The feature-binding problem is an ill-posed problem

The binding problem arises when visual features (colour, orientation), said to be coded in independent brain modules, are to be integrated into unitary percepts. I argue that binding is an ill-posed problem, because those modules are now known to code jointly for multiple features, rendering the feature-binding issue moot. A hierarchical reentrant system explains the emergence of coherent visual objects from primitive features. An initial feed-forward sweep activates many high-level perceptual hypotheses, which descend to lower levels, where they correlate themselves with the ongoing activity. Low correlations are discarded, whereas the hypothesis that yields the highest correlation is confirmed and leads to conscious awareness. In this system, there is no separate binding process that actively assigns features to objects.     

Acquisition of instrumental conditioned reinforcement is resistant to the devaluation of the unconditioned stimulus

The associative mechanisms responsible for the efficacy of Pavlovian stimuli during first- and second-order conditioning have been extensively studied, but little is known about the representations underlying instrumental conditioned reinforcement. The present study investigated the associative structure underlying conditioned reinforcement, by employing an unconditioned stimulus (US) devaluation procedure on a commonly used instrumental task: the acquisition of a new response with conditioned reinforcement. Whilst US-directed behaviour was abolished following devaluation, the conditioned stimulus acting as a conditioned reinforcer supported the acquisition of instrumental responding. In this preparation then, the conditioned reinforcer appears to be impervious to devaluation of its associated US, suggesting that the underlying representation maintaining behaviour is independent of the current value of the US and may reflect the activation of a central appetitive motivational state.     

Sociodemographic and Clinical Differences Between Suicide Ideators and Attempters: A Study of Mood Disordered Patients 50 Years and Older

Our study sought to characterize mood disordered suicide ideators and attempters 50 years and older admitted to a psychiatric ward either for a recent suicide attempt or for ongoing suicidal ideation. We enrolled 50 patients with suicide ideation consecutively admitted to an inpatient department and 50 patients admitted for a suicide attempt made in the last 48 hours. Suicide attempters more frequently had low social support and an age of onset of mood disorder of 46 years and older, and less frequently had a history of suicidal behaviors in the family members and pharmacological treatment, despite the fact that the groups did not differ with regard to antidepressants prescribed. The groups were not distinguishable based on several variables assumed to be risk factors for suicide behavior, such as proximal life events and stressors or alcohol use disorders. In both samples, comorbidity with organic diseases, the presence of stressful life events in the past 12 months, and a diagnosis of major depression were frequently reported. In conclusion, the presence of low social support and the absence of a pharmacotherapy may increase suicidal behaviors in patients at risk.     

Suicide Attempts in Major Depressed Patients with Personality Disorder

Suicide attempters who met criteria for borderline personality disorder (BPD) comorbid with major depressive disorder (MDD) were compared to both suicide attempters suffering from MDD alone and to attempters with comorbid MDD and other personality disorders (PD). Participants were 239 (158 patients with comorbid PD and 81 patients with MDD without comorbidity) inpatients consecutively admitted after a suicide attempt made in the last 24 hours. Suicide attempters with comorbid MDD and BPD had more frequent previous suicide attempts and were more likely to have a history of aggressive behaviors and alcohol and drug use disorders compared with patients suffering from MDD without Axis II comorbidity.