The Times had this article the other day discussing whether TV is good for preschool-age kids. It's not all that interesting, but this bit near the end caught my attention:
Developmental psychologists say the Vanderbilt research offers an intriguing clue to a phenomenon called the "video deficit." Toddlers who have no trouble understanding a task demonstrated in real life often stumble when the same task is shown onscreen. They need repeated viewings to figure it out. This deficit got its name in a 2005 article by Daniel R. Anderson and Tiffany A. Pempek, psychologists at the University of Massachusetts, who reviewed literature on young children and television.
But psychologists still want to get to the bottom of what might explain the difference. Is it the two-dimensionality of the screen? Do young children have some innate difficulty in remembering information transmitted as symbols?
The paper linked in an article is a broad review of early childhood TV viewing, and isn't all that helpful, although it gives about 2 pages of review on the topic. Interestingly, the "video deficit" includes aspects of language learning:
A third line of research is concerned with language learning. Children 2 years and older can clearly learn vocabulary from television (Naigles & Kako,1993; Rice, Huston, Truglio, & Wright, 1990;Rice & Woodsmall, 1988). Nevertheless, when comparisons are made between video and equivalent live conditions in children younger than 2 1/2years, the results suggest a video deficit. Grela, Lin,
and Krcmar (2003) tried to teach object labels either live, in an equivalent video, or in a version of Teletubbies that used the labels. They found better learning in the live as compared to video conditions. Learning from video by children near their 2nd birthday was substantially better than that by younger children.
Infants are able to perceive many phonetic contrasts that are not found in their native language; this ability is lost by about 12 months of age if infants are not exposed to other languages. Kuhl, Tsao, and Liu (2003) exposed American infants to contrasts found in Mandarin. One group of infants was exposed to live speakers of Mandarin for about 5 hours during 12 sessions between 9 and 10 months of age. Other groups were exposed to equivalent audiovisual or audio-only DVDs. The infants exposed to live speakers did not experience the loss of ability to perceive Mandarin contrasts. Infants exposed to the DVD stimuli, however, showed the same loss as infants exposed to no Mandarin at all. Again, this research indicates a profound video (and audio) deficit (Anderson and Pempek 2005:513).
This paper by Georgene Troseth and colleagues delves into the problem:
Young Children's Use of Video as a Source of Socially Relevant Information
Although prior research clearly shows that toddlers have difficulty learning from video, the basis for their difficulty is unknown. In the 2 current experiments, the effect of social feedback on 2-year-olds' use of information from video was assessed. Children who were told "face to face" where to find a hidden toy typically found it, but children who were given the same information by a person on video did not. Children who engaged in a 5-min contingent interaction with a person (including social cues and personal references) through closed-circuit video before the hiding task used information provided to find the toy. These findings have important implications for educational television and use of video stimuli in laboratory-based research with young children.
These researchers frame the issue in terms of the strategies children use to identify socially relevant information:
By the time they reach their second birthday, toddlers have figured out that a prime source of information is other people. They are attuned to socially relevant information: information that is presented by a social partner and accompanied by appropriate cues indicating a shared focus on an aspect of the environment. For instance, numerous studies demonstrate that 2-year-olds are skilled users of a range of social cues for word-learning purposes, including eye gaze, gesture, discourse novelty, and emotional outbursts (see Baldwin & Tomasello, 1998, for a review). Young children's skill at obtaining information from social others may rest in part on their attention to features common to animate agents -- such as the potential for contingent movement and the presence of faces (e.g., Johnson, Booth, & O'Hearn, 2001; Johnson, Slaughter, & Carey, 1998; Shimizu & Johnson, 2004). It is possible that the presence of such features is a precondition for toddlers to use others as potential sources of information. This may be one factor underlying the video deficit in toddlers: in the absence of contingent interaction, they usually fail to regard people on TV as viable information sources. In the current study, when contingent interaction was lacking, children failed to use identical verbal information to solve a problem.
The connection to the ways that children learn to use and respond to explicitly social cues and situations is important. Social interactions are two-way, and that modality is a fundamental part of human reality. Two-way interactions really can't be modeled well by television. But in contrast, three-way interactions are modeled very well by TV. Any program that shows two individuals interacting with each other is fundamentally a three-way interaction, since it implicates the viewer as a third party.
Understanding three-way interactions may be well above the cognitive skills of toddlers. Seeing the relationship between two other individuals is a three-way interaction. Three-way interactions are more difficult for an additional reason -- there are vastly more of them in any social group. With two-way interactions, the total number accessible to any individual is simply the number of individuals in the group, minus the focal individual herself. In other words, it scales linearly with group size. But with three-way interactions, the total possible number of interactions in a group is combinatorial.
Now it is interesting that language learning has been grafted into human development at a time when these kinds of social learning are still being worked out. Plausibly, it reflects the fact that language helps people to organize those more numerous and more complex three-way interactions.
Anderson DR, Pempek TA. 2005. Television and very young children. American Behavioral Scientist 48:505-522. Abstract
Troseth GL, Saylor MM, Archer AH. 2006. Young children's use of video as a source of socially relevant information. Child Development 77:786. DOI link