Loading working memory enhances affective priming

Stronger affective priming (Murphy & Zajonc, 1993) with suboptimal (i.e., reduced consciousness) than with optimal (i.e., full consciousness) prime presentation suggests that nonconscious processes form an important part of emotions. Merikle and Joordens (1997) have argued that both impoverished presentation and divided attention can produce suboptimal conditions and result in parallel effects. We manipulated attention by means of a concurrent working memory load while keeping presentation duration constant, as participants evaluated Japanese ideographs that were preceded by happy, neutral, or angry faces (affective priming) and male or female faces (nonaffective priming). In contrast to nonaffective priming, affective priming was larger with divided attention than with focused attention. It is concluded that manipulations of stimulus quality and of attention can both be used to probe the distinction between conscious and nonconscious processes and that the highest chances of obtaining the pattern of stronger priming with suboptimal presentation than with optimal presentation occur in the affective domain.     

Why aren’t all deep superior colliculus neurons multisensory? A Bayes’ ratio analysis

Multisensory neurons in the deep superior colliculus (SC) show response enhancement to cross-modal stimuli that coincide in time and space. However, multisensory SC neurons respond to unimodal input as well. It is thus legitimate to ask why not all deep SC neurons are multisensory or, at least, develop multisensory behavior during an organism's maturation. The novel answer given here derives from a signal detection theory perspective. A Bayes' ratio model of multisensory enhancement is suggested. It holds that deep SC neurons operate under the Bayes' ratio rule, which guarantees optimal performance-that is, it maximizes the probability of target detection while minimizing the false alarm rate. It is shown that optimal performance of multisensory neurons vis-à-vis cross-modal stimuli implies, at the same time, that modality-specific neurons will outperform multisensory neurons in processing unimodal targets. Thus, only the existence of both multisensory and modality-specific neurons allows optimal performance when targets of one or several modalities may occur.     

Cognitive bias in dizziness: emotional Stroop and autobiographical memories

Dizziness is commonly associated with anxiety, and is often caused by a dysfunction of the balance system. While a link between dizziness and both anxiety disorders and depression has been established, less is known about information processing in dizziness. In the first experiment we tested whether 15 patients with dizziness would display an emotional Stroop effect for panic-related words. Also included was a control group of 15 persons. The Stroop task was preceded by ratings of personal relevance of the Stroop words and followed by a surprise free recall of the words. Results showed a Stroop effect for panic-related words in the dizziness group, but the interaction did not reach significance (p = 0.08). Separate analysis of dizziness-related panic words however resulted in a significant group x condition interaction. In the free recall of Stroop words a main effect of word category was found, with more panic-related words being recalled. The second experiment investigated autobiographical memories in 14 patients with dizziness and 14 matched controls. Results showed a group x condition interaction with less specific memories being recalled following positive cue-words in the dizziness group. The overall pattern of results suggests that dizziness is related to deficits in information processing, which could be targeted in treatment.     

Reconstructing Distances among Objects from Their Discriminability

We describe a principled way of imposing a metric representing dissimilarities on any discrete set of stimuli (symbols, handwritings, consumer products, X-ray films, etc.), given the probabilities with which they are discriminated from each other by a perceiving system, such as an organism, person, group of experts, neuronal structure, technical device, or even an abstract computational algorithm. In this procedure one does not have to assume that discrimination probabilities are monotonically related to distances, or that the distances belong to a predefined class of metrics, such as Minkowski. Discrimination probabilities do not have to be symmetric, the probability of discriminating an object from itself need not be a constant, and discrimination probabilities are allowed to be 0’s and 1’s. The only requirement that has to be satisfied is Regular Minimality, a principle we consider the defining property of discrimination: for ordered stimulus pairs (a,b), b is least frequently discriminated from a if and only if a is least frequently discriminated from b. Regular Minimality generalizes one of the weak consequences of the assumption that discrimination probabilities are monotonically related to distances: the probability of discriminating a from a should be less than that of discriminating a from any other object. This special form of Regular Minimality also underlies such traditional analyses of discrimination probabilities as Multidimensional Scaling and Cluster Analysis. This research was supported by the NSF grant SES 0318010 (E.D.), Humboldt Research Award (E.D.), Humboldt Foundation grant DEU/1038348 (H.C. & E.D.), and DFG grant Co 94/5 (H.C.).     

Self-reported personality traits and disorders (DSM-IV) and risk of criminal recidivism: a prospective study

Assessment and management of criminal offenders require valid methods to recognize personality psychopathology and other risk and protective factors for recidivism. We prospectively explored the association between dimensional and categorical measures of personality disorder (PD) measured with the DSM-IV and ICD-10 Personality Questionnaire (DIP-Q, Ottosson et al., 1995) and registered reconvictions in adult offenders. One hundred and sixty-eight offenders consecutively referred for pre-sentencing forensic psychiatric evaluation in Sweden during 1995-1996 completed DIP-Q self-reports. The subjects received different types of sanctions and were followed for an average of 36 months after release from prison, discharge from a forensic psychiatric hospital, or onset of nondetaining sentences. Age-adjusted odds ratios revealed a 4.8 times higher risk for any recidivism and a 3.7 times higher risk for violent recidivism among subjects whose self-reports suggested a categorical diagnosis of antisocial PD as compared to offenders without antisocial PD. The remaining nine categorical DSM-IV PD diagnoses were not significantly related to recidivism. In dimensional analyses, each additional antisocial and schizoid PD symptom endorsed by participants at baseline increased the risk for violent reoffending. Our results suggest a relationship between self-reported behavioral instability and interpersonal dysfunction captured primarily by DSM-IV antisocial and schizoid PD constructs, and criminal re-offending also in a multi-problem sample of identified offenders.     

The Budapest meeting 2005 intensified networking on ethics of science

This paper reports on the meeting of the Sounding Board of the EU Reprogenetics Project that was held in Budapest, Hungary, 6-9 November 2005. The Reprogenetics Project runs from 2004 until 2007 and has a brief to study the ethical aspects of human reproductive cloning and germline gene therapy. Discussions during The Budapest Meeting are reported in depth in this paper as well as the initiatives to involve the participating groups and others in ongoing collaborations with the goal of forming an integrated network of European resources in the fields of ethics of science.     

Postural control in otolith disorders

It was the aim of the present paper to investigate the influence of otolith disorders on human postural control by different methods. The 33 patients of our study had undergone a minor head injury and suffered subsequently from an utricular or sacculo-utricular disorder as evidenced by vestibular evoked myogenic potential recordings and eccentric rotation recordings of the otolith-ocular responses. Postural control was assessed by performing stance/gait tests (standard balance deficit test, SBDT) and by evaluating trunk sway (using angular velocity sensors). Moreover, classical tests of the posterior column of the spinal tract (Romberg/Unterberger) and the dynamic posturography (sensory organization test, SOT) were included. It could be shown that SBDT tasks with reduced proprioceptive and visual cues (e.g. standing on foam, eyes closed) are most sensitive for an otolith disorder. The patients showed an increased trunk sway in the pitch plane (i.e. linear motion as adequate utricular stimulus) and an increase in sway velocities (i.e. tilting movements as adequate saccular stimulus) compared to controls. The SOT was most sensitive for combined (sacculo-utricular) otolith disorders (78%) while vestibulospinal tests are not enough sensitive. In essence, otolith disorders evidently impair human postural control and have been possibly underestimated as a source of posttraumatic postural imbalance as yet.     

A two-stage model for visual-auditory interaction in saccadic latencies

In two experiments, saccadic response time (SRT) for eye movements toward visual target stimuli at different horizontal positions was measured under simultaneous or near-simultaneous presentation of an auditory nontarget (distractor). The horizontal position of the auditory signal was varied, using a virtual auditory environment setup. Mean SRT to a visual target increased with distance to the auditory nontarget and with delay of the onset of the auditory signal relative to the onset of the visual stimulus. A stochastic model is presented that distinguishes a peripheral processing stage with separate parallel activation by visual and auditory information from a central processing stage at which intersensory integration takes place. Two model versions differing with respect to the role of the auditory distractors are tested against the SRT data.     

War der Sp?te Wittgenstein ein Essentialist?

Ohne Zusammenfassung     

The interleaving of actions in everyday life multitasking demands

It has been argued that executive tests should capture central aspects of executive functions in everyday life such as initiating and monitoring parallel actions in low-structured environments (so-called multitasking; see Burgess, 2000). We present a cooking task in order to assess executive function impairments in brain-damaged patients, which focuses on a central feature of multitasking, the interleaving of tasks (Burgess, 2000). Behavioural performance of 21 brain-damaged patients (stroke, traumatic brain injury) and of a group of matched controls was analysed on the basis of a standardized protocol. In comparison to controls, the patients explored less, were less successful in monitoring their actions and corrected errors less efficiently. Interleaving of actions was observed less frequently in patients, with respect to both cooking itself as well as to subordinate goals (e.g., cleaning up). Interleaving proved efficient, as it was associated with less time to complete the task. Patients' scores in the cooking task correlated with performance in both the Behavioural Assessment of the Dysexecutive Syndrome (BADS) Zoo Map Test and the BADS Six Elements Test, but not with tests of attention, verbal memory, or figural fluency, thus demonstrating convergent and discriminant validity. In summary, our task demonstrates that cooking can provide a valid testing ground for assessing a central aspect of everyday multitasking demands, namely, the interleaving of actions.