Does incidental sequence learning allow us to better manage upcoming conflicting events?

Published online: 13 June 2019Recent proposals emphasize the role of learning in empirical markers of conflict adaptation. Some of these proposals are rooted in the assumption that contingency learning works not only on stimulus–response events but also on covert processes such as selective attention. In the present study, we explored how these learning processes may apply to trial-to-trial modulations of selective attention, mirroring the sequential nature of congruency sequence effects. Two groups of participants performed a four-choice Stroop task in which the color to which they responded on each trial acted as a probabilistic predictor either of the external response to be emitted on the next trial, or the congruency level (and therefore control demands) on the next trial. The results showed clear effects of sequence learning for external responses, but no evidence of learning about sequential stimulus–conflict associations. The implications of these results are discussed in relation to other learning-based phenomena of conflict adaptation and suggest that learning of stimulus–control associations is strongly constrained by event boundaries.The present research was funded by the Spanish Ministerio de Economía y Competitividad with a research Grant to Luis Jiménez (PSI2015-70990-P)

Nicotine induced improvements in cognition: a possible role for the α7 nicotinic acetylcholine receptor

Cognitive dysfunction is evident in a wide variety of neurological disorders from schizophrenia to Alzheimer's disease (AD). Impaired attention has been recorded in each of these patient groups and has been hypothesised to directly impact on their general cognitive ability and symptomatology. To date there is a paucity of treatment options for this impairment. Administration of nicotine, the prototypical agonist of the nicotinic class of acetylcholine receptors (nAChR), improves attention and the overall symptomatology of various CNS disorders. Its use as a possible therapeutic agent is limited by its adverse side-effects profile which includes addictiveness and nausea. Identification of the receptors/pathways through which nicotine produces these beneficial effects is a prerequisite to the discovery of more selective agonists with minimal side-effects. Current interest has focused on the homopentameric alpha 7 (α7) receptor (nAChR) due to its proposed role in attention and memory, and neuroprotection in AD and other neurodegenerative disorders. In the thesis, the role of the α7 nAChR in modulating nicotine-induced cognitive improvement has been studied using both pharmacological and genetic means.Assessment of sustained attention in rodents can be performed using the 5-choice serial reaction-time (5-CSR) task; analogous to the continuous performance test used in man. A protocol was established which allowed the demonstration of nicotine induced improvements in sustained attention in mice. In this task α7 nAChR knockout (KO) mice exhibited impaired acquisition and performance, providing additional evidence that this receptor may be a valid therapeutic target for cognitive enhancement. In order to investigate the role of nAChR manipulation on working memory, the odour span task, a test of olfactory working memory capacity, was established in mice. Nicotine administration did not improve performance of C57B1/6J mice probably as a consequence of ceiling effects. Transgenic mice overexpressing human caspase-3 (hc-3) displayed a robust impairment in the task that was attenuated by nicotine administration. Moreover α7 nAChR KO mice exhibited impaired acquisition and performance in the task but in a different pattern to that of the hc-3 mice. This pattern may reflect an impaired ability to attend to the task as opposed to a working memory deficit. These demonstrations provide further support for a role of the α7 nAChR in cognition. Tg2576 mice represent the best well characterised transgenic mouse model of AD, however there remains a dearth of information on their attentional and olfactory capabilities. The mice exhibited a deficit in sustained attention as measured by the 5-CSR task as well as an age-related impairment in the odour span task.In conclusion the development of the 5-CSR task for mice was used to identify a nicotine-induced improvement in normal mice and impaired performance in α7 KO and Tg2576 mice. The establishment of the odour span task in mice allowed the demonstration of impaired working memory performance in hc-3 mice (attenuated by nicotine administration), α7 KO mice and Tg2576 mice (age-related). In summary these data provide some evidence for a role of the α7 nAChR in nicotineinduced improvement in cognition, and the tasks developed provide new tools for the assessment of putative cognitive enhancing compounds

Thinking Against Burnout? An Individual’s Tendency to Engage in and Enjoy Thinking as a Potential Resilience Factor of Burnout Symptoms and Burnout-Related Impairment in Executive Functioning

The personality trait need for cognition (NFC) refers to individual differences in the tendency to engage in and enjoy cognitive endeavors. In today’s working world, which is characterized by increasing cognitive demands, NFC may contribute to resilience against work-related stress and burnout symptoms. We investigated this question in a large population-wide sample of 4,134 individuals (Study 1) and in a sample of 125 students (Study 2). NFC was consistently negatively related to the burnout facets emotional exhaustion and reduced personal efficacy of the Maslach burnout inventory and explained up to 10% additional variance in burnout symptoms over and above the five-factor model of personality. In the student sample, where stress factors are mainly cognitive in nature, NFC was the most relevant predictor. In this sample, we additionally investigated whether NFC might be a relevant moderator of the inconsistently found associations between burnout and impairments in cognitive functioning. The participants conducted three cognitive tasks (number–letter task, two-back task, and Go/NoGo task) that measure the executive functions switching, updating, and response inhibition, respectively. While burnout was slightly negatively related to working memory performance, NFC did not moderate the relationship between burnout and executive control which could be traced back to the young and healthy sample used to examine this research question. All in all, our results clearly suggest that NFC may be an important individual difference factor contributing to the resilience against burnout, especially if stress factors are cognitive in nature

Neuronal and behavioural pain processing

In our study “Neuronal and Behavioural Pain Processing: A Comparison Between a Strong Brand and a Generic Medication Placebo using the Example of Aspirin vs. 1A Pharma”, we investigated the expectation effects associated with brands by labelling two different placebo interventions. We tested the hypothesis, whether a strong brand can influence the impact of an inert substance. We studied the potential differences between the two placebos on a behavioural and neural level inducing the stimulus with noxious heat pain using Medoc. The research objective was to unveil, whether recipients can be influenced through expectations, verbal suggestions and the brand itself. We applied a two by two design with two identical placebo interventions that differed in their labelling. One group was told that they will receive 500 mg of “Aspirin” (original brand), while the other group was told that they will receive a popular ASA generic (“1A Pharma”). At the beginning, we established the individual pain levels of each subject with the numeric rating scale. Then we measured pain intensities before and after the intervention. The intervention was the administration of the placebo. We investigated behavioural as well as neural differences and looked for corresponding activated brain regions using functional magnetic resonance imaging (fMRI). Those participants, who were administered the original brand in the placebo intervention, showed a decrease in pain intensity. The generic group did not show any significant pain decrease. At the neuronal level, during the native condition, we observed activations of the anterior insula in both groups. After the intervention, the participants showed activations of the dorsomedial prefrontal cortex. The direct comparison of the two placebo conditions – the branded placebo vs. the generic – showed higher activations for the bilateral dorsolateral and dorsomedial prefrontal cortex. During the anticipation phase we observed activations of hippocampal, parahippocampal and adjacent brain areas for the generic group, only. These results suggest that only the original brand appears to evoke a behavioural response measured in terms of pain reduction. On a neuronal level, the activations were significant for the original brand only. Comparing the two placebo interventions, expectations seem to be significantly enhanced by the trusted brand, which appears to boost the placebo effect. Our results suggest that the underlying neural mechanisms of this placebo response are based on fronto-cortical neural networks