Perception & Experience Lab
Research
How experience changes our object representations
Different brain activity patterns have been observed for different categories of objects. The origins of this category selectivity in the object recognition has been a long-standing question. While past studies have shown that experience can change brain responses to objects, it is unknown whether patterns of selectivity for different categories are a result of different types of experience involved. We trained two groups of participants to perform subordinate-level individuation and basic-level categorization respectively with the same set of novel, artificial objects. While local activity increased in the fusiform gyrus after individuation training, categorization training resulted in a wide-spread change in the object processing cortex, with an increased emphasis on the medial relative to the lateral regions. Results provide support for the role of experience in deterining selectivity patterns for different categories in the object recognition system.
Representative papers:
Wong, A.C.-N., Palmeri, T.J., & Gauthier, I. (2009). Conditions
for face-like expertise with objects: Becoming a Ziggerin expert –
but which type? Psychological Science, 20(9), 1108-1117.
Wong, A.C.-N., Palmeri, T.J., Rogers, B.P., Gore, J.C., & Gauthier, I. (2009). Beyond Shape: How You Learn about Objects Affects How They Are Represented in Visual Cortex. PLoS ONE, 4(12), e8405.
Almost no one would disagree that there is something special about face perception. Compared with most other object categories, face perception is highly efficient, and sophisticated as faces contain rich information about one's identity, gender, race, emotional state, intention, etc. Faces also seem to be processed in a unique way. For example, one tends to take all features and their spatial configurations into consideration and find it difficult to selectively attend to a single features. What people debate about face perception is what makes face perception special. In recent years a number of laboratory training studies have shown that hours of experience with discriminating novel, artificial objects can result in behavioral phenomena and brain activity similar to those found for face perception. By comparing multiple training regimens in a single study, we have gone a step further to show that not all types of experience would lead to face-like expertise. Training that requires subordinate-level identification seems to be the key for producing expertise markers similar to face perception. Other studies about face perception include the perceptual nature of holistic face processing, and the neural basis of the own-race advantage.
Representative papers:
Wong, A.C.-N., Palmeri, T.J., & Gauthier, I. (2009). Conditions
for face-like expertise with objects: Becoming a Ziggerin expert –
but which type? Psychological Science, 20(9), 1108-1117.
Richler, J.J., Cheung, O.S., Wong, A.C.-N., Gauthier, I. (2009). Does response interference contribute to face composite effects? Psychonomic Bulletin and Review, 16(2), 258-263.
Expertise in character perception across writing systems
Apart from faces we also develop expertise with other categories of objects. Letter and character perception is a good example as most of us viewing this website are frequent readers. One question is whether face and letter perception belong to the same type of expertise. Our behavioral and fMRI work show that letter perception is associated with different computational demands, behavioral phenomena, and neural selectivity patterns compared with face perception. Recent evidences further suggest that characters across languages with drastically different linguistic properties (e.g., English and Chinese) may share similar shape processing resources. The implication is that experience may play a role in selecting the brain substrates best suited to the processing demands associated with a certain object category.
Representative papers:
Wong, A.C.-N., Bukach, C.M., Yuen, C., Yang, L., Leung, S., & Greenspon,
E. (2011). Holistic processing of words modulated by reading experience.
PLoS ONE, 6(6): e20753.
Wong, A.C.-N., Jobard, G., James, T. W., James, K. H., & Gauthier, I. (2009). Expertise with characters in alphabetic and non-alphabetic writing systems engage the same occipito-temporal area. Cognitive Neuropsychology, 26(1), 111-127.
Wong, A.C.-N., & Gauthier, I. (2007). An analysis of letter expertise in a levels-of-categorization framework. Visual Cognition, 15(7), 854-879.
Wong, A.C.-N., Gauthier, I., Woroch, B., Debuse, C., & Curran, T. (2005). An early electrophysiological potential associated with expertise in letter perception. Cognitive, Affective, and Behavioral Neuroscience, 5(4), 306-318.
Object recognition across views
Object recognition is highly efficient across changes in viewing conditions in terms of size, location, viewpoint, etc. There are theories about the mechanisms under which experience with a limited number of viewpoints contibutes to successful recognition of an object across novel viewpoints. Yet the empirical experience in support of such theories are inconclusive. We used novel objects and exposed participants to either one or two viewpoints and then measured subsequent recognition performance at studied and novel views in a better controlled way compared with previous studies. Our results show that the advantage gained from the study of multiple views is more than the generalization from each of the studied views presented alone, and occurred only for interpolated views (i.e., novel views within the range spanned by the studied views). Our findings also suggest that the similarity between the novel and studied views is the key determinant of the degree of generalization. These findings provide more conclusive support to existing theories of view generalization.
Representative papers:
Wong, A.C.-N., & Hayward, W.G. (2005). Constraints on view combination:
Effects of self-occlusion and difference between familiar views. Journal
of Experimental Psychology: Human Perception & Performance, 31,
110-121.
Hayward, W.G., Wong, A.C.-N., & Spehar, B. (2005). When are viewpoint costs greater for silhouettes than for shaded images? Psychonomic Bulletin & Review, 12, 321-327.
Other topics being explored
> Expertise in music processing
> Perception and emotion
> Using knowledge about perception in education
> Statistical learning
> Attention and training
> Multisensory learning
Contact Us
362A Sino Building
Department of Psychology
The Chinese University of Hong Kong
Shatin, N.T., Hong Kong
Tel: (852) 3943 6505
Fax: (852) 2603 5019
Email: alancnwong et gmail.com