The table-top visual search ability test for children and young people: normative response time data from typically developing children.

Five real-world tasks were developed to test the visual search ability of children and young people, and detect potential deficits in visual search ability. Each task involved searching for a set of target objects among distracting objects on a table-top. Performance on the Table-top Visual Search Ability Test for Children (TVSAT-C) was measured as the time spent searching for targets divided by the number of targets found. 108 typically developing children (3-11 years old) and 8 children with vision impairment (7-12 years old) participated in the study. A significant correlation was found between log-transformed age and log-transformed performance (R^2=0.65, p=4×10^-26) in our normative sample, indicating a monomial power law relationship between age and performance with an exponent of -1.67, 95% CI [-1.90,-1.43]. We calculated age-dependent percentiles and used the 5th percentile as a cut-off for detecting a visual search deficit, giving a specificity of 92.6%, 95% CI [86.1%,96.2%] and sensitivity of 87.5%, 95% CI [52.9%,97.8%] for the test. Further studies are required to calculate measures of reliability and external validity. We have made the protocol and age-dependent normative data available for those interested in using the test in research or practice, and to illustrate the smooth developmental trajectory of visual search ability during childhood.