Code-specific learning rules improve action selection by populations of spiking neurons

Population coding is widely regarded as a key mechanism for achieving reliable behavioral decisions. We previously introduced reinforcement learning for population-based decision making by spiking neurons. Here we generalize population reinforcement learning to spike-based plasticity rules that take account of the postsynaptic neural code. We consider spike/no-spike, spike count and spike latency codes. The multi-valued and continuous-valued features in the postsynaptic code allow for a generalization of binary decision making to multi-valued decision making and continuous-valued action selection. We show that code-specific learning rules speed up learning both for the discrete classification and the continuous regression tasks. The suggested learning rules also speed up with increasing population size as opposed to standard reinforcement learning rules. Continuous action selection is further shown to explain realistic learning speeds in the Morris water maze. Finally, we introduce the concept of action perturbation as opposed to the classical weight- or node-perturbation as an exploration mechanism underlying reinforcement learning. Exploration in the action space greatly increases the speed of learning as compared to exploration in the neuron or weight space.

Shaping gender inequalities: critical moments and critical places

Purpose – There is much scientific interest in the connection between the emergence of gender-based inequalities and key biographical transition points of couples in long-term relationships. Little empirical research is available comparing the evolution of a couple’s respective professional careers over space and time. The purpose of this paper is to contribute to filling this gap by addressing the following questions: what are the critical biographical moments when gender (in)equalities within a relationship begin to arise and consolidate? Which biographical decisions precede and follow such critical moments? How does decision making at critical moments impact the opportunities of both relationship partners in gaining equal access to paid employment? Design/methodology/approach – These questions are addressed from the perspectives of intersectionality and economic citizenship. Biographical interviewing is used to collect the personal and professional narratives of Swiss-, bi-national and migrant couples. The case study of a Swiss-Norwegian couple illustrates typical processes by which many skilled migrant women end up absently or precariously employed. Findings – Analysis reveals that the Scandinavian woman’s migration to Switzerland is a primary and critical moment for emerging inequality, which is then reinforced by relocation (to a small town characterized by conservative gender values) and the subsequent births of their children. It is concluded that factors of traditional gender roles, ethnicity and age intersect to create a hierarchical situation which affords the male Swiss partner more weight in terms of decision making and career advancement. Practical implications – The paper’s findings are highly relevant to the formulation of policies regarding gender inequalities and the implementation of preventive programmes within this context. Originality/value – Little empirical research is available comparing the evolution of a couple’s respective professional careers over space and time. The originality of this paper is to fill this research gap; to include migration as a critical moment for gender inequalities; to use an intersectional and geographical perspective that have been given scant attention in the literature; to use the original concept of economic citizenship; and to examine the case of a bi-national couple, which has so far not been examined by the literature on couple relationships.