Abstract
In the Inattentional Blindness (IB) paradigm, observers, performing an attentionally demanding task, fail to see (or, at least to report) a highly salient stimulus. IB can be modulated by many factors, such as task difficulty, the similarity of the IB stimulus and the primary task stimuli, the spatial proximity of the IB stimulus and the primary task, and more. Factors related to the observers have an impact too (e.g. individual differences, attentional set variations, observer’s interests, etc.). A modest number of studies have also suggested that children and older adults are more prone to IB. In the present study, we revisit the effect of age on IB, using a demanding but child-friendly hybrid-foraging task. In our task, observers memorized seven different images of stuffed animals. They had to collect instances of those targets in a videogame-like task where about 120 animals moved around on the screen. After a few minutes, a cartoon gorilla, much larger than any other stimuli, appeared for about 16 seconds, crossing the screen from right to left. We tested five age groups: 5-6-year-old children, 11-12-year-old children, young adults (18 to 30-years-old), middle-aged adults (31 to 59-years-old) and older adults (over 60-years-old). When observers were subsequently asked about the appearance of the unexpected stimulus, over 85% of children reported having seen the gorilla, followed by about 75% of young adults, 50% of middle-aged adults, and only 20% of older adults. In this setting, it is the children who were least susceptible to IB, and older adults the most, with proportions in between for young and middle age adults. This may reflect differences in the degree to which a gorilla was “unexpected” at different ages, and/or how task-related and observer-related factors impact susceptibility to inattentional blindness.