Attention and personality in augmenting/reducing of visual evoked potentials

Earlier research has shown that extraverts tend to increase their visual evoked potential amplitudes with increasing light intensity (augmenting), while introverts reach their maximum amplitude at lower intensities (reducing). The evoked response has normally been measured from association areas of the brain (at the vertex). The present study measured VEP amplitudes over visual cortex and at the vertex, using four light intensities in two conditions, where attention was either directed towards the light stimuli, or away from them by a concurrent auditory task. Forty subjects were classified as extraverts or introverts based on the Eysenck Personality Inventory. The results show that attention interacted significantly with extraversion. Introverts exhibited a narrower focus of attention, while higher amplitudes and amplitude-intensity functions when attending to the light flashes and lower when distracted. Extraverts showed smaller differences between conditions, indicating a more evenly distributed attention. Higher arousal in introverts is the probable cause of their narrower focus of attention. There were marked differences in the distribution of activity between vertex and occipital cortex. Introverts showed relatively stronger occipital responses and extraverts stronger vertex responses across all intensities and in both conditions. The predisposition for mainly perceptual responses to aversive stimuli in introverts, and for general alerting and motor preparatory responses in extraverts, are interpreted as supportive of Brebner and Cooper's hypothesis that introverts are ‘geared to inspect’ and extraverts are ‘geared to respond’.     

Misalignment Between Research Hypotheses and Statistical Hypotheses: A Threat to Evidence-Based Medicine?

Topoi - Evidence-based medicine frequently uses statistical hypothesis testing. In this paradigm, data can only disconfirm a research hypothesis’ competitors: One tests the negation...     

Cortical midline structures and the self

For a long time philosophers and psychologists have been intrigued by the question of the self. More recently, this has become a topic of discussion in neuroscience. In this article, we suggest that the processing of self-referential stimuli in cortical midline structures (CMS) is a fundamental component in generating a model of the self. Drawing from neuroimaging studies, we distinguish between representation, monitoring, evaluation and integration of self-referential stimuli. All of these subfunctions are related to distinct regions within the CMS. This relationship between self-referential processing and CMS might provide novel insight into the neural correlates underlying the constitution of the self.     

Three turtles in danger: spontaneous construction of causally relevant spatial situation models

In 4 experiments, the author explored the spontaneous construction of spatial situation models during discourse comprehension by using the sentence-recognition paradigm of J. D. Bransford, J. R. Barclay, and J. J. Franks (1972). In Experiment 1, signaling causal relevance of spatial relations was a necessary precondition for replicating their original finding of spontaneously constructed spatial representations. Causal relevance was ensured in the subsequent experiments by a judgment task indirectly demanding the evaluation of described spatial relations with regard to causal relevance. Participants spontaneously constructed spatial situation models of text presented auditorily or visually. Effects of spontaneous construction were more reliable when encoding was easier. The results suggest a revised interpretation of J. D. Bransford et al.'s study and corroborate recent evidence showing that relevant spatial information in texts is reliably represented.     

On the relation between moral, legal and evaluative justifications of pre-implantation genetic diagnosis (PGD)

In Germany the question whether to uphold or repeal the judicial prohibition on Pre-implantation Genetic Diagnosis (PGD) is being debated from quite different standpoints. This paper differentiates the major arguments according to their reasons as a) moral, b) evaluative (i.e. cultural/religious), and c) legal. The arguments for and against PGD can be divided by content into three groups: arguments relating to the status of the embryo, focusing on individual actions in the implementation of PGD, and relating to the foreseeable or probable consequences of PGD. In Germany, from a legal perspective, the status of the embryo does not permit the intervention of PGD; from a purely moral perspective, a prohibition on PGD does not appear defensible. It remains an open question, however, whether the moral argument permitting PGD should be restricted for evaluative (cultural) reasons. The paper discusses the species-ethical reasons, for which Jurgen Habermas sees worrisome consequences in the wake of PGD to the extent that we comprehend it as the forerunner of a 'positive eugenics'. It would so disrupt the natural preconditions of our universal morality. The question of whether to prohibit or allow PGD is not merely a question of simple moral and/or legal arguments, but demands a choice between evaluative, moral and (still to be specified) species-ethical arguments, and the question remains open.     

Repeated exposure of flight phobics to flights in virtual reality

The present study examined the effects of repeated exposure of flight phobics to flights in virtual reality (VR). Flight phobics were randomly assigned either to complete one VR test flight followed by four VR exposure flights (VR group; N=15) in one lengthy session or to complete one VR test flight followed by a lengthy relaxation training session (relaxation group; N=15). All participants completed a second VR test flight at the end of the session. Fear reports and physiological fear reactions (heart rate, skin conductance level) during VR exposures were registered, and fear of flying was assessed psychometrically from 3 weeks before to 3 months after exposure. Exposure to VR flights elicited subjective and physiological fear responses in flight phobics, and these responses attenuated within and across VR flights. Fear reduction associated with repeated VR exposure was greater than fear reduction caused by relaxation training. Fear of flying improved in both treatment groups, but several outcome measures indicated greater effects in the VR treated group than in the relaxation group. These findings indicate that exposure in virtual reality may offer a new and promising approach for the treatment of fear of flying.