Decision-making impairments in patients with Parkinson's disease

A high percentage of Parkinson's disease (PD) patients show cognitive impairments in addition to the cardinal motor symptoms. These deficits primarily concern executive functions most probably linked to dysfunctions in prefrontal regions due to decreased dopaminergic transmission in fronto-striatal loops. To investigate possible associations between decision-making and executive functions in PD, we examined 20 non-demented PD patients and 20 healthy control subjects with a neuropsychological test battery and the Game of Dice Task. In this computerised decision-making task, the rules for gains and losses and the winning probabilities are obvious and stable. Thus, strategic components besides feedback processing might influence decision-making in this task. We found that PD patients were impaired in the Game of Dice task performance and that the frequency of disadvantageous choices correlated with both executive functions and feedback processing. We suggest that decision-making deficits of PD patients in explicit gambling situations might be associated with dysfunctions in two different fronto-striatal loops: the limbic-orbitofrontal-striatal loop, involved in feedback processing, and the dorsolateral prefrontal-striatal loop, involved in executive functions.     

The emerging dialogue between psychoanalysis and neuroscience: neuroimaging perspectives

Current progress in the cognitive neurosciences is highly relevant to the development of psychoanalytic theory and practice. Neuroscience is today becoming mature enough to provide empirical biological approaches for the investigation of psychoanalytic models and observations. The current state of functional neuroimaging techniques is reviewed, selected paradigms and findings relevant to psychotherapy research are presented, and ways to pursue the dialogue between psychoanalysts and neuroscientists are discussed, as are some related obstacles and pitfalls. The emerging dialogue between psychoanalysts and neuroscientists may help not only to reestablish a solid position of psychodynamic theory and treatment in contemporary medicine, but also to bridge the division between "psychological" and "somatic" treatments, and gain important insights into the mind-brain relationship.     

Knowledge level learning and the power law: A soar model of skill acquisition in scheduling

Zusammenfassung. Das hier vorgestellte Modell lernt graduell, Planungsaufgaben aus der Klasse der Maschinenbelegungsprobleme (job-shop-scheduling problems) zu lösen. Mit Hilfe des Chunking-Mechanismus von Soar wird episodisches Wissen über die Belegungsreihenfolge von Aufträgen auf Maschinen memoriert. Bei der Entwicklung des Modells wurden zahlreiche qualitative (z. B. Transfereffekte) und quantitative Befunde (z. B. Bearbeitungszeiten) aus einer früheren empirischen Untersuchung berücksichtigt. In einer Validierungsstudie wurden dieselben Aufgaben von 14 Probanden und dem Modell bearbeitet. Die Passung von Simulationsdaten und empirischen Ergebnissen fiel insgesamt gut aus. Allerdings löst das Modell die Aufgaben schneller und zeigt auch einen etwas besseren Lernverlauf als die Probanden. Das Modell liefert eine Erklärung für das Rauschen, das typischerweise bei Bearbeitungszeiten zu beobachten ist: es handelt sich um erworbenes Wissen, das mehr oder weniger gut und auch unterschiedlich häufig auf neue Situationen übertragen wird. Der Lernverlauf der Probanden entspricht nur für aggregierte Daten einer Potenzfunktion (power law). Der vorgestellte Mechanismus zeigt, wie ein symbolisches Modell der Informationsverarbeitung graduelle Verhaltensänderungen generiert und wie der offensichtliche Erwerb allgemeiner Prozeduren ohne explizites Lernen von deklarativen Regeln erfolgen kann. Es wird nahegelegt, daß es sich hier um die Modellierung einer Form impliziten Lernens handelt. Summary. The model presented here gradually learns how to perform a job-shop scheduling task. It uses Soar's chunking mechanism to acquire episodic memories about the order to schedule jobs. The model was based on many qualitative (e.g., transfer effects) and quantitative (e.g., solution time) regularities found in previously collected data. The model was tested with new data where scheduling tasks were given to the model and to 14 subjects. The model generally fit these data with the restrictions that the model performs the task (in simulated time) faster than the subjects, and its performance improves somewhat more quickly than the subjects' performance. The model provides an explanation of the noise typically found in problem solving times - it is the result of learning actual pieces of knowledge that transfer more or less to new situations but rarely by an average amount. Only when the data are averaged (i.e., over subjects) does the smooth power law appear. This mechanism demonstrates how symbolic models can exhibit a gradual change in behavior and how the apparent acquisition of general procedures can be performed without resorting to explicit declarative rule generation. We suggest that this may represent a type of implicit learning.     

Witnessing across time: accessing the present from the past and the past from the present

We are used to the idea that trauma in the past interrupts our capacity to grasp the present. But present or recent trauma can have a similar dissociative effect on our capacity to experience the more distant past. Contemporary trauma can rob the past of its goodness, leaving one feeling as if the past is gone, dead, separated from the present. The vitalization of the present by the past or the past by the present requires that experiences be linked across time. These links are created, in both directions, via categories of experience characterized by shared affect (Modell 1990, 2006). Such categories are created, in turn, by metaphor; and the construction of these metaphors across time requires that one be able to occupy self-states in both the past and the present that can then bear witness to one another. Trauma can result in the dissociation of these self-states from one another, leading to a disconnection of present and past.     

Dissociable stages of problem solving (II): first evidence for process-contingent temporal order of activation in dorsolateral prefrontal cortex

In a companion study, eye-movement analyses in the Tower of London task (TOL) revealed independent indicators of functionally separable cognitive processes during problem solving, with processes of building up an internal representation of the problem preceding actual planning processes. These results imply that processes of internalization and planning should also be distinguishable in time and space with respect to concomitant brain activation patterns. To investigate this possibility, here we conducted analyses of fMRI data for left and right dorsolateral prefrontal cortex (dlPFC) during problem solving in the TOL task by accounting for the trial-by-trial variability of onsets and durations of the different cognitive processing stages. Comparisons between stimulus-locked and response-locked modeling approaches affirmed that activation in left dlPFC was elicited particularly during early processes of internalization, comprising the extraction of goal information and the generation of an internal problem representation, whereas activation in right dlPFC was predominantly attributable to later processes of mental transformations on this representation, that is planning proper. Thus, present data corroborate the proposal that often observed bilateral dlPFC activation patterns during complex cognitive tasks such as problem solving may reflect functionally and, to some extent, even temporally separable processes with opposing lateralizations.     

Differences between Chinese morphosyllabic and German alphabetic readers in the Stroop interference effect

The goal of our study was to localize the source of the stronger Stroop interference effect found in morphosyllabic readers as compared with alphabetic readers. Twenty-three Chinese and 24 German undergraduate students were tested in a Stroop paradigm with the following stimuli: color patches, colorneutral words (e.g.,friend printed in yellow), incongruent color-associated words (e.g.,blood printed in blue), and incongruent color words (e.g.,yellow printed in blue). Results revealed no differences in German and Chinese students’ response times to color patches. Chinese participants, however, showed longer color naming latencies for neutral words as well as for color words and color-related words. No differences between German and Chinese participants were found when print color latencies for neutral words were subtracted from print color latencies for color words and color-related words. This result does not support theories which suggest that for morphosyllabic readers there is a direct route from orthography to the semantics of a word. We rather argue, with reference to dual route models of reading, that access from print to phonology is faster for morphosyllabic than for alphabetic readers, and therefore interference caused by conflicting phonologies of color name and written word will be stronger in Chinese readers than in German readers.     

The relationship between sensory responsiveness profiles,attachment orientations,and anxiety symptoms

Individual variations in the way people respond to sensory stimuli can sometimes lead to maladaptive representations of the world. Indeed, sensory responsiveness profiles were found to be associated with mood symptoms such as depression and anxiety. The goal of the current study was to investigate whether attachment orientations can account for the relationship between sensory responsiveness profiles and anxiety symptoms. Participants (N = 194) completed a battery of questionnaires assessing sensory responsiveness profiles, attachment orientations, and anxiety symptoms. As expected, various associations between sensory responsiveness profiles and anxiety symptoms were accounted for by attachment anxiety and avoidance. We suggest a possible causal path, in which early‐developing sensory responsiveness profiles lead to attachment insecurities, which in turn may lead to mood symptoms such as anxiety.     

Commentary on Ted Ruffman’s “Belief or not belief: …”

I applaud Ruffman for cautioning us against interpreting early sensitivity to others’ beliefs as evidence for an innate theory of mind and for making room for learning. In turn, however, I caution against his claim that all infants need is to understand that people act depending on what they perceive. Instead, infants may keep experiential records (Perner & Roessler, 2010) for other people or records of what they have registered (Apperly & Butterfill, 2009), which makes it less obvious that all required knowledge can be acquired by statistical learning. As a general criticism I remonstrate with current theory of mind research on its lack of concern that we understand people as acting for reasons which goes beyond detecting lawful regularities in behaviour.     

The Development of Reflective Functioning in a Mother Traumatized by Past and Present Events: Facilitating Change in the Parent-Infant Relationship

This article presents clinical work with a woman who experienced trauma in both her childhood and adult life and who demonstrated poor reflective functioning. Treatment began during the patient’s pregnancy and continued with dyadic work with mother and baby in an effort to help the patient address and reflect on past and current life stressors and to develop a healthy mother-child relationship. A review of reflective functioning precedes the case material.