Changes In Working Memory Research Articles

The Role of Working Memory in Age-Related Emotional Memory Bias

Aging is accompanied by deterioration in both working memory (WM) and long-term memory (LTM), yet whether these changes are related is not understood. Sleep plays a role in the formation of LTM in young adults, but the findings in older adults are not as clear. The types of memories we store also shift with age as young adults preserve a higher proportion of negative experiences when compared to older adults. The reason for this age-related change in emotional memory bias is also not clear; however, some studies have suggested that WM changes across aging may be an important factor. In the current study, we examined performance in WM and emotional LTM in younger and older adults. We added a daytime nap in half the subjects to examine a possible role of sleep on emotional LTM. In the morning, 93 younger (18–39) and 121 older (60–85) adults completed a WM task. Subjects also encoded neutral or negative word pairs and provided valence and arousal ratings for each pair. After half the subjects took a daytime nap, LTM was examined, and valence and arousal ratings were reassessed. Results indicate that older adults showed worse recognition for negative word pairs compared with neutral, as well as decreased negative valence ratings in the afternoon. This decrease in emotional reactivity was correlated with better LTM performance. In contrast, younger adults performed better on the negative compared to neutral word pairs, with no change in emotional reactivity and no association between emotional reactivity and LTM. In addition, WM was positively related to LTM in younger, but not in older adults. Lastly, no differences were shown across sleep, regardless of age. Our findings suggest that the emotional memory bias may be associated with the emotional saliency of the information in older adults, and with WM capacity in younger adults.

Functional neurodevelopment of working memory in early-onset schizophrenia: A longitudinal FMRI study

Schizophrenia, a debilitating disorder with typical manifestation of clinical symptoms in early adulthood, is characterized by cognitive impairments in executive processes such as in working memory (WM). However, there is a rare case of individuals with early-onset schizophrenia (EOS) starting before their 18th birthday, while WM and its neural substrates are still undergoing maturation. Using the WM n-back task with functional magnetic resonance imaging, we assessed the functional neurodevelopment of WM in adolescents with EOS and age- and gender-matched typically developing controls. Participants underwent neuroimaging in the same scanner twice, once at age 17 and at 21 (mean interscan interval = 4.3 years). General linear model analysis was performed to explore WM neurodevelopmental changes within and between groups. Psychopathological scores were entered in multiple regressions to detect brain regions whose longitudinal functional change was predicted by baseline symptoms in EOS. WM neurodevelopment was characterized by widespread functional reductions in frontotemporal and cingulate brain areas in patients and controls. No between-group differences were found in the trajectory of WM change. Baseline symptom scores predicted functional neurodevelopmental changes in frontal, cingulate, parietal, occipital, and cerebellar areas. The adolescent brain undergoes developmental processes such as synaptic pruning, which may underlie the refinement WM of network. Prefrontal and parietooccipital activity reduction is affected by clinical presentation of symptoms. Using longitudinal neuroimaging methods in a rare diagnostic sample of patients with EOS may help the advancement of neurodevelopmental biomarkers intended as pharmacological targets to tackle WM impairment.

SPCR-02 NEUROCOGNITIVE FUNCTION IN PATIENTS WITH LEPTOMENINGEAL METASTASIS TREATED WITH PROTON CRANIOSPINAL IRRADIATION

BACKGROUNDProton craniospinal irradiation (pCSI) as a potential treatment for patients with solid tumor leptomeningeal metastasis (LM) is being assessed in a phase II randomized study comparing it with photon involved-field radiotherapy (RT). We report the preliminary results of prospective neurocognitive function in a subset of patients treated with pCSI. METHODSPatients with LM and without evidence of CNS disease progression completed standardized neurocognitive tests of attention and working memory, executive function, and verbal memory at baseline (pre-pCSI), and 3 and 6 months post-pCSI. All patients received chemotherapy (baseline and follow up) and memantine (follow up). Means across the three timepoints were estimated for each neurocognitive test score using a linear mixed model (LMM) predicting the score by timepoint. Mean changes between pairs of timepoints were similarly estimated from the LMMs and tested for statistical significance using model-based contrasts. RESULTSBaseline, 3-month and 6-month neurocognitive data were available for 12, 11, and 8 patients, respectively. Linear mixed model analyses showed a significant decline in graphomotor speed (Trails A, p=0.03), verbal learning (HVLT-R Total Learning, p<0.001), and verbal recognition memory (HVLT-R Discrimination, p=0.03) from baseline to 3 months post-pCSI, with scores remaining stable at 6 months post-pCSI. There was a significant decline in timed set-shifting (Trails B, p=0.04) from baseline to 6 months post-pCSI. There were no significant changes in attention and working memory over the follow-up period. CONCLUSIONPreliminary results in a subset of patients showed a decline in graphomotor speed and verbal memory at 3 months and executive function at 6 months post-pCSI, possibly related to the early adverse effects of RT. These results are overall consistent with findings in other populations treated with whole-brain RT. However, there was no change in attention and working memory and most cognitive domains remained stable at six months with pCSI.

Association of Posttraumatic Stress Disorder With Accelerated Cognitive Decline in Middle-aged Women

Posttraumatic stress disorder (PTSD) has been hypothesized to lead to impaired cognitive function. However, no large-scale studies have assessed whether PTSD is prospectively associated with cognitive decline in middle-aged adults. To assess the association between PTSD and decline in cognitive function over time. This cohort study included participants from the Nurses' Health Study II, an ongoing longitudinal cohort study involving community-dwelling middle-aged female nurses residing in the US who had at least a 2-year nursing degree at the time of enrollment in 1989. The present study included 12 270 trauma-exposed women who were enrolled in the PTSD substudy of the Nurses' Health Study II and completed 1 to 5 cognitive assessments. Data were collected from March 1, 2008, to July 30, 2019. Lifetime PTSD symptoms, assessed using a validated questionnaire between March 1, 2008, and February 28, 2010. The main outcome was evaluated using the Cogstate Brief Battery, a self-administered online cognitive battery. Cognitive function was measured by a psychomotor speed and attention composite score and a learning and working memory composite score. Women completed the Cogstate Brief Battery every 6 or 12 months (up to 24 months) from October 3, 2014, to July 30, 2019. Linear mixed-effects models were used to evaluate the association of PTSD symptoms with the rate of change in cognition over follow-up, considering a broad range of relevant covariates, including the presence of depression symptoms and history of clinician-diagnosed depression. The rate of cognitive change was adjusted for potential practice effects (ie, potential changes in test results that occur when a test is taken more than once) by including indicators for the number of previous tests taken. Among 12 270 women, the mean (SD) age at the baseline cognitive assessment was 61.1 (4.6) years; 125 women (1.0%) were Asian, 75 (0.6%) were Black, 156 (1.3%) were Hispanic, 11 767 (95.9%) were non-Hispanic White, and 147 (1.2%) were of other race and/or ethnicity. A higher number of PTSD symptoms was associated with worse cognitive trajectories. Compared with women with no PTSD symptoms, women with the highest symptom level (6-7 symptoms) had a significantly worse rate of change in both learning and working memory (β = -0.08 SD/y; 95% CI, -0.11 to -0.04 SD/y; P < .001) and psychomotor speed and attention (β = -0.05 SD/y; 95% CI, -0.09 to -0.01 SD/y; P = .02), adjusted for demographic characteristics. Associations were unchanged when additionally adjusted for behavioral factors (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.08 SD/y; 95% CI, -0.11 to -0.04 SD/y; P < .001) and health conditions (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.08 SD/y; 95% CI, -0.11 to -0.04 SD/y; P < .001) and were partially attenuated but still evident when further adjusted for practice effects (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.07 SD/y; 95% CI, -0.10 to -0.03 SD/y; P < .001) and comorbid depression (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.07 SD/y; 95% CI, -0.11 to -0.03 SD/y; P < .001). In this large-scale prospective cohort study, PTSD was associated with accelerated cognitive decline in middle-aged women, suggesting that earlier cognitive screening among women with PTSD may be warranted. Given that cognitive decline is strongly associated with subsequent Alzheimer disease and related dementias, better understanding of this association may be important to promote healthy aging.

The effects of acute high-intensity interval exercise on the temporal dynamics of working memory and contralateral delay activity.

The present investigation examined the acute effects of high-intensity interval exercise (HIIE) on temporal changes in behavioral and neuroelectrical indices of working memory. Young adults (n=22) performed a visual working memory change detection task of equiprobable 2- to 5-dot set sizes while contralateral delay activity (CDA) and N2pc ERP components were assessed at three consecutive time periods (40-min, 54-min, and 68-min) following three separate counterbalanced 9-min sessions of seated rest, HIIE-aerobic (treadmill intervals of moderate- and high-intensity run/walk periods) and HIIE-aerobic/resistance (intervals of rest and body-weight calisthenics). Behavior results revealed greater 4-dot accuracy for HIIE-aerobic/resistance compared to seated rest only at 40-min, maintenance of 5-dot accuracy across time for HIIE-aerobic compared to HIIE-aerobic/resistance and seated rest, and greater temporal stability in overall accuracy performance (i.e., inter-class correlation between temporally adjacent assessments) for both HIIE conditions compared to seated rest. CDA and N2pc results revealed no change in amplitude across time and between HIIE-aerobic, HIIE-aerobic/resistance, and seated rest. However, greater temporal stability in CDA amplitude was observed for HIIE-aerobic compared to seated rest. These findings suggest that short bouts of HIIE may serve as an effective modality for improvements and temporal stabilization in behavior with some evidence for stabilization of neuroelectrical indices of working memory capacity. Together, these data broadly suggest that short acute bouts of exercise may facilitate improvements in underlying mental operations responsible for temporal stability in cognitive and neurocognitive function.

Similarities and differences in working memory and neurometabolism of obsessive-compulsive disorder and major depressive disorder

BackgroundObsessive-compulsive disorder (OCD) and major depressive disorder (MDD) both showed cognitive impairment, and the altered neurometabolic may associate with cognitive impairment. However, there are limited comparative working memory (WM) and neuroimaging studies on these two disorders. Therefore, we investigated the characteristics of WM and neurometabolic changes in patients with OCD and MDD. MethodsA total of 64 unmedicated patients (32 OCD and 32 MDD), and 33 healthy controls (HC) were included to conduct WM assessment comprising Digit Span Test (DST), 2-back task and Stroop Color and Word Test (SCWT). Additionally, all subjects underwent protons magnetic resonance spectroscopy (1H-MRS) to collect neurometabolic ratios of N-acetyl aspartate (NAA) and choline-containing compounds (Cho) to creatine (Cr) in the prefrontal cortex (PFC) and lentiform nucleus (LN). Finally, differential and correlation analysis were conducted to investigate their characteristics and relationships. ResultsCompared with HC, both OCD and MDD patients exhibited a lower accuracy rate in the 2-back task, and only MDD patients performed worse in DST scores and longer reaction times in SCWT (all p < 0.05). Both OCD and MDD patients had lower NAA/Cr ratios in bilateral PFC (all p < 0.05). And the decreased NAA/Cr ratios in right PFC were positively correlated to DST scores in MDD group (r = 0.518, p = 0.003). ConclusionsBoth OCD and MDD showed WM impairment and neurometabolic alterations in PFC. Besides, MDD performed more severe and broader WM impairment compared to OCD. Moreover, the dysfunction of PFC may underlie the neural basis of WM impairment in MDD.

DHA-Enriched Fish Oil Ameliorates Deficits in Cognition Associated with Menopause and the APOE4 Genotype in Rodents.

Female APOE4 carriers have a greater predisposition to developing Alzheimer’s disease (AD) compared to their male counterparts, which may partly be attributed to menopause. We previously reported that a combination of menopause and APOE4 led to an exacerbation of cognitive and neurological deficits, which were associated with reduced brain DHA and DHA:AA ratio. Here, we explored whether DHA-enriched fish oil (FO) supplementation mitigated the detrimental impact of these risk factors. Whilst DHA-enriched fish oil improved recognition memory (NOR) in APOE4 VCD (4-vinylcyclohexene diepoxide)-treated mice (p < 0.05), no change in spatial working memory (Y-maze) was observed. FO supplementation increased brain DHA and nervonic acid and the DHA:AA ratio. The response of key bioenergetic and blood–brain barrier related genes and proteins provided mechanistic insights into these behavioural findings, with increased BDNF protein concentration as well as mitigation of aberrant Erβ, Cldn1 and Glut-5 expression in APOE4 mice receiving fish oil supplementation (p < 0.05). In conclusion, supplementation with a physiologically relevant dose of DHA-enriched fish oil appears to offer protection against the detrimental effects of menopause, particularly in “at-risk” APOE4 female carriers.

Electric Field Strength From Prefrontal Transcranial Direct Current Stimulation Determines Degree of Working Memory Response: A Potential Application of Reverse-Calculation Modeling?

BackgroundTranscranial direct current stimulation (tDCS) for working memory is an enticing treatment, but there is mixed evidence to date. ObjectivesWe tested the effects of electric field strength from uniform 2 mA dosing on working memory change from prestimulation to poststimulation. Second, we statistically evaluated a reverse-calculation method of individualizing tDCS dose and its effect on normalizing electric field at the cortex. Materials and MethodsWe performed electric field modeling on a data set of 28 healthy older adults (15 women, mean age = 73.7, SD = 7.3) who received ten sessions of active 2 mA tDCS (N = 14) or sham tDCS (N = 14) applied over bilateral dorsolateral prefrontal cortices (DLPFC) in a triple-blind design. We evaluated the relationship between electric field strength and working memory change on an N-back task in conditions of above-median, high electric field from active 2 mA (N = 7), below-median, low electric field from active 2 mA (N = 7), and sham (N = 14) at regions of interest (ROI) at the left and right DLPFC. We then determined the individualized reverse-calculation dose to produce the group average electric field and measured the electric field variance between uniform 2 mA doses vs individualized reverse-calculation doses at the same ROIs. ResultsWorking memory improvements from pre- to post-tDCS were significant for the above-median electric field from active 2 mA condition at the left DLPFC (mixed ANOVA, p = 0.013). Furthermore, reverse-calculation modeling significantly reduced electric field variance at both ROIs (Levene's test; p < 0.001). ConclusionsHigher electric fields at the left DLPFC from uniform 2 mA doses appear to drive working memory improvements from tDCS. Individualized doses from reverse-calculation modeling significantly reduce electric field variance at the cortex. Taken together, using reverse-calculation modeling to produce the same, high electric fields at the cortex across participants may produce more effective future tDCS treatments for working memory.

Postnatal exposure to lipopolysaccharide combined with high-fat diet consumption induces immune tolerance without prevention in spatial working memory impairment

High-fat diet (HFD) consumption has been related to metabolic alterations, such as obesity and cardiovascular problems, and has pronounced effects on brain plasticity and memory impairment. HFD exposure has a pro-inflammatory effect associated with microglial cell modifications in the hippocampus, a region involved in the working memory process. Immune tolerance can protect from inflammation in periphery induced by HFD consumption, when the immune response is desensitized in development period with lipopolysaccharide (LPS) exposure, maybe this previously state can change the course of the diseases associated to HFDs but is not known if can protect the hippocampus’s inflammatory response. In the present study, male mice were injected with LPS (100 μg.kg-1 body weight) on postnatal day 3 and fed with HFD for 16 weeks after weaning. Ours results indicated that postnatal exposure to LPS in the early postnatal developmental stage combined with HFD consumption prevented glycemia, insulin, HOMA-IR, microglial process, and increased pro-inflammatory cytokines mRNA expression, without changes in body weight gain and spatial working memory with respect vehicle + HFD group. These findings suggest that HFD consumption after postnatal LPS exposure induces hippocampal immune tolerance, without prevention in spatial working memory impairment on male mice.

Induced negative arousal modulates the speed of visual working memory consolidation.

This study examines how induced negative arousal influences the consolidation of fragile sensory inputs into durable working memory (WM) representations. Participants performed a visual WM change detection task with different amounts of encoding time manipulated by random pattern masks inserted at different levels of memory-and-mask Stimulus Onset Asynchrony (SOA). Prior to the WM task, negative or neutral emotion was induced using audio clips from the International Affective Digital Sounds (IADS). Pupillometry was simultaneously recorded to provide an objective measure of induced arousal. Self-report measures of early-life stress (i.e., adverse childhood experiences) and current mood states (i.e., depressed mood and anxious feeling) were also collected as covariates. We find that participants initially remember a comparable number of WM items under a short memory-and-mask SOA of 100 ms across emotion conditions, but then encode more items into WM at a longer memory-and-mask SOA of 333 ms under induced negative arousal. These findings suggest that induced negative arousal speeds up WM consolidation. Yet, induced negative arousal does not seem to significantly affect participants' WM storage capacity estimated from a separate no mask condition. Furthermore, this emotional effect on WM consolidation speed is moderated by key affect-related individual differences. Participants who have greater pupil responses to negative IADS sounds or have more early-life stress show faster WM consolidation under induced negative arousal. Collectively, our findings reveal a critical role of phasic adrenergic responses in the rapid consolidation of visual WM content and identify potential moderators of this association. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Personalized Prediction of Postconcussive Working Memory Decline: A Feasibility Study

Concussion, also known as mild traumatic brain injury (mTBI), commonly causes transient neurocognitive symptoms, but in some cases, it causes cognitive impairment, including working memory (WM) deficit, which can be long-lasting and impede a patient’s return to work. The predictors of long-term cognitive outcomes following mTBI remain unclear, because abnormality is often absent in structural imaging findings. Previous studies have demonstrated that WM functional activity estimated from functional magnetic resonance imaging (fMRI) has a high sensitivity to postconcussion WM deficits and may be used to not only evaluate but guide treatment strategies, especially targeting brain areas involved in postconcussion cognitive decline. The purpose of the study was to determine whether machine learning-based models using fMRI biomarkers and demographic or neuropsychological measures at the baseline could effectively predict the 1-year cognitive outcomes of concussion. We conducted a prospective, observational study of patients with mTBI who were compared with demographically matched healthy controls enrolled between September 2015 and August 2020. Baseline assessments were collected within the first week of injury, and follow-ups were conducted at 6 weeks, 3 months, 6 months, and 1 year. Potential demographic, neuropsychological, and fMRI features were selected according to their significance of correlation with the estimated changes in WM ability. The support vector machine classifier was trained using these potential features and estimated changes in WM between the predefined time periods. Patients demonstrated significant cognitive recovery at the third month, followed by worsened performance after 6 months, which persisted until 1 year after a concussion. Approximately half of the patients experienced prolonged cognitive impairment at the 1-year follow up. Satisfactory predictions were achieved for patients whose WM function did not recover at 3 months (accuracy = 87.5%), 6 months (accuracy = 83.3%), and 1 year (accuracy = 83.3%) and performed worse at the 1-year follow-up compared to the baseline assessment (accuracy = 83.3%). This study demonstrated the feasibility of personalized prediction for long-term postconcussive WM outcomes based on baseline fMRI and demographic features, opening a new avenue for early rehabilitation intervention in selected individuals with possible poor long-term cognitive outcomes.

Bidirectional associations among executive functions, visual-spatial skills, and mathematical achievement in primary school students: Insights from a longitudinal study

The current study examined the dynamic and complex interplay among executive functions, visual-spatial skills, and mathematical achievement in primary school students. In particular, we investigated the bidirectional, longitudinal associations among these abilities, with executive functions consisting of working memory, inhibition, and cognitive flexibility. We examined 6- to 7-year-olds (N = 182) at the beginning of primary school and again 3 years later using the Intelligence and Development Scales-2. A cross-lagged panel model identified asymmetrical patterns in the data. Early visual-spatial skills predicted children’s later mathematical achievement; however, working memory predictions of later mathematical achievement depended on the time differences between assessments. Children with higher initial working memory skills showed accelerated gains in mathematical performance when the time difference between assessments was large. Importantly, early mathematical achievement predicted changes in later working memory, pointing to a bidirectional relation between working memory and mathematical achievement.

Interactive effects of age and inflammation on change in ecologically-assessed cognitive functioning

Inflammation has been implicated as a precursor to steeper declines in age-associated cognitive decline. Here we investigated biomarkers of peripheral inflammation [basal cytokines, stimulated cytokines (ex vivo), C-reactive protein (CRP)] as moderators of age-related changes in cognitive functioning. As part of the Effects of Stress on Cognitive Aging, Physiology, and Emotion (ESCAPE) study, participants (N = 233; 65% female; 63% Black, 25% Hispanic; 25-65 years of age) completed up to four instances of ambulatory cognitive testing per day across two weeks, over three waves of annual assessments. After each 2-week ecological momentary assessment (EMA) burst, blood was collected and assayed for inflammatory biomarkers. Performance on spatial working memory (mean Euclidean distance errors), processing speed (mean symbol search reaction time), and working memory (n-back test accuracy) tasks were averaged across all instances within an EMA burst. CRP and age interactively predicted change in spatial working memory (B = 0.003, [0.000, 0.005], t(133.60) = 2.350, p = 0.020) such that higher CRP at older ages (~60 years) was associated with a loss of the expected practice effects across waves; at younger ages, CRP did not relate to change in spatial working memory. In a similar fashion, basal (B = -0.002, [-0.004, -0.000], t(103.26) = -2.399, p = 0.018) and stimulated cytokine levels (B = -0.002, [-0.004, -0.000], t(126.65) = -2.183, p = 0.031) interacted with age to predict change in processing speed across waves. These results indicate that inflammation may be critically associated with changes in cognitive functioning in older mid-life adults.

Effects of dancing on cognition and mobility in Spanish‐speaking older Latinos: findings from the BAILA trial

AbstractBackgroundDespite literature showing the benefits of regular physical activity (PA), 1,2 older Latinos engage in low levels of PA3 putting them at high risk for mobility disability5 and cognitive impairment.2 Engaging Latinos in culturally responsive PA programs is important to improve cognition and physical function. The purpose of the present study was to examine the effect of a 4‐month BAILAMOS™ Latin dance intervention, followed by a 4‐month maintenance program on cognition and mobility in community dwelling older Latinos.MethodSpanish‐speaking older Latinos were randomized to the dance program (n=167) or health education condition (n=166). Participants completed neuropsychological tests that assessed working memory (WM), executive function, and episodic memory and completed a 400‐meter walk test at baseline, 4‐months, and 8‐months post‐intervention. Repeated analyses of covariance were conducted to test change in the outcomes at 4‐months and 8‐months post‐intervention. Significant findings found at the multivariate level were followed by reporting results from the univariate tests.ResultA significant difference in WM was found between the two groups [Wilk’s λ = .98 F 2,329 = 3.97, p = 0.034]. Follow‐up univariate tests found that the two groups were not significantly different at 4‐months, [F 1,329 = 3.74, p = 0.235, (d = .13)], but the dance group demonstrated a significant improvement in WM at 8‐months, [F 1,329 = 6.92, p = 0.017, (d = .20)]. No significant differences were found for executive function or episodic memory. For the 400‐meter walk test, findings show a significant difference between the two groups [Wilk’s λ = .98, F 2,329 = 4.37, p = 0.022]. Univariate tests revealed that the two groups were not significantly different at 4‐months, but were significantly different at 8‐months, [F 1,329 = 7.24, p = 0.013], such that the dance group had better mobility than the health education group, (d = ‐.46).ConclusionFindings indicate that participants who received the 4‐month maintenance dance program led to changes in WM and mobility. This study highlights the cognitive and physical implications and the importance of creating sustainable community‐based PA programs. Funding: National Institute of Nursing Research: R01NR013151.

Network-based rTMS to modulate working memory: The difficult choice of effective parameters for online interventions.

BackgroundOnline repetitive transcranialmagnetic stimulation (rTMS) has been shown to modulate working memory (WM) performance in a site‐specific manner, with behavioral improvements due to stimulation of the dorsolateral prefrontal cortex (DLPFC), and impairment from stimulation to the lateral parietal cortex (LPC). Neurobehavioral studies have demonstrated that subprocesses of WM allowing for the maintenance and manipulation of information in the mind involve unique cortical networks. Despite promising evidence of modulatory effects of rTMS on WM, no studies have yet demonstrated distinct modulatory control of these two subprocesses. The current study therefore sought to explore this possibility through site‐specific stimulation during an online task invoking both skills.MethodsTwenty‐nine subjects completed a 4‐day protocol, in which active or sham 5Hz rTMS was applied over the DLPFC and LPC in separate blocks of trials while participants performed tasks that required either maintenance alone, or both maintenance and manipulation (alphabetization) of information. Stimulation targets were defined individually based on fMRI activation and structural network properties. Stimulation amplitude was adjusted using electric field modeling to equate induced current in the target region across participants.ResultsDespite the use of advanced techniques, no significant differences or interactions between active and sham stimulation were found. Exploratory analyses testing stimulation amplitude, fMRI activation, and modal controllability showed nonsignificant but interesting trends with rTMS effects.ConclusionWhile this study did not reveal any significant behavioral changes in WM, the results may point to parameters that contribute to positive effects, such as stimulation amplitude and functional activation.

Eye Movements Detect Differential Change after Participation in Male Collegiate Collision versus Non-Collision Sports.

Although neuroimaging studies of collision (COLL) sport athletes demonstrate alterations in brain structure and function from pre- to post-season, reliable tools to detect behavioral/cognitive change relevant to functional networks associated with participation in collision sports are lacking. This study evaluated the use of eye-movement testing to detect change in cognitive and sensorimotor processing among male club collegiate athletes after one season of participation in collision sports of variable exposure. We predicted that COLL (High Dose [hockey], n = 8; Low Dose [rugby], n = 9) would demonstrate longer reaction times (antisaccade and memory-guided saccade [MGS] latencies), increased inhibitory errors (antisaccade error rate), and poorer spatial working memory (MGS spatial accuracy) at post-season, relative to pre-season, whereas non-collision collegiate athletes (NON-COLL; n = 17) would remain stable. We also predicted that whereas eye-movement performance would detect pre- to post-season change, ImPACT (Immediate Post-Concussion Assessment and Cognitive Test) performance would remain stable. Our data showed that NON-COLL had shorter (improved performance) post- versus pre-season antisaccade and MGS latencies, whereas COLL groups showed stable, longer, or attenuated reduction in latency (ps ≤ 0.001). Groups did not differ in antisaccade error rate. On the MGS task, NON-COLL demonstrated improved spatial accuracy over time, whereas COLL groups showed reduced spatial accuracy (p < 0.05, uncorrected). No differential change was observed on ImPACT. This study provides preliminary evidence for eye-movement testing as a sensitive marker of subtle changes in attentional control and working memory resulting from participation in sports with varying levels of subconcussive exposure.

Probiotics-induced changes in gut microbial composition and its effects on cognitive performance after stress: exploratory analyses

Stress negatively affects cognitive performance. Probiotics remediate somatic and behavioral stress responses, hypothetically by acting on the gut microbiota. Here, in exploratory analyses, we assessed gut microbial alterations after 28-days supplementation of multi-strain probiotics (EcologicBarrier consisting of Lactobacilli, Lactococci, and Bifidobacteria in healthy, female subjects (probiotics group n = 27, placebo group n = 29). In an identical pre-session and post-session, subjects performed a working memory task before and after an acute stress intervention. Global gut microbial beta diversity changed over time, but we were not able to detect differences between intervention groups. At the taxonomic level, Time by Intervention interactions were not significant after multiple comparison correction; the relative abundance of eight genera in the probiotics group was higher (uncorrected) relative to the placebo group: Butyricimonas, Parabacteroides, Alistipes, Christensenellaceae_R-7_group, Family_XIII_AD3011_group, Ruminococcaceae_UCG-003, Ruminococcaceae_UCG-005, and Ruminococcaceae_UCG-010. In a second analysis step, association analyses were done only within this selection of microbial genera, revealing the probiotics-induced change in genus Ruminococcaceae_UCG-003 was significantly associated with probiotics’ effect on stress-induced working memory changes (rspearman(27) = 0.565; pFDR = 0.014) in the probiotics group only and independent of potential confounders (i.e., age, BMI, and baseline dietary fiber intake). That is subjects with a higher increase in Ruminococcaceae_UCG-003 abundance after probiotics were also more protected from negative effects of stress on working memory after probiotic supplementation. The bacterial taxa showing an increase in relative abundance in the probiotics group are plant fiber degrading bacteria and produce short-chain fatty acids that are known for their beneficial effect on gut and brain health, e.g., maintaining intestinal-barrier and blood–brain-barrier integrity. This study shows that gut microbial alterations, modulated through probiotics use, are related to improved cognitive performance in acute stress circumstances.

Aerobic fitness moderates girls' affective and working memory responses to social exclusion

Because self-regulation skills are in development through adolescence, social exclusion can pose significant challenges to the well-being of young people. Thus, an understanding of factors that may ease the self-regulation demands of social exclusion is particularly important. One such factor is aerobic fitness. Using a quasi-experimental within-subject design in a sample of girls (N = 47, 10.4 ± 1.2 years), we examined whether affective and working memory changes following social exclusion differ by level of aerobic fitness. Overall, findings suggest that more aerobically fit girls may better regulate the demands of social exclusion than less aerobically fit girls. Specifically, girls with higher aerobic fitness evidenced smaller decreases in pleasant affect and larger increases in working memory performance following social exclusion than girls with lower aerobic fitness. This research extends understanding of how aerobic fitness may benefit well-being in young people.

The Effect of Transcranial Random Noise Stimulation on Cognitive Training Outcome in Healthy Aging.

Background and Objective: Aging is associated with a decline in attentional and executive abilities, which are linked to physiological, structural, and functional brain changes. A variety of novel non-invasive brain stimulation methods have been probed in terms of their neuroenhancement efficacy in the last decade; one that holds significant promise is transcranial random noise stimulation (tRNS) that delivers an alternate current at random amplitude and frequency. The aim of this study was to investigate whether repeated sessions of tRNS applied as an add-on to cognitive training (CT) may induce long-term near and far transfer cognitive improvements.Methods: In this sham-controlled, randomized, double-blinded study forty-two older adults (age range 60–86 years) were randomly assigned to one of three intervention groups that received 20 min of 0.705 mA tRNS (N = 14), 1 mA tRNS (N = 14), or sham tRNS (N = 19) combined with 30 min of CT of executive functions (cognitive flexibility, inhibitory control, working memory). tRNS was applied bilaterally over the dorsolateral prefrontal cortices for five sessions. The primary outcome (non-verbal logical reasoning) and other cognitive functions (attention, memory, executive functions) were assessed before and after the intervention and at a 1-month follow-up.Results: Non-verbal logical reasoning, inhibitory control and reaction time improved significantly over time, but stimulation did not differentially affect this improvement. These changes occurred during CT, while no further improvement was observed during follow-up. Performance change in logical reasoning was significantly correlated with age in the group receiving 1 mA tRNS, indicating that older participants profited more from tRNS than younger participants. Performance change in non-verbal working memory was significantly correlated with age in the group receiving sham tRNS, indicating that in contrast to active tRNS, older participants in the sham group declined more than younger participants.Interpretation: CT induced cognitive improvements in all treatment groups, but tRNS did not modulate most of these cognitive improvements. However, the effect of tRNS depended on age in some cognitive functions. We discuss possible explanations leading to this result that can help to improve the design of future neuroenhancement studies in older populations.

Affective forecasting: A selective relationship with working memory for emotion.

Affective forecasting (AF), the ability to predict one's future feelings, is important for decision making. We posit that AF entails the ability to maintain and evaluate an emotional feeling state, and thus requires affective working memory (AWM; Mikels & Reuter-Lorenz, 2019). To test this hypothesis, a series of studies investigated whether individual differences in AWM are related to AF ability. In the first study, we document that measures of AWM and AF are positively related, whereas an analogous measure of visual working memory is unrelated to AF in separate groups of participants. Two further within-group studies (1 preregistered) demonstrate that maintenance of affective information predicts AF performance, whereas maintenance of brightness information does not. Further, 2 additional measures of visual working memory (Corsi block-tapping and change detection) did not independently predict AF ability. Taken together the results demonstrate a reliable and selective relationship between AWM and AF, suggesting that AWM is a separable working memory subsystem and an elemental capacity that contributes to the type of higher-order emotional processes involved in AF. (PsycInfo Database Record (c) 2021 APA, all rights reserved).