Functional neuroimaging evidence for high cognitive effort on the Word Memory Test in the absence of external incentives

Neurocognitive Changes in Patients with Post-COVID Depression

Background: Depression and cognitive impairment are recognized complications of COVID-19. This study aimed to assess cognitive performance in clinically diagnosed post-COVID depression (PCD, n = 25) patients using neuropsychological testing. Methods: The study involved 71 post-COVID patients with matched control groups: recovered COVID-19 individuals without complications (n = 18) and individuals without prior COVID-19 history (n = 19). A post-COVID depression group (PCD, n = 25) was identified based on psychiatric diagnosis, and a comparison group (noPCD, n = 46) included participants with neurological COVID-19 complications, excluding clinical depression. Results: The PCD patients showed gender-dependent significant cognitive impairment in the MoCA, Word Memory Test (WMT), Stroop task (SCWT), and Trail Making Test (TMT) compared to the controls and noPCD patients. Men with PCD showed worse performances on the SCWT, in MoCA attention score, and on the WMT (immediate and delayed word recall), while women with PCD showed a decline in MoCA total score, an increased processing time with less errors on the TMT, and worse immediate recall. No differences between groups in Sniffin's stick test were found. Conclusions: COVID-related direct (post-COVID symptoms) and depression-mediated (depression itself, male sex, and severity of COVID-19) predictors of decline in memory and information processing speed were identified. Our findings may help to personalize the treatment of depression, taking a patient's gender and severity of previous COVID-19 disease into account.

A network-based cognitive training induces cognitive improvements and neuroplastic changes in patients with relapsing-remitting multiple sclerosis: an exploratory case-control study

Cognitive impairments are commonly observed in patients with multiple sclerosis and are associated with lower levels of quality of life. No consensus has been reached on how to tackle effectively cognitive decline in this clinical population non-pharmacologically. This exploratory case-control study aims to investigate the effectiveness of a hypothesis-based cognitive training designed to target multiple domains by promoting the synchronous co-activation of different brain areas and thereby improve cognition and induce changes in functional connectivity in patients with relapsing-remitting multiple sclerosis. Forty-five patients (36 females and 9 males, mean age 44.62 ± 8.80 years) with clinically stable relapsing-remitting multiple sclerosis were assigned to either a standard cognitive training or to control groups (sham training and non-active control). The standard training included twenty sessions of computerized exercises involving various cognitive functions supported by distinct brain networks. The sham training was a modified version of the standard training that comprised the same exercises and number of sessions but with increased processing speed load. The non-active control group received no cognitive training. All patients underwent comprehensive neuropsychological and magnetic resonance imaging assessments at baseline and after 5 weeks. Cognitive and resting-state magnetic resonance imaging data were analyzed using repeated measures models. At reassessment, the standard training group showed significant cognitive improvements compared to both control groups in memory tasks not specifically targeted by the training: the Buschke Selective Reminding Test and the Semantic Fluency test. The standard training group showed reductions in functional connectivity of the salience network, in the anterior cingulate cortex, associated with improvements on the Buschke Selective Reminding Test. No changes were observed in the sham training group. These findings suggest that multi-domain training that stimulates multiple brain areas synchronously may improve cognition in people with relapsing-remitting multiple sclerosis if sufficient time to process training material is allowed. The associated reduction in functional connectivity of the salience network suggests that training-induced neuroplastic functional reorganization may be the mechanism supporting performance gains. This study was approved by the Regional Ethics Committee of Yorkshire and Humber (approval No. 12/YH/0474) on November 20, 2013.

Performance Validity Testing in Justice-Involved Adults with Fetal Alcohol Spectrum Disorder

OBJECTIVES

A number of commonly used performance validity tests (PVTs) may be prone to high failure rates when used for individuals with severe neurocognitive deficits. This study investigated the validity of 10 PVT scores in justice-involved adults with fetal alcohol spectrum disorder (FASD), a neurodevelopmental disability stemming from prenatal alcohol exposure and linked with severe neurocognitive deficits.

METHOD

The sample comprised 80 justice-involved adults (ages 19-40) including 25 with confirmed or possible FASD and 55 where FASD was ruled out. Ten PVT scores were calculated, derived from Word Memory Test, Genuine Memory Impairment Profile, Advanced Clinical Solutions (Word Choice), the Wechsler Adult Intelligence Scale - Fourth Edition (Reliable Digit Span and age-corrected scaled scores (ACSS) from Digit Span, Coding, Symbol Search, Coding - Symbol Search, Vocabulary - Digit Span), and the Wechsler Memory Scale - Fourth Edition (Logical Memory II Recognition).

RESULTS

Participants with diagnosed/possible FASD were more likely to fail any single PVT, and failed a greater number of PVTs overall, compared to those without FASD. They were also more likely to fail based on Word Memory Test, Digit Span ACSS, Coding ACSS, Symbol Search ACSS, and Logical Memory II Recognition, compared to controls (35-76%). Across both groups, substantially more participants with IQ <70 failed two or more PVTs (90%), compared to those with an IQ ≥70 (44%).

CONCLUSIONS

Results highlight the need for additional research examining the use of PVTs in justice-involved populations with FASD.

White Matter Associations With Performance Validity Testing in Veterans With Mild Traumatic Brain Injury: The Utility of Biomarkers in Complicated Assessment

OBJECTIVE

Failure on performance validity tests (PVTs) is common in Veterans with histories of mild traumatic brain injury (mTBI), leading to questionable validity of clinical presentations.

PARTICIPANTS

Using diffusion tensor imaging, we investigated white matter (WM) integrity and cognition in 79 Veterans with history of mTBI who passed PVTs (n = 43; traumatic brain injury [TBI]-passed), history of mTBI who failed at least 1 PVT (n = 13; TBI-failed), and military controls (n = 23; MCs) with no history of TBI.

RESULTS

The TBI-failed group demonstrated significantly lower cognitive scores relative to MCs and the TBI-passed group; however, no such differences were observed between MCs and the TBI-passed group. On a global measure of WM integrity (ie, WM burden), the TBI-failed group showed more overall WM abnormalities than the other groups. However, no differences were observed between the MCs and TBI-passed group on WM burden. Interestingly, regional WM analyses revealed abnormalities in the anterior internal capsule and cingulum of both TBI subgroups relative to MCs. Moreover, compared with the TBI-passed group, the TBI-failed group demonstrated significantly decreased WM integrity in the corpus callosum.

CONCLUSIONS

Findings revealed that, within our sample, WM abnormalities are evident in those who fail PVTs. This study adds to the burgeoning PVT literature by suggesting that poor PVT performance does not negate the possibility of underlying WM abnormalities in military personnel with history of mTBI.

The What, the When, and the Whether of Intentional Action in the Brain: A Meta-Analytical Review

In their attempt to define discrete subcomponents of intentionality, Brass and Haggard (2008) proposed their What, When, and Whether model (www-model) which postulates that the content, the timing and the possibility of generating an action can be partially independent both at the cognitive level and at the level of their neural implementation. The original proposal was based on a limited number of studies, which were reviewed with a discursive approach. To assess whether the model stands in front of the more recently published data, we performed a systematic review of the literature with a meta-analytic method based on a hierarchical clustering (HC) algorithm. We identified 15 PET/fMRI studies well-suited for this quest. HC revealed the existence of a rostro-caudal gradient within the medial prefrontal cortex, with the more anterior regions (the anterior cingulum) involved in more abstract decisions of whether to execute an action and the more posterior ones (the middle cingulum or the SMA) recruited in specifying the content and the timing components of actions. However, in contrast with the original www-model, this dissociation involves also brain regions well outside the median wall of the frontal lobe, in a component specific manner: the supramarginal gyrus for the what component, the pallidum and the thalamus for the when component, the putamen and the insula for the whether component. We then calculated co-activation maps on the three component-specific www clusters of the medial wall of the frontal/limbic lobe: to this end, we used the activation likelihood approach that we applied on the imaging studies on action contained in the BrainMap.org database. This analysis confirmed the main findings of the HC analyses. However, the BrainMap.org data analyses also showed that the aforementioned segregations are generated by paradigms in which subjects act in response to conditional stimuli rather than while driven by their own intentions. We conclude that the available data confirm that the neural underpinnings of intentionality can be fractionated in discrete components that are partially independent. We also suggest that intentionality manifests itself in discrete components through the boosting of general purpose action-related regions specialized for different aspects of action selection and inhibition.

Word Memory Test Predicts Recovery in Claimants With Work-Related Head Injury

OBJECTIVE

To investigate the predictive validity of the Word Memory Test (WMT), a verbal memory neuropsychological test developed as a performance validity measure to assess memory, effort, and performance consistency.

DESIGN

Cohort study with 1-year follow-up.

SETTING

Workers' compensation rehabilitation facility.

PARTICIPANTS

Participants included workers' compensation claimants with work-related head injury (N=188; mean age, 44y; 161 men [85.6%]).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Outcome measures for determining predictive validity included days to suspension of wage replacement benefits during the 1-year follow-up and work status at discharge in claimants undergoing rehabilitation. Analysis included multivariable Cox and logistic regression.

RESULTS

Better WMT performance was significantly but weakly correlated with younger age (r=-.30), documented brain abnormality (r=.28), and loss of consciousness at the time of injury (r=.25). Claimants with documented brain abnormalities on diagnostic imaging scans performed better (∼9%) on the WMT than those without brain abnormalities. The WMT predicted days receiving benefits (adjusted hazard ratio, 1.13; 95% confidence interval, 1.04-1.24) and work status outcome at program discharge (adjusted odds ratio, 1.62; 95% confidence interval, 1.13-2.34).

CONCLUSIONS

Our results provide evidence for the predictive validity of the WMT in workers' compensation claimants. Younger claimants and those with more severe brain injuries performed better on the WMT. It may be that financial incentives or other factors related to the compensation claim affected the performance.

Utility of Green's Word Memory Test Free Recall Subtest as a Measure of Verbal Memory: Initial Evidence from a Temporal Lobe Epilepsy Clinical Sample

This study investigated the Word Memory Test (WMT) Free Recall (FR) subtest as a conventional memory measure. Nineteen participants with pharmacoresistant left temporal lobe epilepsy (LTLE) and 16 with right temporal lobe epilepsy (RTLE) completed the WMT, Rey Auditory Verbal Learning Test (RAVLT), and Wechsler Memory Scale-Fourth Edition Logical Memory (LM) subtest during presurgical evaluation. LTLE participants performed significantly worse on FR subtest (p < .05, [Formula: see text]) and RAVLT Trial 7 (p < .01, [Formula: see text]), but not on LM subtest. Age was a significant covariate for FR (p < .01, [Formula: see text]). Logistic regression revealed FR plus age and RAVLT age-adjusted T-scores both yielded 77.1% classification accuracy and respective diagnostic odds ratios of 11.36 and 11.84. Receiver operating characteristic curves to classify seizure laterality found that RAVLT and FR were significant (area under the curve [AUC] = 0.82 and 0.74), whereas LM was nonsignificant (AUC = 0.67). Cut scores and positive/negative predictive values were established for improved clinical classification.

Effort, symptom validity testing, performance validity testing and traumatic brain injury

BACKGROUND

To understand the neurocognitive effects of brain injury, valid neuropsychological test findings are paramount.

REVIEW

This review examines the research on what has been referred to a symptom validity testing (SVT). Above a designated cut-score signifies a 'passing' SVT performance which is likely the best indicator of valid neuropsychological test findings. Likewise, substantially below cut-point performance that nears chance or is at chance signifies invalid test performance. Significantly below chance is the sine qua non neuropsychological indicator for malingering. However, the interpretative problems with SVT performance below the cut-point yet far above chance are substantial, as pointed out in this review. This intermediate, border-zone performance on SVT measures is where substantial interpretative challenges exist. Case studies are used to highlight the many areas where additional research is needed. Historical perspectives are reviewed along with the neurobiology of effort. Reasons why performance validity testing (PVT) may be better than the SVT term are reviewed.

CONCLUSIONS

Advances in neuroimaging techniques may be key in better understanding the meaning of border zone SVT failure. The review demonstrates the problems with rigidity in interpretation with established cut-scores. A better understanding of how certain types of neurological, neuropsychiatric and/or even test conditions may affect SVT performance is needed.

The impact of age on load-related dorsolateral prefrontal cortex activation

Healthy aging is accompanied by working memory-related functional cerebral changes. Depending on performance accuracy and the level of working memory demands, older adults show task-related patterns of either increased or decreased activation compared to younger adults. Controversies remain concerning the interpretation of these changes and whether they already manifest in earlier decades of life. To address these issues, functional magnetic resonance imaging (fMRI) was used to examine brain activation during spatial working memory retrieval in 45 healthy individuals between 20 and 68 years of age. Participants performed a modified version of the Corsi Block-Tapping test (CBT). The CBT requires the storage and subsequent reproduction of spatial target sequences and allows modulating working memory load by a variation of sequence length. Results revealed that activation intensity at the lowest CBT load level increased with increasing age and positively correlated with the number of errors. At higher CBT load levels, activation intensity decreased with increasing age together with a disproportional accuracy decline on the behavioral level. Moreover, results suggests that younger individuals showed higher activation intensity at high CBT load than at low CBT load switching to the opposite pattern at an age of about 40 years. Consistent with the assumptions of the Compensation-Related Utilization of Neural Circuits Hypothesis (CRUNCH), the present results reveal specific age-related alterations in left dorsolateral prefrontal cortex activation in response to increasing task load. Specifically, the results point toward increasing neural inefficiency with age at low task load and a progressive limitation of resources with age at higher task load. The present findings argue for an increasing functional cerebral dysfunction over a time span of 50 years that may partly be compensated on the behavioral level until a resource ceiling is approached.

Brain activation deficit in increased-load working memory tasks among adults with ADHD using fMRI

Working memory (WM) is impaired among adults with attention-deficit hyperactivity disorder (ADHD). This study aimed to investigate the brain activation deficit for low-level or increased-load WM among adults with ADHD. A total of 20 adults with ADHD and controls were recruited according to diagnostic interviewing by a psychiatrist. Phonological and visual-spatial 2-back and 3-back tasks were performed under functional magnetic resonance scanning. The results demonstrated that both the adults with ADHD and the controls exhibited activation of the fronto-parietal network for WM, and the intensity was greater in the adult ADHD group. The ADHD group had higher brain activation over the bilateral anterior cingulate, left inferior frontal lobe, hippocampus, and supplementary motor area (SMA) for phonological WM than the control group. When the task loading increased from 2-back to 3-back tasks, the adults with ADHD perceived greater difficulty. The control group exhibited increased brain activation over the frontal-parietal network in response to increased phonological WM load. However, the ADHD group showed decreased brain activation over the left precuneus, insula, and SMA. Further analysis demonstrated that the ADHD group exhibited a greater decrease in brain activation over the left fronto-parietal network, including the precuneus, SMA, insula/inferior frontal lobe, and dorsolateral prefrontal cortex, than the control group. These results suggest that adults with ADHD pay more effort to low demanding phonological WM. On the other hand, brain activation of the left fronto-parietal network is impaired when the demands of WM exceed the capacity of adults with ADHD.

Detecting Deceptive Chat-Based Communication Using Typing Behavior and Message Cues

Computer-mediated deception is prevalent and may have serious consequences for individuals, organizations, and society. This article investigates several metrics as predictors of deception in synchronous chat-based environments, where participants must often spontaneously formulate deceptive responses. Based on cognitive load theory, we hypothesize that deception influences response time, word count, lexical diversity, and the number of times a chat message is edited. Using a custom chatbot to conduct interviews in an experiment, we collected 1,572 deceitful and 1,590 truthful chat-based responses. The results of the experiment confirm that deception is positively correlated with response time and the number of edits and negatively correlated to word count. Contrary to our prediction, we found that deception is not significantly correlated with lexical diversity. Furthermore, the age of the participant moderates the influence of deception on response time. Our results have implications for understanding deceit in chat-based communication and building deception-detection decision aids in chat-based systems.

Performance on the Green Word Memory Test following Operation Enduring Freedom/Operation Iraqi Freedom-era military service: Test failure is related to evaluation context

This study investigates prior reports of high neuropsychological symptom validity test (SVT) failure rates in post-deployed Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) active and veteran military personnel, using a large, multi-site sample (N = 214) drawn from three levels of the Department of Defense/Department of Veterans Affairs (VA) Polytrauma System of Care. The sample failure rate and its relationship to research versus dual research/clinical context of evaluation were examined, in addition to secondary variables explored in prior studies. Results yielded an overall failure rate of 25%, lower than prior reports describing OEF/OIF active-duty and veteran military personnel. Findings also supported the hypothesis that SVT failure rates would differ by context (dual > research). Participants with traumatic brain injury (TBI) failed more frequently than those without TBI in the dual context but not in the research context. Secondary analyses revealed that failure rates increased in the presence of depression, posttraumatic stress disorder, and male sex but were unrelated to active versus veteran military status, service connection (SC) or percentage of SC, age, education, or ethnicity. Further research is required to elucidate the underpinnings of these findings in light of the limited literature and variability between OEF/OIF-related SVT studies, as well as the substantial diagnostic and treatment implications for VA.

The neural basis of difficulties disengaging from negative irrelevant material in major depression

Recurrent uncontrollable negative thoughts are a hallmark of depressive episodes. Deficits in cognitive control have been proposed to underlie this debilitating aspect of depression. Here, we used functional neuroimaging during an emotional working memory (WM) task to elucidate the neural correlates of these difficulties in cognitive control. In a WM manipulation involving depressed participants, the dorsal anterior cingulate and parietal and bilateral insular cortices were activated significantly more when negative words were removed from WM than when they were maintained in WM; in contrast, nondepressed participants exhibited stronger neural activations in these regions for positive than for negative material. These findings implicate anomalous activation of components of the task-positive network, known to be modulated by cognitive effort, in depression-associated difficulties in expelling negative material from WM. Future studies should examine the association between these aberrations and the maintenance of depressive symptoms.

Cognitive and neural aspects of information processing in major depressive disorder: an integrative perspective

Researchers using experimental paradigms to examine cognitive processes have demonstrated that Major Depressive Disorder (MDD) is associated not with a general deficit in cognitive functioning, but instead with more specific anomalies in the processing of negatively valenced material. Indeed, cognitive theories of depression posit that negative biases in the processing of information play a critical role in influencing the onset, maintenance, and recurrence of depressive episodes. In this paper we review findings from behavioral studies documenting that MDD is associated with specific difficulties in attentional disengagement from negatively valenced material, with tendencies to interpret information in a negative manner, with deficits in cognitive control in the processing of negative material, and with enhanced memory for negative material. To gain a better understanding of the neurobiological basis of these abnormalities, we also examine findings from functional neuroimaging studies of depression and show that dysfunction in neural systems that subserve emotion processing, inhibition, and attention may underlie and contribute to the deficits in cognition that have been documented in depressed individuals. Finally, we briefly review evidence from studies of children who are at high familial risk for depression that indicates that abnormalities in cognition and neural function are observable before the onset of MDD and, consequently, may represent a risk factor for the development of this disorder. By integrating research from cognitive and neural investigations of depression, we can gain a more comprehensive understanding not only of how cognitive and biological factors interact to affect the onset, maintenance, and course of MDD, but also of how such research can aid in the development of targeted strategies for the prevention and treatment of this debilitating disorder.

Symptom validity testing, effort, and neuropsychological assessment

Symptom validity testing (SVT) has become a major theme of contemporary neuropsychological research. However, many issues about the meaning and interpretation of SVT findings will require the best in research design and methods to more precisely characterize what SVT tasks measure and how SVT test findings are to be used in neuropsychological assessment. Major clinical and research issues are overviewed including the use of the “effort” term to connote validity of SVT performance, the use of cut-scores, the absence of lesion-localization studies in SVT research, neuropsychiatric status and SVT performance and the rigor of SVT research designs. Case studies that demonstrate critical issues involving SVT interpretation are presented.

When doing nothing is an option: the neural correlates of deciding whether to act or not

The neural basis of intentionally deciding between different response alternatives has been extensively investigated and associated with the rostral cingulate zone (RCZ). However, from daily experience we know that the decision whether to do something is often prior to the decision what to do. This raises the fundamental question whether the decision to act and the decision not to act can be considered as functionally equivalent. Interestingly, in the legal domain such an equivalence is implicitly assumed by punishing crimes of omission. The aim of the current study was to explicitly test this assumption by comparing the neural representation of intentional actions with intentional non-actions. Our results suggest, that weighing whether to act or not involves similar areas of the brain, namely RCZ and dorsolateral prefrontal cortex, independent of the outcome of this decision. This finding strongly supports the assumption that intentionally not acting can be considered as a mode of action.

Neuroanatomical correlates of malingered memory impairment: event-related fMRI of deception on a recognition memory task

PRIMARY OBJECTIVE

Event-related, functional magnetic resonance imaging (fMRI) data were acquired in healthy participants during purposefully malingered and normal recognition memory performances to evaluate the neural substrates of feigned memory impairment.

METHODS AND PROCEDURES

Pairwise, between-condition contrasts of neural activity associated with discrete recognition memory responses were conducted to isolate dissociable neural activity between normal and malingered responding while simultaneously controlling for shared stimulus familiarity and novelty effects. Response timing characteristics were also examined for any association with observed between-condition activity differences.

OUTCOMES AND RESULTS

Malingered recognition memory errors, regardless of type, were associated with inferior parietal and superior temporal activity relative to normal performance, while feigned recognition target misses produced additional dorsomedial frontal activation and feigned foil false alarms activated bilateral ventrolateral frontal regions. Malingered response times were associated with activity in the dorsomedial frontal, temporal and inferior parietal regions. Normal memory responses were associated with greater inferior occipitotemporal and dorsomedial parietal activity, suggesting greater reliance upon visual/attentional networks for proper task performance.

CONCLUSIONS

The neural substrates subserving feigned recognition memory deficits are influenced by response demand and error type, producing differential activation of cortical regions important to complex visual processing, executive control, response planning and working memory processes.

The effect of distraction on the Word Memory Test and Test of Memory Malingering performance in patients with a severe brain injury

This research compares the performance of a sample of non-litigating participants with severe brain injury on both the WMT and TOMM under conditions of (1) full effort, (2) distraction, or (3) simulated malingering. The study included 60 participants with a severe brain injury and used restricted randomization to assign participants to the groups. Following Craik (1982) an auditory distraction task was used during the learning phase of each test in the distraction group, while a scenario adapted from Tombaugh (1997) was used to encourage simulation of memory impairment in the simulated malingering group. The results of this study clearly showed that while both tests demonstrated excellent sensitivity, the false positive rates for the WMT were significantly greater than those for the TOMM. It was concluded that the so-called "effort" components of the WMT required more cognitive capacity than was previously believed.