Paced Auditory Serial Addition Task Research Articles

Cognition in patients with myelin oligodendrocyte glycoprotein antibody-associated disease: a prospective, longitudinal, multicentre study of 113 patients (CogniMOG-Study)

BackgroundData on cognition in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are limited to studies with small sample sizes. Therefore, we aimed to analyse the extent, characteristics and the...

Rehabilitative Intervention for Attentional Disturbance

Several evidence-based guidelines of rehabilitative intervention for attentional disturbance following acquired brain injury have been published. The author introduced two cutting-edge guidelines: Japan Stroke Society Guideline 2021 for the Treatment of Stroke [Revised version 2023]; and INCOG 2.0 Guideline for Cognitive Rehabilitation Following Traumatic Brain Injury, PartII: Attention and Information Processing Speed (2023). The effect of the cognitive rehabilitation should be evaluated by change of performance in real-world tasks and activities as well as measures of various neuropsychological tests including paced auditory serial addition task (PASAT) and trail making test. Direct attention training such as Attention Process Training (APT) series or computer-based training may be useful especially for stroke patients. Dual-task training may specifically improve multi-tasking performance. Time pressure management can improve speed of performance on everyday tasks for patients with slowed information processing. Metacognitive training using everyday activities may be recommended for mild to moderate impairments. Modifications of environment and/or tasks may also be helpful to decrease errors in daily activities.

Night Screen Time is Associated with Cognitive Function in Healthy Young Adults: A Cross-Sectional Study.

In recent years, a significant shift toward remote work, virtual education, and social distancing measures was witnessed, thereby leading people to increasingly depend on digital devices for communication, work, and entertainment. This increased exposure to screens has raised concerns regarding its potential impact on cognitive function. This study investigated the relationship between screen time and cognitive function among healthy young adults. One hundred forty-five healthy individuals (mean age 21.55 ± 2.84 years) participated in this cross-sectional study. Sociodemographic information including age, sex, height, weight, and level of education were obtained. Participants reported screen time using a screen time questionnaire. Cognitive function tests including, Paced Auditory Serial Addition Task (PASAT), Montreal Cognitive Assessment (MoCA) and Symbol Digit Modalities Test (SDMT) were conducted. Multilinear regression analyses were used to examine the associations between age, sex, level of education, screen time, and cognitive function. One hundred thirty-nine participants (76 women) completed the study. Increased night screen time, bachelor's educational level, and women were associated with lower PASAT scores (R2=0.258; p≤0.047). Moreover, increased night screen time was associated with lower MoCA scores (R2=0.029; p=0.035). However, no associations were found between night screen time and SDMT scores. Participants who had higher night screen exposure had lower cognitive scores in the information speed processing, working memory, calculation, and attention domains. Considering these findings, this study emphasizes on the importance of setting a future recommended screen time guidelines for young adults as well as to promote healthy cognitive habits in order to preserve cognitive function and reduce the risk of developing neurodegenerative disease in the future. Future prospective cohort studies involving a more diverse age range is needed.

Independent and reproducible hippocampal radiomics biomarkers for multisite multiple sclerosis and neuromyelitis optica spectrum disorders

ObjectiveTo investigate the abnormal radiomics features of the hippocampus in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) and to explore the clinical implications of these features. Methods752 participants were recruited in this retrospective multicenter study (7 centers), which included 236 MS, 236 NMOSD, and 280 normal controls (NC). Radiomics features of each side of the hippocampus were extracted, including intensity, shape, texture, and wavelet features (N = 431). To identify the variations in these features, two-sample t-tests were performed between the NMOSD vs. NC, MS vs. NC, and NMOSD vs. MS groups at each site. The statistical results from each site were then integrated through meta-analysis. To investigate the clinical significance of the hippocampal radiomics features, we conducted further analysis to examine the correlations between these features and clinical measures such as Expanded Disability Status Scale (EDSS), Brief Visuospatial Memory Test (BVMT), California Verbal Learning Test (CVLT), and Paced Auditory Serial Addition Task (PASAT). ResultsCompared with NC, patients with MS exhibited significant differences in 78 radiomics features (P < 0.05/862), with the majority of these being texture features. Patients with NMOSD showed significant differences in 137 radiomics features (P < 0.05/862), most of which were intensity features. The difference between MS and NMOSD patients was observed in 47 radiomics features (P < 0.05/862), mainly texture features. In patients with MS and NMOSD, the most significant features related to the EDSS were intensity and textural features, and the most significant features related to the PASAT were intensity features. Meanwhile, both disease groups observed a weak correlation between radiomics data and BVMT. ConclusionVariations in the microstructure of the hippocampus can be detected through radiomics, offering a new approach to investigating the abnormal pattern of the hippocampus in MS and NMOSD.

45 Differential Clinical Utility of Forward, Backward and Sequencing Components of Digit Span

Objective:Digit Span has been a core Working Memory task, with extensive research conducted on the Forward and Backward components. The latest revision of the WAIS-IV introduced the Sequencing component, designed to increase the working memory and mental manipulation demands. However, relatively little research has been done to understand how Sequencing can be interpreted in clinical settings, as compared to Forward and Backward. The purpose of this study was to investigate how effectively individual components of the Digit Span task predict performance on four independent neuropsychological measures with high working memory demands.Participants and Methods:Subjects included 148 adults (Age: M= 39.22, SD= 13.61; Handedness= 130 right, 10 left and 8 mixed; Males = 88) with refractory epilepsy. Two subjects had primary generalized seizures while 146 subjects had complex partial seizures (EEG Localization: 44 right temporal; 60 left temporal; 24 independent bitemporal; 1 left extratemporal; 17 indeterminant). Dependent variables included the 2.4 second ISI trial of the Paced Auditory Serial Addition Task (PASAT); the sum of correct responses on Trial 1 and List B of the California Verbal Learning Test (CVLT); the DKEFS Tower Test raw score; and completion time on Part B of the Trail Making Test. The independent variables included the individual raw scores for the Forward, Backward and Sequencing components of the WAIS-IV. Hierarchical linear regression was conducted to determine the variance accounted for by each component of the Digit Span and if that variance was redundant or unique. The four dependent variables were analyzed separately with Digits Forward, Backward and Sequencing entered in a single block.Results:PASAT: The overall model was significant, R2= 0.36. When examining the individual components, Sequencing was the only significant predictor (ß = 0.422, p &lt; 0.001). CVLT: The overall model was significant, R2 = 0.203. When examining the individual components, Sequencing was the only significant predictor (ß = 0.410, p &lt; 0.001). Tower Test: The overall model was significant, R2 = 0.176. When examining the individual components, Sequencing was the only significant predictor (ß = 0.373, p = 0.004). Trail Making: The overall model was significant R2 = 0.315. When examining the individual components both Forward (ß = -0.287, p =0.005) and Sequencing (ß= -0.364, p &lt; 0.001) accounted for a significant amount of the variance.Conclusions:The combined model for Digit Span accounted for significant amounts of variance in performance on all dependent measures, ranging from 17.6% to 36%. Sequencing accounted for substantially more variance across all examined tasks. On the PASAT, CVLT and Tower Test, the variance accounted for by the components of Digit Span appears to be redundant. However, on Trail Making, both Forward and Sequencing accounted for significant amounts of variance that appear to be independent of one another. What specific task requirement(s) of the Trail Making Test versus the other measures analyzed are accounted for by Forward span is not clear. But this suggests that the individual components of the Digit Span test may measure different things across different tasks.

11 The Moderating Effect of Depression on Workload Perception in Traumatic Brain Injury

Objective:Individuals who have experienced traumatic brain injury (TBI) are at an elevated risk for worsened physical and psychological outcomes. Increased rates of anxiety and depression, along with cognitive issues, are common post-TBI. While there is some evidence that anxiety and depression may affect objective cognitive performance, less is known about their effect on other factors that are associated with the individual’s capacity to complete the task, such as perceived workload of the cognitive task. Workload represents an individual’s perception of task difficulty and serves as a proxy for the magnitude of mental demands a given task places on an individual. Preliminary findings in the literature suggest that individuals with TBI commonly report greater workload when completing cognitive tasks compared to neurotypical peers, but the influence of anxiety and depression on survivors’ workload remains unclear. Considering the elevated rates of psychological and cognitive problems in individuals with TBI, the present study examined the moderating role of anxiety and depression on TBI survivor workload perception of a stress-inducing working memory task.Participants and Methods:Ten participants with moderate to severe TBI and eight neurologically healthy controls performed the Paced Auditory Serial Addition Task (PASAT). After completing the PASAT, participants reported their subjective workload using the NASA task load index (NASA-TLX). Participants also completed measures of psychological functioning, including the Chicago Multiscale Depression Inventory (CMDI) and the State-Trait Anxiety Inventory (STAI). Relationships between workload and depression and trait anxiety were examined using linear regression.Results:Linear regression was employed for both the TBI and the healthy control groups to assess the influence of trait anxiety and depression on perceived workload. There was no significant difference between the TBI and HC NASA perceived workload scores. Within the TBI group, there was a significant anxiety by depression interaction (b = -.015, p &lt; .001). Simple slopes analyses revealed that for TBI participants reporting low depression, perceived workload increased with increased anxiety (b = .093, p &lt; .001). For TBI participants reporting high depression, perceived workload decreased as anxiety increased (b = -.38, p = .03). While there was also significant anxiety by depression interaction in the healthy control group (b = .033, p = .04), simple slopes analyses revealed that there were no significant associations for healthy controls.Conclusions:These results demonstrate that in TBI, level of depression moderates the relationship between anxiety and workload perception. The pattern observed in the TBI group was unique from controls. The present findings suggest that post-TBI, higher depression may temper the influence of anxiety on stressful cognitive task performance and workload rating. The tempering effect of high depression in TBI may represent a biased reporting style or impaired assessment of task difficulty, which may ultimately affect the individual’s capacity to accomplish a task well.

A - 153 Differing Impacts of Divided Auditory and Visual Attention on Abstract Reasoning among Patients with Mild Traumatic Brain Injury.

Although not all mild traumatic brain injuries (mTBIs) lead to long-term effects, they can still have significant cognitive and emotional impacts. One of the common lasting symptoms of mTBI is attentional deficit, with divided attention being specifically negatively impacted by mTBIs. This study investigated the impacts of divided auditory attention and divided visual attention on executive functioning among patients with mTBI. Participants were 98 mTBI patients. Ethnicity was self-identified as 77.5% White, 6.3%, Asian, 2.7% Hispanic, and 13.5% Mixed/Other, gender was 68% women. Tests included the Neuropsychological Assessment Battery (NAB) Numbers & Letters Test to assess divided visual attention, Paced Auditory Serial Addition Task (PASAT) for divided auditory attention, and the Halstead Category Test (HCT) to assess the abstract reasoning domain of executive functioning as part of a full neuropsychological evaluation at a private outpatient clinic. Multiple linear regression was used to analyze the data. The overall model was statistically significant (F(3,94) = 3.23, p = 0.03, R2 = 0.09). Results indicated a significant positive relationship between abstract reasoning and auditory divided attention (β= 2.42, p = 0.03), but no significant relationship between abstract reasoning and visual divided attention (β= 1.5, p = 0.2). The findings of this study suggest that divided auditory and visual attention may impact the abstract reasoning and problem-solving domain of executive functioning differently among those who have sustained mild traumatic brain injury. Specifically, divided auditory attention may play a more significant role in abstract reasoning abilities than visual divided attention.

Cognition in patients with neuromyelitis optica spectrum disorders: A prospective multicentre study of 217 patients (CogniNMO-Study)

Background: There is limited and inconsistent information on the prevalence of cognitive impairment in neuromyelitis optica spectrum disorders (NMOSD). Objective: To assess cognitive performance and changes over time in NMOSD. Methods: This study included data from 217 aquaporin-4-IgG-seropositive (80%) and double-seronegative NMOSD patients. Cognitive functions measured by Symbol Digit Modalities Test (SDMT), Paced Auditory Serial-Addition Task (PASAT), and/or Multiple Sclerosis Inventory Cognition (MuSIC) were standardized against normative data (N = 157). Intraindividual cognitive performance at 1- and 2-year follow-up was analyzed. Cognitive test scores were correlated with demographic and clinical variables and assessed with a multiple linear regression model. Results: NMOSD patients were impaired in SDMT (p = 0.007), MuSIC semantic fluency (p < 0.001), and MuSIC congruent speed (p < 0.001). No significant cognitive deterioration was found at follow-up. SDMT scores were related to motor and visual disability (pBon < 0.05). No differences were found between aquaporin-4-IgG-seropositive and double-seronegative NMOSD. Conclusions: A subset of NMOSD patients shows impairment in visual processing speed and in semantic fluency regardless of serostatus, without noticeable changes during a 2-year observation period. Neuropsychological measurements should be adapted to physical and visual disabilities.

The effect of biomechanical features on classification of dual-task gait.

Early detection of Alzheimer's Disease and Related Disorders (ADRD) has been a focus of research with the hope that early intervention may improve clinical outcomes. The manifestation of motor impairment in early stages of ADRD has led to the inclusion of gait assessments including spatiotemporal parameters in clinical evaluations. This study aims to determine the effect of adding kinetic and kinematic gait features to classification of different levels of cognitive load in healthy individuals. A dual-task paradigm was used to simulate cognitive impairment in 40 healthy adults, with single-task walking trials representing normal, healthy gait. The Paced Auditory Serial Addition Task was administered at two different inter-stimulus intervals representing two levels of cognitive load in dual-task gait. We predicted that a richer dataset would improve classification accuracy relative to spatiotemporal parameters. Repeated Measures ANOVA showed significant changes in 15 different gait features across all three levels of cognitive load. We used three supervised machine learning algorithms to classify data points using a series of different gait feature sets with performance based on the area under the curve (AUC). Classification yielded 0.778 AUC across all three conditions (0.889 AUC Single vs. Dual) using kinematic and spatiotemporal features compared to 0.724 AUC using spatiotemporal features only (0.792 AUC Single vs. Dual). These data suggest that additional kinematic parameters improve classification performance. However, the benefit of measuring a wider set of parameters compared to their cost needs consideration. Further work will lead to a clinically viable ADRD detection classifier.

Investigating mechanisms of cognitive control training: neural signatures of PASAT performance in depressed patients

Major depression disorder (MDD) is characterized by cognitive control (CC) dysfunctions associated with increased attention toward negative information. The paced auditory serial addition task (PASAT) has been used as a targeted training of CC and studies show promising effects on depressive symptoms. However, neural mechanisms underlying its efficacy are still unclear. Based on previous findings of feedback-locked event-related potentials in healthy subjects, we investigated neural signatures during PASAT performance in 46 depressed patients. We found significantly larger amplitudes after negative than positive feedback for the P300 and late positive potential (LPP). However, this difference was not significant for the feedback-related negativity (FRN). Moreover, no associations of valence-specific ERPs and PASAT performance nor depressive symptoms were found. This indicates that depressed patients seem unable to use neural activation in late feedback processing stages (P300, LPP) to adapt accordingly. Moreover, lack of valence-specific neural reaction in early feedback processing stages (FRN) might point toward emotional indifference in depressed patients.Trial registration number: NCT03518749 Date of registration: May 8, 2018.

The effect of aerobic exercise on interoception and cognitive function in healthy university students: a non-randomized controlled trial

BackgroundInteroception refers to the body’s physiological responses that occur in response to emotions. This phenomenon influences decision-making, an important cognitive ability that affects the maintenance of an exercise routine. However, it is controversial whether interoception is a reliable measure of an individual’s traits or their response to emotion. Given this evidence, we hypothesized that performing an exercise with positive feelings could improve interoception and that the rational decision-making capabilities acquired by improved interoception would, in turn, help in maintaining an exercise routine. Persistent aerobic exercise is essential for improving cognitive and musculoskeletal function in the long term. Therefore, we aimed to investigate changes in interoception during moderate-intensity aerobic exercise at a level that might potentially improve cognitive function.Methods We devided 48 healthy university students into an exercise group (n = 37) and a control group (n = 11). The control group did not perform any exercises, while the exercise group performed bench step exercises at an intensity of 50% of heart rate reserve for 30 min a day, three times a week, for three months. We assessed their cognitive function by measuring their auditory information/working memory processing speed using a paced auditory serial addition task (PASAT) and evaluated their interoceptive accuracy (IA) using a heartbeat tracking task at baseline and 1, 2, and 3 months after the start of the exercise intervention.ResultsThere was a significant positive correlation between IA and PASAT scores at baseline. However, exercise did not lead to a significant increase in PASAT scores of the exercise group as compared with the control group. IA scores increased at 2 and 3 months after the start of exercise only in the exercise group.ConclusionsThis preliminary study showed an improvement in interoception after persistent moderate-intensity aerobic exercise. We believe that exercise-induced improvement of interoception may facilitate exercise maintenance through improved cognitive function. Statistical analysis did not explain the non-uniformity of sample sizes, therefore, future studies should have larger sample sizes with equal subjects in each group to allow for better comparability and generalizability.Trial registration: UMIN, UMIN000042891. 04/01/2021, retrospectively registered.

The Paced Auditory Serial Addition Task (PASAT): normative data for the Italian population

The Paced Auditory Serial Addition Task (PASAT) is a neuropsychological instrument designed to measure attention, working memory and speed of information processing in a complex manner. It is currently used to evaluate different neurological diseases. the purpose of this study was to establish PASAT normative data for the healthy Italian population using the standardized methodology of Equivalents Scores. the brief PASAT auditory version included in the Multiple Sclerosis Functional Composite was administered to 146 healthy Italian participants, distributed for gender (70 men; 76 women), age (range 18-83) and education (8-19). We found that age and education, but not gender, were significant PASAT score predictors. PASAT normative Italian data may represent a useful application for clinicians and researchers to document mild executive deficits in different neurological populations.

Neural Signatures of Performance Feedback in the Paced Auditory Serial Addition Task (PASAT): An ERP Study.

Research on cognitive control has sparked increasing interest in recent years, as it is an important prerequisite for goal oriented human behavior. The paced auditory serial addition task (PASAT) has been used to test and train cognitive control functions. This adaptive, challenging task includes continuous performance feedback. Therefore, additional cognitive control capacities are required to process this information along with the already high task-load. The underlying neural mechanisms, however, are still unclear. To explore the neural signatures of the PASAT and particularly the processing of distractive feedback information, feedback locked event-related potentials were derived from 24 healthy participants during an adaptive 2-back version of the PASAT. Larger neural activation after negative feedback was found for feedback related negativity (FRN), P300, and late positive potential (LPP). In early stages of feedback processing (i.e., FRN), a larger difference between positive and negative feedback responses was associated with poorer overall performance. This association was inverted in later stages (i.e., P300 and LPP). Together, our findings indicate stage-dependent associations between neural activation after negative information and cognitive functioning. Conceivably, increased early responses to negative feedback signify distraction, whereas higher activity at later stages reflects cognitive control processes to preserve ongoing performance.

Combining mental and physical stress: Synergy or interference?

Both cognitive stressors (such as mental arithmetic tasks) and physical stressors (such as the cold pressor test, CP) are among the most widely employed tools in acute stress research, and there is growing evidence for a high degree of stimulus-response specificity, rather than uniformity, in the human stress response. However, little is known about potential synergistic or interfering effects during concurrent administration. While cognitive tasks have been hypothesized to attenuate pain perception during CP, they are also thought to enhance physiological reactivity. Conversely, physical stress might interfere with effective stress induction by cognitive challenges. To address these questions, 56 participants underwent either the CP (3-min ice-water immersion of feet) or a warm-water control condition. In half of the sample, the Paced Auditory Serial Addition Task (PASAT) was performed simultaneously (fully crossed interventions). Salivary cortisol, cardiovascular parameters, and subjective ratings as well as voice pitch (F0) were assessed. Results show that cortisol responses, self-reported pain and subjective arousal were mainly driven by cold exposure, which also led to increased F0. The PASAT incrementally enhanced cardiovascular reactions, but did not affect pain ratings nor cortisol responses to the CP. However, intra-individual concordance between elevated blood pressure and other reactivity measures was enhanced by PASAT administration during the CP. Importantly, performance decrements in the mental-arithmetic task were not associated with diminished stress responses. In conclusion, our results speak against any strong interference when administering cognitive and painful physical stressors simultaneously, pointing rather to specific additive effects, particularly regarding cardiovascular reactivity.

Effects of acute mental stress on conditioned pain modulation in temporomandibular disorders patients and healthy individuals.

Stress is a contributing factor to painful temporomandibular disorders (TMD). Nevertheless, the underpinnings of this relationship are not fully understood. Objective To investigate the effects of acute mental stress on conditioned pain modulation (CPM) in TMD patients compared with healthy individuals.Methodology Twenty women with chronic myofascial TMD diagnosed according to the RDC/TMD and 20 age-matched healthy women had the CPM assessed before and after a stressful task using the Paced Auditory Serial Addition Task (PASAT) in a single session. Subjective stress response was assessed with the aid of visual analog scale (VAS). Pressure pain threshold (PPT) on masseter muscle was the test stimulus (TS) and immersion of the participant’s hand on hot water was the conditioning stimulus (CS) - CPM-sequential paradigm.Results Healthy individuals reported PASAT are more stressful when compared with TMD patients and the stress task did not affect the CPM in neither group. Nonetheless, a negative correlation was observed between change in CPM and change in TS from baseline to post-stress session, which indicates that the greater the increase in PPT after the stress task, the greater was the decrease in CPM magnitude. The correlation was strong for healthy controls (r=- 0.72, p<0.001) and moderate for TMD patients (r=- 0.44, p=0.047).Conclusions The correlation between the change in CPM and the TS change following the stress task may possibly indicate an overlapping pathway between stress-induced analgesia/hyperalgesia and descending pain inhibition.

Blunted cardiovascular reactivity to acute psychological stress predicts low behavioral but not self-reported perseverance: A replication study.

Emerging evidence suggests that individuals with poor behavioral perseverance show low or blunted physiological responses to acute psychological stress. For example, a recent preliminary laboratory study demonstrated that blunted responders give up sooner and take fewer attempts when endeavoring to complete an impossible puzzle, but do not self-report poor perseverance. This present research is a replication of the previous study with an increased sample size, longer recovery periods between tasks and addition of social evaluation to the cold pressor. Participants (147) completed a self-report perseverance questionnaire (Short Grit Scale) and behavioral perseverance tasks (impossible Euler puzzle and socially evaluated cold-pressor (SECPT)). The number of attempts and time spent trying to complete the unsolvable puzzle, and duration of hand submergent during the SECPT, were recorded as behavioral perseverance measures. Difference in blood pressure (BP) and pulse rate (PR) from baseline to a 10-min paced auditory serial addition task (PASAT) were computed as reactivity. As previously, reactivity did not relate to self-reported perseverance and blunted BP reactivity to the PASAT was associated with less time persevering at the unsolvable puzzle. Additionally, blunted BP and PR reactivity to the PASAT related to poorer perseverance during the SECPT. These findings, replicating the previous study, increase confidence that blunted reactivity is a physiological marker of poor behavioral perseverance. Moreover, given that self-reported perseverance does not relate to reactivity, this suggests that blunted responders are not conscious of this detriment in perseverance, but likely need additional support when persistence is critical (e.g., during behavior change).

Effects of Acute Experimental Stress on Pain Sensitivity and Cortisol Levels in Healthy Participants: A Randomized Crossover Pilot Study.

To investigate pain sensitivity in the masseter muscle and index finger in response to acute psychologic stress in healthy participants. Fifteen healthy women (23.7 ± 2.3 years) participated in two randomized sessions: in the experimental stress session, the Paced Auditory Serial Addition Task (PASAT) was used to induce acute stress, and in the control session, a control task was performed. Salivary cortisol, perceived stress levels, electrical and pressure pain thresholds (PTs), and pain tolerance levels (PTLs) were measured at baseline and after each task. Mixed-model analysis was used to test for significant interaction effects between time and session. An interaction effect between time and session occurred for perceived stress levels (P < .001); perceived stress was significantly higher after the experimental task than after the control task (P < .01). No interaction effects occurred for salivary cortisol levels, electrical PTs, or pressure PTLs. Although significant interactions did occur for electrical PTL (P < .05) and pressure PT (P < .001), the simple effects test could not identify significant differences between sessions at any time point. The PASAT evoked significant levels of perceived stress; however, pain sensitivity to mechanical or electrical stimuli was not significantly altered in response to the stress task, and the salivary cortisol levels were not altered in response to the PASAT. These results must be interpreted with caution, and more studies with larger study samples are needed to increase the clinical relevant understanding of the pain mechanisms and psychologic stress.

Normative Data for Two Working Memory Tasks in Spanish-Speaking US-Dwelling Adults

Abstract Objective Working memory assessment is an important component of a neuropsychological evaluation. The Paced Auditory Serial Addition Task (PASAT) and the Wechsler Adult Intelligence Scale – Third Edition Letter Number Sequencing subtest (LNS) are two commonly used measures of working memory. Demographic variables (age, education, ethnicity, and country of origin) can impact performance on these measures, underscoring the need for demographically adjusted norms when utilizing these tests. We aimed to develop normative data for the PASAT and LNS for Spanish-speaking adults living in the US. Participants and Method The PASAT and LNS were administered to Spanish-speaking adults living in the US-Mexico border regions of California and Arizona as part of a larger normative effort in this population. Two hundred and forty-nine participants completed the PASAT and a subset (n = 202) also completed LNS. Ages ranged from 19-60 and education from 0-20 years. Results Older age was associated with lower scores on LNS (p &amp;lt; .01), but not the PASAT. Lower education was associated with lower scores on both tests (ps &amp;lt; .001). Females obtained lower raw scores than males on the PASAT (ps &amp;lt; .003), and there were no significant main effects of gender on LNS raw scores. Raw-to-scaled score conversions were calculated for the PASAT-50 item, PASAT-200 item, and LNS, and fractional polynomial equations were developed to calculate demographically-adjusted T-scores accounting for age, education, and gender. Published norms for English-speaking non-Hispanic Whites drastically overestimated rates of impairment (defined as T-score &amp;lt; 40) on both the PASAT and LNS. Conclusions The use of the population-specific normative data may improve detection of working memory dysfunction in Spanish-speaking adults living in the US and contribute to improved diagnostic accuracy and treatment planning in this population.

Test-retest reproducibility of a combined physical and cognitive stressor

When studying the factors which influence stress reactivity in within-subject designs, test-retest reproducibility data is needed to estimate power and sample size. We report such data regarding a new experimental stress protocol, based on simultaneous application of the socially evaluated, bilateral feet Cold Pressor Test (CPT) and the Paced Auditory Serial Addition Task (PASAT). Cardiovascular, neuroendocrine, and subjective (affective) stress responses of 32 healthy males were measured twice, at an interval of one week. The novel protocol induced substantial stress reactivity in all parameters at both test and retest. Cardiovascular reactivity remained unchanged, but cortisol and subjective responses were lower at second stress exposure, with high test-retest stability of neuroendocrine (r>.7) and cardiovascular measures (r = .5 to r = .9). PASAT performance improved. Response attenuation suggests habituation-like and/or learning effects. Data provided by our study demonstrate feasibility and power of this stress protocol for investigating changes in stress reactivity in repeated, within-subject designs.

Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition

BackgroundThe main psychoactive component of cannabis, delta-9-tetrahydrocannabinol (THC), can impair driving performance. Cannabidiol (CBD), a non-intoxicating cannabis component, is thought to mitigate certain adverse effects of THC. It is possible then that cannabis containing equivalent CBD and THC will differentially affect driving and cognition relative to THC-dominant cannabis.AimsThe present study investigated and compared the effects of THC-dominant and THC/CBD equivalent cannabis on simulated driving and cognitive performance.MethodsIn a randomized, double-blind, within-subjects crossover design, healthy volunteers (n = 14) with a history of light cannabis use attended three outpatient experimental test sessions in which simulated driving and cognitive performance were assessed at two timepoints (20–60 min and 200–240 min) following vaporization of 125 mg THC-dominant (11% THC; < 1% CBD), THC/CBD equivalent (11% THC, 11% CBD), or placebo (< 1% THC/CBD) cannabis.Results/outcomesBoth active cannabis types increased lane weaving during a car-following task but had little effect on other driving performance measures. Active cannabis types impaired performance on the Digit Symbol Substitution Task (DSST), Divided Attention Task (DAT) and Paced Auditory Serial Addition Task (PASAT) with impairment on the latter two tasks worse with THC/CBD equivalent cannabis. Subjective drug effects (e.g., “stoned”) and confidence in driving ability did not vary with CBD content. Peak plasma THC concentrations were higher following THC/CBD equivalent cannabis relative to THC-dominant cannabis, suggesting a possible pharmacokinetic interaction.Conclusions/interpretationCannabis containing equivalent concentrations of CBD and THC appears no less impairing than THC-dominant cannabis, and in some circumstances, CBD may actually exacerbate THC-induced impairment.