Exploring the interaction between working memory and long-term memory: Evidence for the workspace model

There is a large range of models of working memory, each with different scopes and emphases. Current interest focuses strongly on the interaction of working memory with long-term memory, as it has become clear that models of working memory alone are incapable of capturing some of our complex cognitive abilities. Most models have contrasting views on how this interaction is implemented. In this thesis, three classes of models are defined, each proposing a different type of interaction. The first model proposes that working memory acts as a gateway for perceptual input on its way to long-term memory. In the unitary model, working memory is seen as comprising the activated portion of long-term memory. The workspace model views working memory as a workspace that is separate from, and deals with the activated contents of long-term memory. The main aim of this thesis was to address the differences between these three models experimentally. Experiments 1 – 7 employed a dual-task paradigm to investigate the effects of irrelevant visual input on visuo-spatial working memory tasks. Two main findings emerged: (1) maintenance of images in working memory was largely insensitive to the effects of concurrent perceptual input; (2) mental imagery was susceptible to interference from irrelevant visual input. This interference effect was selective, as demonstrated by a lack of disruption of imagery by other secondary tasks. Experiment 8 further tested the three models by investigating implicit processing of visual information by neglect patients. It was found that implicit processing is mediated by the activation of long-term memory, in the absence of a conscious representation in working memory. These results together converge to support the workspace model, and suggest a view in which perceptual input activates the contents of long-term memory, prior to these activated representations being made available in a functionally separate working memory system for further processing. The gateway model and unitary model are unable to accommodate all findings. The implications of these results for existing theories about working memory are discussed

The Importance of Narrative and Other Lessons from an Evaluation of an NLG System that Summarises Clinical Data

This research was funded by the UK Engineering and Physical Sciences Research Council, under grant EP/D049520/1.Publisher PD

Cognitive Modulation Of Pain By Attention: The Role Of Executive Functioning In Aging

Attention is acknowledged as an effective strategy to modulate pain, as shown by various studies of acute and chronic pain. Here executive functioning (EF) plays a key role, with poorer EF related to less successful inhibition of pain, both relying on the prefrontal cortex (PFC). With age, structural and volume changes in the PFC are accompanied by age-related cognitive decline. So far, only a few studies investigated how age-related cognitive decline affect cognitive distraction from pain.In a two-session design, healthy young (18-30 years) and older participants (60+ years) performed four EF tasks shown to either reveal age-related cognitive decline or not. Afterwards, participants performed a pain distraction task, a n-Back working memory task with low and high cognitive load, during which participants received individually adjusted transdermal electrical pulse trains in non-painful and moderately painful intensities to the inner forearm. Participants rated them regarding their intensity and unpleasantness. Stimulus-related (EF tasks) and pain-related evoked potentials were recorded with a 64-channel EEG.Preliminary results suggest a similar effective subjective pain relief during high and low working memory load in both age groups, which is reflected in a similar reduced N1-P2 pain-related ERPs in older but not in younger participants. However, including executive functioning showing age-related cognitive decline, revealed less successful pain reduction in the high working memory load condition in older adults. These findings could lead to a better understanding how to adapt pain treatments in the older population by including selective cognitive trainings, optimizing pain modulation settings

The impact of executive functioning and age-related cognitive decline on distraction from pain

Older people, suffering from pain and its consequences more often than younger people, would benefit significantly from non-pharmacological pain treatment. So far, little is known about how age affects psychological pain modulation strategies. Preliminary findings hint towards a less efficient pain inhibition through cognition-based pain modulation strategies, as cognitive distraction from pain. Here, executive functions (EFs) have been considered a key factor in the age – pain relationship, with age-related cognitive decline in EFs being associated with reduced pain relief through distraction in older adults. We investigated influence of four core EFs on distraction from pain in aging. In a two-session design, healthy young (18-30 years) and older participants (60+ years) performed a Go-Nogo task, the Stroop-Color-Word-Task, the Sternberg-Task, and the Attentional Network Task. Afterwards, participants performed a pain distraction task, namely a n-Back working memory task with low and high cognitive load, during which participants received individually adjusted transdermal electrical pulse trains in non-painful and moderately painful intensities to the inner forearm. Ratings of intensity and unpleasantness were collected and stimulus-related (EF tasks) and pain-related evoked potentials were recorded with a 64-channel EEG. Unexpectedly, first analyses on the currently small sample suggest a more efficient pain relief through distraction under low relative to high cognitive load in older adults. The distraction effect was related to EFs, some of which showed age-related cognitive impairment. Our findings could lead to a better understanding how to adapt pain treatments in this population by including selective cognitive trainings and optimizing distraction task difficulty

The role of cognitive reappraisal in placebo analgesia: an fMRI study

Placebo analgesia (PA) depends crucially on the prefrontal cortex (PFC), which is assumed to be responsible for initiating the analgesic response. Surprisingly little research has focused on the psychological mechanisms mediated by the PFC and underlying PA. One increasingly accepted theory is that cognitive reappraisal—the reinterpretation of the meaning of adverse events—plays an important role, but no study has yet addressed the possible functional relationship with PA. We studied the influence of individual differences in reappraisal ability on PA and its prefrontal mediation. Participants completed a cognitive reappraisal ability task, which compared negative affect evoked by pictures in a reappraise versus a control condition. In a subsequent fMRI session, PA was induced using thermal noxious stimuli and an inert skin cream. We found a region in the left dorsolateral PFC, which showed a positive correlation between placebo-induced activation and (i) the reduction in participants’ pain intensity ratings; and (ii) cognitive reappraisal ability scores. Moreover, this region showed increased placebo-induced functional connectivity with the periaqueductal grey, indicating its involvement in descending nociceptive control. These initial findings thus suggest that cognitive reappraisal mechanisms mediated by the dorsolateral PFC may play a role in initiating pain inhibition in P

Cognitive control of pain in Aging – comparison of different pain modulation strategies

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

Brief mindfulness training can mitigate the influence of prior expectations on pain perception

Background Recent neuroimaging evidence suggests that mindfulness practice may mitigate the biasing influence of prior cognitive and emotional expectations on pain perception. The current study tested this hypothesis using a pain-cueing paradigm, which has reliably been shown to elicit conditioned hypoalgesic and hyperalgesic effects. Specifically, we aimed to investigate whether the instructed use of a mindfulness compared to a suppression strategy differentially modulates the magnitudes of conditioned hypoalgesia and hyperalgesia. Methods Sixty-two healthy non-meditators were assigned to listen to either brief mindfulness or suppression instructions, in between the conditioning and testing phases of a pain-cueing task. Participants provided ratings of anticipatory anxiety, pain intensity and pain unpleasantness throughout the task. They also completed trait and state self-report measures of mindfulness and pain catastrophizing. Results Results indicated that the paradigm was successful in inducing conditioned hyperalgesic and hypoalgesic effects. Importantly, while we found evidence of cue-induced hyperalgesia in both groups, only the suppression group reported cue-induced hypoalgesia. No group differences in pain ratings were found for unconditioned (novel-cued) stimuli. Conclusions These findings provide partial support for recently proposed predictive processing models, which posit that mindfulness may lead to a prioritization of current sensory information over previous expectations. We explore potential explanations for the asymmetrical group differences in conditioned hypoalgesia versus conditioned hyperalgesia, and discuss our results in light of recent neuroimaging insights into the neuropsychological mechanisms of mindfulness and expectancy-driven pain modulation. Significance The current study provides novel insights into the working mechanisms of mindfulness-driven pain modulation. Our data suggest that brief mindfulness training may reduce the influence of prior beliefs and expectations on pain perception. This finding adds to growing evidence suggesting that mindfulness may alleviate pain via neuropsychological mechanisms opposite to those typically observed in conditioning/placebo procedures and other cognitive manipulations. These unique mechanisms underline the potential of mindfulness as an alternative to traditional cognitive pain regulatory strategies

The Neural Basis of Age-Related Changes in Motor Imagery of Gait: An fMRI Study

Background. Aging is often associated with modifications of gait. Recent studies have revealed a strong relationship between gait and executive functions in healthy and pathological aging. We hypothesized that modification of gait due to aging may be related to changes in frontal lobe function. Methods. Fourteen younger (27.0±3.6 years) and 14 older healthy adults (66.0±3.5 years) performed a motor imagery task of gait as well as a matched visual imagery task. Task difficulty was modulated to investigate differential activation for precise control of gait. Task performance was assessed by recording motor imagery latencies, eye movements, and electromyography during functional magnetic resonance imaging scanning. Results. Our results showed that both healthy older and young adults recruited a network of brain regions comprising the bilateral supplementary motor cortex and primary motor cortex, right prefrontal cortex, and cerebellum, during motor imagery of gait. We observed an age-related increase in brain activity in the right supplementary motor area (BA6), the right orbitofrontal cortex (BA11), and the left dorsolateral frontal cortex (BA10). Activity in the left hippocampus was significantly modulated by task difficulty in the elderly participants. Executive functioning correlated with magnitude of increases in right primary motor cortex (BA4) during the motor imagery task. Conclusions. Besides demonstrating a general overlap in brain regions recruited in young and older participants, this study shows age-related changes in cerebral activation during mental imagery of gait. Our results underscore the importance of executive function (dorsolateral frontal cortex) and spatial navigation or memory function (hippocampus) in gait control in elderly individual

„Does acute Stress influence the successful Distraction from Pain in young and older Adults?”

Previous research has shown that cognitive modulation of pain through psychological strategies can contribute to pain relief and that distraction from pain through cognitive engagement represents an efficient method of these strategies. However, little is known about the impacts of stress and age on pain modulation, although previous findings suggest a negative effect of stress and that the efficacy may be impaired due to age-related cognitive decline. The present study therefore investigated the impact of acute stress on the efficacy of pain modulation through distraction in aging. Before and after an acute stress induction using the Trier Social Stress Test (TSST) or a control condition, healthy younger (18-30 years) and older (60+ years) adults performed a n-back working memory task with low (0-back) and high (2-back) working memory load serving as the distraction paradigm, during which participants received individual adjusted non-painful and moderately painful electrical stimuli transmitted transdermal to the left inner forearm and rated them regarding intensity and unpleasantness on a visual analogue scale. Stress response was measured using heart rate and pulse and mood questionnaires about the stress experience. Preliminary results suggest more effective pain distraction under low working memory load for older adults, while in younger adults, pain reduction was higher under high load condition. So far, acute stress did not affect pain distraction in both age groups. The final results may contribute to a deeper understanding of pain modulation in aging and the impact of stress for a helpful optimization of pain therapy in older age

Heritability of aggression following social evaluation in middle childhood: An fMRI study.

Middle childhood marks an important phase for developing and maintaining social relations. At the same time, this phase is marked by a gap in our knowledge of the genetic and environmental influences on brain responses to social feedback and their relation to behavioral aggression. In a large developmental twin sample (509 7- to 9-year-olds), the heritability and neural underpinnings of behavioral aggression following social evaluation were investigated, using the Social Network Aggression Task (SNAT). Participants viewed pictures of peers that gave positive, neutral, or negative feedback to the participant’s profile. Next, participants could blast a loud noise toward the peer as an index of aggression. Genetic modeling revealed that aggression following negative feedback was influenced by both genetics and environmental (shared as well as unique environment). On a neural level (n 5 385), the anterior insula and anterior cingulate cortex gyrus (ACCg) responded to both positive and negative feedback, suggesting they signal for social salience cues. The medial prefrontal cortex (mPFC) and inferior frontal gyrus (IFG) were specifically activated during negative feedback, whereas positive feedback resulted in increased activation in caudate, supplementary motor cortex (SMA), and dorsolateral prefrontal cortex (DLPFC). Decreased SMA and DLPFC activation during negative feedback was associated with more aggressive behavior aft