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How category structure influences the perception of object similarity: the atypicality bias.

Tanaka JW, Kantner J, Bartlett M - Front Psychol (2012)

Bottom Line: If similarity judgments are guided purely by their physical properties, the morph should be perceived to be equally similar to its typical parent as its atypical parent.In this framework, atypical stimuli are located in a sparser region of the space where there is less competition for recognition and therefore, these representations capture a broader range of inputs.These results suggest that the perceived likeness of an object is influenced by the organization of surrounding exemplars in the category space.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Victoria Victoria, BC, Canada.

ABSTRACT
Why do some faces appear more similar than others? Beyond structural factors, we speculate that similarity is governed by the organization of faces located in a multi-dimensional face space. To test this hypothesis, we morphed a typical face with an atypical face. If similarity judgments are guided purely by their physical properties, the morph should be perceived to be equally similar to its typical parent as its atypical parent. However, contrary to the structural prediction, our results showed that the morph face was perceived to be more similar to the atypical face than the typical face. Our empirical studies show that the atypicality bias is not limited to faces, but extends to other object categories (birds) whose members share common shape properties. We also demonstrate atypicality bias is malleable and can change subject to category learning and experience. Collectively, the empirical evidence indicates that perceptions of face and object similarity are affected by the distribution of stimuli in a face or object space. In this framework, atypical stimuli are located in a sparser region of the space where there is less competition for recognition and therefore, these representations capture a broader range of inputs. In contrast, typical stimuli are located in a denser region of category space where there is increased competition for recognition and hence, these representation draw a more restricted range of face inputs. These results suggest that the perceived likeness of an object is influenced by the organization of surrounding exemplars in the category space.

No MeSH data available.


Related in: MedlinePlus

Examples of birds and car exemplars rated high or low in typicality and their 50/50 morphs used in Tanaka and Corneille (2007) study.
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Figure 5: Examples of birds and car exemplars rated high or low in typicality and their 50/50 morphs used in Tanaka and Corneille (2007) study.

Mentions: To assess the structure of non-face object spaces, typicality ratings were collected for the car and bird exemplars to determine the typical and atypical members of these categories. The typical and atypical exemplars were then morphed together (see Figure 5). A naive group of participants judged whether the morphed object more closely resembled the atypical object parent or the typical object parent. The prediction was that if the typicality effect is special to faces, participants should be just as likely to judge the bird or automobile morph more similar to its typical or atypical parent. On the other hand, if the perception of objects, like faces, is influenced by structural typicality, participants should demonstrate an atypicality bias for the birds and automobiles. Tanaka and Corneille, 2007, Experiment 3) found a significant atypicality bias for both birds (66%) and cars (58%), extending the phenomenon to non-face objects. These findings indicate that the notion of a similarity space applies to birds and cars (and, presumably, to many other object classes beyond faces) and suggests that the attractor field model is applicable to non-face object classes in which a given exemplar may be placed along a continuum of typicality.


How category structure influences the perception of object similarity: the atypicality bias.

Tanaka JW, Kantner J, Bartlett M - Front Psychol (2012)

Examples of birds and car exemplars rated high or low in typicality and their 50/50 morphs used in Tanaka and Corneille (2007) study.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368386&req=5

Figure 5: Examples of birds and car exemplars rated high or low in typicality and their 50/50 morphs used in Tanaka and Corneille (2007) study.
Mentions: To assess the structure of non-face object spaces, typicality ratings were collected for the car and bird exemplars to determine the typical and atypical members of these categories. The typical and atypical exemplars were then morphed together (see Figure 5). A naive group of participants judged whether the morphed object more closely resembled the atypical object parent or the typical object parent. The prediction was that if the typicality effect is special to faces, participants should be just as likely to judge the bird or automobile morph more similar to its typical or atypical parent. On the other hand, if the perception of objects, like faces, is influenced by structural typicality, participants should demonstrate an atypicality bias for the birds and automobiles. Tanaka and Corneille, 2007, Experiment 3) found a significant atypicality bias for both birds (66%) and cars (58%), extending the phenomenon to non-face objects. These findings indicate that the notion of a similarity space applies to birds and cars (and, presumably, to many other object classes beyond faces) and suggests that the attractor field model is applicable to non-face object classes in which a given exemplar may be placed along a continuum of typicality.

Bottom Line: If similarity judgments are guided purely by their physical properties, the morph should be perceived to be equally similar to its typical parent as its atypical parent.In this framework, atypical stimuli are located in a sparser region of the space where there is less competition for recognition and therefore, these representations capture a broader range of inputs.These results suggest that the perceived likeness of an object is influenced by the organization of surrounding exemplars in the category space.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Victoria Victoria, BC, Canada.

ABSTRACT
Why do some faces appear more similar than others? Beyond structural factors, we speculate that similarity is governed by the organization of faces located in a multi-dimensional face space. To test this hypothesis, we morphed a typical face with an atypical face. If similarity judgments are guided purely by their physical properties, the morph should be perceived to be equally similar to its typical parent as its atypical parent. However, contrary to the structural prediction, our results showed that the morph face was perceived to be more similar to the atypical face than the typical face. Our empirical studies show that the atypicality bias is not limited to faces, but extends to other object categories (birds) whose members share common shape properties. We also demonstrate atypicality bias is malleable and can change subject to category learning and experience. Collectively, the empirical evidence indicates that perceptions of face and object similarity are affected by the distribution of stimuli in a face or object space. In this framework, atypical stimuli are located in a sparser region of the space where there is less competition for recognition and therefore, these representations capture a broader range of inputs. In contrast, typical stimuli are located in a denser region of category space where there is increased competition for recognition and hence, these representation draw a more restricted range of face inputs. These results suggest that the perceived likeness of an object is influenced by the organization of surrounding exemplars in the category space.

No MeSH data available.


Related in: MedlinePlus