Decay of Stimulus Spatial Code in Horizontal and Vertical Simon Tasks

Evidence on the processes underlying the horizontal and vertical Simon effect is still controversial. The present study uses experimental manipulations to selectively delay the stages of response execution, response selection, and stimulus identification in three experiments. A reduction is observed for both horizontal and vertical Simon effects when response execution is delayed by a go-signal presented 400–600 ms post-stimulus onset or when a spatial precue is presented 200–400 ms before the stimulus. When the overlap between stimulus spatial code formation and response selection is prevented by decreasing stimulus discriminability, the horizontal Simon effect decays, but the vertical Simon effect does not change. Activation theories, which propose a decay of the automatically activated response ipsilateral to the stimulus, mainly apply to the horizontal Simon effect. In contrast, translation theories, which propose that the effect occurs when stimulus features are translated into a response code, are more suitable to account for the vertical Simon effect.     

Acquiring contextualized concepts: a connectionist approach

Conceptual knowledge is acquired through recurrent experiences, by extracting statistical regularities at different levels of granularity. At a fine level, patterns of feature co-occurrence are categorized into objects. At a coarser level, patterns of concept co-occurrence are categorized into contexts. We present and test CONCAT, a connectionist model that simultaneously learns to categorize objects and contexts. The model contains two hierarchically organized CALM modules (Murre, Phaf, & Wolters, 1992). The first module, the Object Module, forms object representations based on co-occurrences between features. These representations are used as input for the second module, the Context Module, which categorizes contexts based on object co-occurrences. Feedback connections from the Context Module to the Object Module send activation from the active context to those objects that frequently occur within this context. We demonstrate that context feedback contributes to the successful categorization of objects, especially when bottom-up feature information is degraded or ambiguous.     

Blind individuals show pseudoneglect in bisecting numerical intervals

Neurologically normal individuals typically show a leftward bias--known as pseudoneglect--in bisecting physical lines as well as numerical intervals. The latter bias may reflect the spatial nature in which numbers are represented (i.e., the mental number line). In previous studies, we found that congenitally blind individuals show such leftward bias in haptic bisection. Here, we demonstrate that blind individuals also show a consistent leftward bias in numerical bisection. The leftward bias was greater when numbers were presented in descending rather than ascending order, and the magnitude of the leftward bias was comparable to that shown by a control group of blindfolded sighted participants. Our findings thus support the view that pseudoneglect operates at a mental representational level rather than being perceptually based. Moreover, the consistent leftward bias shown by blind individuals in both line and numerical bisection suggests that the right hemisphere dominance in spatial processing, resulting in an overestimation of the left side of space, develops even in the absence of any visual input.     

General principles for treating personality disorder with a prominent inhibitedness trait: towards an operationalizing integrated technique

Psychotherapists need to perform tasks such as being empathetic, performing an ongoing assessment of cases, self-disclosing, making explicit treatment contracts, validating patients' experiences and promoting awareness of psychological experience, if they are to be effective in treating personality disorder (PD). Successful therapy also requires a systematic accurate PD model. We suggest here that it is still unclear how, when, and according to what session markers therapists need to perform specific operations to maximize therapeutic gains. This article describes and operationalizes a step-by-step procedure for organizing and delivering the interventions necessary for effective outcomes, such as maintaining a good therapeutic relationship, increasing understanding of mental states, reducing symptoms and improving social adaptation. The procedure is illustrated by reference to the treatment of cases of emotionally overly-constricted PDs. We include a theoretical proposal to facilitate the development of measures for evaluating the efficacy of therapist actions.