English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Perception of Dynamic Facial Expressions Probed by a New High-Level After-Effect

Curio, C., Giese, M., Breidt, M., Kleiner, M., & Bülthoff, H. (2007). Perception of Dynamic Facial Expressions Probed by a New High-Level After-Effect. Poster presented at 10th Tübinger Wahrnehmungskonferenz (TWK 2007), Tübingen, Germany.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/11858/00-001M-0000-0013-CD03-6 Version Permalink: http://hdl.handle.net/21.11116/0000-0003-FFE2-F
Genre: Poster

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Curio, C1, 2, 3, Author              
Giese, MA, Author              
Breidt, M1, 2, 3, Author              
Kleiner, M1, 2, 3, Author              
Bülthoff, HH1, 2, Author              
Affiliations:
1Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497797              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497794              
3Project group: Cognitive Engineering, Max Planck Institute for Biological Cybernetics, Max Planck Society, Spemannstrasse 38, 72076 Tübingen, DE, ou_2528702              

Content

show
hide
Free keywords: -
 Abstract: High-level after-effects have been reported for the recognition of static faces [1,2]. It has been shown that the presentation of static ‘anti-faces’ biases the perception of neutral test faces temporarily towards the perception of specific identities. Recent studies have demonstrated high-level after-effects also for point-light walkers, resulting in shifts of perceived gender [3,4]. We present an experiment showing for the first time high-level after-effects in the recognition of dynamic facial expressions. Facial expressions were generated as a morph animation based on a weighted sum of 3D shapes derived from scans of facial action units [5]. With this technique we were able to define a metric space of dynamic expressions by morphing, similar to face spaces for static stimuli. Morphing between prototypical expressions (happy and disgust) and a neutral face without intrinsic facial motion we generated ‘anti-expressions’ by choosing negative weights for the prototypes. In addition, for testing we generated expressions with reduced recognizability choosing small positive weights of the prototypes. The morphing space was equilibrated for recognizability by measuring the psychometric functions that map the morphing weights on the recognition rates of the two expressions (happy and disgust) in a 2 AFC task. Only the non-rigid intrinsic face motion was morphed. In addition, a meaningless 3D head motion was added in order to minimize the influence of low-level adaptation effects. Subjects were adapted for 8s with 5 repetitions of the anti-expressions. They were tested with happy and disgust expressions with reduced expression strength. Adaptation stimuli were simulated with 2 facial identities and were shown either in forward or reverse time order. We found strong expression-related after-effects (increased and decreased recognition for matching and non-matching expression, respectively, p < 0.05, N=13). We investigated the influence of static vs. dynamic representations in the observed after-effect. The temporal order of the adapting stimuli does not have a significant influence on the strength of the observed after-effect. The analysis of the 2D optic flow patterns of adaptation and test stimuli rules out the possibility that the observed after-effects reflect classical low-level motion after effects. Instead, the results seem compatible with the adaptation of neural representations of ‘snapshot keyframes’ [6] that arise during the presentation of dynamic facial expressions.

Details

show
hide
Language(s):
 Dates: 2007-07
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: BibTex Citekey: 4884
 Degree: -

Event

show
hide
Title: 10th Tübinger Wahrnehmungskonferenz (TWK 2007)
Place of Event: Tübingen, Germany
Start-/End Date: 2007-07-27 - 2007-07-29

Legal Case

show

Project information

show

Source 1

show
hide
Title: 10th Tübinger Perception Conference: TWK 2007
Source Genre: Proceedings
 Creator(s):
Bülthoff, HH1, 2, Editor            
Chatziastros, A1, 2, Editor            
Mallot, HA, Editor            
Ulrich, R, Editor
Affiliations:
1 Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497797            
2 Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497794            
Publ. Info: Kirchentellinsfurt, Germany : Knirsch
Pages: - Volume / Issue: - Sequence Number: - Start / End Page: 111 Identifier: ISBN: 3-927091-77-4