A Too-Good-to-be-True Prior to Reduce Shortcut Reliance

Despite their impressive performance in object recognition and other tasks under standard testing conditions, deep networks often fail to generalize to out-of-distribution (o.o.d.) samples. One cause for this shortcoming is that modern architectures tend to rely on ǣshortcutsǥ superficial features that correlate with categories without capturing deeper invariants that hold across contexts. Real-world concepts often possess a complex structure that can vary superficially across contexts, which can make the most intuitive and promising solutions in one context not generalize to others. One potential way to improve o.o.d. generalization is to assume simple solutions are unlikely to be valid across contexts and avoid them, which we refer to as the too-good-to-be-true prior. A low-capacity network (LCN) with a shallow architecture should only be able to learn surface relationships, including shortcuts. We find that LCNs can serve as shortcut detectors. Furthermore, an LCN’s predictions can be used in a two-stage approach to encourage a high-capacity network (HCN) to rely on deeper invariant features that should generalize broadly. In particular, items that the LCN can master are downweighted when training the HCN. Using a modified version of the CIFAR-10 dataset in which we introduced shortcuts, we found that the two-stage LCN-HCN approach reduced reliance on shortcuts and facilitated o.o.d. generalization

The role of executive control in the activation of manual affordances

We investigated the role of executive control processes in the activation of manual affordances in two experiments combining stimulus–response compatibility (SRC) and dual-task paradigms. We registered an inverse SRC effect in the presence of a parallel backward-counting task in Experiment 1, and a cancellation of the SRC effect in Experiment 2 when a parallel Stroop-like task was used. We interpret our data as supporting a self-inhibition account of the affordance activation control. Accordingly, the role of executive processes is to prevent self-inhibition in supraliminal conditions: when cognitive resources are depleted by a parallel task, the self-inhibition mechanism becomes active and irrelevantly potentiated affordances are inhibited, leading to the emergence of an inverse SRC effect. In addition, the difference between data patterns observed in the two experiments suggests that the exact roles of the executive processes involved during the activation of affordances may differ. The results suggest a mechanism for action-related activation monitoring based on a flexible control over automatically potentiated actions. The paper discusses the proposed mechanism in detail and outlines further research directions

New insight in beryllium toxicity excluding exposure to beryllium-containing dust : accumulation patterns, target organs, and elimination

There is much contradiction between different experimental studies on beryllium (Be) toxicity. The majority of studies focus on occupational pathologies, caused by the exposure to Be dust. However, Be pollution may affect wide population groups through other exposure routes. The discrepancies between experimental studies may be attributed to the lack of adequate Be toxicity model since conventional administration routes are hampered by high acidity and low solubility of Be compounds. This study was aimed to develop a novel way to implement Be toxicity avoiding side effects, related to high acidity or low solubility of Be salts. Intraperitoneal injection of Be–glycine composition (containing BeSO4, glycine, purified water, pH adjusted to 5.5 with NaOH) was tested in the dose range 238–7622 µmol Be kg−1 (body weight, b/w) in full-grown Wistar male rats. The model provided reliable uptake of Be from the peritoneum into general circulation for at least 48 h. LD50 was found to be 687 µmol Be kg−1 (b/w). The established LD50 value differed from previous data on gastrointestinal, intramuscular or intravenous administration of Be compounds. The liver was found to act as a primary elimination route for Be and related to the highest Be content in the animal. However, it had no signs of morphological damage, which was observed only in the testes (deterioration of germinal epithelium). At the same time, the lungs, stated as a primary target tissue for Be in the models of chronic beryllium disease, did not show strong Be accumulation nor morphological changes. Survived animals showed behavioral changes, including increased motor activity and aggressive reactions in some cases, and complete spasticity in other. The obtained data show the applicability of the established modeling protocol and testified for the independence of chronic beryllium disease on Be2+ ion toxicity per se