Familiarity breeds distortion: the effects of media exposure on false reports concerning media coverage of the terrorist attacks in London on 7 July 2005

The present experiment investigated whether increased media exposure could lead to an increase in memory distortions regarding a traumatic public event: the explosion of the No. 30 bus in Tavistock Square, London on 7 July 2005. A total of 150 Swedish and 150 UK participants completed a series of questionnaires about their memory of either (i) the aftermath of the explosion, (ii) a non-existent computerised reconstruction of the moment of the explosion, or (iii) non-existent closed circuit television footage of the moment of the explosion. In line with the availability heuristic, UK participants were more likely than Swedish participants to claim to have seen all three types of footage. Furthermore, a sub-sample of UK participants who appeared to have developed false “memories” of seeing the No. 30 bus explode scored significantly higher on measures of dissociation and fantasy proneness than participants who did not develop false “memories”. This experiment provides further support for the role of imaginative processes in the development of false memories.