Learning and adult neurogenesis: survival with or without proliferation?

Recent high quality papers have renewed interest in the phenomenon of neurogenesis within the adult mammalian brain. Many studies now show that neurogenesis can be modulated by environmental factors including physical activity, stress, and learning. These findings have considerable implications for neuroscience in general, including the study of learning and memory, neural network plasticity, aging, neurodegeneration, and the recovery from brain injury. Although new light has been shed on this field, many contradictory findings have been reported. Here we propose two principle issues which underlie these inconsistencies, with particular focus on the interaction between learning and neurogenesis. The first issue relates to the basic methodology of measuring the generation of new brain cells, i.e., proliferation, as compared to survival of the newly made cells. Mostly, measures of neurogenesis reported are a combination of proliferation and survival, making it impossible to distinguish between these separate processes. The second aspect is in regards to the role of environmental factors which can affect both proliferation and survival independently. Especially the interaction between stress and learning is of importance since these might counteract each other in some circumstances. Reviewing the literature while taking these issues into account indicates that, in contrast to some findings, cell proliferation in the dentate gyrus of the hippocampus as a result of learning cannot be ruled out yet. On the other hand, increased survival of granule cells in the dentate gyrus as a result of hippocampal-dependent learning has been clearly demonstrated. Moreover, this learning-induced survival of granule cells, which were born before the actual learning experience, might provide a molecular mechanism for the 'use it or lose it' principle.     

What does it take to be a virtual team player? The knowledge,skills, abilities,and other characteristics required in virtual teams

Competency models are available for many aspects of work that cut across various occupations (such as leadership, teamwork, etc.). Although virtual teamwork has developed to a highly prevalent aspect of work, very little is known about the knowledge, skills, abilities, and other characteristics (KSAOs) required. In the current study, KSAO requirements of virtual and traditional business teams (n = 175 and 205, respectively) were compared and aligned to the Great Eight competency model. Results showed that KSAOs pertaining to Leading and Deciding and to Analyzing and Interpreting were more important in virtual teams. Conversely, virtual and traditional teams did not differ in terms of broad personality (Big Five) requirements. Together, these findings contribute to deeper knowledge on selection and training in virtual teams.     

A response to commentaries on positivity

In our response, we aim to further contribute to the ongoing discussion of the construct of positivity and of the related research. We believe that each of the three commentaries has something unique to offer to the literature. By this response we take the opportunity to discuss the ideas that they present, and to illustrate some additional thoughts about positivity and its relationships with germane psychological constructs.     

Evaluation of the Tobii EyeX Eye tracking controller and Matlab toolkit for research

The Tobii Eyex Controller is a new low-cost binocular eye tracker marketed for integration in gaming and consumer applications. The manufacturers claim that the system was conceived for natural eye gaze interaction, does not require continuous recalibration, and allows moderate head movements. The Controller is provided with a SDK to foster the development of new eye tracking applications. We review the characteristics of the device for its possible use in scientific research. We develop and evaluate an open source Matlab Toolkit that can be employed to interface with the EyeX device for gaze recording in behavioral experiments. The Toolkit provides calibration procedures tailored to both binocular and monocular experiments, as well as procedures to evaluate other eye tracking devices. The observed performance of the EyeX (i.e. accuracy < 0.6°, precision < 0.25°, latency < 50 ms and sampling frequency ≈55 Hz), is sufficient for some classes of research application. The device can be successfully employed to measure fixation parameters, saccadic, smooth pursuit and vergence eye movements. However, the relatively low sampling rate and moderate precision limit the suitability of the EyeX for monitoring micro-saccadic eye movements or for real-time gaze-contingent stimulus control. For these applications, research grade, high-cost eye tracking technology may still be necessary. Therefore, despite its limitations with respect to high-end devices, the EyeX has the potential to further the dissemination of eye tracking technology to a broad audience, and could be a valuable asset in consumer and gaming applications as well as a subset of basic and clinical research settings.     

Translating self-efficacy in job performance over time: The role of job crafting

This investigation intends to uncover the mechanisms linking self-efficacy to job performance by analyzing the mediating role of job crafting. A two-wave study on 465 white-collar workers was conducted, matching participants’ self-report data (i.e., self-efficacy and job crafting) with supervisory performance ratings. The structural equation model showed a positive reciprocal relationship between self-efficacy and crafting behaviors. In turn, job crafting predicted performance positively over time. More importantly, results confirmed the mediating role of crafting actions, which may represent the behavioral process underlying the positive effect of self-efficacy on individual outcomes. Practical implications for organizations, such as encouraging bottom-up job design or designing job-crafting interventions, and future research directions are also offered.     

Hobbes on Teleology and Reason

Starting from considering how radical Hobbes' rejection of teleology was, this paper presents a coherent reading of Hobbesian reason, as applied to the justification of political obligation, striking a more perspicuous third way between the ‘orthodox’ (based on self‐interest and consequentialism) and the ‘revisionist’ (moralizing, or variously substantive) readings. Both families of interpretations are partial to some elements of Hobbes' thought, therefore incapable of providing a coherent reading of its whole. A precise rendering of Hobbes' deontological reason allows a better hermeneutical understanding of his philosophy as well as a keener appreciation of its relevance for past and present political thought.     

The force of dissimilar analogies in bioethics

Although analogical reasoning has long been a popular method of reasoning in bioethics, current literature does not sufficiently grasp its variety. We assert that the main shortcoming is the fact that an analogy’s value is often judged on the extent of similarity between the source situation and the target situation, while in (bio)ethics, analogies are often used because of certain dissimilarities rather than in spite of them. We make a clear distinction between dissimilarities that aim to reinforce a similar approach in the source situation and the target situation and dissimilarities that aim to undermine or denounce a similar approach. The former kind of dissimilarity offers the analogy more normative force than if there were no dissimilarities present; this is often overlooked by authors who regard all relevant dissimilarities as detrimental to the analogy’s strength. Another observation is that an evaluation of the normative force of an analogy cannot be made independently of moral principles or theories. Without these, one cannot select which elements in an analogy are morally relevant nor determine how they should be interpreted.     

Levels of modality for BDI Logic

The use of rational agents for modelling real world problems has both been heavily investigated and become well accepted, with BDI (Beliefs, Desires, and Intentions) Logic being a widely used architecture to represent and reason about rational agency. However, in the real world, we often have to deal with different levels of confidence in the beliefs we hold, desires we have, and intentions that we commit to. This paper extends our previous framework that integrated qualitative levels of beliefs, desires, and intentions into BDI Logic. We describe an expanded set of axioms and properties of the extended logic. We present a modular structure for the semantics which involves a non-normal Kripke type semantics that may be used for other agent systems. Further, we demonstrate the usefulness of our framework with a scheduling task example.     

Re-locating colors in the OSA space

A monolexemic color-naming experiment in the Italian language was performed on a sample of 1,014 colors obtained extending the OSA-UCS color system (E-OSA). Colors were rendered on a Mitsubishi Diamond pro 2070 monitor as patches subtending 10° of visual angle in a completely dark room. The 11 universal categories proposed by Berlin and Kay (Basic color terms: Their universality and evolution, 1969) were considered. Consensus, consistency and focal colors were determined for each category. Comparisons were performed among the results obtained using Boynton & Olson (B&O), the extended OSA (E-OSA), a subset of it covering almost all the B&O sample (R-OSA) and the Sturges & Whitfield (S&W) sample sets. A good overlap could be observed among the locations of the consensus colors in the {L, j, g} color model between B&O and R-OSA, as well as a close proximity among the centroids of homologue regions for the majority of the classes. The analysis of the location of focal colors versus the centroids suggests that an additional basic term could be missing for the Italian language in the blue category.