The {binding problem} refers to {the puzzle of how the brain reunites perceptual features processed by parallel systems}.
It seems that the brian encodes related attributes using {neural synchrony}; that is: if a line is moving vertically, neurons detecting a vertical edge and those detecting vertical movement might {fire in synchrony}.
{Feature integration theory} proposes that {feature binding} occurs in two stages: a {preattentive} stage in which {features are analyzed separately} and a {focused attention} stage in which {features are combined to create whole-object percepts}.
Errors in feature binding are called {conjunction errors}: for example, someone shown a blue ‘H’ and a red ’T’ might report {seeing a blue ’T’ and a red ‘H’}.