Abstract: Visual images scanning paradigm had been regarded as an effective approach to explore the structural and functional properties of mental imagery. However, the role of reference frames (RF) as well as the control processes in images scanning had not been studied. On the other hand, the mechanism of executive control had been the focus of research in perception and attention, whereas not being investigated in visual images processing. Griffin & Nobre (2003) revealed the similarity between attention to outer space and attention to mental representation. Based on these studies, the purpose of the present study was to explore the mechanism of control process that resolve conflicts among various reference frames in images scanning. Theoretically, the study also aimed at extending Visual Images Processing Subsystems Model established by Kosslyn (1994).
Eighty undergraduates, from 17 to 23 years old, attended four experiments respectively. All participants didn’t know the purpose of the experiment and had normal or corrected-to-normal vision. Stimuli were made by using Photoshop 6.0 software. Stimulus presentation and data collection were controlled by a Lenovo microcomputer running E-prime software. The images scanning process cued by arrows or Chinese characters were compared in Experiment 1. In Experiment 2, conceptual RF was dissociated from environmental RF in order to see how it interacted with and whether it had priorities over other RFs. A new conflict among various RFs was induced by rotating the Chinese characters’ intrinsic RF with conceptual RF and the mechanism of resolving this RF conflict was explored in experiment 3.
The results revealed that (1) reference axis effect appeared when cued by Chinese characters, but not when cued by arrows. This suggested that different spatial relationships between cue and target were computed. (2) During the process of conceptual control in visual images scanning, conceptual RF, environmental RF and Chinese characters’ intrinsic RF were activated simultaneously, and they conflicted with each other. To deal with these conflicts, different cognitive costs were needed. (3) Conceptual RF always had priority over the other RFs. This suggested that human cognitive system can exert voluntary control on visual images processing. This voluntary control reflected a kind of executive function.

Key words: visual images scanning, conflicting reference frames, conceptual control, executive control