Effects of intranasal methamphetamine on metacognition of agency

Sense of control, selective attention, cognitive inhibition, and psychosocial outcomes after Retraining and Control Therapy (ReACT) in pediatric functional seizures

BACKGROUND

Differences in sense of control, cognitive inhibition, and selective attention in pediatric functional seizures (FS) versus matched controls implicate these as potential novel treatment targets. Retraining and Control Therapy (ReACT), which targets these factors, has been shown in a randomized controlled trial to be effective in improving pediatric FS with 82% of patients having complete symptom remission at 60 days following treatment. However, post-intervention data on sense of control, cognitive inhibition, and selective attention are not yet available. In this study, we assess changes in these and other psychosocial factors after ReACT.

METHODS

Children with FS (N = 14, Mage = 15.00, 64.3% female, 64.3% White) completed 8 weeks of ReACT and reported FS frequency at pre and post-1 (7 days before and after ReACT). At pre, post-1, and post-2 (60 days after ReACT), all 14 children completed the Pediatric Quality of Life Inventory Generic Core Scales, Behavior Assessment System (BASC2), and Children's Somatic Symptoms Inventory-24 (CSSI-24), and 8 children completed a modified Stroop task with seizure symptoms condition in which participants are presented with a word and respond to the ink color (e.g., "unconscious" in red) to assess selective attention and cognitive inhibition. At pre and post-1, ten children completed the magic and turbulence task (MAT) which assesses sense of control via 3 conditions (magic, lag, turbulence). In this computer-based task, participants attempt to catch falling X's while avoiding falling O's while their control over the task is manipulated in different ways. ANCOVAs controlling for change in FS from pre- to post-1 compared Stroop reaction time (RT) across all time points and MAT conditions between pre and post-1. Correlations assessed the relationships between changes in Stroop and MAT performance and change in FS from pre- to post-1. Paired samples t-tests assessed changes in quality of life (QOL), somatic symptoms, and mood pre to post-2.

RESULTS

Awareness that control was manipulated in the turbulence condition of the MAT increased at post-1 vs. pre- (p = 0.02, η2 = 0.57). This change correlated with a reduction in FS frequency after ReACT (r = 0.84, p < 0.01). Reaction time significantly improved for the seizure symptoms Stroop condition at post-2 compared to pre- (p = 0.02, η2 = 0.50), while the congruent and incongruent conditions were not different across time points. Quality of life was significantly improved at post-2, but the improvement was not significant when controlling for change in FS. Somatic symptom measures were significantly lower at post-2 vs. pre (BASC2: t(12) = 2.25, p = 0.04; CSSI-24: t(11) = 4.17, p < 0.01). No differences were observed regarding mood.

CONCLUSION

Sense of control improved after ReACT, and this improvement was proportional to a decrease in FS, suggesting this as a possible mechanism by which ReACT treats pediatric FS. Selective attention and cognitive inhibition were significantly increased 60 days after ReACT. The lack of improvement in QOL after controlling for change in FS suggests QOL changes may be mediated by decreases in FS. ReACT also improved general somatic symptoms independent of FS changes.

Methamphetamine, amphetamine, and aggression in humans: A systematic review of drug administration studies

The relationship between amphetamine use and aggressive or violent behaviour is unclear. This review examined laboratory data collected in humans, who were administered an acute dose of amphetamine or methamphetamine, in order to investigate the link between amphetamines and aggression. It is registered with PROSPERO (CRD42019127711). Included in the analysis are data from twenty-eight studies. Behavioural and/or subjective measures of aggression were assessed in one thousand and sixty-nine research participants, with limited amphetamine-use histories, following a single amphetamine dose (0-35mg). The available published evidence indicates that neither amphetamine nor methamphetamine acutely increased aggression as assessed by traditional laboratory measures. Future research should assess supratherapeutic amphetamine doses as well as include a broader range of multiple aggression measures, facilitating simultaneous assessment of the various components that comprise this complex, multifaceted construct.

Cross domain self-monitoring in anosognosia for memory loss in Alzheimer's disease

Anosognosia for memory loss is a common feature of Alzheimer's disease (AD). Recent theories have proposed that anosognosia, a disruption in awareness at a global level, may reflect specific deficits in self-monitoring, or local awareness. Though anosognosia for memory loss has been shown to relate to memory self-monitoring, it is not clear if it relates to self-monitoring deficits in other domains (i.e., motor). The current study examined this question by analyzing the relationship between anosognosia for memory loss, memory monitoring, and motor monitoring in 35 individuals with mild to moderate AD. Anosognosia was assessed via clinical interview before participants completed a metamemory task to measure memory monitoring, and a computerized agency task to measure motor monitoring. Cognitive and psychological measures included memory, executive functions, and mood. Memory monitoring was associated with motor monitoring; however, anosognosia was associated only with memory monitoring, and not motor monitoring. Cognition and mood related differently to each measure of self-awareness. Results are interpreted within a hierarchical model of awareness in which local self-monitoring processes are associated across domain, but appear to only contribute to a global level awareness in a domain-specific fashion.

Effects of d-amphetamine upon psychosocial stress responses

Psychostimulant drugs alter the salience of stimuli in both laboratory animals and humans. In animals, stimulants increase rates of responding to conditioned incentive stimuli, and in humans, amphetamine increases positive ratings of emotional images. However, the effects of stimulants on real-life emotional events have not been studied in humans. In this study, we examined the effect of d-amphetamine on responses to acute psychosocial stress using a public speaking task. Healthy volunteers (N=56) participated in two experimental sessions, one with a psychosocial stressor (the Trier Social Stress Test) and one with a non-stressful control task. They were randomly assigned to receive d-amphetamine (5 mg n=18, 10 mg n=20) or placebo (n=18) on both sessions under double blind conditions. Salivary cortisol, subjective mood, and vital signs were measured at regular intervals during the session. Subjects also provided cognitive appraisals of the tasks before and after their performances. Amphetamine produced its expected mood and physiological effects, and the Trier Social Stress Test produced its expected effects on cortisol and mood. Although neither dose of amphetamine altered cardiovascular or hormonal responses to stress, amphetamine (10 mg) increased participants' pre-task appraisals of how challenging the task would be, and it increased post-task ratings of self-efficacy. Paradoxically, it also increased ratings of how stressful the task was, and prolonged aversive emotional responses. These findings suggest that amphetamine differentially affects stress response components: it may increase participants' appraisals of self-efficacy without dampening the direct emotional or physiological responses to the stress.

Intimate insight: MDMA changes how people talk about significant others

RATIONALE

±3,4-methylenedioxymethamphetamine (MDMA) is widely believed to increase sociability. The drug alters speech production and fluency, and may influence speech content. Here, we investigated the effect of MDMA on speech content, which may reveal how this drug affects social interactions.

METHOD

Thirty-five healthy volunteers with prior MDMA experience completed this two-session, within-subjects, double-blind study during which they received 1.5 mg/kg oral MDMA and placebo. Participants completed a five-minute standardized talking task during which they discussed a close personal relationship (e.g. a friend or family member) with a research assistant. The conversations were analyzed for selected content categories (e.g. words pertaining to affect, social interaction, and cognition), using both a standard dictionary method (Pennebaker's Linguistic Inquiry and Word Count: LIWC) and a machine learning method using random forest classifiers.

RESULTS

Both analytic methods revealed that MDMA altered speech content relative to placebo. Using LIWC scores, the drug increased use of social and sexual words, consistent with reports that MDMA increases willingness to disclose. Using the machine learning algorithm, we found that MDMA increased use of social words and words relating to both positive and negative emotions.

CONCLUSIONS

These findings are consistent with reports that MDMA acutely alters speech content, specifically increasing emotional and social content during a brief semistructured dyadic interaction. Studying effects of psychoactive drugs on speech content may offer new insights into drug effects on mental states, and on emotional and psychosocial interaction.

Depression and executive dysfunction contribute to a metamemory deficit among individuals with methamphetamine use disorders

OBJECTIVE

Chronic methamphetamine (MA) use is associated with moderate deficits in learning and memory, but the extend to which MA users are aware of such memory deficits (i.e., metamemory) is not known.

METHODS

In the current study, 195 participants with lifetime MA use diagnoses (MA +) and 195 non-MA-using comparison subjects (MA -) underwent comprehensive neuropsychiatry research assessments, including performance-based and self-report measures of episodic memory.

RESULTS

MA use disorders, major depressive disorder (MDD), and their interaction were uniquely associated with metamemory functioning, such that MDD increased the likelihood of a metamemory deficit among MA + participants. Within the MA group, individuals who over-estimated their memory abilities demonstrated greater executive dysfunction and lower cognitive reserve.

CONCLUSIONS

Chronic MA use is associated with reduced awareness of objective deficits in memory acquisition and recall, which is particularly exacerbated by the presence of major depression. Efforts to enhance metamemory accuracy and deployment of compensatory mnemonic strategies may benefit substance abuse treatment outcomes.

The disruptive effects of methamphetamine on delayed-matching-to-sample performance reflect proactive interference and are reduced by SCH23390

Different drugs produce different patterns of impairment on delayed matching-to-sample tasks. For example, (+/-)3,4-methylenedioxymethamphetamine (MDMA) produces an increase in proactive interference. That is, subjects are less accurate when they are required to make a response different to the one they made on the immediately previous trial. The current study assessed whether methamphetamine also produces this particular pattern of disruption in delayed matching-to-sample performance in rats. Methamphetamine primarily reduced accuracy on trials where the correct response differed from the one made on the previous trial. Thus methamphetamine, like MDMA and other stimulant-based drugs of abuse, increased proactive interference. This impairment was reduced by prior administration of the dopamine D1 antagonist SCH23390. These results further extend a general conclusion that a range of stimulant-based drugs may disrupt working memory function indirectly via a tendency to repeat previously made responses and that this disruption is related to D1 receptor activity.

Judgements of agency in schizophrenia: an impairment in autonoetic metacognition

We investigated judgements of agency in participants with schizophrenia and healthy controls. Participants engaged in a computer game in which they attempted to touch downward falling Xs and avoid touching Os. On some trials, participants were objectively in perfect control. On other trials, they were objectively not in complete control because the movement of the cursor on the screen was distorted with respect to the position of the mouse by random noise (turbulence), or it was lagged by 250 or 500 ms. Participants made metacognitive judgements of agency as well as judgements of performance. Control participants' judgements of agency were affected by the turbulence and lag variables-indicating that they knew they were objectively not in control in those conditions, and they were also influenced by their assessments of performance. The patients also used their assessments of performance but neither turbulence nor lag affected their judgements of agency. This indicated an impairment in agency monitoring. The patients, unlike the healthy controls, used only publically available external cues about performance in making judgements of 'agency' and did not rely on any additional access to internal self-relevant cues that were diagnostic in indicating whether or not they were, in fact, in control.

Is cognitive functioning impaired in methamphetamine users? A critical review

The prevailing view is that recreational methamphetamine use causes a broad range of severe cognitive deficits, despite the fact that concerns have been raised about interpretations drawn from the published literature. This article addresses an important gap in our knowledge by providing a critical review of findings from recent research investigating the impact of recreational methamphetamine use on human cognition. Included in the discussion are findings from studies that have assessed the acute and long-term effects of methamphetamine on several domains of cognition, including visuospatial perception, attention, inhibition, working memory, long-term memory, and learning. In addition, relevant neuroimaging data are reviewed in an effort to better understand neural mechanisms underlying methamphetamine-related effects on cognitive functioning. In general, the data on acute effects show that methamphetamine improves cognitive performance in selected domains, that is, visuospatial perception, attention, and inhibition. Regarding long-term effects on cognitive performance and brain-imaging measures, statistically significant differences between methamphetamine users and control participants have been observed on a minority of measures. More importantly, however, the clinical significance of these findings may be limited because cognitive functioning overwhelmingly falls within the normal range when compared against normative data. In spite of these observations, there seems to be a propensity to interpret any cognitive and/or brain difference(s) as a clinically significant abnormality. The implications of this situation are multiple, with consequences for scientific research, substance-abuse treatment, and public policy.

Finding the self in metacognitive evaluations: metamemory and agency in nondemented elders

OBJECTIVE

Metacognitive methodologies are used to examine the integrity of self-referential processing in healthy adults and have been implemented to study disorders of the self-concept in neurologic and psychiatric populations. However, the extent to which metacognitive evaluations assess a uniquely self-evaluative capacity that cannot be explained fully by primary cognitive functions, demographics, or mood is not clear. The objective of the current study was to examine whether metamemory and a metacognitive test of agency shared a self-referential association that would not be explained by cognition, demographics, or mood.

METHOD

Thirty-eight nondemented older adults (Mini Mental State Examination [MMSE] ≥24 and mean age = 68.13) participated in metacognitive testing and completed cognitive testing and mood questionnaires. Bivariate correlations were used to evaluate the association between metamemory and agency, and to determine the cognitive (memory, attention, and executive functioning), demographic (age and education), and mood (anxiety and depression) correlates of each. Correlates of metamemory and agency were then entered into linear regression models to determine whether any association between metacognitive measures remained.

RESULTS

Metamemory was associated with agency judgments (n = 27), specifically those on self-controlled rather than computer-controlled trials (r = .41, p = .03). Regression results supported a role for agency in predicting metamemory, above and beyond memory and education (β = .39, p = .034). Metamemory was also an independent predictor of agency judgments (β = .36, p = .049).

CONCLUSIONS

The interrelation between metamemory and agency judgments suggests that metacognitive testing captures an important aspect of self-referential processing not otherwise assessed in a standard cognitive evaluation and may provide unique information about self-evaluative capacities in clinical populations.

Dissociating neural correlates of action monitoring and metacognition of agency

Judgments of agency refer to people's self-reflective assessments concerning their own control: their assessments of the extent to which they themselves are responsible for an action. These self-reflective metacognitive judgments can be distinguished from action monitoring, which involves the detection of the divergence (or lack of divergence) between observed states and expected states. Presumably, people form judgments of agency by metacognitively reflecting on the output of their action monitoring and then consciously inferring the extent to which they caused the action in question. Although a number of previous imaging studies have been directed at action monitoring, none have assessed judgments of agency as a potentially separate process. The present fMRI study used an agency paradigm that not only allowed us to examine the brain activity associated with action monitoring but that also enabled us to investigate those regions associated with metacognition of agency. Regarding action monitoring, we found that being "out of control" during the task (i.e., detection of a discrepancy between observed and expected states) was associated with increased brain activity in the right TPJ, whereas being "in control" was associated with increased activity in the pre-SMA, rostral cingulate zone, and dorsal striatum (regions linked to self-initiated action). In contrast, when participants made self-reflective metacognitive judgments about the extent of their own control (i.e., judgments of agency) compared with when they made judgments that were not about control (i.e., judgments of performance), increased activity was observed in the anterior PFC, a region associated with self-reflective processing. These results indicate that action monitoring is dissociable from people's conscious self-attributions of control.

Amphetamine analogs methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) differentially affect speech

RATIONALE

Most reports of the effects of methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) on speech have been anecdotal.

OBJECTIVES

The current study used a within-participant design to assess the effects of methamphetamine and MDMA on speech.

MATERIALS AND METHODS

Eleven recreational users of amphetamines completed this inpatient, within-participant, double-blind study, during which they received placebo, methamphetamine (20, 40 mg), and MDMA (100 mg) on separate days. Following drug administration, study participants described movies viewed the previous evening and completed mood scales.

RESULTS

Methamphetamine increased quantity of speech, fluency, and self-ratings of talkativeness and alertness, while it decreased the average duration of nonjuncture unfilled pauses. MDMA decreased fluency and increased self-ratings of inability to concentrate. To determine if methamphetamine- and MDMA-related effects were perceptible, undergraduates listened to the participants' movie descriptions and rated their coherence and the speaker's mood. Following methamphetamine, descriptions were judged to be more coherent and focused than they were following MDMA.

CONCLUSIONS

Methamphetamine improved verbal fluency and MDMA adversely affected fluency. This pattern of effects is consistent with the effects of these drugs on functioning in other cognitive domains. In general, methamphetamine effects on speech were inconsistent with effects popularly attributed to this drug, while MDMA-related effects were in agreement with some anecdotal reports and discordant with others.