The boundary conditions for Bohr’s law: when is reacting faster than acting?

In gunfights in Western movies, the hero typically wins, even though the villain draws first. Niels Bohr (Gamow, The great physicists from Galileo to Einstein. Chapter: The law of quantum, 1988) suggested that this reflected a psychophysical law, rather than a dramatic conceit. He hypothesized that reacting is faster than acting. Welchman, Stanley, Schomers, Miall, and Bülthoff (Proceedings of the Royal Society of London B: Biological Sciences, 277, 1667-1674, 2010) provided empirical evidence supporting "Bohr's law," showing that the time to complete simple manual actions was shorter when reacting than when initiating an action. Here we probe the limits of this effect. In three experiments, participants performed a simple manual action, which could either be self-initiated or executed following an external visual trigger. Inter-button time was reliably faster when the action was externally triggered. However, the effect disappeared for the second step in a two-step action. Furthermore, the effect reversed when a choice between two actions had to be made. Reacting is faster than acting, but only for simple, ballistic actions.     

Obsessive compulsive personality disorder as a predictor of exposure and ritual prevention outcome for obsessive compulsive disorder

Despite elevated rates of obsessive compulsive personality disorder (OCPD) in patients with obsessive compulsive disorder (OCD), no study has specifically examined comorbid OCPD as a predictor of exposure and ritual prevention (EX/RP) outcome. Participants were adult outpatients (n = 49) with primary OCD and a Yale-Brown Obsessive Compulsive Scale (YBOCS) total score ≥ 16 despite a therapeutic serotonin reuptake inhibitor dose for at least 12 weeks prior to entry. Participants received 17 sessions of EX/RP over 8 weeks. OCD severity was assessed with the YBOCS pre- and post-treatment by independent evaluators. At baseline, 34.7% of the OCD sample met criteria for comorbid DSM-IV OCPD, assessed by structured interview. OCPD was tested as a predictor of outcome both as a diagnostic category and as a dimensional score (severity) based on the total number of OCPD symptoms coded as present and clinically significant at baseline. Both OCPD diagnosis and greater OCPD severity predicted worse EX/RP outcome, controlling for baseline OCD severity, Axis I and II comorbidity, prior treatment, quality of life, and gender. When the individual OCPD criteria were tested separately, only perfectionism predicted worse treatment outcome, over and above the previously mentioned covariates. These findings highlight the importance of assessing OCPD and suggest a need to directly address OCPD-related traits, especially perfectionism, in the context of EX/RP to minimize their interference in outcome.     

Can shame memories become a key to identity? The centrality of shame memories predicts psychopathology

This study investigates the premise that a shame memory can become a central component of personal identity, a turning point in the life story and a reference point for everyday inferences. We assessed shame, centrality of shame memory, depression, anxiety, stress and traumatic stress reactions in 811 participants from general population (481 undergraduate students and 330 subjects from normal population) to explore the interactions between these variables. Results show that early shame experiences do indeed reveal centrality of memory characteristics. Furthermore, the centrality of shame memories is associated with current feelings of internal and external shame in adulthood. Key to our findings is that the centrality of shame memories shows a unique and independent contribution to depression, anxiety and stress prediction, even when controlling for shame measures. In addition, our results show that the centrality of shame memories is highly and positively associated with traumatic stress reactions. Copyright © 2010 John Wiley & Sons, Ltd.     

Singularity and consciousness: A neuropsychological contribution

In common sense experience based on introspection, consciousness is singular. There is only one ‘me’ and that is the one that is conscious. This means that ‘singularity’ is a defining aspect of ‘consciousness’. However, the three main theories of consciousness, Integrated Information, Global Workspace and Recurrent Processing theory, are generally not very clear on this issue. These theories have traditionally relied heavily on neuropsychological observations and have interpreted various disorders, such as anosognosia, neglect and split-brain as impairments in conscious awareness without any reference to ‘the singularity’. In this review, we will re-examine the theoretical implications of these impairments in conscious awareness and propose a new way how to conceptualize consciousness of singularity. We will argue that the subjective feeling of singularity can coexist with several disunified conscious experiences. Singularity awareness may only come into existence due to environmental response constraints. That is, perceptual, language, memory, attentional and motor processes may largely proceed unintegrated in parallel, whereas a sense of unity only arises when organisms need to respond coherently constrained by the affordances of the environment. Next, we examine from this perspective psychiatric disorders and psycho-active drugs. Finally, we present a first attempt to test this hypothesis with a resting state imaging experiment in a split-brain patient. The results suggest that there is substantial coherence of activation across the two hemispheres. These data show that a complete lesioning of the corpus callosum does not, in general, alter the resting state networks of the brain. Thus, we propose that we have separate systems in the brain that generate distributed conscious. The sense of singularity, the experience of a ‘Me-ness’, emerges in the interaction between the world and response-planning systems, and this leads to coherent activation in the different functional networks across the cortex.     

Effects of dopamine transporter and receptor polymorphisms on smoking cessation in a bupropion clinical trial.

This study examined the role of dopaminergic genes in prospective smoking cessation and response to bupropion treatment in a placebo-controlled clinical trial. Smokers of European ancestry (N=418) provided blood samples for genetic analysis and received either bupropion or placebo (10 weeks) plus counseling. Assessments included the dopamine D2 receptor (DRD2) genotype, dopamine transporter (SLC6A3) genotype, demographic factors, and nicotine dependence. Smoking status was verified at the end of treatment (EOT) and at 6-month follow-up. The results provided evidence for a significant DRD2 * SLC6A3 interaction effect on prolonged smoking abstinence and time to relapse at EOT, independent of treatment condition. Such effects were no longer significant at 6-month follow-up, however. These results provide the first evidence from a prospective clinical trial that genes that alter dopamine function may influence smoking cessation and relapse during the treatment phase.