The evolution of a visual-to-auditory sensory substitution device using interactive genetic algorithms

Sensory Substitution is a promising technique for mitigating the loss of a sensory modality. Sensory Substitution Devices (SSDs) work by converting information from the impaired sense (e.g. vision) into another, intact sense (e.g. audition). However, there are a potentially infinite number of ways of converting images into sounds and it is important that the conversion takes into account the limits of human perception and other user-related factors (e.g. whether the sounds are pleasant to listen to). The device explored here is termed “polyglot” because it generates a very large set of solutions. Specifically, we adapt a procedure that has been in widespread use in the design of technology but has rarely been used as a tool to explore perception – namely Interactive Genetic Algorithms. In this procedure, a very large range of potential sensory substitution devices can be explored by creating a set of ‘genes’ with different allelic variants (e.g. different ways of translating luminance into loudness). The most successful devices are then ‘bred’ together and we statistically explore the characteristics of the selected-for traits after multiple generations. The aim of the present study is to produce design guidelines for a better SSD. In three experiments we vary the way that the fitness of the device is computed: by asking the user to rate the auditory aesthetics of different devices (Experiment 1), by measuring the ability of participants to match sounds to images (Experiment 2) and the ability to perceptually discriminate between two sounds derived from similar images (Experiment 3). In each case the traits selected for by the genetic algorithm represent the ideal SSD for that task. Taken together, these traits can guide the design of a better SSD

The prefigurative power of urban political agroecology: rethinking the urbanisms of agroecological transitions for food system transformation

In recent years, urban contexts and urban-rural linkages have become central for scholars and activists engaged in agrarian questions, agroecological transitions and food system transformation. Grassroots experimentations in urban agroecology and farmers' engagement with urban policies have marked the rise of a new agenda aiming to bridge urban and agrarian movements. Departing from the work of Eric Holt-Gimenez and Annie Shattuck, this paper argues that the way urban-rural links have been conceptualized is occasionally progressive, and that an agroecology-informed food system transformation needs radical approaches. Acknowledging that processes of urbanization are dynamic, driven by specific lifestyles, consumption patterns, and value orientations - producing ongoing suburbanization, land enclosures, farmers displacement and food-knowledge loss - the paper argues that thinking transitions through new rural-urban links is unfit to tackle the evolving nature of these geographies, and reproduces the distinction between consumers and producers, living on either side of what Mindi Schneider and Philip McMichael have described as an epistemic and ecological rift. Building on insights from four case-studies across global north and south, the paper reframes agroecological transitions as a paradigmatic change in biopolitical spatial relations, economic values and planning agency - what we call an 'agroecological urbanism'. The paper articulates a transformation agenda addressing urban nutrients, peri-urban landuse, community food pedagogies and farmers' infrastructure

The Synthesis of Cyclic Combinatorial Circuits

To be added