Biomedical subjects

P A Arnett

Publications and source records attributed to P A Arnett.

14 recordsLinked to original sources

PubMed2006

Longitudinal course of depression symptoms in multiple sclerosis.

BACKGROUND: Despite the high lifetime prevalence of depression in multiple sclerosis (MS), its longitudinal course is poorly understood. OBJECTIVE: To examine the longitudinal course of and reliable change in different depression symptom clusters in MS, and the longitudinal association of interferon beta treatment and coping with depression symptoms. METHODS: 53 MS patients were examined at two time points three years apart on the Beck Depression Inventory (BDI) and the Chicago Multiscale Depression Inventory (CMDI). RESULTS: Correlations from time 1 to time 2 for BDI, CMDI-total, CMDI-evaluative scale, and CMDI-vegetative scale were all highly significant, and reliable change indices reflected little change over time. In contrast, the correlation over time for the CMDI-mood scale was significantly lower (p<0.05) than the CMDI-evaluative and CMDI-vegetative scale correlations, and over 40% of patients showed reliable change. Patients who improved in their mood showed increased use of active coping, while patients who worsened showed decreased active coping strategies; the latter were also significantly more likely to have been taking interferon beta drugs at both time points than patients who did not change in their mood functioning. CONCLUSIONS: Mood symptoms of depression are significantly more variable over time than neurovegetative or negative evaluative symptoms in MS patients. Decreased use of active coping strategies may put patients at risk of increased depressed mood, whereas increased use of active coping may result in decreased depressed mood longitudinally. Interferon beta use may put patients at risk of increases in depressed mood.

Adaptation, Psychological↗

PubMed2001

Measuring central executive functioning: what's in a reading span?

Although variations of Daneman and Carpenter's (1980) Reading Span Test (RST) have seen increasing use in both cognitive and neuropsychological research, the specific mental operations involved in performing it remain unclear. We tested 80 undergraduates to examine the extent to which speed of processing, manipulation capacity, and susceptibility to interference contributed to RST performance. The results suggest that, rather than unitary central executive or processing speed functions underlying RST performance, at least two factors, manipulation capacity and susceptibility to interference, underlie the task. Further study of RST operations may lead to a better understanding of the nature of the central executive itself.

Cognition↗

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↗

PubMed2001

Metamemory and tested cognitive functioning in multiple sclerosis.

Metamemory, or one's knowledge and self-report of memory ability, has been researched extensively; however, few studies have examined it in multiple sclerosis (MS). Because impairment in cognitive domains besides memory may affect memory functioning, patients may self-report problems with memory that are indicative of impairment in cognitive domains besides memory. One goal of the current study was to test this hypothesis in MS. A group of 55 MS patients were administered a variety of cognitive tasks and a self-report metamemory measure; patients' significant others were also given a metamemory measure requiring them to rate patients' memory abilities. Results indicated that patients' metamemory reports were significantly (p < .05) correlated with verbal recall, attentional, and executive tasks. Significant other ratings of patients' metamemory were correlated with verbal recall and attentional measures. Stepwise regression analyses including all relevant cognitive and demographic variables indicated that only education and Symbol Digit accounted for significant independent variance in patients' current memory reports. Our results suggest: (1) subjective complaints of memory difficulties by MS patients reflect difficulty in cognitive domains besides memory, (2) MS patient self-reports of memory difficulty are at least as accurate as significant other reports, and (3) patients with more education are more accurate in their metamemory ratings. These findings have implications not only for a better understanding of metamemory in MS, but also for more effective treatment and rehabilitation of MS patients.

Cognition Disorders↗

PubMed2000

Neurovegetative symptoms in multiple sclerosis: relationship to depressed mood, fatigue, and physical disability.

Some authors have suggested that when evaluating depression in multiple sclerosis (MS) patients, neurovegetative symptoms should be discounted and/or not considered, given the ostensibly high overlap between symptoms of MS (e.g., sleep disturbance, fatigue) and neurovegetative symptoms of depression. A further assertion is that inclusion of items assessing neurovegetative symptoms may artificially inflate overall depression scores and that mood scales may provide more accurate indices of depression in MS patients. The current study investigated the possibility that some neurovegetative symptoms may be specifically related to MS patients' depressed mood and are not simply indicators of physical disability and/or fatigue. Seventy-six clinically definite MS patients in the northwestern United States were administered two depression inventories and measures of physical disability and fatigue as part of a larger study. Results revealed that one neurovegetative symptom--disinterest in sex--was uniquely associated with depressed mood, and other neurovegetative symptoms were associated with both depression and fatigue but not physical disability. The present findings suggest that certain neurovegetative symptoms are differentially associated with depression, fatigue, and physical disability in MS. Routinely discounting all neurovegetative symptoms when assessing depression in MS patients may thus be unwarranted.

Journal Article↗

PubMed2000

The ecological validity of clinical tests of memory and attention in multiple sclerosis.

Ecological validity--the degree to which clinical tests of cognitive functioning predict functional impairment--has recently become an area of interest in neuropsychology. The current study used a sample of 31 cognitively and functionally impaired multiple sclerosis (MS) patients to determine if tests commonly used to assess memory and attentional functioning in MS are ecologically valid. Two methods of improving the ecological validity of cognitive testing were employed. Stepwise multiple regression analyses suggested that tests of memory and attention more analogous to everyday tasks are better predictors of functional impairment in MS than both standard clinical tests of memory and attention, and memory questionnaires completed by the patient or a significant other. Nonetheless, both standard clinical tests and more ecologically valid tests significantly predicted functional impairment. Importantly, they were not significantly correlated with one another, suggesting that the inclusion of both types of tests in evaluating MS patients is warranted.

Journal Article↗

PubMed1999

Depressed mood in multiple sclerosis: relationship to capacity-demanding memory and attentional functioning.

Because it is theorized that depression results in reduced available attentional capacity that, in turn, can explain the impaired performance on capacity-demanding tasks in depressed individuals, the authors predicted that multiple sclerosis (MS) patients with depressed mood would have difficulty with these types of tasks. Twenty depressed mood MS participants were compared with 41 nondepressed mood MS participants and 8 nondepressed mood controls on 5 attentional capacity-demanding clinical memory and attentional tasks and 3 tasks with minimal capacity demands. Depressed mood MS patients performed significantly worse than both nondepressed mood groups on the 3 speeded capacity-demanding attentional measures but not on any of the tasks requiring few capacity demands, supporting the authors' predictions. The possibility that the impaired performance of depressed mood MS patients on speeded attentional tasks was mediated by reduced verbal working memory capacity, impaired deployment of executive strategies that access working memory capacity, or psychomotor slowing is explored.

Attention↗

PubMed1999

Depression in multiple sclerosis: relationship to working memory capacity.

Recent research has shown that depression in multiple sclerosis (MS) is associated with deficits on cognitively demanding tasks. One explanation for this relationship is that depressed MS patients may have reduced working memory capacity. The present study was designed to test this hypothesis. Depressed MS patients were compared with nondepressed MS patients and nondepressed healthy controls on a task of working memory capacity (reading span) and a short-term memory task not taxing working memory capacity (word span). In support of the capacity-reduction model, compared with the nondepressed groups, depressed MS patients performed significantly worse on reading span (p<.001) but not on word span. Additionally, reading span was significantly correlated with capacity-demanding tasks shown to be impaired in depressed MS patients in previous reports. Results suggest that depressed MS patients are characterized by limited working memory capacity and that the central executive component of the working memory system may be most affected.

Adult↗

PubMed1997

Autonomic responsivity in psychopaths: a critical review and theoretical proposal.

The literature on autonomic responsivity in psychopaths is reviewed and critically evaluated with Fowles' (1980) psychophysiological adaptation of Gray's two-factor learning theory used as an organizing framework. It is concluded that, although much recent research has focused on assessing psychopaths' response to punishment in familiar paradigms, several intriguing new paradigms for assessing psychopaths' autonomic responsivity have been developed. A new conceptualization of the existing data is considered involving a motivational imbalance theory based on the Gray/Fowles model. This theory connects autonomic psychophysiological research on psychopaths to literatures on cognition, emotion, and behavior. Research directions for evaluating the validity of the theory are proposed.

Antisocial Personality Disorder↗

PubMed1997

Approach and avoidance motivation in psychopathic criminal offenders during passive avoidance.

The authors evaluated competing theories that attribute psychopathic individuals' poor passive avoidance to a strong activating system, a weak inhibitory system, or poor modulation of behavioral activation when inhibitory cues appear. In Study 1, the continuous motor task involved a reward phase to elicit the activating system followed by a passive avoidance phase. Study 2 tested the generality of the theories by using an active avoidance phase to elicit the activating system. Heart rate and response speed results from Study 1 best supported the strong activating system and poor response modulation models in low-anxiety psychopathic offenders. Study 2 results did not clearly support any of the models. Further research is needed to determine if excessive activation by reward and poor response modulation are associated with passive avoidance deficits and other characteristics of low-anxiety psychopathic offenders.

Adult↗

PubMed1997

Executive functions in multiple sclerosis: an analysis of temporal ordering, semantic encoding, and planning abilities.

Previous studies have consistently demonstrated impairments in conceptual reasoning and set-shifting abilities in patients with multiple sclerosis (MS). Other executive functions have been less frequently examined. We compared 44 MS patients and 48 demographically matched controls on a temporal-ordering and semantic-encoding task and on a test of planning (Tower of Hanoi). Compared with controls, MS patients experienced deficient semantic encoding and planning but unimpaired temporal-order memory. For both tasks, post hoc analyses indicated that chronic-progressive MS patients contributed most to the group differences. A combination of poor planning and slowed information-processing speed was hypothesized to have contributed to MS patients' impaired Tower of Hanoi performance. Further research is needed to explore the possible relationship between semantic-encoding and planning deficits in MS and social and occupational disabilities.

Cues↗

PubMed1997

Performance of substance abusers with memory deficits on measures of malingering.

The effects of memory impairment on various malingering indices were assessed in a substance abusing population. Groups were formed by using scores from the Delayed Memory Index of the Wechsler Memory Scale-Revised and selecting individuals from an addictions recovery unit in the top and bottom quintiles. Quintile group differences were found for number correct on free and forced-choice recall on the 21-Item Wordlist; total time for grouped and ungrouped dots on the Rey Dot Counting procedure; and addition errors on the Memorization of 16 Items test. All differences found were in the direction of better performance by subjects with better Delayed Memory Index scores; however, all of the differences were small. With the exception of the free recall index from the 21-Item Wordlist, all subjects had scores on the malingering measures beyond the cutoffs typically used to detect malingering in clinical populations. These findings suggest that, even in memory-impaired populations, memory measures of malingering are valid.

Journal Article↗

PubMed1996

Conduction aphasia in multiple sclerosis: a case report with MRI findings.

Aphasia is an uncommon manifestation of MS, which is somewhat surprising because various disconnection syndromes, such as conduction aphasia, would be expected to occur with some regularity in this white matter disease. We present a case study of an MS patient with conduction aphasia associated with a large white matter lesion underlying the left supramarginal gyrus.

Adult↗

PubMed1994

Relationship between frontal lobe lesions and Wisconsin Card Sorting Test performance in patients with multiple sclerosis.

Conceptual reasoning deficits are common in patients with multiple sclerosis (MS) and are typically associated with focal lesions involving the frontal lobes. In this study, we predicted that MS patients with frontal white matter lesions (MS-F) would be more impaired on a standard conceptual reasoning task (Wisconsin Card Sorting Test; WCST) than patients with minimal frontal lesions (MS-NF), even if the total cerebral lesion area (TLA), measured from MRI, was equivalent across groups. We subdivided 43 definite MS patients into three groups based on MRI findings: seven in the MS-F group (mean TLA = 41.4 cm2) and seven in the MS-NF group (mean TLA = 50.0 cm2); 29 MS patients served as a low lesion burden control group (MS-C; mean TLA = 6.4 cm2). The groups did not differ with regard to demographic and illness characteristics. Although the three subgroups obtained comparable scores on a measure of global cognitive functioning (verbal intelligence), the MS-F group achieved significantly fewer categories and made more total errors on the WCST than did the MS-NF and MS-C groups. The MS-F group made significantly more perseverative responses than the MS-C group and nonsignificantly more than the MS-NF group. These results suggest that the pattern of cognitive decline in MS is a function of the location of demyelinating lesions within the cerebral hemispheric white matter. Finally, we supplement the group study results with a case report of an MS patient who was studied serially with MRI and cognitive testing.

Adult↗