Early television exposure and subsequent attentional problems in children

Article Outline

• References
• Copyright

Christakis DA, Zimmerman FJ, DiGiuseppe DL, McCarty CA. Pediatrics 2004;113:708-13

Context Cross-sectional research has suggested that television viewing may be associated with decreased attention spans in children. However, longitudinal data of early television exposure and subsequent attentional problems have been lacking.

Objective To test the hypothesis that early television exposure (at ages 1 and 3) is associated with attentional problems at age 7.

Design Longitudinal population survey, using data from the National Longitudinal Survey of Youth.

Participants More than 11,000 children of a nationally representative sample.

Main outcome measure The hyperactivity subscale of the Behavioral Problems Index determined on all participants at age 7. Children who were ≥1.2 SD above the mean were classified as having attentional problems. The main predictor was hours of television watched daily at ages 1 and 3 years.

Results Data were available for 1278 children at age 1, and 1345 children at age 3; 10% of children had attentional problems at age 7. In a logistic regression model, hours of television viewed per day at both ages 1 and 3 was associated with attentional problems at age 7 (1.09 [1.03–1.15] and 1.09 [1.02–1.16]), respectively.

Conclusions Early television exposure is associated with attentional problems at age 7. Efforts to limit television viewing in early childhood may be warranted, and additional research is needed.

Comment The provocative findings by Christakis et al are long overdue. The researchers' systematic approach, wide variety of variables, and group size all lend credibility and create a new imperative for follow-up investigations quantifying more specifically the diagnosis of “attentional problem,” potential mechanisms underlying this relationship, and the effects of various types of programming content.

Neuroscience confirms the power of environmental experiences in shaping the developing brain. Repeated exposure to any stimulus in a child's environment may forcibly impact mental and emotional growth, either by activity-induced growth (“wiring by firing”) or by neural pruning of neglected potential (“use it or lose it.”).¹ These shaping processes, affecting structure and function, involve both cellular development and neurotransmitter regulation. Although little developmental research has specifically targeted attention systems, which include interlocking feed-forward and feed-back loops and associated catecholamine neurotransmitters in prefrontal and subcortical areas,² there is every reason to believe that their gradual maturation implies a degree of malleability. Interesting unanswered questions are to what degree catecholamine mechanisms, implicated in stimulus-seeking and addictive behaviors as well as in attention disorders, can be “set” by childhood experiences such as exposure to arousing types of electronic media, or whether insistent noise of television in the home may interfere with the development of “inner speech,” by which a child learns to think through problems and plans and restrain impulsive responding.

Research has clearly demonstrated a genetic component in attention deficit-hyperactivity disorder (ADHD)³; current treatments emphasize well-advertised drugs that purport to normalize catecholamine (dopamine, norepinephrine) function.⁴ Often dramatic improvement is seen on a drug regimen, so writing a prescription is an obvious choice for overscheduled physicians. Yet the contribution of environmental factors to attention disorder has barely been touched by systematic research. This study's indication that an omnipresent environmental agent is associated with ADHD suggests that early preventive efforts should also be emphasized.

A recent survey found that 43% of children aged 2 and younger watch television everyday, and 26% have a television in their bedrooms. The study also showed 68% of children under the age of 2 spend slightly more than 2 hours per day using screen media.⁵

Now that we have an “epidemic” of ADHD, it is indeed time to ask the research questions so ably initiated by Christakis et al and to consider pediatricians' responsibility in educating parents about placing limits on “screen time.”

Back to Article Outline

References 

1. LeDoux J. Synaptic self. New York: Viking/Penguin; 2002;
   • View In Article
2. In:  Solitano MV,  Arnsten AFT,  Castellanos FX editor. Stimulant drugs and ADHD: basic and clinical neuroscience. Oxford (UK): Oxford University Press; 2001;
   • View In Article
3. Barkley RA. Attention-deficit hyperactivity disorder: a handbook for diagnosis and treatment. 2nd ed.. New York (NY): Guilford; 1998;
   • View In Article
4. ADHD and executive functions: impact of age, gender, and new treatment options. Seminar sponsored by Eli Lilly and Co. Presented at the 111th Annual Convention of the American Psychological Association, August 9, 2003, Toronto, Ontario, Canada.
   • View In Article
5. Rideout VJ, Vandewater EA, Wartella EA. Zero to six: electronic media in the lives of infants, toddlers, and preschoolers. Publication no. 3378. Menlo Park (CA): Kaiser Family Foundation; 2003;
   • View In Article