Human learning is often motivated by self-imposed challenges, which guide behavior even in the absence of external rewards. Previous studies have shown that humans can use personal goals to “hack” the definition of reward, warranting an extension of the classic reinforcement learning framework to account for the flexible attribution of value to outcomes according to current goals. However, previous studies have shown that learning through goal-derived outcomes is less efficient than learning through more established reinforcers, such as numeric points. At least three possible explanations exist for this sort of impairment. First, such differences may be due to occasional lapses in executive function, which is required to encode and recognize goals, resulting in subsequent failure to update values accordingly. Second, the higher working memory load required to encode one-shot, novel stimuli as desirable outcomes may impair people’s ability to update and remember correct stimulus-reward associations. Third, a weaker commitment to arbitrary goals may result in dimmer appetitive signals. By extending existing experimental paradigms that include learning from both familiar rewards and abstract, goal-contingent outcomes and combining them with computational modeling techniques, we find evidence for each of the proposed accounts. While other factors might also play a role in this process, our results provide an initial indication of the key elements supporting (or impairing) the attribution of rewarding properties to otherwise neutral stimuli, which enable humans to better pursue arbitrarily set goals.


Human hacks and bugs in the recruitment of reward systems for goal achievement

SUMOylation, the covalent attachment of the small ubiquitin-like modifier (SUMO) to target proteins, is emerging as a key modulator of eukaryotic immune function. In plants, a SUMO1/2-dependent process has been proposed to control the deployment of host defense responses. Our findings suggest that increasing nitric oxide levels following pathogen recognition promote S-nitrosylation of the Arabidopsis SUMO E2 enzyme, SCE1, at Cys139. The SUMO-conjugating activities of both SCE1 and its human homolog, UBC9, were inhibited following this modification. Accordingly, mutation of Cys139 resulted in increased levels of SUMO1/2 conjugates, disabled immune responses, and enhanced pathogen susceptibility. Our findings imply that S-nitrosylation of SCE1 at Cys139 enables NO bioactivity to drive immune activation by relieving SUMO1/2-mediated suppression. The control of global SUMOylation is thought to occur predominantly at the level of each substrate via complex local machineries. Our findings uncover a parallel and complementary mechanism by suggesting that total SUMO conjugation may also be regulated directly by SNO formation at SCE1 Cys139. This Cys is evolutionary conserved and specifically S-nitrosylated in UBC9, implying that this immune-related regulatory process might be conserved across phylogenetic kingdoms.

A role for S-nitrosylation of the SUMO-conjugating enzyme SCE1 in plant immunity

With plant-anthropo-genesis we address the entanglements between plants and people over time, drawing on wide-ranging ethnographic and historical research to offer new and critical insights into the ways in which plant-human lifeworlds co-produce one another -- from racializations in plantation societies to the aspirational interventions of gardeners, farmers and scientists aiming for redemption from chemical industrial agriculture. Invoking Despret’s (2004) notion of anthropo-zoo-genesis for the ways ethologists and animals become attuned to and transform one another, plant-anthropo-genesis substantiates the ‘plant turn’ extending beyond Lewis-Jones (2016). If the current moment of climate crisis, the so-called Anthropocene, originates not from fossil capital, but from the global disruption of biosocial life wrought by European imperial expansion, the trans-Atlantic slave trade, and the decimation of indigenous peoples by disease -- the Plantationocene -- imagining other possible futures may well benefit from embracing an aspirational Planthroposcene (Myers 2018). This roundtable covers a variety of contexts and perspectives, from how monocrops and plantations displace human lives, shape racialized existences, and naturalize social inequalities, to ritual and religious dimensions of plant-human interactions, and to the regenerative alternatives to extractivist agriculture that re-imagine plant-human relations and agro-ecological possibilities, even as various registers of global power and crises contaminate the emergent scope of plant-anthropo-worlds.

Welcome to Underline's collection of Life Science conference videos

Featured presentations

Content from leading global institutions

Cell Biology

Animal Biology

Plant Biology

Agricultural and Biological Sciences

Stay up to date with the latest Underline news!

PRODUCT

COMPANY

RESOURCES