Selective Visual Attention: Computational Models and Applications

2.5 Competition, Normalization and Whitening

The model of synchronous oscillation simulates the internal activity of the neuron and considers contextual relation between neurons, which is more biologically plausible. However, it is difficult for engineering applications due to the structural complexity of a single neuron, where a neuron is a pulse generator. Actually, regardless of the inner workings of a cell, only from physiological and anatomical data, cells' activity in the HVS can exhibit various phenomena and behaviours that represent more contextual relations. For instance, competition, normalization and whitening are just the behaviours between cells. Competition exists everywhere between neurons in separate visual areas of the brain or between objects in the visual field. As a result of this, the preponderant object in a visual field or cells in the visual areas can win over others and stand out. Normalization of the cells' response is another behaviour caused by lateral inhibition of cells with the same characteristics. This suppression of cells with the same feature can pop out larruping features or cells. Frequency whitening because of RF centre–surround properties of a retinal ganglion cell also possibly leads to visual attention. The rest of this section introduces the viewpoints based on some recorded data of a single cell in animals or the data from functional brain imaging studies.

2.5.1 Competition and Visual Attention

As discussed in Chapter 1 and earlier in ...