corrected scores to account for motor dysfunction. To examine central cognitive processing speed as an early marker of HD onset using the CTiP. The CTiP and other measures were administered to 102 HD gene carriers and 55 healthy adults (HA). Gene carriers included presymptomatic HD (pre-HD; n = 33), prodromal HD (pro-HD; ie, individuals close to disease onset; n = 23), and mild-moderate HD (HD; n = 46). The HD group performed significantly slower than all other groups (HA, pre-HD, and pro-HD) on most subtests (Ps < .05). Moreover, the pro-HD group performed significantly slower than the HA group on both motor-corrected subtests (Ps < 0.05). Effect sizes associated with significant group differences between the pro-HD and HA groups on motor-corrected CTiP subtests (d = 0.73 and 0.84) were similar to effect sizes associated with group differences on the Symbol Digit Modalities Test (d = .82) and other traditional cognitive assessments (Montreal Cognitive Assessment, d = .75; Mini-Mental State Examination, d = .84). The CTiP may be a useful marker of deficits in central cognitive processing speed in individuals close to manifest onset of HD.

Reliability and validity of a motion-based reaction time assessment using a mobile device

Information processing speed is often altered following a concussion. Few portable assessments exist to evaluate simple reaction time (SRT) in hospitals and clinics. We evaluated the use of a SRT application for mobile device measurement. 27 healthy adults (age = 30.7 ± 11.5 years) completed SRT tests using a mobile device with Sway, an application for SRT testing. Participants completed computerized SRT tests using the Computerized Test of Information Processing (CTIP). Test–retest reliability was assessed using intraclass correlation coefficients (ICC) between Sway trials. Pearson correlations and Bland-Altman analyses were used to assess criterion validity between Sway and CTIP means. ICC comparisons between Sway tests were all statistically significant. ICCs ranged from 0.84–0.90, with p-values <.001. A one-way analysis of variance (ANOVA) revealed no significant differences between trials (F3,104 = 1.35, p = .26. Pearson correlation between Sway and CTIP outcomes yielded a significant correlation (r = 0.59, p = .001). The mean difference between measurement methods was 43.7 ms, with limits of agreement between −140.8–53.4 ms. High ICC indicates Sway is a reliable method to assess SRT. A strong correlation and clinically acceptable agreement between Sway and the computer-based test indicates that Sway is suited for rapid administration of SRT testing in healthy individuals. Future research using Sway to assess altered information processing in a population of individuals after concussion is warranted.

Longitudinal Comparison of Desktop and fMRI Scanner Versions of the Computerized Test of Information Processing in Multiple Sclerosis: A Pilot Study

Deficits in information processing speed are common in individuals with MS, but adequate detection of such is fraught with methodological difficulties. The Computerized Test of Information Processing (CTIP) is a relatively new measure that addresses some of these methodological concerns. The equivalency of a desktop and fMRI scanner version of the CTIP at detecting cognitive impairment and monitoring cognition over time was examined in a sample of individuals with multiple sclerosis (MS). Six individuals with a confirmed diagnosis of MS completed both the desktop and a modified scanner version of the CTIP at baseline and 3 year follow-up. Both forms of the task remained equally as sensitive at detecting cognitive impairment across the two time points. Similarly, reaction time performance was generally equivalent across both forms although participants made more errors on the scanner task. No participant demonstrated reliably significant change in performance over time. A modified version of the CTIP adapted for use in an fMRI environment holds promise for the detection of information processing speed deficits in MS.

Intra-individual variability in information processing speed reflects white matter microstructure in multiple sclerosis

Slowed information processing speed is commonly reported in persons with multiple sclerosis (MS), and is typically investigated using clinical neuropsychological tests, which provide sensitive indices of mean-level information processing speed. However, recent studies have demonstrated that within-person variability or intra-individual variability (IIV) in information processing speed may be a more sensitive indicator of neurologic status than mean-level performance on clinical tests. We evaluated the neural basis of increased IIV in mildly affected relapsing–remitting MS patients by characterizing the relation between IIV (controlling for mean-level performance) and white matter integrity using diffusion tensor imaging (DTI). Twenty women with relapsing–remitting MS and 20 matched control participants completed the Computerized Test of Information Processing (CTIP), from which both mean response time and IIV were calculated. Other clinical measures of information processing speed were also collected. Relations between IIV on the CTIP and DTI metrics of white matter microstructure were evaluated using tract-based spatial statistics. We observed slower and more variable responses on the CTIP in MS patients relative to controls. Significant relations between white matter microstructure and IIV were observed for MS patients. Increased IIV was associated with reduced integrity in more white matter tracts than was slowed information processing speed as measured by either mean CTIP response time or other neuropsychological test scores. Thus, despite the common use of mean-level performance as an index of cognitive dysfunction in MS, IIV may be more sensitive to the overall burden of white matter disease at the microstructural level. Furthermore, our study highlights the potential value of considering within-person fluctuations, in addition to mean-level performance, for uncovering brain–behavior relationships in neurologic disorders with widespread white matter pathology.

Tests of Information Processing Speed

Reduction in information processing speed (IPS) is a key deficit in multiple sclerosis (MS). The Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), and Computerized Test of Information Processing (CTIP) are used to measure IPS. Both the PASAT and SDMT are sensitive to deficits in IPS. The CTIP, a newer task, also shows promise. The PASAT has several limitations, and it is often perceived negatively by patients. Yet little supporting quantitative evidence of such perceptions has been presented. Therefore, in this study, subjective ratings of likeability, difficulty, and appropriateness of the PASAT, CTIP, and SDMT were obtained. Ratings were compared between MS patients and healthy controls. It was hypothesized that ratings of the PASAT would differ significantly from those of the SDMT and CTIP. The relationship between subjective ratings and objective performance was evaluated. Sixty-nine MS patients and 68 matched controls rated the three tests in terms of likeability, difficulty, and appropriateness for capturing cognitive deficits often associated with MS using a Likert scale. Both groups rated the PASAT as most difficult and least likeable. The MS group rated the PASAT and SDMT as more appropriate for measuring MS-related deficits than the CTIP. Subjects who performed better on the PASAT were more likely to rate it as easier. Ratings of the SDMT and CTIP did not vary consistently with performance. The findings lend quantitative support to the common belief that the PASAT is perceived as unpleasant. Other tests are available that are similarly sensitive to deficits in IPS and more palatable to the patient.

Intra-individual Variability as a Measure of Information Processing Difficulties in Multiple Sclerosis

Deficits in information processing speed are among the most commonly reported impairments in multiple sclerosis (MS) and are generally assessed by evaluating mean-level performance on time-limited tests. However, this approach to assessing performance ignores potential within-subject differences in MS patients that may be useful for characterizing cognitive difficulties in MS. An alternative method of measuring performance is by examining the degree of within-subject variability, termed intra-individual variability (IIV). Intra-individual variability provides information about the characteristics of a person's performance over time and may provide novel information about cognitive functioning in MS. This study examined IIV in performance on the Computerized Test of Information Processing (CTIP) using two within-subject variability methods: individual standard deviation and coefficient of variation. Eighteen females with relapsing-remitting MS and 18 healthy female controls completed the CTIP. Consistent with previous research, MS patients demonstrated slower overall mean performance on the CTIP compared with controls, with patients becoming increasingly slower than controls as cognitive demands increased across the tasks. Furthermore, MS patients demonstrated greater IIV as measured by individual standard deviations on all subtests of the CTIP, even with mean-level group differences as well as practice and learning effects controlled. These between-group differences were not found when the coefficient of variation, a more coarse measure of within-subject variability, was used. Intra-individual variability was also found to be a better predictor of neurologic status than mean-level performance. These results suggest that IIV may provide unique insight into cognitive functioning in MS.

Introduction: Cognitive Dysfunction in Multiple Sclerosis

Introduction: Cognitive Dysfunction in Multiple Sclerosis

Detecting cognitive fatigue in multiple sclerosis: Method matters

BackgroundFatigue is a frequently reported and debilitating symptom in multiple sclerosis (MS). Cognitive fatigue (CF) can be defined as decreased performance with sustained cognitive effort. The effectiveness of the Paced Auditory Serial Addition Task (PASAT) and the Computerized Test of Information Processing (CTIP) at detecting CF was examined, as was the impact of methodology. Subjective fatigue was measured using the Fatigue Impact Scale (FIS). The relationship between objective and subjective fatigue was examined. Methods70 MS and 72 healthy controls (HC) completed the PASAT (3″ and 2″), CTIP, and FIS as part of a larger battery. ResultsThe MS and HCs performed worse on cognitively demanding tasks. Depending on methodology, PASAT performance varied between groups at the 3″ inter-stimulus interval (ISI) and the MS group showed greater susceptibility to CF as their ability to meet task demands declined as the task progressed. CTIP performance for both groups varied differently over time depending on task. The relationship between subjective and objective measures of fatigue varied depending on methodology, with PASAT generally correlating well with the Cognitive Dimension of the FIS. ConclusionsThe PASAT is a sensitive measure of CF in MS. Additional information is obtained with different scoring methods, with percent dyad scoring method being most sensitive to CF. The ability to detect a relationship between objective and subjective measures varied with methodology.

Activation patterns in multiple sclerosis on the Computerized Tests of Information Processing

Rationale Multiple sclerosis (MS) patients exhibit cognitive deficits that negatively impact quality of life. The Relative Consequence Model suggests that problems with information processing speed (IPS) may be the basis for many of these cognitive difficulties. Objective To investigate, with functional magnetic resonance imaging (fMRI), if an IPS task (the Computerized Test of Information Processing (CTIP)) would reveal neurophysiological differences between MS patients and matched controls. Methods Performance and neural activation were investigated in twelve cognitively impaired MS patients and 12 matched controls as each performed the CTIP. The CTIP measures reaction time (RT) and errors on three tasks (simple RT, choice RT and semantic search RT) with increasing cognitive demands. Results Participants demonstrated increased RT with increased task complexity. Patients showed longer RTs for the choice RT condition than controls but the pattern of performance across tasks did not vary between groups. Errors were not significantly different between groups. Imaging results for both the choice and the semantic search conditions revealed significant differences between groups involving a compensatory increase in activation in MS participants compared to controls in prefrontal cortex and right temporal gyri. However, there were also areas of decreased activity in MS participants when compared with controls in left temporal gyri. Conclusions Significantly different neural activation patterns between MS patients and controls were associated with IPS, as measured by the CTIP.

The Computerized Test of Information Processing (CTIP) Offers an Alternative to the PASAT for Assessing Cognitive Processing Speed in Individuals With Multiple Sclerosis

To compare the ability of the Computerized Test of Information Processing (CTIP) to detect impaired cognitive processing speed in patients with multiple sclerosis (MS) with a traditional 3.0 second Paced Auditory Serial Addition Test (PASAT) and the Adjusting-PASAT which allows for calculation of a speed score. A primary cognitive deficit in MS is an impaired ability to process information quickly. Unfortunately, relatively few clinical tests effectively measure information processing speed. Of these, the PASAT is generally acknowledged to be the most sensitive, but use of this test is constrained by several factors. All tests were administered to 30 adults with relapsing-remitting MS and 30 control participants. A series of analysis of variances revealed MS participants performed significantly worse than controls on the CTIP and the 3.0 second PASAT, whereas no significant difference was observed for the Adjusting-PASAT. The results suggest the CTIP can detect deficits in the speed at which people with MS process information. Thus, the CTIP offers an alternative means to the 3.0 second PASAT included in the Multiple Sclerosis Functional Composite for assessing such impairment.

The ability of reaction time tests to detect simulation: An investigation of contextual effects and criterion scores

Two experiments examined whether experience gained with a series of reaction time tests [Computerized Tests of Information Processing (CTIP); Tombaugh, T. N. & Rees, L. (in press). Computerized Tests of Information Processing (CTIP). Toronto, Canada: Multi-Health Systems Inc.] influenced the performance of individuals instructed to simulate the cognitive effects of a traumatic brain injury. Experience with the tests was manipulated by varying the order and number of tests administered for simulator and control groups. Simulators responded significantly slower and exhibited increased variability compared to controls. Performance was not affected by order or number of tests. The results of a third experiment showed that criterion scores could be established that correctly classified members of control, simulator, mild TBI, and severe TBI groups. Overall, the results suggest that the performance of the simulators was based on a context-free, absolute judgment and that reaction time measures show considerable promise for detecting low effort.

Reaction time: An alternative method for assessing the effects of multiple sclerosis on information processing speed

The ability of a newly developed measure of information processing to detect deficits in cognitive functioning associated with multiple sclerosis (MS) was investigated. The Computerized Tests of Information Processing (CTIP; Tombaugh, T., & Rees, L. (1999). Computerized Tests of Information Processing (CTIP). Unpublished test. Ottawa, Ontario, Canada: Carleton University) was administered to 60 clinically definite MS patients and 60 healthy controls. MS patients responded significantly slower than controls on the reaction time tests composing the CTIP. Moreover, as the CTIP tests became more difficult (i.e. as processing demands increased), the difference between the performances of the two groups progressively increased. These results suggest the CTIP is sensitive to the cognitive deficits observed in MS and that this measure has the potential to serve as a viable alternative to traditional measures of information processing speed currently in use with MS patients.

The Effects of Practice on Speed of Information Processing Using the Adjusting-Paced Serial Addition Test (Adjusting-PSAT) and the Computerized Tests of Information Processing (CTIP)

Three experiments were conducted to determine the effects of practice on the Adjusting-Paced Serial Addition Task (Adjusting-PSAT) (Tombaugh, 1999) and the Computerized Tests of Information Processing (CTIP) (Tombaugh & Rees, 2000). The Adjusting-PSAT is a computerized modification of the Paced Auditory Serial Addition Test (PASAT) (Gronwall, 1977) that makes the interval between digits contingent on the correctness of the response. This titration procedure permits a threshold value to be derived that represents the shortest presentation interval in which a person can process the digits to produce the correct sum. The CTIP consists of three reaction time tests that are progressively more difficult. Results showed that robust practice effects occurred with the Adjusting-PSAT, with the greatest increase in performance occurring on the first retest trial. Practice effects were equally prominent regardless of whether the first retest trial occurred 20 min, 1 week, or 3 months after the first administration. These gains were maintained for periods up to 6 months and were independent of modality of presentation (visual or auditory) and type of number list (easy or hard). In contrast to the findings with the Adjusting-PSAT, only minimal practice effects were observed with the CTIP. The major clinical implication of the study is that the high reliability coefficients for the CTIP, the lack of anxiety associated with its administration, and its insensitivity to variables such as numerical and verbal ability make the CTIP ideally suited for the serial evaluation of cognitive status. These characteristics also make the CTIP a viable alternative to the Adjusting-PSAT or PASAT for measuring speed of information processing. If the Adjusting-PSAT is administered repeatedly in clinical evaluations, a “dual baseline” or “run in” procedure should be used, with the second administration serving as the baseline measurement.

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.

Detecting simulation of attention deficits using reaction time tests

The current study examined if a newly developed series of reaction time tests, the Computerized Tests of Information Processing (CTIP) [Tombaugh, T. N., & Rees, L. (2000). Manual for the Computerized Tests of Information Processing (CTIP). Ottawa, Ontario: Carleton University (unpublished test)], were sensitive to simulation of attention deficits commonly caused by traumatic brain injury (TBI). The CTIP consists of three reaction time tests: Simple RT, Choice RT, and Semantic Search RT. These tests were administered to four groups: Control, Simulator, Mild TBI, and Severe TBI. Individuals attempting to simulate attention deficits produced longer reaction time scores, made more incorrect responses, and exhibited greater variability than cognitively-intact individuals and those with TBI. Sensitivity and specificity values were comparable or exceeded those obtained on the Test of Memory Malingering [Tombaugh, T. N. (1996). The Test of Memory Malingering (TOMM). Toronto, Canada: Multi-Health Systems Inc.]. As such, the CTIP offers considerable promise of serving as a viable malingering test that uses a distinctively different paradigm than the two-item, forced-choice procedure employed by traditional symptom validity tests.