Common and distinct neural correlates of trial-by-trial expectancies for feature-based as compared to spatial attention

Since our brain can only process a small amount of sensory information at a time, attention systems select specific aspects for prioritized processing – such as features or locations – that are expected to be most relevant in a given context. The present thesis investigated responses of visual attention systems to expected and unexpected sensory events during uncertainty, when the probability of sensory events needs to be inferred from environmental observations. In the spatial attention domain these processes have already been described with the help of computational models and the underlying neural mechanisms have been explored with functional neuroimaging. However, it is not known whether other attentional subsystems such as feature-based attention behave similarly during uncertainty. The core aim of this thesis was to characterize the modulation of attentional deployment by inferred probabilities during feature-based as compared to spatial attention. This was realized using a Posner-cueing paradigm in which feature and spatial cues were presented. Classically these cues predict the color or the location of an upcoming target with a fixed high probability, so that participants expect the cues to be valid and respond slower and less accurate when attention needs to be reoriented to invalidly cued targets. In the present paradigm, this probability was varied by changing the percentage cue validity (%CV) unpredictably over time. In a behavioral experiment (Experiment 1) three different color cues were used to identify cue-related factors which influence the effects of probabilistic inference on feature-based attention and to establish an experimental paradigm for the comparison of feature-based and spatial attention systems. It was observed that all color cues affected attentional deployment. However, probability-dependent effects differed depending on the level of cue abstraction: More automatically processed cues required more observations of cue-target outcomes to establish probabilistic learning than abstract cues. Experiment 2 employed functional magnetic resonance imaging (fMRI) to investigate the computational and neural mechanisms that modulate probabilistic inference using the experimental paradigm from Experiment 1 with abstract feature and spatial cues. The results indicated that probabilistic inference follows similar principles for both attention systems. However, their neural implementations seemed to be confined to domain-specific subsystems: The right temporoparietal junction (TPJ) was particularly involved in spatial attention, while the left intraparietal sulcus (IPS) was most crucial for feature-based attention. However, the left anterior IPS showed an effect of probability-dependent attention in both attention systems. These findings provide novel insights into the generality and specificity of the functional basis of visual attention, suggesting that probabilistic inference can distinctively affect each attentional subsystem, but that the left anterior IPS may establish probabilistic inference in a domain general manner. Taken together our findings speak against a unitary visual attention network. Rather, we propose that depending on the nature of the selected aspects different attentional subsystems are activated following expectancy violations and these processes can even differ within one single domain such as feature-based attention

Men Presenting With Sexual Thoughts of Children or Coercion: Flights of Fancy or Plans for Crime?

Introduction. There is limited evaluation of clinical and theoretical claims that sexual thoughts of children and coercing others facilitate sexual offending. The nature of these thoughts (what they contain) is also unknown. Aims. To examine the relationship between child/coercive sexual thoughts and sexual offending, and to determine the nature of these thoughts and any differences between sexual offending (SO), non-sexual offending (NSO) and non-offending (NO) men. Methods. In a cross-sectional computerized survey, anonymous qualitative and quantitative self-reported sexual thought and experience data were collected from 279 adult volunteers, comprising equal numbers of SO, NSO and NO men recruited from a medium-security UK prison and a community sample of 6081 men. Main Outcome Measures. Computerized Interview for Sexual Thoughts and Computerized Inventory of Sexual Experiences. Results. Three analytical approaches found child sexual thoughts were related to sexual offending; sexual thoughts with coercive themes were not. Latent class analyses identified three types of child sexual thought (primarily differentiated by interpersonal context: the reporting of own emotions, emotions of others or both) and four types of sexual thoughts of coercing others (chiefly discriminated by the other person’s response: no emotional states reported, consent, non-consent, mixed). Type of child sexual thought and participant group were not significantly related. Type of coercive sexual thought and group were marginally related; the consensual type was more common for the NO group, the non-consensual type more common for the SO group, than expected statistically. Conclusions. Child sexual thoughts are a risk factor for sexual offending and should be assessed by clinicians. Generally, sexual thoughts with coercive themes are not a risk factor, though thought type may be important (i.e. thoughts where the other person expresses an enduring lack of consent). Exploring the dynamic risk factors associated with each type of child/coercive thought may lead to more targeted treatment

“It’s not something I chose you know”: making sense of pedophiles’ sexual interest in children and the impact on their psychosexual identity

Sexual interest in children is one of the most strongly predictive of the known risk factors for sexual reconviction. It is an important aspect of risk assessment to identify the presence of such interest, and an important task for treatment providers to address such a sexual interest where it is present. It has been argued that understanding pedophiles’ deviant sexual interest in children can enhance risk assessment, management, and treatment planning. This research study aims to explore the phenomenology of deviant sexual interest in children, the impact it has on pedophilic offenders’ identities, and their views on the treatability of that interest. The study used semistructured interviews and repertory grids to make sense of participants’ experiences. The results revealed three superordinate themes: “‘living’ with a deviant sexual interest,” “relational sexual self,” and “possible and feared sexual self.” The analysis unpacks these themes and repertory grid analysis is used to explore a subset of participants’ identities in more detail. The results reveal that there needs to be an acceptance from both client and therapist that their sexual interest in children may never go away. Through this acceptance, clients could work on enhancing sexual self-regulation, recognizing their triggers, and so managing their sexual thoughts, feelings, and behavior. Implications for treatment are also discussed

Cue-target contingencies modulate voluntary orienting of spatial attention: dissociable effects for speed and accuracy

Voluntary orienting of spatial attention is typically investigated by visually presented directional cues, which are called predictive when they indicate where the target is more likely to appear. In this study, we investigated the nature of the potential link between cue predictivity (the proportion of valid trials) and the strength of the resulting covert orienting of attention. Participants judged the orientation of a unilateral Gabor grating preceded by a centrally presented, non-directional, color cue, arbitrarily prompting a leftwards or rightwards shift of attention. Unknown to them, cue predictivity was manipulated across blocks, whereby the cue was only predictive for either the first or the second half of the experiment. Our results show that the cueing effects were strongly influenced by the change in predictivity. This influence differently emerged in response speed and accuracy. The speed difference between valid and invalid trials was significantly larger when cues were predictive, and the amplitude of this effect was modulated at the single trial level by the recent trial history. Complementary to these findings, accuracy revealed a robust effect of block history and also a different time-course compared with speed, as if it mainly mirrored voluntary processes. These findings, obtained with a new manipulation and using arbitrary non-directional cueing, demonstrate that cue-target contingencies strongly modulate the way attention is deployed in space

Neurofilament depletion improves microtubule dynamics via modulation of Stat3/stathmin signaling

In neurons, microtubules form a dense array within axons, and the stability and function of this microtubule network is modulated by neurofilaments. Accumulation of neurofilaments has been observed in several forms of neurodegenerative diseases, but the mechanisms how elevated neurofilament levels destabilize axons are unknown so far. Here, we show that increased neurofilament expression in motor nerves of pmn mutant mice, a model of motoneuron disease, causes disturbed microtubule dynamics. The disease is caused by a point mutation in the tubulin-specific chaperone E (Tbce) gene, leading to an exchange of the most C-terminal amino acid tryptophan to glycine. As a consequence, the TBCE protein becomes instable which then results in destabilization of axonal microtubules and defects in axonal transport, in particular in motoneurons. Depletion of neurofilament increases the number and regrowth of microtubules in pmn mutant motoneurons and restores axon elongation. This effect is mediated by interaction of neurofilament with the stathmin complex. Accumulating neurofilaments associate with stathmin in axons of pmn mutant motoneurons. Depletion of neurofilament by Nefl knockout increases Stat3-stathmin interaction and stabilizes the microtubules in pmn mutant motoneurons. Consequently, counteracting enhanced neurofilament expression improves axonal maintenance and prolongs survival of pmn mutant mice. We propose that this mechanism could also be relevant for other neurodegenerative diseases in which neurofilament accumulation and loss of microtubules are prominent features

Synthese von enantiomerenreinen 1(6)-Anhydrohexitolen und Conduriten

SIGLEAvailable from TIB Hannover: DW 5573 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Migrantes venezolanos y venezolanas en España

Venezuela is experiencing an unprecedented exodus as a result of ongo­ing political, economic and humanitarian crises. While the majority of emigrants remain in neighbouring Latin American countries, the US and Europe are also among the preferred destinations. The way migrants are covered in the media shapes public opinion and has an impact on their integration into society. Therefore, the aim of this paper is to examine the coverage of Venezuelan migrants in the Spanish press in a timeframe from 2015 to 2020. For this purpose, a linguistic discourse analysis is conducted. The results contrast with the current state of research. With the help of the sociological othering-theory and the concept of the so-called aporof obia, it is possible to explain how the image of good (and bad) migrants is discursively constructed.Venezuela está expe­rimentando una emigración sin precedentes como resultado de las actuales crisis políticas, económicas y humanitarias. Aunque la mayo­ría de los emigrantes permanezca en los países vecinos de América Latina, los Estados Unidos y Europa también se encuentran entre los destinos. La forma en que los migrantes son reportados en los medios de comunicación influye en su integración en la sociedad. Por lo tanto, el objetivo de este artículo es examinar como la prensa española infor­mó sobre los migrantes venezolanos en el período comprendido entre 2015 y 2020. Para ello, se realiza un análisis del discurso lingüístico. Los resultados contrastan con el estado de la investigación hasta la fecha. Con la ayuda de la teoría del othering de las ciencias sociales y el concepto de aporofobia, se puede explicar cómo se construye dis­cursivamente la imagen de los buenos (y de los malos) migrantes