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Neural dynamics of feedforward and feedback processing in figure-ground segregation
Oliver W Layton1, Ennio Mingolla2, Arash Yazdanbakhsh3
1The Perception and Action Lab, Department of Cognitive Science, Rensselaer Polytechnic Institute Troy, NY, USA ; Vision Lab, Center for Computational Neuroscience and Neural Technology, Boston University Boston, MA, USA.
Frontiers in Psychology
|October 28, 2014
Summary
Figure-ground segregation in primates relies on a dynamical model where feedback, not just feedforward connections, is crucial. This model uses neural processing strategies to differentiate object interiors from exteriors.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Primate Vision
Background:
- Figure-ground segregation is a fundamental visual processing task.
- Existing models often emphasize feedforward processing, with feedback playing a minor role.
Purpose of the Study:
- To propose a dynamical model of figure-ground segregation in the primate ventral stream.
- To investigate the crucial role of feedback mechanisms in disambiguating figure interiors and exteriors.
Main Methods:
- Developed a dynamical model incorporating feedforward and feedback connections.
- Introduced a processing strategy exploiting RF center jitter and size variation.
- Modeled V4 curved contour cells and predicted IT teardrop cells.
Main Results:
- The model enhances neural activity inside figures and suppresses it outside.
- Maximal model activity was observed along the medial axis of figures.
- The model successfully segregated well-known and algorithmically generated shapes.
Conclusions:
- Feedback plays a critical role in figure-ground segregation, challenging feedforward-centric models.
- Dynamic balancing of feedforward and feedback signals is essential for visual perception.
- The proposed model offers a new framework for understanding primate visual processing.
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