New Caledonian crows rapidly solve a collaborative problem without cooperative cognition

There is growing comparative evidence that the cognitive bases of cooperation are not unique to humans. However, the selective pressures that lead to the evolution of these mechanisms remain unclear. Here we show that while tool-making New Caledonian crows can produce collaborative behavior, they do not understand the causality of cooperation nor show sensitivity to inequity. Instead, the collaborative behavior produced appears to have been underpinned by the transfer of prior experience. These results suggest that a number of possible selective pressures, including tool manufacture and mobbing behaviours, have not led to the evolution of cooperative cognition in this species. They show that causal cognition can evolve in a domain specific manner-understanding the properties and flexible uses of physical tools does not necessarily enable animals to grasp that a conspecific can be used as a social tool

The importance of the altricial – precocial spectrum for social complexity in mammals and birds:A review

Various types of long-term stable relationships that individuals uphold, including cooperation and competition between group members, define social complexity in vertebrates. Numerous life history, physiological and cognitive traits have been shown to affect, or to be affected by, such social relationships. As such, differences in developmental modes, i.e. the ‘altricial-precocial’ spectrum, may play an important role in understanding the interspecific variation in occurrence of social interactions, but to what extent this is the case is unclear because the role of the developmental mode has not been studied directly in across-species studies of sociality. In other words, although there are studies on the effects of developmental mode on brain size, on the effects of brain size on cognition, and on the effects of cognition on social complexity, there are no studies directly investigating the link between developmental mode and social complexity. This is surprising because developmental differences play a significant role in the evolution of, for example, brain size, which is in turn considered an essential building block with respect to social complexity. Here, we compiled an overview of studies on various aspects of the complexity of social systems in altricial and precocial mammals and birds. Although systematic studies are scarce and do not allow for a quantitative comparison, we show that several forms of social relationships and cognitive abilities occur in species along the entire developmental spectrum. Based on the existing evidence it seems that differences in developmental modes play a minor role in whether or not individuals or species are able to meet the cognitive capabilities and requirements for maintaining complex social relationships. Given the scarcity of comparative studies and potential subtle differences, however, we suggest that future studies should consider developmental differences to determine whether our finding is general or whether some of the vast variation in social complexity across species can be explained by developmental mode. This would allow a more detailed assessment of the relative importance of developmental mode in the evolution of vertebrate social systems

Monitoring fluorescent calcium signals in neural cells with organic photodetectors

Optical imaging of biological activities is used to monitor the functional aspects of neural circuits by reporting activities via fluorescent and molecular probes. Current imaging approaches encompass different optical components, inorganic sensors-based detection units and image processing elements, in order to measure optical activities. Inorganic sensors have important drawbacks that create certain difficulties for biological studies, such as high energy consumption and high dark-noise at physiological temperature. Organic photodetectors (OPD) as optical sensors have numerous advantages including high temporal resolution and sensitivity. They have also demonstrated a high performance at both room and relatively high temperatures, without needing cooling systems, unlike inorganic-based sensors. However, their performance in detecting fluorescent biological signals, reported by molecular probes or genetically encoded-indicators, remains to be established. In this work, we fabricated a standalone simple-structure OPD in open-air, with an active layer consisting of eXtra Large bandgap Polymer (XPL) blended with fullerene. We demonstrate the excellent performance of OPDs in the sensing of fluorescent calcium signals reported by chemical and genetically encoded fluorescent calcium indicators from living brain cells with a high temporal resolution. This work paves the way for the integration of OPDs as highly sensitive optical sensors in a broad range of biomedical devices