Effects of Nicotine Content and Preferred Flavor on Subjective Responses to E-cigarettes: A Randomized, Placebo-controlled Laboratory Study.

INTRODUCTION: Evidence suggests that e-liquid flavor and nicotine concentration are important factors in the initiation and maintenance of e-cigarette use (vaping). Flavors may increase the initiation and maintenance of vaping, and nicotine content is a factor in e-cigarette dependence and the efficacy of e-cigarettes for cigarette smoking cessation. Few human laboratory studies have assessed the joint and interactive effects of flavor and nicotine on subjective responses to e-cigarettes. METHODS: Regular e-cigarette users (N = 89) completed a multi-session study involving a paced vaping procedure with e-liquid cartridges containing their preferred flavor (berry, menthol, or tobacco) or no flavor, with or without nicotine (18 mg). Subjective effects of vaping (satisfaction, reward, aversion, airway sensations, and craving relief) were assessed. RESULTS: Nicotine significantly increased psychological reward and craving relief, whereas flavor significantly increased vaping satisfaction and taste. Nicotine dependence severity moderated the effect of nicotine on reward, such that those with the greatest dependence severity reported the greatest reward. CONCLUSIONS: These findings support differential and noninteractive effects of e-liquid nicotine content and flavor on reinforcing effects of e-cigarettes. IMPLICATIONS: E-liquid flavor and nicotine content have independent, non-interactive effects on subjective responses to vaping under controlled laboratory conditions. Among regular e-cigarette users, vaping a preferred flavor increased taste and satisfaction, but did not interact with nicotine to alter reward or craving. Further research on the ways in which these subjective effects may motivate vaping behavior among different populations of e-cigarette users would be useful to inform regulatory policy of ENDS products.

Aperiodic Neural Activity is a Better Predictor of Schizophrenia than Neural Oscillations.

Diagnosis and symptom severity in schizophrenia are associated with irregularities across neural oscillatory frequency bands, including theta, alpha, beta, and gamma. However, electroencephalographic signals consist of both periodic and aperiodic activity characterized by the (1/fX) shape in the power spectrum. In this paper, we investigated oscillatory and aperiodic activity differences between patients with schizophrenia and healthy controls during a target detection task. Separation into periodic and aperiodic components revealed that the steepness of the power spectrum better-predicted group status than traditional band-limited oscillatory power in classification analysis. Aperiodic activity also outperformed the predictions made using participants' behavioral responses. Additionally, the differences in aperiodic activity were highly consistent across all electrodes. In sum, compared to oscillations the aperiodic activity appears to be a more accurate and more robust way to differentiate patients with schizophrenia from healthy controls.

Event related potentials indexing the influence of emotion on cognitive processing in veterans with comorbid post-traumatic stress disorder and traumatic brain injury.

OBJECTIVE: Emotion regulation and cognitive executive control are significantly impaired in both post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI). These illnesses are increasingly common in veterans and their co-occurrence may exacerbate symptoms and recovery. The current study sought to investigate neural correlates of these impairments via event-related potentials (ERPs) and examined the association of PTSD symptom severity and impulsivity with these correlates. METHODS: Electroencephalographic data from seventy-nine veterans with PTSD and TBI and 17 control participants were recorded during a visual emotional oddball task and analyzed for the N2 and P3b ERPs. RESULTS: Results revealed that veterans showed a reduced P3b ERP in response to both target images and standard images. However, for standard images that followed a negative emotional distractor, the veterans showed a heightened N2 amplitude while the controls did not. In addition, impulsivity predicted modulation of the P3b across stimulus conditions, with a greater P3b amplitude associated with an increase in impulsivity. CONCLUSIONS: These findings suggest that veterans showed hyper-responsivity to background information and reduced ERPs to task-relevant information. SIGNIFICANCE: These findings may reflect heightened internal states that create neural noise and a reduced ability to modulate relevant responses.

Improving Cognitive Workload in Radiation Therapists: A Pilot EEG Neurofeedback Study.

Radiation therapy therapists (RTTs) face challenging daily tasks that leave them prone to high attrition and burnout and subsequent deficits in performance. Here, we employed an accelerated alpha-theta neurofeedback (NF) protocol that is implementable in a busy medical workplace to test if 12 RTTs could learn the protocol and exhibit behavior and brain performance-related benefits. Following the 3-week protocol, participants showed a decrease in subjective cognitive workload and a decrease in response time during a performance task, as well as a decrease in desynchrony of the alpha electroencephalogram (EEG) band. Additionally, novel microstate analysis for neurofeedback showed a significant decrease in global field power (GFP) following neurofeedback. These results suggest that the RTTs successfully learned the protocol and improved in perceived cognitive workload following 3 weeks of neurofeedback. In sum, this study presents promising behavioral improvements as well as brain performance-related evidence of neurophysiological changes following neurofeedback, supporting the feasibility of implementing neurofeedback in a busy workplace and encouraging the further study of neurofeedback as a tool to mitigate burnout.

Embedding an enriched environment in an acute stroke unit increases activity in people with stroke: a controlled before-after pilot study.

OBJECTIVES: To determine whether an enriched environment embedded in an acute stroke unit could increase activity levels in acute stroke patients and reduce adverse events. DESIGN: Controlled before-after pilot study. SETTING: An acute stroke unit in a regional Australian hospital. PARTICIPANTS: Acute stroke patients admitted during (a) initial usual care control period, (b) an enriched environment period and (c) a sustainability period. INTERVENTION: Usual care participants received usual one-on-one allied health intervention and nursing care. The enriched environment participants were provided stimulating resources, communal areas for eating and socializing and daily group activities. Change management strategies were used to implement an enriched environment within existing staffing levels. MAIN MEASURES: Behavioural mapping was used to estimate patient activity levels across groups. Participants were observed every 10 minutes between 7.30 am and 7.30 pm within the first 10 days after stroke. Adverse and serious adverse events were recorded using a clinical registry. RESULTS: The enriched environment group ( n = 30, mean age 76.7 ± 12.1) spent a significantly higher proportion of their day engaged in 'any' activity (71% vs. 58%, P = 0.005) compared to the usual care group ( n = 30, mean age 76.0 ± 12.8). They were more active in physical (33% vs. 22%, P < 0.001), social (40% vs. 29%, P = 0.007) and cognitive domains (59% vs. 45%, P = 0.002) and changes were sustained six months post implementation. The enriched group experienced significantly fewer adverse events (0.4 ± 0.7 vs.1.3 ± 1.6, P = 0.001), with no differences found in serious adverse events (0.5 ± 1.6 vs.1.0 ± 2.0, P = 0.309). CONCLUSIONS: Embedding an enriched environment in an acute stroke unit increased activity in stroke patients.

The effect of an enriched environment on activity levels in people with stroke in an acute stroke unit: protocol for a before-after pilot study.

BACKGROUND: Clinical practice guidelines advocate engaging stroke survivors in as much activity as possible early after stroke. One approach found to increase activity levels during inpatient rehabilitation incorporated an enriched environment (EE), whereby physical, cognitive, and social activity was enhanced. The effect of an EE in an acute stroke unit (ASU) has yet not been explored. METHODS/DESIGN: We will perform a prospective non-randomized before-after intervention study. The primary aim is to determine if an EE can increase physical, social, and cognitive activity levels of people with stroke in an ASU compared to usual care. Secondary aims are to determine if fewer secondary complications and improved functional outcomes occur within an EE. We will recruit 30 people with stroke to the usual care block and subsequently 30 to the EE block. Participants will be recruited within 24-72 h after onset of stroke, and each block is estimated to last for 12 weeks. In the usual care block current management and rehabilitation within an ASU will occur. In the EE block, the ASU environment will be adapted to promote greater physical, social, and cognitive activity. Three months after the EE block, another 30 participants will be recruited to determine sustainability of this intervention. The primary outcome is change in activity levels measured using behavioral mapping over 12 h (7.30 am to 7.30 pm) across two weekdays and one weekend day within the first 10 days of admission. Secondary outcomes include functional outcome measures, adverse and serious adverse events, stroke survivor, and clinical staff experience. DISCUSSION: There is a need for effective interventions that starts directly in the ASU. The EE is an innovative intervention that could increase activity levels in stroke survivors across all domains and promote early recovery of stroke survivors in the acute setting. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registry, ANZCTN12614000679684.

Electrophysiological Correlates of Aberrant Motivated Attention and Salience Processing in Unaffected Relatives of Schizophrenia Patients.

Patients with schizophrenia (SCZ) exhibit debilitating deficits in attention and affective processing, which are often resistant to treatment and associated with poor functional outcomes. Impaired orientation to task-relevant target information has been indexed by diminished P3b event-related potentials in patients, as well as their unaffected first-degree relatives, suggesting that P3b may be a vulnerability marker for schizophrenia. Despite intact affective valence processing, patients are unable to employ cognitive change strategies to reduce electrophysiological responses to aversive stimuli. Less is known about the attentional processing of emotionally salient task-irrelevant information in patients and unaffected first-degree relatives. The goal of the present study was to examine the neural correlates of salience processing, as indexed by the late positive potential (LPP), during the processing of emotionally salient distractor stimuli in 31 patients with SCZ, 28 first-degree relatives, and 47 control participants using an oddball paradigm. Results indicated that despite intact novelty detection (P3a), both SCZ and first-degree relatives demonstrated deficiencies in attentional processing, reflected in attenuated target-P3b, and aberrant motivated attention, with reduced early-LPP amplitudes for aversive stimuli relative to controls. First-degree relatives revealed a unique enhancement of the late-LPP response, possibly underlying an exaggerated evaluation of salient information and a compensatory engagement of neural circuitry. Furthermore, reduced early-LPP and target-P3b amplitudes were associated with enhanced symptom severity. These findings suggest that, in addition to P3b, LPP may be useful for monitoring clinical state. Future studies will explore the value of P3 and LPP responses as vulnerability markers for early detection and prediction of psychopathology.

Levels of attention and task difficulty in the modulation of interval duration mismatch negativity.

Time perception has been described as a fundamental skill needed to engage in a number of higher level cognitive processes essential to successfully navigate everyday life (e.g., planning, sequencing, etc.) Temporal processing is often thought of as a basic neural process that impacts a variety of other cognitive processes. Others, however, have argued that timing in the brain can be affected by a number of variables such as attention and motivation. In an effort to better understand timing in the brain at a basic level with minimal attentional demands, researchers have often employed use of the mismatch negativity (MMN). MMN, specifically duration MMN (dMMN) and interval MMN (iMMN) have been popular methods for studying temporal processing in populations for which attention or motivation may be an issue (e.g., clinical populations, early developmental studies). There are, however, select studies which suggest that attention may in fact modify both temporal processing in general and the MMN event-related potential. It is unclear the degree to which attention affects MMN or whether the effects differ depending on the complexity or difficulty of the MMN paradigm. The iMMN indexes temporal processing and is elicited by introducing a deviant interval duration amid a series of standards. A greater degree of difference in the deviant from the standard elicits a heightened iMMN. Unlike past studies, in which attention was intentionally directed toward a closed-captioned move, the current study had participants partake in tasks involving varying degrees of attention (passive, low, and high) with varying degrees of deviants (small, medium, and large) to better understand the role of attention on the iMMN and to assess whether level of attention paired with changes in task difficulty differentially influence the iMMN electrophysiological responses. Data from 19 subjects were recorded in an iMMN paradigm. The amplitude of the iMMN waveform showed an increase with attention, particularly for intervals that were the most distinct from a standard interval (p < 0.02). Results suggest that the role of attention on the iMMN is complex. Both the degree of attention paid as well as the level of difficulty of the MMN task likely influence the neuronal response within a timing network. These results suggest that electrophysiological perception of time is modified by attention and that the design of the iMMN study is critical to minimize the possible confounding effects of attention. In addition, the implications of these results for future studies assessing interval duration-based MMN in clinical populations is also addressed.

Cognitive function predicts neural activity associated with pre-attentive temporal processing.

Temporal processing, or processing time-related information, appears to play a significant role in a variety of vital psychological functions. One of the main confounds to assessing the neural underpinnings and cognitive correlates of temporal processing is that behavioral measures of timing are generally confounded by other supporting cognitive processes, such as attention. Further, much theorizing in this field has relied on findings from clinical populations (e.g., individuals with schizophrenia) known to have temporal processing deficits. In this study, we attempted to avoid these difficulties by comparing temporal processing assessed by a pre-attentive event-related brain potential (ERP) waveform, the mismatch negativity (MMN) elicited by time-based stimulus features, to a number of cognitive functions within a non-clinical sample. We studied healthy older adults (without dementia), as this population inherently ensures more prominent variability in cognitive function than a younger adult sample, allowing for the detection of significant relationships between variables. Using hierarchical regression analyses, we found that verbal memory and executive functions (i.e., planning and conditional inhibition, but not set-shifting) uniquely predicted variance in temporal processing beyond that predicted by the demographic variables of age, gender, and hearing loss. These findings are consistent with a frontotemporal model of MMN waveform generation in response to changes in the temporal features of auditory stimuli.

The impact of verbal framing on brain activity evoked by emotional images.

Emotional stimuli generally command more brain processing resources than non-emotional stimuli, but the magnitude of this effect is subject to voluntary control. Cognitive reappraisal represents one type of emotion regulation that can be voluntarily employed to modulate responses to emotional stimuli. Here, the late positive potential (LPP), a specific event-related brain potential (ERP) component, was measured in response to neutral, positive and negative images while participants performed an evaluative categorization task. One experimental group adopted a "negative frame" in which images were categorized as negative or not. The other adopted a "positive frame" in which the exact same images were categorized as positive or not. Behavioral performance confirmed compliance with random group assignment, and peak LPP amplitude to negative images was affected by group membership: brain responses to negative images were significantly reduced in the "positive frame" group. This suggests that adopting a more positive appraisal frame can modulate brain activity elicited by negative stimuli in the environment.