Environmental Context Influences Visual Attention to Responsible Drinking Messages.

Aims: Responsible drinking messages (RDMs) are used as a key tool to reduce alcohol-related harms. A common form of RDM is in a poster format displayed in places such as bars, bus stops and toilet cubicles. However, evidence for the effectiveness of RDMs remains limited.

Ensemble representations: effects of set size and item heterogeneity on average size perception.

Observers can accurately perceive and evaluate the statistical properties of a set of objects, forming what is now known as an ensemble representation. The accuracy and speed with which people can judge the mean size of a set of objects have led to the proposal that ensemble representations of average size can be computed in parallel when attention is distributed across the display. Consistent with this idea, judgments of mean size show little or no decrement in accuracy when the number of objects in the set increases.

Priming by the mean representation of a set.

Recent evidence suggests that sets of similar objects can be represented in terms of their statistical parameters, such as mean size. Observers are more likely to indicate that a probe item was part of a previously presented set of items when the probe has the same size as the mean size of the set than when it has the same size as one of the set members (e.g.

Attention modulates set representation by statistical properties.

Recent reports have claimed that observers show accurate knowledge of the mean size of a group of similar objects, a finding that has been interpreted to suggest that sets of multiple objects are represented in terms of their statistical properties, such as mean size (Ariely, 2001; Chong & Treisman, 2003, 2005a, 2005b). In the present study, we directed visual attention to a single set member and found that mean estimations were modulated according to the size of the attended item, regardless of whether size was the relevant search criterion (Experiment 1) or not (Experiment 2). These findings suggest that observers do not always accurately average together the entire set, and that instead the average is either biased by the features of the attended item, or based on a short-cut strategy of extracting the mean of a smaller subset.