Overcoming residual interference in mental set switching: neural correlates and developmental trajectory

Common and distinct neural correlates of dual-tasking and task-switching: a meta-analytic review and a neuro-cognitive processing model of human multitasking

Although there are well-known limitations of the human cognitive system in performing two tasks simultaneously (dual-tasking) or alternatingly (task-switching), the question for a common vs. distinct neural basis of these multitasking limitations is still open. We performed two Activation Likelihood Estimation meta-analyses of neuroimaging studies on dual-tasking or task-switching and tested for commonalities and differences in the brain regions associated with either domain. We found a common core network related to multitasking comprising bilateral intraparietal sulcus (IPS), left dorsal premotor cortex (dPMC), and right anterior insula. Meta-analytic contrasts revealed eight fronto-parietal clusters more consistently activated in dual-tasking (bilateral frontal operculum, dPMC, and anterior IPS, left inferior frontal sulcus and left inferior frontal gyrus) and, conversely, four clusters (left inferior frontal junction, posterior IPS, and precuneus as well as frontomedial cortex) more consistently activated in task-switching. Together with sub-analyses of preparation effects in task-switching, our results argue against purely passive structural processing limitations in multitasking. Based on these findings and drawing on current theorizing, we present a neuro-cognitive processing model of multitasking.

Physiological substrates of executive functioning: a systematic review of the literature

Executive function (EF) is a multifaceted construct that has been defined as a set of higher-order cognitive processes that allow for flexibility, self-regulation, strategic planning, and goal-directed behaviors. EFs have been studied in numerous clinical disorders using a variety of neuropsychological tasks and, more recently, neuroimaging techniques. The underlying physiological substrates of EF were historically attributed to the frontal lobes; however, recent studies suggest more widespread involvement of additional brain regions. The purpose of the present study was to conduct a systematic review (using PRISMA 2009 guidelines) of neuroimaging studies employing functional magnetic resonance imaging and diffusion tensor imaging methods investigating the physiological substrates of EFs in attention-deficit/hyperactivity disorder compared to other clinical groups and non-clinical participants. Research articles were retrieved using PsycINFO, PsycARTICLES, MEDLINE, and ScienceDirect, beginning February 2015 through May 2016. A total of 42 studies met eligibility. Of those 42 studies, 22 studies included clinical participants and 20 studies included non-clinical participants. Results revealed increased activation of the frontal brain region in the majority of non-clinical studies and approximately 50% of the clinical studies, albeit with some inconsistencies across subregions, tasks, and age groups. Implications, methodological limitations, and suggestions for future research are discussed.

fMRI response to negative words and SSRI treatment outcome in major depressive disorder: a preliminary study

Clinically useful predictors of treatment outcome in major depressive disorder (MDD) remain elusive. We examined associations between functional magnetic resonance imaging (fMRI) blood oxygen level dependent (BOLD) signal during active negative word processing and subsequent selective serotonin reuptake inhibitor (SSRI) treatment outcome in MDD. Unmedicated MDD subjects (n=17) performed an emotional word processing fMRI task, and then received eight weeks of standardized antidepressant treatment with escitalopram. Lower pre-treatment BOLD responses to negative words in midbrain, dorsolateral prefrontal cortex, paracingulate, anterior cingulate, thalamus and caudate nuclei correlated significantly with greater improvement following escitalopram treatment. Activation of these regions in response to negative words correlated significantly with reaction time for rating word relevance. Maximally predictive clusters of voxels identified using a cross-validation approach predicted 48% of the variance in response to treatment. This study provides preliminary evidence that SSRIs may be most beneficial in patients who are less able to engage cognitive control networks while processing negative stimuli. Differences between these findings and previous fMRI studies of SSRI treatment outcome may relate to differences in task design. Regional BOLD responses to negative words predictive of SSRI outcome in this study were both overlapping and distinct from those predictive of outcome with cognitive behavioral therapy (CBT) in previous studies using the same task. Future studies may examine prediction of differential outcome across treatments in the context of a randomized controlled trial.

Psychosocial working conditions and cognitive complaints among Swedish employees

BACKGROUND

Cognitive complaints involving problems with concentration, memory, decision-making and thinking are relatively common in the work force. The sensitivity of both subjective and objective cognitive functioning to common psychiatric conditions, stress levels and to cognitive load makes it plausible that psychosocial working conditions play a role in cognitive complaints. Thus, this study aimed to test the associations between psychosocial work factors and cognitive complaints in nationally representative samples of the Swedish work force. Cross-sectional (n = 9751) and prospective (n = 3644; two time points two years apart) sequential multiple regression analyses were run, adjusting for general confounders, depressive- and sleeping problems. Additional prospective analyses were run adjusting for baseline cognitive complaints.

CROSS/SECTIONAL RESULTS

High quantitative demands, information and communication technology (ICT) demands, under qualification and conflicts were positively associated with cognitive complaints, while social support, good resources at work and over qualification were negatively associated with cognitive complaints in all models. Skill discretion and decision authority were weakly associated with cognitive complaints. Conflicts were more strongly associated with cognitive complaints in women than in men, after adjustment for general confounders.

PROSPECTIVE RESULTS

Quantitative job demands, ICT demands and under qualification were positively associated with future cognitive complaints in all models, including when adjusted for baseline cognitive complaints. Decision authority was weakly positively associated with future cognitive complaints, only after adjustment for depressive- and sleeping problems respectively. Social support was negatively associated with future cognitive complaints after adjustment for general confounders and baseline cognitive complaints. Skill discretion and resources were negatively associated with future cognitive complaints after adjustment for general confounders. The associations between quantitative demands and future cognitive complaints were stronger in women.

DISCUSSION/CONCLUSIONS

The findings indicate that psychosocial working conditions should be taken into account when considering cognitive complaints among employees.