Timing Drosophila development through steroid hormone action.

Specifically timed pulses of the moulting hormone ecdysone are necessary for developmental progression in insects, guiding development through important milestones such as larval moults, pupation and metamorphosis. It also coordinates the acquisition of cell identities, known as cell patterning, and growth in a tissue-specific manner. In the absence of ecdysone, the ecdysone receptor heterodimer Ecdysone Receptor and Ultraspiracle represses expression of target primary response genes, which become de-repressed as the ecdysone titre rises. However, ecdysone signalling elicits both repressive and activating responses in a temporal and tissue-specific manner. To understand how ecdysone achieves such specificity, this review explores the layers of gene regulation involved in stage-appropriate ecdysone responses in Drosophila fruit flies.

Augmenting ideational fluency in a creativity task across multiple transcranial direct current stimulation montages.

Neuroimaging and transcranial direct current stimulation (tDCS) research has revealed that generating novel ideas is associated with both reductions and increases in prefrontal cortex (PFC) activity, and engagement of posterior occipital cortex, among other regions. However, there is substantial variability in the robustness of these tDCS-induced effects due to heterogeneous sample sizes, different creativity measures, and methodological diversity in the application of tDCS across laboratories. To address these shortcomings, we used twelve different montages within a standardized tDCS protocol to investigate how altering activity in frontotemporal and occipital cortex impacts creative thinking. Across four experiments, 246 participants generated either the common or an uncommon use for 60 object pictures while undergoing tDCS. Participants also completed a control short-term memory task. We applied active tDCS for 20 min at 1.5 mA through two 5 cm × 5 cm electrodes over left or right ventrolateral prefrontal (areas F7, F8) or occipital (areas O1, O2) cortex, concurrent bilateral stimulation of these regions across polarities, or sham stimulation. Cathodal stimulation of the left, but not right, ventrolateral PFC improved fluency in creative idea generation, but had no effects on originality, as approximated by measures of semantic distance. No effects were obtained for the control tasks. Concurrent bilateral stimulation of the ventrolateral PFC regardless of polarity direction, and excitatory stimulation of occipital cortex did not alter task performance. Highlighting the importance of cross-experimental methodological consistency, these results extend our past findings and contribute to our understanding of the role of left PFC in creative thinking.

What Does a Horgous Look Like? Nonsense Words Elicit Meaningful Drawings.

To what extent do people attribute meanings to "nonsense" words? How general is such attribution of meaning? We used a set of words lacking conventional meanings to elicit drawings of made-up creatures. Separate groups of participants rated the nonsense words and the drawings on several semantic dimensions and selected what name best corresponded to each creature. Despite lacking conventional meanings, "nonsense" words elicited a high level of consistency in the produced drawings. Meaning attributions made to nonsense words corresponded with meaning attributions made by separate people to drawings that were inspired by the name. Naïve participants were able to recover the name that inspired the drawing with greater-than-chance accuracy. These results suggest that people make liberal and consistent use of non-arbitrary relationships between forms and meanings. OPEN RESEARCH BADGES: This article has been awarded Open Materials and Open Data badges. All materials and data are publicly accessible via the Open Science Framework at https://osf.io/8juyc/. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.