Conference Publication Details
Mandatory Fields
Elliott, M.A. Kelly, J. Friedel, J., Brodsky, J., and Mulcahy, P
Fechner Day 2013: 29th Annual Meeting of the International Society for Psychophysics
Golden Section Effects in Visual Cognition: A Signature for Complex-System Organization?
Optional Fields
Golden Section Cognition Visual Search Spatial Frequency coding
Jiri Wackermann and Marc Wittmann
Freiburg i Br. Germany
We [1] reported a series of experiments in which decision reaction-time (RT) to the shading (light or dark) of the smallest section of multi-sectioned displays was significantly slowed when the ratio between larger to smaller sections was equivalent to 1.61803, a ratio also known as the Golden Section. However, we have failed to find any conclusive evidence from paired comparison tasks that Golden Sectioned displays are preferred over displays otherwise sectioned. Nevertheless we replicated the RT effects on several occasions and have found the effect to generalize to displays oriented 90˚ (to control for the possibility of visual field effects) as well as displays positioned further ways and closer to the experimental participants (which changed the retinal size of displays). Using a simulation of the circular on-off surround structure of neurons in the retina we analyzed the spatial frequency structure of our display matrices. Unlike all of the other ratios used (over the range 1.468 1.668) the Golden Sectioned displays failed to include any frequency components in the range ~3-8˚ of visual angle. It might be that the additional time take to respond reflects an additional step in processing, such as feedback from later neurons coding global display structure to reinforce a weak bottom-up signal in visual and extra-striate visual cortex where neurons possess receptive fields of size 3-8˚. To test this hypothesis, we added visual noise to each display matrix, convoluting the existing spatial frequency structure with a uniform distribution of visual signal across the displays. We reasoned this would be sufficient signal to activate neurons in all visual areas and would thus reduce the requirement for feedback and so reduce the extent to which RTs would be slowed to Golden Sectioned displays. Our findings confirmed this hypothesis. We deliberately used matrix areas in different ratios because area will be directly analogous to the numbers of neurons engaged, and synchronized into assemblies, and this relates to EEG work which has identified an absence of synchronization between assemblies synchronized at frequencies where the ratio of one to another frequency is the Golden Ratio [2]. This is strongly suggestive of a basis for Golden Sectioning in the dynamics of neural activity.References and notes1. Elliott, M.A., Mulcahy, P., Kelly, J., Twomey, D., & Brosnan, J. (2011). Effects of golden sectioning on search and discrimination in Mondrian-like grids. In D. Algom, D. Zakay, E. Chajut, S. Shaki, Y. Mama & V. Shakuf (Eds.) Fechner Day 2011: The 27th Annual Meeting of the International Society for Psychophysics, Raanana, Israel: The International Society for Psychophysics (pp. 137-142).2. Pletzer, B., Kerschbaum, H., & Klimesch, W. (2010). When frequencies never synchronize: The golden mean and the resting EEG, Brain Research, 1335, 91-102
Presentation of this work is supported by the NUI Galway millennium travel fund
Grant Details
Scholarship to Paul Mulchay
Publication Themes