The Riddoch syndrome is one in which patients blinded by lesions to their primary visual cortex can consciously perceive visual motion in their blind field, an ability that correlates with activity in motion area V5. Our assessment of the characteristics of this syndrome in patient ST, using multimodal MRI, showed that: 1. ST’s V5 is intact, receives direct subcortical input, and decodable neural patterns emerge in it only during the conscious perception of visual motion; 2. moving stimuli activate medial visual areas but, unless associated with decodable V5 activity, they remain unperceived; 3. ST’s high confidence ratings when discriminating motion at chance levels, is associated with inferior frontal gyrus activity. Finally, we report that ST’s Riddoch Syndrome results in hallucinatory motion with hippocampal activity as a correlate. Our results shed new light on perceptual experiences associated with this syndrome and on the neural determinants of conscious visual experience.

We have enquired into the neural activity which correlates with the experience of beauty aroused by abstract paintings consisting of arbitrary assemblies of lines and colours. During the brain imaging experiments, subjects rated abstract paintings according to aesthetic appeal. There was low agreement on the aesthetic classification of these paintings among participants. Univariate analyses revealed higher activity with higher declared aesthetic appeal in both the visual areas and the medial frontal cortex. Additionally, representational similarity analysis (RSA) revealed that the experience of beauty correlated with decodable patterns of activity in visual areas. These results are broadly similar to those obtained in previous studies on facial beauty. With abstract art, it was the involvement of visual areas implicated in the processing of lines and colours while with faces it was of visual areas implicated in the processing of faces. Both categories of aesthetic experience correlated with increased activity in medial frontal cortex. We conclude that the sensory areas participate in the selection of stimuli according to aesthetic appeal and that it is the co-operative activity between the sensory areas and the medial frontal cortex that is the basis for the experience of abstract visual beauty. Further, this co-operation is enabled by "experience dependent" functional connections, in the sense that currently the existence and high specificity of these connections can only be demonstrated during certain experiences.

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SummaryThe Riddoch syndrome is one in which patients blinded by lesions to their primary visual cortex can consciously perceive visual motion in their blind field, an ability that correlates with activity in motion area V5. Our assessment of the characteristics of this syndrome in patient ST, using multimodal MRI, showed that: 1. ST’s V5 is intact, receives direct subcortical input, and decodable neural patterns emerge in it only during the conscious perception of visual motion; 2. moving stimuli activate medial visual areas but, unless associated with decodable V5 activity, they remain unperceived; 3. ST’s high confidence ratings when discriminating motion at chance levels, is associated with inferior frontal gyrus activity. Finally, we report that ST’s Riddoch Syndrome results in hallucinatory motion with hippocampal activity as a correlate. Our results shed new light on perceptual experiences associated with this syndrome and on the neural determinants of conscious visual experience.

Using functional magnetic resonance imaging (fMRI), we have enquired into the neural activity which correlates with the experience of beauty aroused by abstract paintings consisting of arbitrary assemblies of lines and colours. During the imaging experiments, 18 subjects viewed and rated 120 images of abstract paintings according to how beautiful they perceived them to be. There was a low agreement on the aesthetic classification of these paintings among participants. In contrast, a re-analysis of behavioural data from our previous study on face beauty revealed a much stronger inter-subject agreement for faces compared with abstract art. Representational similarity analysis (RSA) revealed that the experience of beauty when viewing abstract paintings correlated with the emergence of decodable patterns of activity in visual areas implicated in the processing of lines and colours (V1 through V4). Additionally, a parametric univariate analysis revealed higher activity in medial frontal cortex with higher aesthetic appeal. Both univariate and multivariate analyses of the imaging experiments gave broadly similar results to those obtained in previous studies on facial beauty. With abstract art, it was the involvement of visual areas implicated in the processing of lines and colours while with faces it was of visual areas implicated in the processing of faces. Both categories of aesthetic experience correlated with increased activity in medial frontal cortex. We conclude that, as with the experience of beauty in human faces, it is fundamentally the co-operative activity in these two geographically and functionally distant areas of the brain that is the basis for the experience of beauty. Further, this co-operation is enabled by “experience dependent” functional connections, in the sense that currently the existence and high specificity of these connections can only be demonstrated during certain aesthetic experiences. This does not exclude a role in aesthetic experiences for other areas which our imaging experiments have also revealed. We also conclude that the sensory areas of the visual brain have the additional role of participating in the selection of stimuli according to certain significant configurations which make them aesthetically appealing to the observer.