Title of paper Author=Jeff Jones

Lateral Inhibition (LI) phenomena occur in a wide range of neural sensory modalities, but are most famously described in the visual system of humans and other animals. The general mechanism can be summarised as when a stimulated neuron is itself excited and also suppresses the activity of its local neighbours via inhibitory connections. The effect is to generate an increase in contrast between spatial environmental stimuli. Simple organisms, such as the single-celled slime mould Physarum polycephalum possess no neural tissue yet, despite this, are known to exhibit complex computational behaviour. Could simple organisms such as slime mould approximate LI without recourse to neural tissue? We describe a model whereby LI can emerge without explicit inhibitory wiring, using only bulk transport effects. We use a multi-agent model of slime mould to reproduce the characteristic edge contrast amplification effects of LI using excitation via attractant based stimuli. We also explore a counterpart behaviour, Lateral Activation (where stimulated regions are inhibited and lateral regions are excited), using simulated exposure to light irradiation. In both cases restoration of baseline activity occurs when the stimuli are removed. In addition to the enhancement of local edge contrast the long-term change in population density distribution corresponds to a collective response to the global brightness of 2D image stimuli, including the scalloped intensity profile of the Chevreul staircase and the perceived difference of two identically bright patches in the Simultaneous Brightness Contrast (SBC) effect. This simple model approximates LI contrast enhancement phenomena and global brightness perception in collective unorganised systems without fixed neural architectures. This may encourage further research into unorganised analogues of neural processes in simple organisms and suggests novel mechanisms to generate collective perception of contrast and brightness in distributed computing and robotic devices. Jeff Dale Jones Centre for Unconventional Computing, University of the West of England, Bristol, UK, e-mail: [email protected] 1 ar X iv :1 51 1. 05 77 9v 1 [ cs .E T ] 1 8 N ov 2 01 5