arXiv subjects

James V Stone

Publications and source records attributed to James V Stone.

5 recordsLinked to original sources

arXiv2026

Efficient Coding Predicts Synaptic Conductance

Synapses are information efficient in the sense that their natural conductance values convey as many bits per Joule as possible, but efficiency falls rapidly if the conductance is forced to deviate from its natural value (Harris et al, 2015. However, the exact manner in which efficiency falls as conductance deviates from its natural value remains unexplained. Recently, Malkin et al (2026) showed that synaptic noise is minimised given the available energy, consistent with a minimal energy boundary. This minimal energy boundary is a necessary, but not sufficient, condition for maximising information efficiency. By expressing the minimal energy boundary in terms of Shannon's information theory (Shannon, 1949), we show that synapses operate at signal-to-noise ratios which maximise information efficiency, and that this accurately predicts the decrease in efficiency values observed in Harris et al (2015) across a wide range of synaptic conductances. Crucially, the proposed model contains no free parameters because it is derived from the biophysics of the synapse. The results reported here are consistent with the general principle that neuronal systems in the brain have evolved to be as efficient as possible in terms of the number of bits per Joule.

q-bio.NC↗

arXiv2022

Methods for Estimating Neural Information

Estimating the Shannon information associated with individual neurons is a non-trivial problem. Three key methods used to estimate the mutual information between neuron inputs and outputs are described, and a list of further readings is provided.

q-bio.NC↗

arXiv2021

Using Information Theory to Measure Psychophysical Performance

Most psychophysical experiments discard half the data collected. Specifically, experiments discard reaction time data, and use binary responses (e.g. yes/no) to measure performance. Here, Shannon's information theory is used to define Shannon competence $s'$, which depends on the mutual information between stimulus strength (e.g. luminance) and a combination of reaction times and binary responses. Mutual information is the entropy of the joint distribution of responses minus the residual entropy after a model has been fitted to these responses. Here, this model is instantiated as a proportional rate diffusion model, with the additional innovation that the full covariance structure of responses is taken into account. Results suggest information associated with reaction times is independent of (i.e. additional to) information associated with binary responses, and that reaction time and binary responses together provide substantially more than the sum of their individual contributions (i.e. they act synergistically). Consequently, the additional information supplied by reaction times suggests that using combined reaction time and binary responses requires fewer stimulus presentations, without loss of precision in psychophysical parameters. Finally, because s' takes account of both reaction time and binary responses, (and in contrast to d') $s'$ is immune to speed-accuracy trade-offs, which vary between observers and experimental designs.

q-bio.NC↗

arXiv2021

Who's the Daddy? Infidelity Favours Father-Son Facial Dissimilarity

Evolutionary theory predicts that children fare better if they resemble their father. However, if a man is promiscuous then his children tend to be (unwittingly) raised within other families; such children should fare better if they do not resemble their father. This suggests that father-son facial similarity should decrease as a function of male promiscuity. To test this hypothesis, the degree of similarity between each of 37 pairs of father-son photographs was rated by 83 participants. The promiscuity score of a father was defined as the number of sexual relationships he had been involved in. A linear regression of father-son similarity ratings against fathers' promiscuity scores indicated that the slope of the fitted line was significantly less than zero (slope=-0.176, p < 0.001), and that fathers' promiscuity scores account for 75% of the variance father-son facial similarity ratings. Additionally, a significant negative non-parametric correlation (Spearman's rho rho=-0.886, p=0.019) between father-son similarity ratings and fathers' promiscuity scores was found.

q-bio.PE↗

arXiv2019

Information Theory: A Tutorial Introduction

Shannon's mathematical theory of communication defines fundamental limits on how much information can be transmitted between the different components of any man-made or biological system. This paper is an informal but rigorous introduction to the main ideas implicit in Shannon's theory. An annotated reading list is provided for further reading.

cs.IT↗