Community Research and Development Information Service - CORDIS

ERC

WMOSPOTWU Report Summary

Project ID: 310829
Funded under: FP7-IDEAS-ERC
Country: United Kingdom

Final Report Summary - WMOSPOTWU (What makes our subjective perception of the world unique?)

Despite how it subjectively appears to us, our perception of the world around us is not even and seamless. Our subjective experience of identical pictures can be dramatically different for different people – a powerful example of this was the infamous ‘Dress’ photo that can be perceived either as white-and-gold or black-and-blue resulting in enormous publicity on social and mainstream media. Moreover, even simple perceptual experiences, such as how large an object appears or whether you see a face as male or female vary considerably within the same individual when the image is shown at different times or different locations. The WMOSPOTWU project aimed to gain a better understanding of the neural mechanisms that give rise to such inter- and intra-individual differences in our perceptual experience. Knowing how our subjective experience of the world arises in the brain is essential for understanding perceptual processing. Perception guides our actions and behaviour and thus ultimately contributes considerably to what makes a person who they are.

WMOSPOTWU conducted a series of experiments exploring the unique spatial patterns of perceptual biases for size and also more complex visual attributes (orientation, motion, depth, shape). We developed a novel behavioural task to map the pattern of biases efficiently and under ecologically more relevant conditions than would be possible with traditional psychophysical studies. This method also provides better control of confounds from cognitive factors like decision bias. We further developed an analysis toolbox to map tuning functions of voxels, so-called population receptive fields (pRF), in functional MRI data. Both of these developments have the potential to make a valuable methodological contribution to the wider research community; in fact, our pRF mapping toolbox is used by numerous collaborators across the world, including the UK, the EU, the US, and China, and New Zealand. Because it is user-friendly and integrates smoothly with widely used MRI analysis packages (FreeSurfer, SPM, FSL) it is an attractive choice for many researchers planning to use pRF analysis. In our own research, we have recently shown that idiosyncrasies in the spatial tuning of visual cortex can predict patterns of perceptual biases for simple size perception while the macroscopic morphology (surface area) of visual cortex is linked to contextual interactions. These findings support theoretical accounts of how size perception works in the brain that were mainly based only on psychophysical observations and further explains previous neuroimaging results on contextual processing. Moreover, it lays the groundwork for studying more complex perception of shape and object identity. In addition, we also performed a longitudinal study to establish the reliability of our pRF measures. We further investigated the heritability of visual perceptual biases and the functional brain architecture using a classical twin design which suggests that while gross individual differences in perceptual function are heritable, more fine-grained patterns of biases arise during a person’s lifetime. Other experiments investigated an interaction between spatial tuning and the preference for facial features. Yet more experiments explored the heterogeneity in complex object perception using Rubin’s face-vase illusion. This work suggests that the heterogeneity of complex shape perception is largely inherited from heterogeneity in the processing of low-level visual attributes. We also studied how occluded objects, illusory contours, and global motion (the grouping of small moving stimuli into a coherent whole) are represented in visual cortex. From this we learned that mapping studies of visual cortex are strongly dependent on visual spatial attention, an important caveat for future mapping studies that has not been sufficiently appreciated in the literature.

Finally, we studied the neural correlates of subjective size perception and perceptual grouping. This work directly uses brain activity to reconstruct an individual’s subjective percept of relatively complex stimuli – a first step towards an insight into a person’s mind’s eye.

Reported by

UNIVERSITY COLLEGE LONDON
United Kingdom
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