For a background on what binding is and how it applies to recognizing objects, please read this.

To determine the binding process, we must first know of how many objects are minds are aware at any single point in time. The first division would be whether we are aware of only one object or multiple objects. Furthermore, if we are aware of multiple objects, is our brain attending to only one at a time by rapidly switching between different objects, attending to only one object at a time but remembering objects which have recently been attended to, or actually attending to multiple objects simultaneously? Any of these situations is possible, so a description of a possible type of binding is given for each of them.

The simplest possibility is that only one sort of neuronal cell is responsible for visual consciousness. These cells, each in their own area within the visual cortex, fire either at extremely high frequencies or for extended periods of time. Each neuron would have certain cells attached to it which are responsible for identifying characteristics of objects. Thus binding would be the result of the cells attached to the firing neurons both being stimulated by these rapidly firing neurons, and themselves stimulating those neurons based on changes in the characteristic which they record. These small groups of neurons all firing together would establish the identity of the object.

This proposal does not seem very likely, however. It only works if the mind is aware of only one object, and even then, the object would have to be distinguished from its surroundings. To oversimplify, assume their are only two objects to distinguish between, a green circle and a red square. There would be four different sets of neurons firing. One saying "green," another "red," another "circle," and the last "square."

One possibility for overcoming this difficulty is that an object only enters vivid awareness (i.e. consciousness) when the mind attends to it. This process of attending to it could possibly strengthen the firings of certain sets of neurons (e.g. "green" and "circle") while weakening the firing of others ("red" and "square"). Attention could then rapidly shift between several objects, giving the appearance of attending to all of them simultaneously. Alternatively, another mechanism could be responsible for remembering objects which were recently attended to but which are not currently being attended to. The attentional mechanism itself would not then be required to switch so rapidly.

Another possibility is that these different sets of neurons all fire over the same period of time, but that the different sets fire in slightly different ways. For example, the neurons might fire in short bursts every 100 milliseconds. The green and circle groups would fire, then 50 milliseconds later, the red and square neurons would fire. Thus the mind would be aware of both objects at the same time, but no confusion would ensue since each set fires only at the same time as the other sets corresponding to the same object. Other variables, such as frequency of the firing, could also be invoked to make the mind capable of identifying more than just two objects.