Placebo Analgesia in Aging – the Impact of age-related cognitive decline

Poster (2023, May 12)

Background. While older people report acute and chronic pain more often than younger people, and, therefore, would benefit significantly from non-pharmacological pain treatment, little is known about how ... [more ▼]

Background. While older people report acute and chronic pain more often than younger people, and, therefore, would benefit significantly from non-pharmacological pain treatment, little is known about how age affects different psychological strategies of pain modulation. The few studies on cognitive distraction from pain suggest a reduced pain relief in older adults, whereas studies on placebo analgesia revealed inconsistent results. So far, distraction and hypnotic analgesia have hardly been investigated in aging. Methods. Healthy young and older participants underwent either a cognitive pain distraction task (working memory task), a placebo analgesia realized with a sham TENS intervention, a hypnotic analgesia intervention or a verbal pain distraction intervention, while receiving non-painful and moderate painful individually adjusted transdermal electrical pulse trains to the inner forearm. Pain ratings and pain-related evoked potentials via 64-channel EEG were recorded. Results. First analyses on the currently small sample suggest a differential impact of age on pain modulation strategies. Since the current sample size is too small to draw reliable conclusions, results will be presented and discussed at the conference. Conclusion. Our results will contribute to a deeper understanding on the efficacy of cognitive pain modulation in aging, helping to optimize pain treatments in this population. [less ▲]

Cognitive Pain Modulation in Young and Older Adults: Understanding the Role of Individual Differences in Frontal Functioning

Doctoral thesis (2022)

Cognitive pain modulation is integral to our quality of life and deeply interwoven with the success of pain treatments but is also characterized by large interindividual variations. Emerging evidence ... [more ▼]

Cognitive pain modulation is integral to our quality of life and deeply interwoven with the success of pain treatments but is also characterized by large interindividual variations. Emerging evidence suggests that one of the driving factors behind these variations are individual differences in frontal functioning. Further evidence indicates that pain-related cognitions, and possibly also emotional distress, may influence the efficacy of pain modulation. Central aim of this project was to assess the role of individual differences in frontal functioning in cognitive pain modulation, with a specific focus on older adults. With respect to this, we also wanted to assess whether individual differences in frontal functions could explain conflicting previous results on age-related changes in the efficacy of cognitive pain modulation. In addition, we wanted to address the role of negative pain-related mindsets and emotional distress on the efficacy of cognitive pain modulation. We tested these research questions across four different studies using two prime paradigms of cognitive pain modulation, namely distraction from pain and placebo analgesia. In Study I, we assessed the role of individual differences in executive functions, emotional distress, and pain-related cognitions in modulating heat pain thresholds in healthy young adults in virtual reality environments with different levels of cognitive load. We found that emotional distress and visuo-spatial short-term memory significantly predicted how participants responded to the low vs high load environment. In Study II, we investigated the role of different forms of cognitive inhibition abilities and negative pain-related cognitions in modulating the efficacy of distraction from (heat) pain by cognitive demand in healthy young adults. We found a significant influence of better cognitive inhibition and selective attention abilities on the size of the distraction effect; however, this association was moderated by the participant’s level of pain catastrophizing, i.e., high pain catastrophizers showed an especially strong association. In Study III, we tested potential age-related differences in distraction from pain in a group of young and older adults while simultaneously acquiring functional brain images. We found no age-related changes at the behavioural level, but a slightly reduced neural distraction effect in older adults. The neural distraction effect size in older adults was furthermore significantly positively related to better cognitive inhibition abilities. In Study IV, we explored potential age-related differences in placebo analgesia in a group of young and older adults (who were partly re-recruited from Study III) while recording their brain activity with an electroencephalogram. Results revealed no age-related differences in the magnitude of the behavioural or electrophysiological placebo response, but older adults showed a neural signature of the placebo effect that was distinct from young participants. Regression analyses revealed that executive functions that showed an age-related decline (as established via group comparisons) were significant predictors of the behavioural placebo response. We furthermore found that better executive functions significantly moderated the association between age group and placebo response magnitude: older adults with better executive functions showed a larger placebo response than young adults whereas worse executive functions were associated with a smaller placebo response, possibly explaining why we found no significant difference at the group level. In summary, all studies provide converging evidence that differences in cognitive functions can significantly affect the efficacy of cognitive pain modulation. Although older adults showed a significant decline in most cognitive functions that we assessed, we found no systematic reduction in the efficacy of cognitive pain modulation (except for a slight reduction in the neural distraction effect size). Closer inspection of the data revealed that older adults may have engaged compensatory mechanisms that enabled them to experience the same (or even higher) level of pain relief as younger adults. We furthermore found evidence for the notion that pain-related cognitions and emotional distress may affect how individuals respond to cognitive pain modulation although this association was less systematic than for cognitive functions. Overall, the present thesis adds to the emerging body of evidence highlighting the importance of executive functions, as indicators of frontal functioning, in cognitive pain modulation. [less ▲]

Pain Processing in Older Age – Evidence from Event-Related Potentials

Scientific Conference (2021, June)

Aging is known to affect neurobiological and physiological aspects of pain perception and has been associated with reduced pain sensitivity and a deterioration of descending pain inhibitory mechanisms. To ... [more ▼]

Aging is known to affect neurobiological and physiological aspects of pain perception and has been associated with reduced pain sensitivity and a deterioration of descending pain inhibitory mechanisms. To investigate age differences in neural electrophysiological correlates of pain processing, we induced acute pain in healthy older (60 yrs+) and younger adults (18 to 35 yrs), using short transdermal electrical pulses administered to the inner forearm, with individually adjusted stimulation intensities. Participants received alternating blocks of painful and non-painful control stimulation and rated the intensity and unpleasantness of each stimulus on two visual analog scales. Pain-related evoked potentials were recorded with a 64-channel EEG. Preliminary results indicate that younger and older participants rated painful stimuli more intensive and unpleasant compared to the control stimulation, with older adults showing a slight habituation over time. In younger adults, ERP amplitudes (N2, P2 P3) of painful stimulation were enhanced compared to non- painful stimulation. In contrast, older participants showed generally reduced ERPs, no difference between pain and non-painful stimulation and by tendency longer latencies for painful stimulation. This suggests that nociceptive neural processing is altered in aging, while the reported pain perception is unaffected. Given that aging is also associated with a decline of cognitive functions and PFC volume and activity changes, this could have implications for the efficacy of cognitive pain modulation. Altogether, our results highlight the need for a deeper understanding of the mechanisms underlying pain processing in older adults, and how these age-related changes affect (cognitive) pain treatments in this population. [less ▲]

Analgesic effects of interacting with a VR game and associated psychophysiological responses

Scientific Conference (2021, June)

Introduction: Virtual reality (VR) has been shown to be an effective tool for pain distraction by redirecting attention away from painful stimuli. Although VR therapy has been successfully implemented in ... [more ▼]

Introduction: Virtual reality (VR) has been shown to be an effective tool for pain distraction by redirecting attention away from painful stimuli. Although VR therapy has been successfully implemented in clinical settings, little is known about the underlying factors that modulate analgesic responses, such as cognitive load, executive functions and VR or gaming experience. Methods: A final sample of N = 90 healthy participants played the VR game Subnautica in a high and a low cognitive load condition. In the low load condition, participants explored the VR along a predefined route. In the high load condition, participants had to additionally memorize eight digits presented along the route. Pain heat thresholds as well as psychophysiological measures (ECG, EDA) were recorded during a non-interactive resting state period prior to playing as well as during the two VR sessions. Furthermore, participants completed questionnaires (e.g., pain attitude) and executive functioning tasks (e.g., go/nogo task). Results: Pain thresholds did not differ for high versus low demand. However, participants achieved higher threshold for the interactive playing sessions compared to the resting state period. Psychophysiological markers (e.g., HRV) indicate lower sympathetic activity during the resting state compared to the playing session (resting state < low load < high load). Moreover, pain catastrophizing and fear of pain were significant predictors of pain thresholds. Discussion: Results shed light on the role of inter-individual differences and psychophysiological markers of VR-based pain sensitivity and indicate factors that facilitate/impair distraction effects. This may have important implication for the use of VR-therapy. [less ▲]

Virtual reality gaming for pain distraction - Investigation of attentional and psychophysiological effects

Scientific Conference (2021, May)

Virtual reality has been shown to be a powerful method to divert attention away from pain (Malloy & Milling, 2010) and has been used successfully to temporally relieve patients from pain in clinical ... [more ▼]

Virtual reality has been shown to be a powerful method to divert attention away from pain (Malloy & Milling, 2010) and has been used successfully to temporally relieve patients from pain in clinical settings. However, little is known about the underlying attentional processes involved in pain processing in virtual reality. Therefore, as one of the first studies, this project investigates the role of especially cognitive factors influencing distraction from pain. N = 90 healthy participants played the video game Subnautica in two virtual reality conditions (high vs. low cognitive load). To assess the distraction effect, pain thresholds and psychophysiological measures were assessed during play. Additionally, executive functions and self-reported measures on, e.g., presence, simulation sickness and pain-related subjects were assessed. Results suggest that interactive virtual reality games are a potential tool to alter pain processing, regardless of the level of cognitive load. [less ▲]

Distraction from pain: The role of selective attention and pain catastrophizing

in European Journal of Pain (2020), 24(10), 1880-1891

In context: emotional intent and temporal immediacy of contextual descriptions modulate affective ERP components to facial expressions

in Social Cognitive and Affective Neuroscience (2020)

In this study, we explored how contextual information about threat dynamics affected the electrophysiological correlates of face perception. Forty-six healthy native Swedish speakers read verbal ... [more ▼]

In this study, we explored how contextual information about threat dynamics affected the electrophysiological correlates of face perception. Forty-six healthy native Swedish speakers read verbal descriptions signaling an immediate vs delayed intent to escalate or deescalate an interpersonal conflict. Each verbal description was followed by a face with an angry or neutral expression, for which participants rated valence and arousal. Affective ratings confirmed that the emotional intent expressed in the descriptions modulated emotional reactivity to the facial stimuli in the expected direction. The electrophysiological data showed that compared to neutral faces, angry faces resulted in enhanced early and late event-related potentials (VPP, P300 and LPP). Additionally, emotional intent and temporal immediacy modulated the VPP and P300 similarly across angry and neutral faces, suggesting that they influence early face perception independently of facial affect. By contrast, the LPP amplitude to faces revealed an interaction between facial expression and emotional intent. Deescalating descriptions eliminated the LPP differences between angry and neutral faces. Together, our results suggest that information about a person’s intentions modulates the processing of facial expressions. [less ▲]

Investigating the role of individual differences in the analgesic response to a virtual reality game: An exploratory analysis (accepted submission, but symposium was cancelled due to COVID-19)

Scientific Conference (2020, March)

Virtual reality (VR) has been shown to be a powerful method of redirecting attention away from pain and is increasingly used in clinical settings as a therapeutic tool for pain treatment. Yet, little is ... [more ▼]

Virtual reality (VR) has been shown to be a powerful method of redirecting attention away from pain and is increasingly used in clinical settings as a therapeutic tool for pain treatment. Yet, little is known about the underlying factors that modulate the size of the analgesic response to a VR game, such as task difficulty and inter-individual differences in pain attitude, emotion regulation habits, executive functions and virtual reality experience. Methods: 101 healthy participants played two versions of the VR game Subnautica, differing in cognitive load (low load vs. high load). In the low load condition, participants navigated along a predefined route. In the high load condition, participants additionally memorized a series of single digits presented along the route. Pain heat thresholds as well as psychophysiological measures (ECG, EDA) were recorded during a resting state period prior to, as well as during, the two VR playing sessions. In addition, participants completed several psychological questionnaires and different executive functioning tasks (Corsi block tapping task, flanker task, go/nogo task) prior to the VR sessions. Results: Preliminary results of a subgroup (N = 66) of the total sample revealed that pain thresholds were significantly higher for the VR playing sessions when compared to the resting state period, with a trend of a higher threshold for the high load condition. Moreover, pain catastrophizing and fear of pain were significant predictors of pain threshold measurements. The complete results will be presented at the symposium. Discussion: Results could shed light on the role of inter-individual differences on the efficacy of VR-based distraction from pain, and potentially elucidate factors that render an individual more likely to benefit from VR as a pain-relieving tool. This may have important consequences for the use of VR as a therapeutic treatment for pain patients. [less ▲]

The destruction of distraction? Neural mechanisms of reduced task-related analgesia with aging.

Poster (2019, September 06)

A meta-analysis of suppression-induced forgetting in neurotypical and clinical populations

Scientific Conference (2018, May)