Schizophrenia, dissociation, and consciousness

Current thinking suggests that dissociation could be a significant comorbid diagnosis in a proportion of schizophrenic patients with a history of trauma. This potentially may explain the term “schizophrenia” in its original definition by Bleuler, as influenced by his clinical experience and personal view. Additionally, recent findings suggest a partial overlap between dissociative symptoms and the positive symptoms of schizophrenia, which could be explained by inhibitory deficits. In this context, the process of dissociation could serve as an important conceptual framework for understanding schizophrenia, which is supported by current neuroimaging studies and research of corollary discharges. These data indicate that the original conception of “split mind” may be relevant in an updated context. Finally, recent data suggest that the phenomenal aspects of dissociation and conscious disintegration could be related to underlying disruptions of connectivity patterns and neural integration.     

What's new? Children prefer novelty in referent selection

Determining the referent of a novel name is a critical task for young language learners. The majority of studies on children’s referent selection focus on manipulating the sources of information (linguistic, contextual and pragmatic) that children can use to solve the referent mapping problem. Here, we take a step back and explore how children’s endogenous biases towards novelty and their own familiarity with novel objects influence their performance in such a task. We familiarized 2-year-old children with previously novel objects. Then, on novel name referent selection trials children were asked to select the referent from three novel objects: two previously seen and one completely novel object. Children demonstrated a clear bias to select the most novel object. A second experiment controls for pragmatic responding and replicates this finding. We conclude, therefore, that children’s referent selection is biased by previous exposure and children’s endogenous bias to novelty.     

Can't get over me: Ego depletion attenuates prosocial effects of perspective taking

Many studies attest to the beneficial and prosocial effects of perspective taking. The present research tests the notion that such perspective taking is a process involving active self‐regulation and, hence, that effects of perspective taking on prosocial behaviour are more pronounced when self‐control resources are high, rather than low. Results confirmed this hypothesis. Across two experiments using acts of compliance as a specific form of prosocial behaviour, perspective‐taking participants were more willing to comply with a request for help by the experimenter (experiment 1) and donated more time to a charitable cause (experiment 2) than participants who did not engage in perspective taking, but only when self‐regulatory resources were in sufficient supply. Under conditions of ego depletion, the impact of perspective taking on compliance was attenuated. Copyright © 2011 John Wiley & Sons, Ltd.     

How prior knowledge affects selective attention during category learning: An eyetracking study

Research has shown that category learning is affected by (a) attention, which selects which aspects of stimuli are available for further processing, and (b) the existing semantic knowledge that learners bring to the task. However, little is known about how knowledge affects what is attended. Using eyetracking, we found that (a) knowledge indeed changes what features are attended, with knowledge-relevant features being fixated more often than irrelevant ones, (b) this effect was not due to an initial attentional bias toward relevant dimensions but rather emerged gradually as a result of observing category members, and (c) this effect grew even after a learning criterion was reached, that is, despite the absence of negative feedback. We argue that models of knowledge-based learning will remain incomplete until they specify mechanisms that dynamically select prior knowledge in response to observed category members and which then directs attention to knowledge-relevant dimensions and away from irrelevant ones.     

Dissociative states and neural complexity

Recent findings indicate that neural mechanisms of consciousness are related to integration of distributed neural assemblies. This neural integration is particularly vulnerable to past stressful experiences that can lead to disintegration and dissociation of consciousness. These findings suggest that dissociation could be described as a level of neural disintegration reflecting a number of independent processes by means of neural complexity. In the present study measurement of dissociation, traumatic stress symptoms and neural complexity calculated using nonlinear analysis of EEG [during rest conditions], and electrodermal activity (EDA) [during rest and Stroop task] were performed in 52 university students (mean age 24.1). Neural complexity has been described using pointwise correlation dimension (PD2) calculated from EEG and EDA records. While no significant relationship was found between EEG complexity and dissociative symptoms, statistically significant relationship between EDA complexity and dissociative symptoms during rest, but not during the Stroop task, has been found. These results indicate that electrodermal complexity during rest may reflect a level of dissociative symptoms.     

Using variability to guide dimensional weighting: associative mechanisms in early word learning

At 14 months, children appear to struggle to apply their fairly well-developed speech perception abilities to learning similar sounding words (e.g., bih/dih; Stager & Werker, 1997). However, variability in nonphonetic aspects of the training stimuli seems to aid word learning at this age. Extant theories of early word learning cannot account for this benefit of variability. We offer a simple explanation for this range of effects based on associative learning. Simulations suggest that if infants encode both noncontrastive information (e.g., cues to speaker voice) and meaningful linguistic cues (e.g., place of articulation or voicing), then associative learning mechanisms predict these variability effects in early word learning. Crucially, this means that despite the importance of task variables in predicting performance, this body of work shows that phonological categories are still developing at this age, and that the structure of noninformative cues has critical influences on word learning abilities.     

Picturing classical and quantum Bayesian inference

We introduce a graphical framework for Bayesian inference that is sufficiently general to accommodate not just the standard case but also recent proposals for a theory of quantum Bayesian inference wherein one considers density operators rather than probability distributions as representative of degrees of belief. The diagrammatic framework is stated in the graphical language of symmetric monoidal categories and of compact structures and Frobenius structures therein, in which Bayesian inversion boils down to transposition with respect to an appropriate compact structure. We characterize classical Bayesian inference in terms of a graphical property and demonstrate that our approach eliminates some purely conventional elements that appear in common representations thereof, such as whether degrees of belief are represented by probabilities or entropic quantities. We also introduce a quantum-like calculus wherein the Frobenius structure is noncommutative and show that it can accommodate Leifer??s calculus of ??conditional density operators??. The notion of conditional independence is also generalized to our graphical setting and we make some preliminary connections to the theory of Bayesian networks. Finally, we demonstrate how to construct a graphical Bayesian calculus within any dagger compact category.     

Acceptance and Commitment Therapy for a Heterogeneous Group of Treatment-Resistant Clients: A Treatment Development Study

Acceptance and commitment therapy (ACT) has been shown to have broad applicability to different diagnostic groups, and there are theoretical reasons to consider its use with clients with chronic mental health problems. We report an innovative treatment development evaluation of ACT for a heterogeneous group of ”treatment-resistant clients” (N = 10) who had attended a mean of 3.5 previous psychological interventions. All clients had Axis I presentations and half met diagnostic criteria for Axis II disorders. Functioning, assessed at pre- and postintervention, and at 6- and 12-month follow-up, showed improvements over time on all primary outcome measures, driven largely by significant changes occurring between baseline and 6-month follow-up. Improvements were associated with ACT processes of change. The data thus suggest that a broad range of clients who had not benefited from standard care may benefit from ACT.