Validation of real-time fMRI neurofeedback procedure for cognitive training using counterbalanced active-sham study design.

Investigation of neural mechanisms of real-time functional MRI neurofeedback (rtfMRI-nf) training requires an efficient study control approach. A common rtfMRI-nf study design involves an experimental group, receiving active rtfMRI-nf, and a control group, provided with sham rtfMRI-nf. We report the first study in which rtfMRI-nf procedure is controlled through counterbalancing training runs with active and sham rtfMRI-nf for each participant. Healthy volunteers (n = 18) used rtfMRI-nf to upregulate fMRI activity of an individually defined target region in the left dorsolateral prefrontal cortex (DLPFC) while performing tasks that involved mental generation of a random numerical sequence and serial summation of numbers in the sequence. Sham rtfMRI-nf was provided based on fMRI activity of a different brain region, not involved in these tasks. The experimental procedure included two training runs with the active rtfMRI-nf and two runs with the sham rtfMRI-nf, in a randomized order. The participants achieved significantly higher fMRI activation of the left DLPFC target region during the active rtfMRI-nf conditions compared to the sham rtfMRI-nf conditions. fMRI functional connectivity of the left DLPFC target region with the nodes of the central executive network was significantly enhanced during the active rtfMRI-nf conditions relative to the sham conditions. fMRI connectivity of the target region with the nodes of the default mode network was similarly enhanced. fMRI connectivity changes between the active and sham conditions exhibited meaningful associations with individual performance measures on the Working Memory Multimodal Attention Task, the Approach-Avoidance Task, and the Trail Making Test. Our results demonstrate that the counterbalanced active-sham study design can be efficiently used to investigate mechanisms of active rtfMRI-nf in direct comparison to those of sham rtfMRI-nf. Further studies with larger group sizes are needed to confirm the reported findings and evaluate clinical utility of this study control approach.

Sex- and Age-Related Differences in Post-Concussive Symptom Reporting Among Children and Their Parents.

Pediatric mild traumatic brain injury (pmTBI) has received increased public attention over the past decade, especially for children who experience persistent post-concussive symptoms (PCS). Common methods for obtaining pediatric PCS rely on both self- and parental report, exhibit moderate test-retest reliability, and variable child-parent agreement, and may yield high false positives. The current study investigated the impact of age and biological sex on PCS reporting (Post-Concussion Symptom Inventory) in patients with pmTBI (n = 286) at retrospective, 1 week, 4 months, and 1 year post-injury time points, as well as reported symptoms in healthy controls (HC; n = 218) at equivalent assessment times. HC and their parents reported higher PCS for their retrospective rating relative to the other three other study visits. Child-parent agreement was highest for female adolescents, but only approached acceptable ranges (≥ 0.75) immediately post-injury. Poor-to-fair child/parental agreement was observed for most other study visits for pmTBI and at all visits for HC. Parents rated female adolescents as being more symptomatic than their male counterparts in spite of small (pmTBI) or no (HC) sex-related differences in self-reported ratings, suggestive of a potential cultural bias in parental ratings. Test-retest reliability for self-report was typically below acceptable ranges for both pmTBI and HC groups, with reliability decreasing for HC and increasing for pmTBI as a function of time between visits. Parental test-retest reliability was higher for females. Although continued research is needed, current results support the use of child self-report over parental ratings for estimating PCS burden. Results also highlight the perils of relying on symptom self-report for diagnostic and prognostic purposes.

Neural correlates of cognitive control deficits in pediatric mild traumatic brain injury.

There is a growing body of research showing that cerebral pathophysiological processes triggered by pediatric mild traumatic brain injury (pmTBI) may extend beyond the usual clinical recovery timeline. It is paramount to further unravel these processes, because the possible long-term cognitive effects resulting from ongoing secondary injury in the developing brain are not known. In the current fMRI study, neural processes related to cognitive control were studied in 181 patients with pmTBI at sub-acute (SA; ~1 week) and early chronic (EC; ~4 months) stages post-injury. Additionally, a group of 162 age- and sex-matched healthy controls (HC) were recruited at equivalent time points. Proactive (post-cue) and reactive (post-probe) cognitive control were examined using a multimodal attention fMRI paradigm for either congruent or incongruent stimuli. To study brain network function, the triple-network model was used, consisting of the executive and salience networks (collectively known as the cognitive control network), and the default mode network. Additionally, whole-brain voxel-wise analyses were performed. Decreased deactivation was found within the default mode network at the EC stage following pmTBI during both proactive and reactive control. Voxel-wise analyses revealed sub-acute hypoactivation of a frontal area of the cognitive control network (left pre-supplementary motor area) during proactive control, with a reversed effect at the EC stage after pmTBI. Similar effects were observed in areas outside of the triple-network during reactive control. Group differences in activation during proactive control were limited to the visual domain, whereas for reactive control findings were more pronounced during the attendance of auditory stimuli. No significant correlations were present between task-related activations and (persistent) post-concussive symptoms. In aggregate, current results show alterations in neural functioning during cognitive control in pmTBI up to 4 months post-injury, regardless of clinical recovery. We propose that subacute decreases in activity reflect a general state of hypo-excitability due to the injury, while early chronic hyperactivation represents a compensatory mechanism to prevent default mode interference and to retain cognitive control.

Test-Retest Reliability of Microlinguistic Information Derived From Spoken Discourse in Persons With Chronic Aphasia.

PURPOSE: The purpose of this study was to characterize test-retest reliability of discourse measures across a battery of common tasks in individuals with aphasia and prospectively matched adults without brain damage. METHOD: We collected spoken discourse during five monologue tasks at two timepoints (test and retest; within 2 weeks apart) in an aphasia group (n = 23) and a peer group with no brain damage (n = 24). We evaluated test-retest reliability for percentage of correct information units, correct information units per minute, mean length of utterance, verbs per utterance, noun/verb ratio, open/closed class word ratio, tokens, sample duration (seconds), propositional idea density, type-token ratio, and words per minute. We explored reliability's relationship with sample length and aphasia severity. RESULTS: Rater reliability was excellent. Across tasks, both groups demonstrated discourse measures with poor, moderate, and good reliability, with the aphasia group having measures demonstrating excellent test-retest reliability. When evaluating measures within each task, test-retest reliability again ranged from poor to excellent for both groups. Across groups and task, measures that appeared most reliable appeared to reflect lexical, informativeness, or fluency information. Sample length and aphasia severity impacted reliability, and this differed across and by task. CONCLUSIONS: We identified several discourse measures that were reliable across and within tasks. Test-retest statistics are intimately linked to the specific sample, emphasizing the importance of multiple baseline studies. Task itself should be considered an important variable, and it should not be assumed that discourse measures found to be reliable across several tasks (averaged) are likewise reliable for a single task. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23298032.

Conducting a Virtual Study With Special Considerations for Working With Persons With Aphasia.

Purpose The use of technology (e.g., telehealth) in clinical settings has rapidly increased, and its use in research settings continues to grow. The aim of this report is to present one potential solution to a clinical issue that of virtual and remote assessment for the purposes of spoken language research in persons with aphasia (PWA). To do so, we report detailed methods for conducting a multitimepoint (test-retest) virtual paradigm, assessing lifestyle, physiological, cognitive, and linguistic factors in persons with and without aphasia. Method Procedures for virtual assessment are detailed in a sample of adults with no brain damage (N = 24) and PWA (N = 25) on a test-retest paradigm (data collection approximately 10 ± 3 days apart). This report provides practical information about pre-assessment (e.g., recruitment, scheduling), assessment (e.g., aphasia-friendly consent presentation, investigator fidelity), and postassessment (e.g., data storage, quality check) procedures for human behavior research using a virtual platform. Results Preliminary study data are provided, indicating high retention rates, high rates of data acquisition, and feasibility. Common technological troubles and solutions are discussed, and solutions are offered. The results suggest that our pre-assessment, assessment, and postassessment procedures contributed to the success of our study. Conclusions We provide a practical methodology for conducting a multitimepoint study, with considerations for PWA, adding to the body of research on telehealth in clinical populations. Future studies should continue to evaluate telemethodology, which may be core for diversifying studies, improving study retention, and enrolling larger sample sizes. Supplemental Material https://doi.org/10.23641/asha.14608101.