Binocular rivalry alternations and their relation to visual adaptation

When different stimuli are presented dichoptically, perception alternates between the two in a stochastic manner. After a long-lasting and rigorous debate, there is growing consensus that this phenomenon, known as binocular rivalry (BR), is the result of a dynamic competition occurring at multiple levels of the visual hierarchy. The role of low- and high-level adaptation mechanisms in controlling these perceptual alternations has been a key issue in the rivalry literature. Both types of adaptation are dispersed throughout the visual system and have an equally influential, or even causal, role in determining perception. Such an explanation of BR is also in accordance with the relationship between the latter and attention. However, an overall explanation of this intriguing perceptual phenomenon needs to also include noise as an equally fundamental process involved in the stochastic resonance of perceptual bistability

Improving the reliability of model-based decision-making estimates in the two-stage decision task with reaction-times and drift-diffusion modeling

A well-established notion in cognitive neuroscience proposes that multiple brain systems contribute to choice behaviour. These include: (1) a model-free system that uses values cached from the outcome history of alternative actions, and (2) a model-based system that considers action outcomes and the transition structure of the environment. The widespread use of this distinction, across a range of applications, renders it important to index their distinct influences with high reliability. Here we consider the two-stage task, widely considered as a gold standard measure for the contribution of model-based and model-free systems to human choice. We tested the internal/temporal stability of measures from this task, including those estimated via an established computational model, as well as an extended model using drift-diffusion. Drift-diffusion modeling suggested that both choice in the first stage, and RTs in the second stage, are directly affected by a model-based/free trade-off parameter. Both parameter recovery and the stability of model-based estimates were poor but improved substantially when both choice and RT were used (compared to choice only), and when more trials (than conventionally used in research practice) were included in our analysis. The findings have implications for interpretation of past and future studies based on the use of the two-stage task, as well as for characterising the contribution of model-based processes to choice behaviour

The neurobiology of functional neurological disorders characterised by impaired awareness

We review the neurobiology of Functional Neurological Disorders (FND), i.e., neurological disorders not explained by currently identifiable histopathological processes, in order to focus on those characterised by impaired awareness (functionally impaired awareness disorders, FIAD), and especially, on the paradigmatic case of Resignation Syndrome (RS). We thus provide an improved more integrated theory of FIAD, able to guide both research priorities and the diagnostic formulation of FIAD. We systematically address the diverse spectrum of clinical presentations of FND with impaired awareness, and offer a new framework for understanding FIAD. We find that unraveling the historical development of neurobiological theory of FIAD is of paramount importance for its current understanding. Then, we integrate contemporary clinical material in order to contextualise the neurobiology of FIAD within social, cultural, and psychological perspectives. We thus review neuro-computational insights in FND in general, to arrive at a more coherent account of FIAD. FIAD may be based on maladaptive predictive coding, shaped by stress, attention, uncertainty, and, ultimately, neurally encoded beliefs and their updates. We also critically appraise arguments in support of and against such Bayesian models. Finally, we discuss implications of our theoretical account and provide pointers towards an improved clinical diagnostic formulation of FIAD. We suggest directions for future research towards a more unified theory on which future interventions and management strategies could be based, as effective treatments and clinical trial evidence remain limited

Adapting the queen square guided self help (QGSH) for functional neurological disorders as a stand-alone intervention: an exonian pilot study

Aim: Functional neurological disorders (FND) are one of the most common presentation in neurology clinics, causing a significant disability and economic burden. Cognitive behavioural therapy (CBT) has one of the best available evidence in managing FND, although access remains limited. Queen Square, London neuropsychiatry experts have established an excellent model for a CBT based, Guided Self Help (GSH) programme, which is preparatory to a multidisciplinary inpatient treatment. It has been shown to have good outcomes. This study was designed to ascertain the feasibility and acceptance of this QGSH model, in an Exonian cohort of FND patients, whilst piloting its stand-alone version, without the inpatient component. Additionally, the study explores the need and types of modifications required for the stand-alone adaptation of QGSH. Method: Consecutive patients referred to Exeter FND Service, between February to June 2020, who had internet access, were offered the QGSH pilot. Patients with a primary mental disorder concurrent drug/alcohol misuse or risk of self-harm or suicide were excluded. Ethics approval was not required. The QGSH intervention constitutes of 11 modules focussing on specific elements crucial to FND management along with homework tasks, delivered by the author, under supervision by QGSH experts. Patients completed Pre and Post-intervention questionnaires as well as structured feedback. Results: Three successive patients with varied FND symptoms were recruited to the pilot between February and June 2020. The baseline health status of these patients was worse as compared to EQ-5D-5L population norms with significant baseline psychiatric comorbidity. Outcome measures used before and after QGSH intervention included PHQ 9, GAD 7, EQ-5D-5L and a locally devised symptom severity questionnaire. Necessary modifications were made to the program based on the patients informal feedback and structured formal feedback was sought in the end. Conclusion: All patients derived some benefit from QGSH and certain modifications were suggested in patient feedback to improve engagement. Despite study limitations, especially small size and the impact of Covid 19 pandemic during the intervention; QGSH model appears acceptable and feasible in an Exonian cohort, however, some modifications are recommended for the stand-alone version to succeed. The recommendations will be presented

How People Use Social Information to Find out What to Want in the Paradigmatic Case of Inter-temporal Preferences.

The weight with which a specific outcome feature contributes to preference quantifies a person's 'taste' for that feature. However, far from being fixed personality characteristics, tastes are plastic. They tend to align, for example, with those of others even if such conformity is not rewarded. We hypothesised that people can be uncertain about their tastes. Personal tastes are therefore uncertain beliefs. People can thus learn about them by considering evidence, such as the preferences of relevant others, and then performing Bayesian updating. If a person's choice variability reflects uncertainty, as in random-preference models, then a signature of Bayesian updating is that the degree of taste change should correlate with that person's choice variability. Temporal discounting coefficients are an important example of taste-for patience. These coefficients quantify impulsivity, have good psychometric properties and can change upon observing others' choices. We examined discounting preferences in a novel, large community study of 14-24 year olds. We assessed discounting behaviour, including decision variability, before and after participants observed another person's choices. We found good evidence for taste uncertainty and for Bayesian taste updating. First, participants displayed decision variability which was better accounted for by a random-taste than by a response-noise model. Second, apparent taste shifts were well described by a Bayesian model taking into account taste uncertainty and the relevance of social information. Our findings have important neuroscientific, clinical and developmental significance

Group psychotherapy format guided self-help for patients with FNSD awaiting inpatient multidisciplinary treatment: A pilot study

Background: We describe our experience of developing Guided Self Help for patients with Functional Neurological Symptom Disorder as group therapy, delivered remotely, via Zoom. // Aims: The aims of the current study are (a) to describe how the original Queen Square Guided Self-Help (QGSH) was adapted for group therapy, and (b) to present a service evaluation of the first 8 months of running QGSH therapy groups remotely. // Methods: We carried out a review after 8 months, from 11 May 2021 until 31 January 2022. // Results: A total of 16 patients were treated in three groups. Assessing our outcomes in terms of Yalom's framework for group psychotherapy, we found that the group provided 10/11 of Yalom's therapeutic factors. Patient satisfaction was high. // Discussion: We outline for plans for further devaluation and development, including the development of a stand-alone group. // Conclusion: The group therapy format is a promising addition to our service

Simulating the computational mechanisms of cognitive and behavioral psychotherapeutic interventions: insights from active inference

Cognitive-behavioral therapy (CBT) leverages interactions between thoughts, feelings, and behaviors. To deepen understanding of these interactions, we present a computational (active inference) model of CBT that allows formal simulations of interactions between cognitive interventions (i.e., cognitive restructuring) and behavioral interventions (i.e., exposure) in producing adaptive behavior change (i.e., reducing maladaptive avoidance behavior). Using spider phobia as a concrete example of maladaptive avoidance more generally, we show simulations indicating that when conscious beliefs about safety/danger have strong interactions with affective/behavioral outcomes, behavioral change during exposure therapy is mediated by changes in these beliefs, preventing generalization. In contrast, when these interactions are weakened, and cognitive restructuring only induces belief uncertainty (as opposed to strong safety beliefs), behavior change leads to generalized learning (i.e., “over-writing” the implicit beliefs about action-outcome mappings that directly produce avoidance). The individual is therefore equipped to face any new context, safe or dangerous, remaining in a content state without the need for avoidance behavior—increasing resilience from a CBT perspective. These results show how the same changes in behavior during CBT can be due to distinct underlying mechanisms; they predict lower rates of relapse when cognitive interventions focus on inducing uncertainty and on reducing the effects of automatic negative thoughts on behavior

Dialogue entre les humanitaires français et anglo-saxons

Ce livre est l’édition anglaise du livre publié en français en 2006 et intitulé Critique de la raison humanitaire. Le titre français invite le lecteur à une analyse critique de l’humanitaire, ce qui signifie réfléchir à ce que l’on peut comprendre de l’action humanitaire et considérer les limites de cette analyse. Ce livre utilise une approche unique pour stimuler et informer le lecteur dans sa propre analyse : juxtaposer des textes traitant des organisations humanitaires écrits par des auteu..

Dialogue entre les humanitaires français et anglo-saxons

Ce livre est l’édition anglaise du livre publié en français en 2006 et intitulé Critique de la raison humanitaire. Le titre français invite le lecteur à une analyse critique de l’humanitaire, ce qui signifie réfléchir à ce que l’on peut comprendre de l’action humanitaire et considérer les limites de cette analyse. Ce livre utilise une approche unique pour stimuler et informer le lecteur dans sa propre analyse : juxtaposer des textes traitant des organisations humanitaires écrits par des auteu..