The infant is faced with a barrage of complex information in the world, being conveyed through every sense modality. The infant must isolate streams of information specifying unified objects and events (e.g., object with impact sound, moving face with voice) in order to perceive an organized flow of information. However, research has suggested that information from different modalities may interact with one another to alter perception of an object or event. The objective of this project is to investigate audiovisual interactions in categorization and identify their developmental course. The central hypothesis for the proposed research is that auditory information plays an important role in categorization and that this role is modified during development, based on the extent of the individual's category knowledge. The proposed investigations are significant because they will provide a link between research in intersensory perception and categorization to demonstrate the role of multimodal information in the development of categories. Gender is a natural category that varies along a continuum and has been shown to have a long developmental trajectory that continues well into childhood. Previous research has demonstrated a typicality effect in gender categorization in which more masculine or feminine faces are categorized more accurately and quickly by both adults and children. Infants and adults will be tested to determine if categorization of facial gender can be biased based on the gender of a synchronous voice. The range, and development, of this effect will be tested by varying the typicality of the face which individuals are asked to categorize. Five- and ten-month-old infants will be tested in an infant-controlled habituation procedure in which gender-ambiguous or less typical faces of a single gender are paired with very typical voices and tested with very typical male and female faces. Preference for the opposite gender of the habituation voices indicates that infants categorized the habituation faces based on the gender of the synchronous voices. Adult participants will be asked to identify the gender of a series of gender-ambiguous and less typical faces synchronized with very typical voices. Accuracy and reaction time data will be analyzed for trials in which the gender of face and voice match versus trials in which the gender of face and voice are mismatched. Future research will include investigations of other categories and interactions of other modality combinations.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Small Research Grants (R03)
Project #
1R03HD052602-01
Application #
7076616
Study Section
Pediatrics Subcommittee (CHHD)
Program Officer
Freund, Lisa S
Project Start
2006-04-01
Project End
2008-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
1
Fiscal Year
2006
Total Cost
$69,200
Indirect Cost
Name
Florida International University
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
071298814
City
Miami
State
FL
Country
United States
Zip Code
33199
Bahrick, Lorraine E; Todd, James Torrence; Castellanos, Irina et al. (2016) Enhanced attention to speaking faces versus other event types emerges gradually across infancy. Dev Psychol 52:1705-1720
Vaillant-Molina, Mariana; Bahrick, Lorraine E; Flom, Ross (2013) Young Infants Match Facial and Vocal Emotional Expressions of Other Infants. Infancy 18:
Vaillant-Molina, Mariana; Bahrick, Lorraine E (2012) The role of intersensory redundancy in the emergence of social referencing in 5ýý-month-old infants. Dev Psychol 48:1-9
Bahrick, Lorraine E; Lickliter, Robert; Castellanos, Irina et al. (2010) Increasing task difficulty enhances effects of intersensory redundancy: testing a new prediction of the Intersensory Redundancy Hypothesis. Dev Sci 13:731-7
Flom, Ross; Bahrick, Lorraine E (2010) The effects of intersensory redundancy on attention and memory: infants' long-term memory for orientation in audiovisual events. Dev Psychol 46:428-36
Bahrick, Lorraine E; Newell, Lisa C (2008) Infant discrimination of faces in naturalistic events: actions are more salient than faces. Dev Psychol 44:983-96
Lickliter, Robert; Bahrick, Lorraine E (2007) Thinking About Development: The Value of Animal-Based Research for the Study of Human Development. Eur J Dev Sci 1:172-183