Brain responses to the vicarious facilitation of pain by facial expressions of pain and fear.

Observing pain in others facilitates self-pain in the observer. Vicarious pain facilitation mechanisms are poorly understood. We scanned 21 subjects while they observed pain, fear and neutral dynamic facial expressions. In 33% of the trials, a noxious electrical stimulus was delivered. The nociceptive flexion reflex (NFR) and pain ratings were recorded. Both pain and fear expressions increased self-pain ratings (fear > pain) and the NFR amplitude. Enhanced response to self-pain following pain and fear observation involves brain regions including the insula (INS) (pain > fear in anterior part), amygdala, mid-cingulate cortex (MCC), paracentral lobule, precuneus, supplementary motor area and pre-central gyrus. These results are consistent with the motivational priming account where vicarious pain facilitation involves a global enhancement of pain-related responses by negatively valenced stimuli. However, a psychophysiological interaction analysis centered on the left INS revealed increased functional connectivity with the aMCC in response to the painful stimulus following pain observation compared to fear. The opposite connectivity pattern (fear > pain) was observed in the fusiform gyrus, cerebellum (I-IV), lingual gyrus and thalamus, suggesting that pain and fear expressions influence pain-evoked brain responses differentially. Distinctive connectivity patterns demonstrate a stronger effect of pain observation in the cingulo-insular network, which may reflect partly overlapping networks underlying the representation of pain in self and others.

The effect of continuation and maintenance electroconvulsive therapy on cognition: A systematic review of the literature and meta-analysis.

BACKGROUND: Electroconvulsive therapy (ECT) is an effective treatment for depression, mania, and refractory schizophrenia. Its tolerability profile is established for acute treatment, but less is known regarding the effects of longer treatment courses, particularly on cognitive performance. OBJECTIVES: To assess the effect of the long-term ECT on cognition. METHODS: We searched CINAHL, EMBASE, PsychInfo and Pubmed, for the period between January 1, 2010, and June 30, 2022, in English or French, for randomized controlled trials, prospective or retrospective studies of ECT continued for at least 2 months for the treatment of mood or schizophrenic disorders and which measured cognition before and at the end of treatment. Non-peer reviewed records were excluded. The Cochrane Risk of Bias tool was used to assess study quality. Classical meta-analyses, with heterogeneity statistics (tau2, I2) were complemented with three level-meta-analysis and Bayesian Meta-analyses. RESULTS: Nine studies were included in the narrative and quantitative review. Controlled comparison at 6 months (k = 6, n = 334) and at 12 months (k = 3, n = 56), within-subject comparisons at 6 (k = 6, n = 218) and 12 months (k = 4, n = 147) showed no detrimental effect of maintenance or continuation ECT on cognition, with little to no heterogeneity. Bayesian analysis further confirmed that data better supported the no effects hypothesis. LIMITATIONS: Insufficient data resulted in imprecision in estimates. CONCLUSIONS: Continuation and maintenance ECT do not appear detrimental for cognitive performance. However, the low number of studies limit the interpretation of the results.

Effects of Brief Mindfulness Interventions on the Interference Induced by Experimental Heat Pain on Cognition in Healthy Individuals.

Background: Pain captures attention and interferes with competing tasks demanding cognitive effort. Brief mindfulness interventions involving both conceptual learning and meditation exercises have been shown to improve attention and reduce pain sensitivity, and could potentially reduce pain interference. This study assesses the effect of a 5-day mindfulness intervention (20 min/day) on the interference produced by thermal pain on working memory performance using a 2-back task. Methods: Healthy participants were randomized into three groups exposed to mindfulness meditation training (n = 15), an active educational control intervention comprising only conceptual information on mindfulness (n = 15), or no intervention (n = 15). The two active interventions were administered in a dual-blind fashion and outcomes were assessed by research personnel blind to this allocation. Evaluation sessions were conducted before and after the interventions to assess the effect of pain on 2-back performance (pain interference). Importantly, both pain stimuli and the 2-back task were calibrated individually and in each session before assessing pain interference, thereby controlling for possible changes in baseline pain sensitivity and cognitive performance. Secondary outcomes included heat pain sensitivity, cold pain tolerance, cognitive inhibition, cognitive flexibility, and divided attention. Results: Manipulation checks confirmed that heat pain interferes with the performance of the working-memory task. Compared to the no-intervention control group, pain interference was significantly reduced following the conceptual intervention but not the meditation intervention, although a corollary analysis suggests the effect might be due to regression toward the mean caused by baseline imbalance in pain interference. Secondary outcomes also suggested an increase in pain tolerance in the conceptual learning group only. Discussion: A short mindfulness meditation intervention was insufficient to reduce pain interference but conceptual learning about mindfulness produced some unexpected benefits. Although the generalization of experimental findings to clinical pain conditions may be premature, these results highlight the importance of distinguishing the contribution of mindfulness education and meditation training in future studies. Understanding the effects of mindfulness training on pain regulation and management must take into consideration the multiple factors underlying this complex intervention.

Mindfulness induction and cognition: A systematic review and meta-analysis.

Mindfulness meditation might improve a variety of cognitive processes, but the available evidence remains fragmented. This preregistered meta-analysis (PROSPERO-CRD42018100320) aimed to provide insight into this hypothesis by assessing the effects of brief mindful attention induction on cognition. Articles were retrieved from Pubmed, PsycInfo and Web of Science up until August 1, 2018. A total of 34 studies were included. The outcomes were categorized into four cognitive domains: attentional functioning, memory, executive functioning and higher-order function. A small effect was found across all cognitive domains (Hedges' g = 0.18, 95% IC = 0.07-0.29). Separated analyses for each cognitive domain revealed an effect only in higher-order cognitive functions (k = 10, Hedges' g = 0.35, 95% IC = 0.20-0.50). Results suggest that mindfulness induction improves cognitive performance in tasks involving complex higher-order functions. There was no evidence of publication bias, but studies generally presented many methodological flaws.

Reduced Fear-Conditioned Pain Modulation in Experienced Meditators: A Preliminary Study.

OBJECTIVE: Mindfulness-based practice is a form of cognitive/affective training that may help reduce suffering by attenuating maladaptive anticipatory processes. This study's objective was to examine the pain modulating impact of classical fear learning in meditation practitioners. METHODS: The hyperalgesic effects of pain expectation and uncertainty were assessed outside formal meditation in 11 experienced meditators (>1000 hours) compared with meditation-naive controls during a Pavlovian classical fear-conditioning paradigm involving two visual stimuli (CS+/CS-), one of which (CS+) co-terminated with a noxious electrical stimulus (unconditioned stimulus) on 50% of trials. A Rescorla-Wagner/Pearce-Hall hybrid model was fitted onto the conditioned skin conductance responses using computational modeling to estimate two learning parameters: expected shock probability and associability (i.e., uncertainty). RESULTS: Using a scale ranging between 0 (no pain) and 100 (extremely painful), meditators reported less pain (M = 19.9, SE = 5.1 for meditators, M = 32.4, SE = 2.4 for controls) but had comparable spinal motor responses (nociceptive flexion reflex) to the unconditioned stimulus. Multilevel mediation analyses revealed that meditators also exhibited reduced hyperalgesic effects of fear learning on higher-order pain responses but comparable effects on the nociceptive flexion reflex. These results suggest that mindfulness affects higher-order perceptual processes to a greater extent than from descending inhibitory controls. Furthermore, meditators showed reduced hyperalgesic effects of fear conditioning with no significant group difference in conditioned learning as evidenced by discriminative anticipatory skin conductance responses and learning parameters derived from computational modeling. CONCLUSIONS: These results highlight potential mechanisms underlying mindfulness-related hypoalgesia, relevant to clinical conditions in which repeated pain exposure might reinforce hyperalgesic processes through fear conditioning.