A new study provides more support for the idea that cognitive decline in older adults is a product of a growing inability to ignore distractions. Moreover, the study, involving 21 older adults (60-80) shown random sequences of pictures containing faces and scenes and asked to remember only the scene or the face, reveals that being given forewarning about which specific pictures would be relevant (say the second, or the fourth) did not help. The findings suggest that the failure to suppress irrelevant information is not due to a failure in quickly assessing what is relevant, but is a related to mechanisms that occur early in the visual processing stream.
(2010). Predictive knowledge of stimulus relevance does not influence top-down suppression of irrelevant information in older adults.
Cortex. 46(4), 564 - 574.