Let's say that we have a set of shapes. They can be grouped according to the different Gestalt laws of grouping. However, different Gestalt principles will divide the set into different groups, e.g. grouping by proximity will give us A,B,C | D,E,F, and grouping by similarity will give us A,B,D,F | C, E.
Is it possible to predict which laws would gain precedence over the others? What's the "order of processing" of the different visual properties?
I am not sure whether there is a hierarchy as such but there is the concept of Global vs Local Precedence. Global precedence can be seen to be closely related to the Gestalt principles of grouping (particularly the principle of similarity) in that the global whole is a grouping of proximal and similar objects.
Global precedence was first studied using Navon figures (Navon, 1977), where many small letters are arranged to form a larger letter that either does or does not match.
Do we perceive a visual scene feature-by-feature? Or is the process instantaneous and simultaneous as some Gestalt psychologists believed? Or is it somewhere in between? (Navon, 1977 p. 353)
Variations of the original Navon figures include both shapes and objects (Poirel, et al. 2008).
In general, reaction time for identifying the larger letter is faster than for the smaller letters that make up the shape (Navon, 1977). Navon directed participants to focus either globally (to the overall shape of the letter formed out of the smaller letters) or locally (to the small letters making up the overall shape of a letter) that were consistent, neutral, or conflicting on the global and local levels.
| Consistent | Neutral | Conflicting |
|---|---|---|
| TTTTTTTTTTTT TTTTTTTTTTTT TTTT TTTT TTTT TTTT TTTT |
++++++++++++ ++++++++++++ ++++ ++++ ++++ ++++ ++++ |
SSSSSSSSSSSS SSSSSSSSSSSS SSSS SSSS SSSS SSSS SSSS |
In general, reaction time for identifying the larger letter (global) is faster than for the smaller letters that make up the shape (local), showing global precedence.
However, global precedence is not a universal phenomenon (Davidoff, et al. 2008). As well as Davidoff's study, Poirel, et al. (2008) found that experiments like this depend on whether the stimuli are either meaningful or meaningless. For example, letters and familiar objects, like a cup, are meaningful, while unidentifiable and non-geometric shapes are not. In both types of stimuli, the global advantage is observed, but the global interference effect only occurs with meaningful stimuli.
Plus, when presented with a Navon figure, there is a slight local preference for Caucasians, but East Asians show an obvious global preference and are faster and more accurate at global processing (McKone, et al. 2010).
The Navon figure has been used in relating theories regarding processing to assessing cognitive learning disabilities. People who are diagnosed with Obsessive-compulsive personality disorder (OCPD) are prone to be distracted by the local aspects of stimuli when asked to identify global aspects of the Navon figure (Yovel, et al. 2005). In general, autistic children demonstrate much weaker global precedence than those without the disorder (Gross, 2005).
Davidoff, J., Fonteneau, E., & Fagot, J. (2008). Local and global processing: Observations from a remote culture. Cognition, 108(3), 702-709. https://doi.org/10.1016/j.cognition.2008.06.004
Gross, T.F. (2005). Global-Local Precedence in the Perception of Facial Age and Emotional Expression by Children with Autism and other Developmental Disabilities. Journal of Autism and Developmental Disorders. 35(6): 773–785 https://doi.org/10.1007%2Fs10803-005-0023-8
McKone, E., Davies, A. A., Fernando, D., Aalders, R., Leung, H., Wickramariyaratne, T., & Platow, M. J. (2010). Asia has the global advantage: Race and visual attention. Vision research, 50(16), 1540-1549. https://doi.org/10.1016/j.visres.2010.05.010
Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive psychology, 9(3), 353-383. https://doi.org/10.1016/0010-0285(77)90012-3
Poirel, N., Pineau, A., & Mellet, E. (2008). What does the nature of the stimuli tell us about the Global Precedence Effect?. Acta psychologica, 127(1), 1-11. https://doi.org/10.1016/j.actpsy.2006.12.001
Yovel, I., Revelle, W., & Mineka, S. (2005). Who Sees Trees before Forest? The Obsessive-Compulsive Style of Visual Attention. Psychological Science. 16(2): 123–129. https://doi.org/10.1111%2Fj.0956-7976.2005.00792.x
