ICAT: a computational model for the adaptive control of fixation durations

Eye movements depend on cognitive processes related to visual information processing. Much has been learned about the spatial selection of fixation locations, while the principles governing the temporal control (fixation durations) are less clear. Here, we review current theories for the control of fixation durations in tasks like visual search, scanning, scene perception, and reading and propose a new model for the control of fixation durations. We distinguish two local principles from one global principle of control. First, an autonomous saccade timer initiates saccades after random time intervals (local-I). Second, foveal inhibition permits immediate prolongation of fixation durations by ongoing processing (local-II). Third, saccade timing is adaptive, so that the mean timer value depends on task requirements and fixation history (Global). We demonstrate by numerical simulations that our model qualitatively reproduces patterns of mean fixation durations and fixation duration distributions observed in typical experiments. When combined with assumptions of saccade target selection and oculomotor control, the model accounts for both temporal and spatial aspects of eye movement control in two versions of a visual search task. We conclude that the model provides a promising framework for the control of fixation durations in saccadic tasks.     

How the 2SLS/IV estimator can handle equality constraints in structural equation models: A system‐of‐equations approach

Parameters in structural equation models are typically estimated using the maximum likelihood (ML) approach. Bollen (1996) proposed an alternative non‐iterative, equation‐by‐equation estimator that uses instrumental variables. Although this two‐stage least squares/instrumental variables (2SLS/IV) estimator has good statistical properties, one problem with its application is that parameter equality constraints cannot be imposed. This paper presents a mathematical solution to this problem that is based on an extension of the 2SLS/IV approach to a system of equations. We present an example in which our approach was used to examine strong longitudinal measurement invariance. We also investigated the new approach in a simulation study that compared it with ML in the examination of the equality of two latent regression coefficients and strong measurement invariance. Overall, the results show that the suggested approach is a useful extension of the original 2SLS/IV estimator and allows for the effective handling of equality constraints in structural equation models.     

Heterogeneity of treatment changes after psychodynamic therapy within a one year follow‐up: A replication study

Naturalistic psychotherapy effect studies commonly report effect sizes for the total sample. However, a previous study of SCL‐90 Global Severity Index (GSI) improvement in a large outpatient sample used a cluster analytic strategy and reported clinical relevant outcome trajectories that could be grouped into early within‐treatment improvement, late improvement in the follow‐up period, and deteriorating patients with slight improvement that was lost at follow‐up. We explore GSI outcome trajectories and clinical significant change in a sample of 320 patients at a public psychiatric outpatient psychodynamic group therapy unit, the majority with anxiety, personality, and mood disorders. The study revealed large discharge and follow‐up effect sizes but more than one third of the patients were without measurable improvement. The major clusters described above were confirmed, and revealed unique clinical and socio‐demographic characteristics. Late improvers, as compared with early improvers, were characterized by anxiety symptoms and lack of network support after controlling for GSI at admission. Similarly, deteriorating patients had longer duration of illness and less favourable social characteristics compared with the other two groups. Early improving patients were less likely to have participated in short‐term groups, and only one third participated in additional treatment compared with more than 69% of the other patients. Severe and socially affected psychiatric patients, and patients with anxiety and agoraphobic symptoms may be less optimally treated in short‐term time limited psychodynamic groups. There is an obvious need for diversity of treatment offers, better integration of psycho‐social treatment components, and long‐term open ended treatment.     

Reward-driven modulation of adaptive control: How prospective monetary gains interact with unpredictable control demands

Shifting attention is an effortful control process and incurs a cost on the cognitive system. Previous research suggests that rewards, such as monetary gains, will selectively enhance the ability to shift attention when this demand for control is explicitly cued. Here, we hypothesized that prospective monetary gains will selectively enhance the ability to shift attention even when control demand is unpredictable and not cued beforehand in a modality shift paradigm. In two experiments we found that target detection was indeed facilitated by reward signals when an unpredictable shift of attention was required. In these crossmodal trials the target stimulus was preceded by an unpredictive stimulus directing attention to the opposite modality (i.e., visual–auditory or auditory–visual). Importantly, there was no reward effect in ipsimodal trials (i.e., visual–visual or auditory–auditory). Furthermore, the absence of the latter effect could not be explained in terms of physical limits in speed of responding. Potential motivation of monetary rewards thus selectively translates into motivational intensity when control (i.e., switching) is demanded in unpredictable ways.     

Plural self-awareness

It has been claimed in the literature that collective intentionality and group attitudes presuppose some “sense of ‘us’” among the participants (other labels sometimes used are “sense of community,” “communal awareness,” “shared point of view,” or “we-perspective”). While this seems plausible enough on an intuitive level, little attention has been paid so far to the question of what the nature and role of this mysterious “sense of ‘us’” might be. This paper states (and argues for) the following five claims: (1) it is neither the case that the sense in question has the community (or “us”) in its content or as its object nor does the attitude in question presuppose a preexistent community (or “us”) as its subject. (2) The “sense of ‘us’” is plural pre-reflective self-awareness. (3) Plural pre-reflective self-awareness plays the same role in the constitution of a common mind that singular pre-reflective self-awareness plays in the individual mind. (4) The most important conceptions of plural subjects, collective persons, or group agents in the current literature fail to recognize the nature and role of plural self-awareness, and therefore fall short in important respects. (5) In spite of the striking similarities between the plural and the singular mind, there are important differences to consider. The authority of the singular first person point of view has no equivalent in the plural case.     

Reading about explanations enhances perceptions of inevitability and foreseeability: a cross-cultural study with Wikipedia articles

In hindsight, people often perceive events to be more inevitable and foreseeable than in foresight. According to Causal Model Theory (Nestler et al. in J Exp Psychol Learn Mem Cogn 34: 1043–1054, 2008), causal explanations are crucial for such hindsight distortions to occur. The present study provides further empirical support for this notion but extends previous findings in several ways. First, ecologically valid materials were used. Second, the effect of causal information on hindsight distortions was investigated in the realm of previously known events. Third, cross-cultural differences in reasoning (analytic vs. holistic) were taken into account. Specifically, German and Vietnamese participants in our study were presented with Wikipedia articles about the nuclear power plant in Fukushima Daiichi, Japan. They read either the version that existed before the nuclear disaster unfolded (Version 1) or the article that existed 8 weeks after the catastrophe commenced (Version 2). Only the latter contained elaborations on causal antecedents and therefore provided an explanation for the disaster. Reading that version led participants to perceive the nuclear disaster to be more likely inevitable and foreseeable when compared to reading Version 1. Cultural background did not exert a significant effect on these perceptions. Hence, hindsight distortions were obtained for ecologically valid materials even if the event was already known. Implications and directions for future research are discussed.     

Higher-Level Perspectives and Ethics of Technoscience

New accents in the philosophy of technology and philosophy of science amounting, e.g., to the so-called schools of the “New Experimentalism”, “New Instrumentalism” and, recently, “New Mechanism” emphasize the impact of instruments, experiments, and “mechanisms” of the respective technologies opened up by the progress of ever-improving measuring instruments, procedures etc. In addition, it would be necessary to accentuate the process- and action-orientation including practical responsibility problems and dynamic systems models from an epistemological perspective of the methodological scheme-interpretationist approach developed by the author since the seventies of last century. The necessity of multi-disciplinary mutual influences was already time and again stressed regarding philosophy of science. But relatively new is not only the methodological turn involved but also the necessity to go to higher levels of abstraction, metatheories, action- and value-orientation. Therefore, we have to go more interdisciplinary, systems-oriented, and higher-level. That implies notable consequences for an ethics, or rather, meta-ethics for philosophy of science. Practice-oriented philosophers of (techno-)science will have to go more methodological, multidisciplinary and even (meta-)responsible.     

Qualitative job insecurity and in-role performance: a bidirectional longitudinal relationship?

This study adds to the understanding of the relationship between qualitative job insecurity and employee in-role performance, by analysing the association longitudinally. While social exchange theory predicts that the relationship should be negative and bidirectional, the job preservation motivation model indicates a self-correcting mechanism, where job insecurity leads to increased performance, which, in turn, could decrease job insecurity. We developed competing hypotheses and examined them using structural equation modelling in a heterogeneous sample of 337 employees. For employees with a higher professional level, results pointed towards a reciprocal causal relationship between qualitative job insecurity and in-role performance, indicating a loss cycle. For employees with a lower professional level, results showed a small positive direct causal relationship between qualitative job insecurity and in-role performance, while the negative direct path from in-role performance to qualitative job insecurity did not reach statistical significance. This is the first study to test the diverging theoretical predictions of social exchange theory and the job preservation motivation model, with regard to the relationship between qualitative job insecurity and in-role performance. Being longitudinal, our study only allows us to hint at possible causal relationships between the involved variables, the chronological order being necessary, but not sufficient to prove causality.     

Scientists Still Behaving Badly? A Survey Within Industry and Universities

Little is known about research misconduct within industry and how it compares to universities, even though a lot of biomedical research is performed by–or in collaboration with–commercial entities. Therefore, we sent an e-mail invitation to participate in an anonymous computer-based survey to all university researchers having received a biomedical research grant or scholarship from one of the two national academic research funders of Belgium between 2010 and 2014, and to researchers working in large biomedical companies or spin-offs in Belgium. The validated survey included questions about various types of research misconduct committed by respondents themselves and observed among their colleagues in the last three years. Prevalences of misconduct were compared between university and industry respondents using binary logistic regression models, with adjustments for relevant personal characteristics, and with significance being accepted for p < 0.01. The survey was sent to 1766 people within universities and an estimated 255 people from industry. Response rates were 43 (767/1766) and 48% (123/255), and usable information was available for 617 and 100 respondents, respectively. In general, research misconduct was less likely to be reported by industry respondents compared to university respondents. Significant differences were apparent for one admitted action (gift authorship) and three observed actions (plagiarism, gift authorship, and circumventing animal-subjects research requirements), always with lower prevalences for industry compared to universities, except for plagiarism. This survey, based on anonymous self-report, shows that research misconduct occurs to a substantial degree among biomedical researchers from both industry and universities.