Illusory conjunctions

For example, in a study designed by Anne Treisman and Schmidt, participants were required to view a visual presentation of numbers and shapes in different colors.

[1] In order for an illusory conjunction to occur, the two objects that are not the focus of attention need to be within the visual field.

When objects are outside of attention in order for an illusory conjunction to occur they must be adjacent to each other to combine features.

[6] It has also been found in a few studies on visual illusory conjunctions that two objects that are not the focus of attention are also more likely to be combined when they are adjacent to each other.

[2] Visual illusory conjunctions can occur in long and brief exposure times along with the different levels of attention paid to the objects involved.

This increase in objects creates a prime situation for memory to lapse and form an illusory conjunction.

Most listeners hear this sequence as a single tone that repeatedly changes both in pitch and in location.

[13] It has been suggested that time limitations contribute to this auditory illusory conjunction[12] but see other explanations in terms of separate 'what' and 'where' pathways.

This phenomenon is also more common when only one of the cerebral hemispheres is perceiving and processing the visual and tactile stimuli.