Jennifer M. Glass

Virtually Perfect Time Sharing in Dual-Task Performance: Uncorking the Central Cognitive Bottleneck

A fundamental issue for psychological science concerns the extent to which people can simultaneously perform two perceptual-motor tasks. Some theorists have hypothesized that such dual-task performance is severely and persistently constrained by a central cognitive “bottleneck,” whereas others have hypothesized that skilled procedural decision making and response selection for two or more tasks can proceed at the same time under adaptive executive control. The three experiments reported here support this latter hypothesis. Their results show that after relatively modest amounts of practice, at least some participants achieve virtually perfect time sharing in the dual-task performance of basic choice reaction tasks. The results also show that observed interference between tasks can be modulated by instructions about differential task priorities and personal preferences for daring (concurrent) or cautious (successive) scheduling of tasks. Given this outcome, future research should investigate exactly when and how such sophisticated skills in dual-task performance are acquired.

Fibromyalgia syndrome module at OMERACT 9: domain construct.

The objective of the module was to (1) establish a core domain set for fibromyalgia (FM) assessment in clinical trials and practice, (2) review outcome measure performance characteristics, (3) discuss development of a responder index for assessment of FM in clinical trials, (4) review objective markers, (5) review the domain of cognitive dysfunction, and (6) establish a research agenda for outcomes research. Presentations at the module included: (1) Results of univariate and multivariate analysis of 10 FM clinical trials of 4 drugs, mapping key domains identified in previous patient focus group: Delphi exercises and a clinician/researcher Delphi exercise, and breakout discussions to vote on possible essential domains and reliable measures; (2) Updates regarding outcome measure status; (3) Update on objective markers to measure FM disease state; and (4) Review of the issue of cognitive dysfunction (dyscognition) in FM. Consensus was reached as follows: (1) Greater than 70% of OMERACT participants agreed that pain, tenderness, fatigue, patient global, multidimensional function and sleep disturbance domains should be measured in all FM clinical trials; dyscognition and depression should be measured in some trials; and stiffness, anxiety, functional imaging, and cerebrospinal fluid biomarkers were identified as domains of research interest. (2) FM domain outcome measures have generally proven to be reliable, discriminative, and feasible. More sophisticated and comprehensive measures are in development, as is a responder index for FM. (3) Increasing numbers of objective markers are being developed for FM assessment. (4) Cognitive dysfunction assessment by self-assessed and applied outcome measures is being developed. In conclusion, a multidimensional symptom core set is proposed for evaluation of FM in clinical trials. Research on improved measures of single domains and composite measures is ongoing.

Review of cognitive dysfunction in fibromyalgia: a convergence on working memory and attentional control impairments.

Clinical and laboratory evidence confirm that dyscognition is a real and troubling symptom in fibromyalgia (FM), and that the cognitive mechanisms most affected in FM are working memory, episodic memory, and semantic memory. Recent evidence provides further convergence on specific difficulty with attentional control. Dyscognition in FM cannot be attributed solely to concomitant psychiatric conditions such as depression and poor sleep, but does seem to be related to the level of pain. This article presents recent contributions regarding the etiology of the cognitive dysfunction, its impact on patients, and highlights the need for further research on this facet of FM.

The relationship of pain and depression to cognitive function in rheumatoid arthritis patients

&NA; The purpose of this study was to assess the hypothesis that pain and depression negatively impact the cognitive functioning of individuals with rheumatoid arthritis (RA). One hundred twenty‐one community‐dwelling RA patients (ages 34–84) completed a battery of cognitive tasks and multiple measures of pain and depression. Structural equation modeling techniques were used to assess the relative contributions of pain, depression, and age to cognitive performance. Individuals who performed poorly on cognitive tasks reported more pain and depression and were older than those individuals who performed well on cognitive tasks. Moreover, high levels of pain were associated with depression. Further analyses revealed that depression mediated the relationship between pain and cognition. That is, when depression was entered into the analyses, the previously significant effects of pain on cognition were no longer found. Interestingly, depression still mediated the pain–cognition relationship even after controlling for age. These findings suggest the importance of both pain and depression for understanding cognitive function in RA and may have important implications for treating this disease.

Adaptive executive control: Flexible multiple-task performance without pervasive immutable response-selection bottlenecks

Abstract A new theoretical framework, the EPIC (Executive-Process/Interactive-Control) architecture, provides the basis for accurate detailed computational models of human multiple-task performance. Contrary to the traditional response-selection bottleneck hypothesis, EPICs cognitive processor can select responses and do other procedural operations simultaneously for multiple concurrent tasks. Using this capacity together with flexible executive control of peripheral perceptual-motor components, EPIC computational models account well for various patterns of mean reaction times, systematic individual differences in multiple-task performance, and influences of special training on peoples task-coordination strategies. These diverse phenomena, and EPICs success at modeling them, raise strong doubts about the existence of a pervasive immutable response-selection bottleneck in the human information-processing system. The present research therefore helps further characterize the nature of discrete versus continuous information processing.

Childhood and adolescent resiliency, regulation, and executive functioning in relation to adolescent problems and competence in a high-risk sample

This study first examined the respective relations of resiliency and reactive control with executive functioning. It then examined the relationship of these different domains to the development of academic and social outcomes, and to the emergence of internalizing and externalizing problem behavior in adolescence. Resiliency and reactive control were assessed from preschool to adolescence in a high-risk sample of boys and girls (n = 498) and then linked to component operations of neuropsychological executive functioning (i.e., response inhibition, interference control, fluency, working memory/set-shifting, planning, and alertness), assessed in early and late adolescence. Consistent, linear relations were found between resiliency and executive functions (average r = .17). A curvilinear relationship was observed between reactive control and resiliency, such that resiliency was weaker when reactive control was either very high or very low. In multivariate, multilevel models, executive functions contributed to academic competence, whereas resiliency and interference control jointly predicted social competence. Low resiliency, low reactive control, and poor response inhibition uniquely and additively predicted internalizing problem behavior, whereas low reactive control and poor response inhibition uniquely predicted externalizing problem behavior. Results are discussed in relation to recent trait models of regulation and the scaffolded development of competence and problems in childhood and adolescence.

Executive function in chronic pain patients and healthy controls: different cortical activation during response inhibition in fibromyalgia.

UNLABELLED The primary symptom of fibromyalgia (FM) is chronic, widespread pain; however, patients report additional symptoms including decreased concentration and memory. Performance-based deficits are seen mainly in tests of working memory and executive function. Neural correlates of executive function were investigated in 18 FM patients and 14 age-matched healthy controls during a simple Go/No-Go task (response inhibition) while they underwent functional magnetic resonance imaging (fMRI). Performance was not different between FM and healthy control, in either reaction time or accuracy. However, fMRI revealed that FM patients had lower activation in the right premotor cortex, supplementary motor area, midcingulate cortex, putamen and, after controlling for anxiety, in the right insular cortex and right inferior frontal gyrus. A hyperactivation in FM patients was seen in the right inferior temporal gyrus/fusiform gyrus. Despite the same reaction times and accuracy, FM patients show less brain activation in cortical structures in the inhibition network (specifically in areas involved in response selection/motor preparation) and the attention network along with increased activation in brain areas not normally part of the inhibition network. We hypothesize that response inhibition and pain perception may rely on partially overlapping networks, and that in chronic pain patients, resources taken up by pain processing may not be available for executive functioning tasks such as response inhibition. Compensatory cortical plasticity may be required to achieve performance on a par with control groups. PERSPECTIVE Neural activation (fMRI) during response inhibition was measured in fibromyalgia patients and controls. FM patients show lower activation in the inhibition and attention networks and increased activation in other areas. Inhibition and pain perception may use overlapping networks: resources taken up by pain processing may be unavailable for other processes.

Impulsive and non-impulsive suicide attempts in patients treated for alcohol dependence

BACKGROUND Suicidal behavior has been recognized as an increasing problem among alcohol-dependent subjects. The aim of the study was to identify correlates of impulsive and non-impulsive suicide attempts among a treated population of alcohol-dependent patients. METHODS A total of 154 patients with alcohol dependence consecutively admitted for addiction treatment participated in the study. Suicidal behavior was assessed together with severity of alcohol dependence, childhood abuse, impulsivity, and family history. A stop-signal procedure was used as a behavioral measure of impulsivity. RESULTS AND CONCLUSIONS Lifetime suicide attempts were reported by 43% of patients in alcohol treatment; of which 62% were impulsive. Compared to patients without a suicide attempt, those with a non-impulsive attempt were more likely to have a history of sexual abuse (OR=7.17), a family history of suicide (OR=4.09), and higher scores on a personality measure of impulsiveness (OR=2.27). The only significant factor that distinguished patients with impulsive suicide attempts from patients without a suicide attempt and from patients with a non-impulsive suicide attempt was a higher level of behavioral impulsivity (OR=1.84-2.42). LIMITATIONS Retrospective self-report of suicide attempts and family history. Lack of diagnostic measure.

Effects of alcoholism severity and smoking on executive neurocognitive function.

AIMS Neurocognitive deficits in chronic alcoholic men are well documented. Impairments include memory, visual-spatial processing, problem solving and executive function. The cause of impairment could include direct effects of alcohol toxicity, pre-existing cognitive deficits that predispose towards substance abuse, comorbid psychiatric disorders and abuse of substances other than alcohol. Cigarette smoking occurs at higher rates in alcoholism and has been linked to poor cognitive performance, yet the effects of smoking on cognitive function in alcoholism are often ignored. We examined whether chronic alcoholism and chronic smoking have effects on executive function. METHODS Alcoholism and smoking were examined in a community-recruited sample of alcoholic and non-alcoholic men (n = 240) using standard neuropsychological and reaction-time measures of executive function. Alcoholism was measured as the average level of alcoholism diagnoses across the study duration (12 years). Smoking was measured in pack-years. RESULTS Both alcoholism and smoking were correlated negatively with a composite executive function score. For component measures, alcoholism was correlated negatively with a broad range of measures, whereas smoking was correlated negatively with measures that emphasize response speed. In regression analyses, both smoking and alcoholism were significant predictors of executive function composite. However, when IQ is included in the regression analyses, alcoholism severity is no longer significant. CONCLUSIONS Both smoking and alcoholism were related to executive function. However, the effect of alcoholism was not independent of IQ, suggesting a generalized effect, perhaps affecting a wide range of cognitive abilities of which executive function is a component. On the other hand, the effect of smoking on measures relying on response speed were independent of IQ, suggesting a more specific processing speed deficit associated with chronic smoking.

Trajectories of childhood aggression and inattention/hyperactivity: Differential effects on substance abuse in adolescence

OBJECTIVE Aggression and hyperactivity/inattention each are linked to risk of alcohol use disorder (AUD), but their unique contributions remain ambiguous. The present study disaggregated these two domains developmentally and examined the relation between childhood behavior trajectories and adolescent substance use. METHOD A total of 335 children of alcoholic and nonalcoholic fathers were studied prospectively. Parallel process latent trajectory class analysis was developed with behavioral ratings by parents and teachers of aggression and inattention/hyperactivity across ages 7 to 16. Membership in the four latent classes was used as a predictor for problem adolescence alcohol use and substance onset. RESULTS Youths in the four latent trajectory classes differed in number of alcohol problems at age 16: healthy class (39% of sample, mean 2.1 alcohol-related problems), inattentive/hyperactive but not aggressive (33%; mean 2.7 problems), aggressive but not inattentive/hyperactive (4%, mean 5.0 problems), and comorbid (24%; mean 4.0 problems). Survival analysis revealed that the aggressive, comorbid, and inattentive/hyperactive classes had significantly earlier onsets of drinking, drunkenness, and marijuana use than the healthy class. Illicit drug use was also significantly increased in the comorbid, aggressive, and inattentive/hyperactive classes compared to the healthy class. CONCLUSIONS Three levels of behavioral risk of substance abuse exist, the highest having trajectories of increased aggressive and inattentive/hyperactive problems throughout childhood, the next involving only an increased inattentive/hyperactive behavioral trajectory, and the lowest involving those with neither type of problem. Children with both inattention/hyperactivity and aggression have the greatest need for childhood intervention to prevent substance abuse in adolescence.