Effects of V1 surround modulation tuning on visual saliency and the tilt illusion
Neurons in the primary visual cortex respond to oriented stimuli placed in the center of their receptive field, yet their response is modulated by stimuli outside the receptive field (the surround). Classically, this surround modulation is assumed to be strongest if the orientation of the surround s...
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| Format: | Article |
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American Physiological Society
2018
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| Online Access: | https://eprints.nottingham.ac.uk/52883/ |
| _version_ | 1848798832196845568 |
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| author | Keemink, Sander Wessel Boucsein, Clemens van Rossum, Mark C.W. |
| author_facet | Keemink, Sander Wessel Boucsein, Clemens van Rossum, Mark C.W. |
| author_sort | Keemink, Sander Wessel |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Neurons in the primary visual cortex respond to oriented stimuli placed in the center of their receptive field, yet their response is modulated by stimuli outside the receptive field (the surround). Classically, this surround modulation is assumed to be strongest if the orientation of the surround stimulus aligns with the neuron's preferred orientation - irrespective of the actual center stimulus. This neuron-dependent surround modulation has been used to explain a wide range of psychophysical phenomena, such as biased tilt perception and saliency of stimuli with contrasting orientation. However, several neurophysiological studies have shown that for most neurons surround modulation is instead center-dependent: it is strongest if the surround orientation aligns with the center stimulus. As the impact of such center-dependent modulation on the population level is unknown, we examine this using computational models. We find that with neuron-dependent modulation the biases in orientation coding, commonly used to explain the tilt illusion, are larger than psychophysically reported, but disappear with center-dependent modulation. Therefore we suggest that a mixture of the two modulation types is necessary to quantitatively explain the psychophysically observed biases. Next, we find that under center-dependent modulation average population responses are more sensitive to orientation differences between stimuli, which in theory could improve saliency detection. However, this effect depends on the specific saliency model. Overall, our results thus show that center-dependent modulation reduces coding bias, while possibly increasing the sensitivity to salient features. |
| first_indexed | 2025-11-14T20:26:02Z |
| format | Article |
| id | nottingham-52883 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T20:26:02Z |
| publishDate | 2018 |
| publisher | American Physiological Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-528832020-05-04T19:38:04Z https://eprints.nottingham.ac.uk/52883/ Effects of V1 surround modulation tuning on visual saliency and the tilt illusion Keemink, Sander Wessel Boucsein, Clemens van Rossum, Mark C.W. Neurons in the primary visual cortex respond to oriented stimuli placed in the center of their receptive field, yet their response is modulated by stimuli outside the receptive field (the surround). Classically, this surround modulation is assumed to be strongest if the orientation of the surround stimulus aligns with the neuron's preferred orientation - irrespective of the actual center stimulus. This neuron-dependent surround modulation has been used to explain a wide range of psychophysical phenomena, such as biased tilt perception and saliency of stimuli with contrasting orientation. However, several neurophysiological studies have shown that for most neurons surround modulation is instead center-dependent: it is strongest if the surround orientation aligns with the center stimulus. As the impact of such center-dependent modulation on the population level is unknown, we examine this using computational models. We find that with neuron-dependent modulation the biases in orientation coding, commonly used to explain the tilt illusion, are larger than psychophysically reported, but disappear with center-dependent modulation. Therefore we suggest that a mixture of the two modulation types is necessary to quantitatively explain the psychophysically observed biases. Next, we find that under center-dependent modulation average population responses are more sensitive to orientation differences between stimuli, which in theory could improve saliency detection. However, this effect depends on the specific saliency model. Overall, our results thus show that center-dependent modulation reduces coding bias, while possibly increasing the sensitivity to salient features. American Physiological Society 2018-05-30 Article PeerReviewed Keemink, Sander Wessel, Boucsein, Clemens and van Rossum, Mark C.W. (2018) Effects of V1 surround modulation tuning on visual saliency and the tilt illusion. Journal of Neurophysiology . ISSN 1522-1598 surround modulation population coding tilt illusion orientation saliency https://www.physiology.org/doi/10.1152/jn.00864.2017 doi:10.1152/jn.00864.2017 doi:10.1152/jn.00864.2017 |
| spellingShingle | surround modulation population coding tilt illusion orientation saliency Keemink, Sander Wessel Boucsein, Clemens van Rossum, Mark C.W. Effects of V1 surround modulation tuning on visual saliency and the tilt illusion |
| title | Effects of V1 surround modulation tuning on visual saliency and the tilt illusion |
| title_full | Effects of V1 surround modulation tuning on visual saliency and the tilt illusion |
| title_fullStr | Effects of V1 surround modulation tuning on visual saliency and the tilt illusion |
| title_full_unstemmed | Effects of V1 surround modulation tuning on visual saliency and the tilt illusion |
| title_short | Effects of V1 surround modulation tuning on visual saliency and the tilt illusion |
| title_sort | effects of v1 surround modulation tuning on visual saliency and the tilt illusion |
| topic | surround modulation population coding tilt illusion orientation saliency |
| url | https://eprints.nottingham.ac.uk/52883/ https://eprints.nottingham.ac.uk/52883/ https://eprints.nottingham.ac.uk/52883/ |