Face and object recognition
Saturday, October 01st, 2011 [17:20 - 19:20]
PS_2.020 - Perceiving faces with different kinds of glasses: Distinctiveness, beauty and intelligence
Forster, M. , Leder, H. & Gerger, G.
Faculty of Psychology. University of Vienna. Vienna, Austria.
Faces are very important objects in our visual environment. The eye region - with its importance for a person’s identity, gaze direction, and emotional expression - plays a crucial role in many face-related tasks. Functionally, the eyes are the entry points for visual information processing. However, over a lifetime they lose their effectiveness. This is often corrected by means of eyeglasses. Therefore, beyond physiognomic changes over time, such accessories influence facial appearance in everyday face perception. In a series of experiments, we studied perception and appreciation of faces with and without glasses. We found some data in accordance with the stereotype that glasses make wearers look more intelligent but less attractive. Comparing glasses with and without rims the difference in the amount of area in the face covered by rims affects face perception, recognition, distinctiveness, and the assignment of stereotypes. Moreover, when we measured eye movements, glasses on the face generally directed gaze to the eye regions. Thus, glasses affect how we perceive faces, and in accordance with the old stereotype, they can decrease attractiveness but increase perceived intelligence and trustworthiness. These effects depend on the kind of glasses, probably due to amount they conceal areas of the eye region.
PS_2.021 - Categorical perception of face is mediated by the compression effect
Suegami, T. 1 & Michimata, C. 2
1 University of Oslo
2 Sophia University
Categorical perception (better discrimination for the cross-category stimuli relative to the within-category) is observed in face recognition (e.g., Beale & Keil, 1995). There are two possible mechanisms: The one is an expansion effect, in which the discrimination for the cross-category stimuli is intensified. The other is a compression effect, in which the discrimination for the within-category stimuli is attenuated. We examined which mechanism underlies the categorical perception of face by successive 3 experiments. Eleven participants learned to classify 17 successive morphed faces into two categories, and then they rated how each stimulus represented its category. Finally, they performed the face discrimination task. Another 11 participants performed only the discrimination task without learning and rating task, as a control. The results for the rating task revealed the boundary and the prototypes of the two categories. The results for the discrimination task showed that the accuracy for the cross-category discrimination was higher than the within-category discrimination in the category learner group. Such a categorical perception was not obtained in the control group. The accuracy for within-category discrimination, moreover, was lower in the category learner group than the control group, suggesting that the categorical perception of face is mediated the compression effect.
PS_2.022 - Inversion effect of “old” vs “new” faces, face-like objects, and objects in a healthy student sample
Sierro, G. 1 , Mohr, C. 1 , Hadjikhani, N. 2, 3 & Brandner, C. 1
1 Laboratory for Experimental Study of Behavior. Université de Lausanne. Lausanne, Switzerland.
2 Brain Mind Institute. École Polytechnique Fédérale de Lausanne. Lausanne, Switzerland.
3 Martinos Center for Biomedical Imaging. Harvard Medical School. Boston, USA
Processing of social stimuli seems impaired in conditions such as autism and schizophrenia. In autism, a bias for local information has been described, while apophenia might explain faulty interpretations in schizophrenia. To test such impaired social processing, the use of face stimuli has been popular. Based on previous findings, we suggest that such processing biases should be established with face-like stimuli lying between faces and objects stimuli. To assess face-like stimuli processing, we here evaluated in 48 healthy participants whether configural processing performance for face-like stimuli would lie between the one for faces and objects in a recognition task with inversion. After a first encoding block, participants made old-new judgments on upright or inverted “old” and “new” stimuli, randomly intermixed in a second block. Accuracy and reaction time analyses yielded the commonly observed face inversion effect. Despite no inversion effect for face-like stimuli, overall performance was lying between the ones for faces and objects. Also, reaction times were comparable for inverted faces and both inverted and upright face-like stimuli. These results indicate that face-like stimuli might be a promising stimulus type to assess local and configural processing biases, in particular when autistic and schizophrenic pathological or personality dimensions are considered.
PS_2.024 - Perceptual completion facilitates object-based feature binding for two features from the same dimension
Davies, S. 1 , Walker, P. 2 & Ziessler, M. 1
1 Psychology Department, Liverpool Hope University, Liverpool, UK.
2 Department of Psychology, Lancaster University, Lancaster, UK.
Previous research suggests that binding between features from different dimensions supports the view that representations in visual short-term memory (VSTM) can be object-based. An alternative account to object-based storage is independent feature-based modules. To test for this previous research used bi-coloured objects in a VSTM task and observed object-based binding. These results have not successfully been replicated. To further explore the possibility of object-based within-dimension feature binding in VSTM, two change detection experiments are reported. These involved memory for either two pairs of coloured squares abutting one another (forming single bi-coloured objects) or two pairs of coloured squares separated by a small gap. Using these stimuli the first experiment saw no object-based benefit for bi-coloured objects. The second experiment used the same stimuli with the exception that all displays were partially covered by an occluding surface with holes through which surface colours could be seen. Same-object benefits were observed when perceptual completion was possible, demonstrating object-based feature binding for features from the same dimension. The role of perceptual completion as an object-based mechanism is discussed, as is the nature of object-based representations in VSTM.