Post-training Unilateral Vagal Stimulation Enhances Retention Performance in the Rat

Many peripherally administered substances which modulate memory do not freely enter the brain. Such compounds may act through peripheral receptors that send messages centrally through vagal afferents. To explore this hypothesis, rats were chronically implanted with cuff electrodes on the left cervical vagus nerve. Each animal was trained 48 h after surgery on a one-trial inhibitory-avoidance task with a 0.75-mA, 1.0-s footshock. Immediately following training, each animal received either no stimulation or vagal stimulation (0.5-ms biphasic pulses; 20 Hz, 30 s) at one of three intensities (0.2, 0.4, 0.8 mA; eight animals per group). Retention was tested 24 h later. Neither the 0.2-in or 0.8-mA groups (22.1-s; 53.7-s median latency) showed altered retention performances, whereas the 0.4-mA group showed significantly improved retention (881.0 s) compared to unstimulated controls (21.1 s; U = 6, p < .01). This inverted-U shaped function indicates that vagal activation during memory consolidation modulates retention for memory tasks.     

Motivationally neutral stimulation of the nucleus basalis induces specific behavioral memory

The cholinergic system has been implicated in learning and memory. The nucleus basalis (NB) provides acetylcholine (ACh) to the cerebral cortex. Pairing a tone with NB stimulation (NBstm) to alter cortical state induces both associative specific tuning plasticity in the primary auditory cortex (A1) and associative specific auditory behavioral memory. NB-induced memory has major features of natural memory that is induced by pairing a tone with motivational reinforcers, e.g., food or shock, suggesting that the cholinergic system may be a “final common pathway” whose activation promotes memory storage. Alternatively, NB stimulation might itself be motivationally significant, either rewarding or punishing. To investigate these alternatives, adult male rats (n = 7) first formed a specific NB-induced memory (CS = 8.0 kHz, 2.0 s paired with NBstm, ISI = 1.8 s, 200 trials), validated by post-training (24 h) frequency generalization gradients (1–15 kHz) of respiration interruption that were specific to the CS frequency. Thereafter, they received the same level of NBstm that had induced memory, while confined to one quadrant of an arena, and later tested for place-preference, i.e., avoidance or seeking of the quadrant of NBstm. This NBstm group exhibited neither preference for nor against the stimulated quadrant, compared to sham-operated subjects (n = 7). The findings indicate that specific associative memory can be induced by direct activation of the NB without detectable motivational effects of NB stimulation. These results are concordant with a memory-promoting role for the nucleus basalis that places it “downstream” of motivational systems, which activate it to initiate the storage of the current state of its cholinergic targets.     

Memory lapses during a pandemic: Differential associations between COVID-stress and daily memory lapses?

The policies related to COVID-19 pandemic such as stay at home orders and social distancing increased daily stress and associated impairments in mental health. This study examines the association between COVID-related stress and cognitive functioning by examining two different types of daily memory lapses, those related to prospective memory (i.e., memory for future plans) and retrospective memory (i.e., memory for past information) as well as the perceived emotional and functional consequences of daily memory problems. As part of a larger study, 58 adults (18 men; 22 ± 3 years) completed a web-based version of the daily inventory of stressful events including stress related to COVID-19 and positive/negative affect for eight consecutive days between 8 September 2020 and 11 November 2020. Findings showed that prospective lapses were positively correlated with COVID-19 stressors (r = 0.41, p = 0.002). At the within-person level, daily COVID-19 stressors were significantly associated with the number of prospective lapses (b = 0.088, SE = 0.040). COVID-19-related stressors were not significantly related to retrospective lapses (all ps > 0.05). Our findings suggested that more daily COVID-19 stressors were related to greater numbers of prospective lapses in daily life even among healthy younger adults. Thus, future research should address long term relations of COVID-19 stress and cognitive functioning in addition to the specific cognitive impairments related to COVID-19 infection.     

经皮迷走神经刺激对抑制控制的调节机制

近年众多研究表明,经皮迷走神经刺激(tVNS)作为一种新型、非侵入式的神经调控技术对个体的抑制控制功能具有积极的调节作用。已有研究发现, tVNS对抑制控制的调节作用可能是通过调控蓝斑核-去甲肾上腺素系统(LC-NE)的活动和神经递质GABA的浓度来实现的。然而,目前对tVNS调控抑制控制的神经机制仍存在诸多尚未明确的问题。未来研究在进一步优化tVNS的刺激参数后,可以从tVNS对抑制控制能力受损群体的调控作用及机制、如何实现和增强tVNS长期积极效应等方面进行深入探索。     

Involvement of the σ Receptor inPassive-Avoidance Learning in the Day-Old Chick during the Second Wave of Neuronal Activity

The specific σ-receptor agonist (+)-SKF 10047 and antagonist BD 1047 were used to investigate whether this receptor was involved in passive-avoidance training in the day-old chick. We found 300 μM (+)-SKF 10047 to be amnesic when injected into the lobus parolfactorius 5 h after training (p < .01). Higher or lower concentrations of (+)-SKF 10047 did not disrupt memory formation. The amnesia produced by the efficacious dose of (+)-SKF 10047 was reversed by the specific antagonist, BD 1047. It is suggested that the σ-receptor may exert its effect on passive-avoidance memory consolidation during the later stages of long-term memory formation by modulation of memory-related neurotransmission.     

Adaptive working memory training can reduce anxiety and depression vulnerability in adolescents

Adolescents can be at heightened risk for anxiety and depression, with accumulating research reporting on associations between anxiety and depression and cognitive impairments, implicating working memory and attentional control deficits. Several studies now point to the promise of adaptive working memory training to increase attentional control in depressed and anxious participants and reduce anxiety and depression symptoms, but this has not been explored in a non‐clinical adolescent population. The current study explored the effects of adaptive dual n‐back working memory training on sub‐clinical anxiety and depression symptomology in adolescents. Participants trained on either an online adaptive working memory task or non‐adaptive control task for up to 20 days. Primary outcome measures were self‐reported anxiety and depression symptomology, before and after intervention, and at 1‐month follow‐up. Self‐reported depression (p = 0.003) and anxiety (p = 0.04) decreased after training in the adaptive n‐back group relative to the non‐adaptive control group in the intention‐to‐treat sample (n = 120). These effects were sustained at follow‐up. Our findings constitute proof of principle evidence that working memory training may help reduce anxiety and depression vulnerability in a non‐clinical adolescent population. We discuss the findings’ implications for reducing risk of internalizing disorders in youth and the need for replication.     

Construct validity for the verbal associated pairs screen

The present study introduces the Verbal Associated Pairs Screen (VAPS) as a new measure for assessing performance validity in pediatric populations. This study presents initial data on psychometric properties and establishes construct validity for the VAPS in a sample of 30 adolescent healthy controls and 206 youths with traumatic brain injury (TBI: moderate/severe, N = 30; mild, N = 176). The control group’s age (M = 14.93, SD = 1.8) was significantly higher than the moderate/severe TBI (M = 13.9, SD = 2.8), t(68.508) = ?3.038, p = .003, and mild TBI (mTBI) groups (M = 14, SD = 2.8), t(54.147) = 2.038, p = .046. The TBI groups were administered the VAPS in accord with other established performance validity tests (PVTs) and well-established memory tests as part of routine clinical evaluations. The healthy control group was administered the VAPS only. VAPS score distributions for the control group were negatively skewed and highly kurtotic. VAPS scores from the moderate/severe TBI and control groups were indistinguishable for Trial 2 (U = 274, p < .01) and the Delay (U = 396, p = .218). In the mTBI group, convergent and divergent validity was established with other well-validated PVTs and memory tests, respectively. ROC curve analyses identified optimal cutoff scores for the VAPS Total Score, with acceptable sensitivity (55%) and excellent specificity (100%), as well as strong detectability (AUC = .829, 95% CI: 0.731 – 0.928, p < .001). Clinical applications, limitations, and directions for future research with the VAPS are discussed.     

Early motor development and cognitive abilities among Mexican preschoolers

Psychomotricity plays a very important role in children’s development, especially for learning involving reading–writing and mathematical calculations. Evaluate motor development in children 3 years old and its relationship with their cognitive abilities at the age of 5 years. Based on a cohort study, we analyzed the information about motor performance evaluated at 3 years old by Peabody Motor Scale and cognitive abilities at 5 years old. The association was estimated using linear regression models adjusted by mother’s intelligence quotient, sex, Bayley mental development index at 18 months, and quality of the environment at home (HOME scale). 148 children whose motor performance was determined at age 3 and was evaluated later at age 5 to determine their cognitive abilities. Cognitive abilities (verbal, quantitative, and memory) measured by McCarthy Scales. Significant positive associations were observed between stationary balance at age 3 with verbal abilities (β = 0.67, p = .04) and memory (β = 0.81, p = .02) at 5 years. Grasping and visual-motor integration were significant and positively associated with quantitative abilities (β = 0.74, p = .005; β = 0.61, p = .01) and memory (β = 2.11, p = .001; β = 1.74, p = .004). The results suggest that early motor performance contributes to the establishment of cognitive abilities at 5 years. Evaluation and early motor stimulation before the child is faced with formal learning likely helps to create neuronal networks that facilitate the acquisition of academic knowledge.     

Conscientiousness and adherence to the oral contraceptive pill: A prospective study

Objective: We assess the association between conscientiousness and adherence to the oral contraceptive pill (OCP), and examine if such a relationship is independent of a measure of prospective memory and a range of social cognitive variables.

Method: Data were collected from 150 OCP users at baseline, and 99 provided follow-up data four weeks later. Conscientiousness, a range of social cognitive predictors and prospective memory were assessed at baseline. OCP adherence was measured at baseline, and again at Time 2. Data were analysed using correlation and multiple linear regression.

Results: Higher conscientiousness was associated with higher overall OCP adherence in both cross-sectional (r = ?0.28, p < 0.01) and prospective analysis (r = ?0.34, p < 0.01). Conscientiousness predicted OCP adherence at Time 2, adjusting for OCP adherence at Time 1 (R² change = 0.02, p = 0.04). The association was reduced to non-significance when social cognitive predictors and prospective memory were included in the multivariable model. Prospective memory was an independent predictor of OCP adherence at Time 2.

Discussion: This is the first study to identify an association between conscientiousness and OCP adherence. The association is not independent from social cognitive predictors and prospective memory. Facet-level analysis of conscientiousness and formal mediation analyses are recommended in future replications.     

Vagal activity, early growth and emotional development

A review of the research on infant vagal tone suggests that vagal activity is associated with both infant growth and infant socioemotional development. Vagal activity has been noted to increase following the stimulation of pressure receptors as in massage therapy. Vagal activity, in turn, stimulates gastric motility which mediates weight gain in infants. Vagal activity has also been notably elevated during synchronous mother–infant interactions and positive affect, providing confirmatory data for the Porges “social engagement system” model. In contrast, low vagal activity has been noted in prenatally depressed mothers (and prenatally angry and anxious mothers) and their infants, as well as in children with autism. These studies highlight the relations between vagal activity and the social behaviors of attentiveness, facial expressions and vocalizations.     

Epinephrine administration increases neural impulses propagated along the vagus nerve: Role of peripheral beta-adrenergic receptors

A significant number of animal and human studies demonstrate that memories for new experiences are encoded more effectively under environmental or laboratory conditions which elevate peripheral concentrations of the hormone epinephrine and in turn, induce emotional arousal. Although this phenomenon has been replicated across several learning paradigms, understanding of how this arousal related hormone affects memory processing remains obscure because epinephrine does not freely enter into the central circulation to produce any direct effects on the brain. This study examined whether epinephrine's actions on the CNS may be mediated by the initial activation of peripheral vagal fibers that project to the brain. The vagus was selected as a candidate for this role since it is densely embedded with beta-adrenergic receptors and the peripheral endings of this nerve innervate a broad spectrum of sensory organs that are directly affected by epinephrine release. Electrophysiological recordings of cervical vagal activity was measured over 110 min in urethane-anesthetized Sprague-Dawley rats given saline, epinephrine (0.3 mg/kg), the peripherally acting beta-adrenergic antagonist sotalol (2.0 mg/kg), or a combination of sotalol followed 15 min later by an injection of epinephrine. Epinephrine produced a significant increase in vagal nerve firing 10 min post-injection (p < .05) relative to controls and neural impulses recorded from the vagus remained significantly elevated for the remaining 55 min collection period. The excitatory actions of epinephrine were not observed in groups given an identical dose of the hormone after peripheral beta-adrenergic receptor blockade with sotalol. These findings demonstrate that neural discharge in vagal afferent fibers is increased by elevations in peripheral concentrations of epinephrine and the significance of these findings in understanding how epinephrine modulates brain limbic structures to encode and store new information into memory is discussed.     

Does message framing affect changes in behavioural intentions in people with psoriasis? A randomized exploratory study examining health risk communication

Message framing is important in health communication research to encourage behaviour change. Psoriasis, a long-term inflammatory skin condition, has additional comorbidities including high levels of anxiety and cardiovascular disease (CVD), making message framing particularly important. This experimental study aimed to: (1) identify whether health messages about psoriasis presented as either gain- or loss-framed were more effective for prompting changes in behavioural intentions (BI), (2) examine whether BI were driven by a desire to improve psoriasis or reduce CVD risk; (3) examine emotional reactions to message frame; and (4) examine predictors of BI. A two by two experiment examined the effects on BI of message frame (loss vs. gain) and message focus (psoriasis symptom reduction vs. CVD risk reduction). Participants with psoriasis (n = 217) were randomly allocated to one of four evidence-based health messages related to either smoking, alcohol, diet or physical activity, using an online questionnaire. BI was the primary outcome. Analysis of variance tests and hierarchical multiple regression analyses were conducted. A significant frame by focus interaction was found for BI to reduce alcohol intake (p = .023); loss-framed messages were more effective for CVD risk reduction information, whilst gain-framed messages were more effective for psoriasis symptom reduction information. Message framing effects were not found for BI for increased physical activity and improving diet. High CVD risk was a significant predictor of increased BI for both alcohol reduction (β = .290, p < .01) and increased physical activity (β = ?.231, p < .001). Message framing may be an important factor to consider depending on the health benefit emphasised (disease symptom reduction or CVD risk reduction) and patient-stated priorities. Condition-specific health messages in psoriasis populations may increase the likelihood of message effectiveness for alcohol reduction.     

False memory,attentional bias and future thinking among people living with HIV with posttraumatic stress disorder

People living with HIV can experience posttraumatic stress disorder (PTSD). Complex relationships exist between HIV, PTSD and cognitive impairments. This cross-sectional study compared three cognitive impairments (false memory, attentional bias, deficits in future thinking) among people living with HIV with and without PTSD in Iran. People living with HIV with PTSD (n = 20) and without PTSD (n = 20) completed measures of psychological symptomatology, dot-probe task, Deese Roediger McDermott paradigm and future thinking task at Razavi Khorasan Health Center. The PTSD group, when compared to the non-PTSD group, recognised a significantly greater number of false memories (p < .001; η² = .58), had an attentional bias toward threat-related words (p < .001; η² = .35) and imagined fewer specific future events (p < .001; η² = .31). People living with HIV with PTSD may have difficulties with false memory, attentional biases, and generating future events. Since psychological treatments are limited in Iran, this research highlighted some potential cognitive targets for people living with HIV.     

Vagal influence during worry and cognitive challenge

Abstract

The primary foci of the study were exploration of the linkage between cognitive and autonomic inflexibility of worry and generalized anxiety disorder (GAD) and examination of the effects of an analog cognitive restructuring task on this relationship. Cardiac responses of GAD and non-GAD participants were measured to examine the sympathetic and parasympathetic effects of worry and cognitive challenge. Diagnostic groups of undergraduate students were determined via administration of a structured interview, yielding a GAD group (n=16) and a control group (n=19) of individuals without GAD, depression, or panic disorder diagnoses. Cardiac autonomic responses were acquired via electrocardiogram during rest, worry, and cognitive challenge conditions by an experimenter blind to diagnosis. Metrics were compared between the two groups and across the three conditions. Individuals diagnosed with GAD did not differ significantly from controls on autonomic indices. Worry was associated with significantly decreased parasympathetic influence and increased sympathetic activity. Cognitive challenge did not result in significant increased cardiac responsivity. The results indicate that worry behavior is associated with decreased vagal activity, suggest a linkage between autonomic and cognitive inflexibility, and provide further suggestions for improving protocols to assess the autonomic effects of cognitive therapy techniques.     

Long-term memory of haptic and visual information in older adults

ABSTRACT

The present study examined haptic and visual memory capacity for familiar objects through the application of an intentional free-recall task with three-time intervals in a sample of 78 healthy older adults without cognitive impairment. A wooden box and a turntable were used for the presentation of haptic and visual stimuli, respectively. The procedure consisted of two phases, a study phase that consisted of the presentation of stimuli, and a test phase (free-recall task) performed after one hour, one day or one week. The analysis of covariance (ANCOVA) indicated that there was a main effect only for the time intervals (F (2,71) = 12.511, p = .001, η² = 0.261), with a lower recall index for the interval of one week compared to the other intervals. We concluded that the memory capacity between the systems (haptic and visual) is similar for long retrieval intervals (hours to days).     

Clarifying the role of impulsivity in dietary restraint: A structural equation modeling approach

This study was designed to clarify the relationship between the four dimensions of impulsivity in Whiteside and Lynam’s (2001) model and the two aspects of dietary restraint (Concern for Dieting and Weight Fluctuation) in a non-clinical sample. Data were collected from a volunteer community sample (N = 216) of women who responded to two self-report instruments related to impulsivity (UPPS Impulsive Behavior Scale, Whiteside & Lynam, 2001) and dietary restraint (Restraint Scale, Polivy, Herman, & Warsh, 1978). A structural equation model was tested. The model provided a good fit to the data (χ²/df = 1.64, p < .0001, RMSEA = 0.054, 90% CI = 0.050–0.058, p-value for test of close fit (RMSEA > 0.05) = .035) and revealed that Concern for Dieting was positively related to Urgency (standardized β = 0.25, p < .01). Weight Fluctuation was related to lack of Perseverance (standardized β = 0.25, p < .01) and tended to relate to Sensation Seeking (standardized β = 0.17, p = .056). Urgency and lack of Perseverance were found to play a significant role in predicting Concern for Dieting and Weight Fluctuation.     

Reversible inactivation of the nucleus of the solitary tract impairs retention performance in an inhibitory avoidance task.

Several peripherally acting hormones and drugs are known to modulate memory storage processes, yet the mechanisms which permit these agents to influence memory is not well understood since they do not freely enter the brain. The nucleus of the solitary tract (NTS) is one brainstem structure which receives important neural input from the periphery. Therefore, the objective of this experiment was to determine whether the NTS is involved in modulating processes contributing to memory formation. Male Sprague-Dawley rats were trained in a one-trial inhibitory avoidance task (0.35 mA, 0.5 s footshock). Immediately or 2 h after training microinjections of 2% lidocaine hydrochloride (20 mg/kg) or a phosphate buffer solution were administered bilaterally into the NTS. Two other groups received microinjections of lidocaine into the fourth ventricle or cerebellum. On retention tests given 48 h after training the latency to reenter the dark compartment of the apparatus was recorded. The retention latencies of rats receiving bilateral microinjections of 0.5 microliter of lidocaine hydrochloride into the NTS were significantly shorter than those of animals given injections of a buffer solution (0.5 microliter), delayed injections of buffer or lidocaine, or control injections of lidocaine into the cerebellum or fourth ventricle. These findings suggest that memory storage processes are impaired by reversible inactivation of the NTS after training. The implications of these findings in terms of a possible role of the NTS in modulating brain processes involved in memory storage are discussed.     

Working memory and fine motor skills predict early numeracy performance of children with cerebral palsy

Early numeracy is an important precursor for arithmetic performance, academic proficiency, and work success. Besides their apparent motor difficulties, children with cerebral palsy (CP) often show additional cognitive disturbances. In this study, we examine whether working memory, non-verbal intelligence, linguistic skills, counting and fine motor skills are positively related to the early numeracy performance of 6-year-old children with CP. A total of 56 children (M = 6.0, SD = 0.61, 37 boys) from Dutch special education schools participated in this cross-sectional study. Of the total group, 81% of the children have the spastic type of CP (33% unilateral and 66% bilateral), 9% have been diagnosed as having diskinetic CP, 8% have been diagnosed as having spastic and diskinetic CP and 2% have been diagnosed as having a combination of diskinetic and atactic CP. The children completed standardized tests assessing early numeracy performance, working memory, non-verbal intelligence, sentence understanding and fine motor skills. In addition, an experimental task was administered to examine their basic counting performance. Structural equation modeling showed that working memory and fine motor skills were significantly related to the early numeracy performance of the children (β = .79 and p < .001, β = .41 and p < .001, respectively). Furthermore, counting was a mediating variable between working memory and early numeracy (β = .57, p < .001). Together, these findings highlight the importance of working memory for early numeracy performance in children with CP and they warrant further research into the efficacy of intervention programs aimed at working memory training.     

Apodemus sylvaticus (LOXT) is a suitable mouse strain for testing spatial memory retention in the Morris water maze

Information on the difference in cognitive function between laboratory and wild-caught mice is anecdotal and this question has not been systematically studied. Moreover, studying a wild-caught mouse strain per se may add information to the repertoire of mouse strains available. We aimed to study spatial memory in a wild mouse strain (Apodemus sylvaticus, AS) as compared to two individual laboratory mouse strains.Male AS (n = 20), CD1 (n = 19) and C57BL/6J mice (n = 19), 12–14 weeks old, were used in the experiments. The Morris water maze (MWM) was used for determination of spatial memory and time spent in the target quadrant at time points 5 (D5) and 12 days (D12) was evaluated. During the acquisition phase latency to reach the platform and path length to reach the platform was evaluated.Following four training days on day 5 (D5), time spent in the target quadrant was highest in AS > CD1 > C57BL/6J (P < 0.006). On day 12 (D12), time spent in the target quadrant was significantly higher in AS than in both other strains (P < 0.001).All animals learned the task and during the acquisition phase, latency to reach the platform as well as path length decreased significantly in AS.It is concluded that the AS is the most suitable strain for the evaluation of spatial memory in the MWM and is presenting with memory retention superior to laboratory mouse strains CD1 and C57BL/6J.     

Effects of sleep on positive,negative and neutral valenced story and image memory

During sleep, emotional memories are preferentially strengthened. However, most studies on sleep and emotional memory focus on comparing negative valence with neutral valence stimuli. This study compared the sleep-dependent memory effects for stories and images, each comprising negative, neutral, and positive stimuli. It was hypothesized that a sleep effect would be seen for negatively and positively valenced stimuli. A novel story memory task (comprising three stories), and photographs from the Nencki Affective Picture database were presented for learning to 61 healthy adults (ages 18–25). They were tested for memory on the two tasks immediately, and then again after either a 2-hr nap (n = 31; 17 women, 14 men) or 2-hr wake period (n = 30; 13 women, 17 men). At second testing, the sleep condition had significantly better recall compared to the wake condition on both tasks. There was a relationship with valence only for the story task, with better performance for the sleep condition on the negatively and positively valenced texts, but not on the neutral text. There were no significant relationships between memory measures and sleep-stage duration and EEG power variables. The story memory findings support the hypothesis that memory consolidation prioritizes emotional memory, whether positively or negatively valenced.