bottom-up attention

From Scholarpedia

Curator: Dr. Naotsugu Tsuchiya, California Institute of Technology, Pasadena, CA, USA
Curator: Dr. Christof Koch, Division of Biology, Caltech, Pasadena, CA

Bottom-up or exogenous components of attention

Exogenous cues are image-immanent features that transiently attract attention or eye gaze, independent of any particular task. Thus, if an object attribute (for example, flicker, motion, color, orientation, depth, or texture) differs significantly from its value in some neighborhood, the object will be salient.

This definition of bottom-up saliency has been implemented into a popular suite of neuromorphic vision algorithms that have at their core a topographic saliency map that encodes the saliency or conspicuity of locations in the visual field independent of the task (Itti and Koch, 2001) (see http://iLab.caltech.edu for a C++ implementation and http://www.saliencytoolbox.net/ for a Matlab toolbox implementation). Such algorithms account for a significant fraction of fixation eye movements (Parkhurst et al., 2002; Peters et al., 2005).

Candidates for such a map in the primate brain include the initial responses of neurons in the frontal eye field (FEF) and the lateral intraparietal sulcus (LIP) (Constantinidis and Steinmetz, 2005; Thompson and Bichot, 2005).

See also

Attention and Consciousness/How to Manipulate Attention, Saliency Map

References

• Constantinidis C, Steinmetz MA (2005) Posterior parietal cortex automatically encodes the location of salient stimuli. J Neurosci 25:233-238.
• Itti L, Koch C (2001) Computational modelling of visual attention. Nat Rev Neurosci 2:194-203.
• Parkhurst D, Law K, Niebur E (2002) Modeling the role of salience in the allocation of overt visual attention. Vision Res 42:107-123.
• Peters RJ, Iyer A, Itti L, Koch C (2005) Components of bottom-up gaze allocation in natural images. Vision Res 45:2397-2416.
• Thompson KG, Bichot NP (2005) A visual salience map in the primate frontal eye field. Prog Brain Res 147:251-262.

Invited by:	Dr. Anil K Seth, University of Sussex, UK
Action editor:	Dr. Eugene M. Izhikevich, Editor-in-Chief of Scholarpedia, the peer-reviewed open-access encyclopedia
Action editor:	Dr. Anil K Seth, University of Sussex, UK
Assistant editor:	Mr. Srivas Chennu, PhD Student, Computing Laboratory, University of Kent, Canterbury, U.K.
Reviewer B:	Dr. Susana Martinez-Conde, Barrow Neurological Institute, Phoenix, AZ
Reviewer C:	Dr. Lawrence M. Ward, University of British Columbia, Vancouver, CANADA