Expectation creates something out of nothing: The role of attention in iconic memory reconsidered.
Consciousness and cognition August 1, 2017 Peer reviewed DOI: 10.1016/j.concog.2017.06.017 via PubMed
Summary
Conscious experience is influenced by attention and expectation, but some theories claim it can be independent of attention. In iconic memory experiments, diverting attention caused participants to fail to notice missing letters and even perceive illusory letters. Expectation created illusory content that replaced valid iconic memory content. These findings suggest the experimental paradigm cannot support claims about iconic memory content.
Study at a glance
| Design | experimental study |
|---|---|
| Key finding | When attention is diverted, participants fail to see the absence of letters and perceive illusory letters, indicating expectation creates illusory content that overwrites valid iconic memory content. |
Abstract
Conscious experience is modulated by attention and expectation, yet is believed to be independent of attention. The experiments on iconic memory (IM) are usually taken as support for this claim. However, a recent experiment demonstrated that when attention is diverted away from the IM letter display subjects fail to see the absence of IM letters. Here we contribute to the ongoing debate by overcoming experimental shortcomings of this previous experiment, by measuring subjective visibility and by testing the effect of the post-cue. We were able to replicate these earlier findings and extend them by demonstrating that subjects who do not realize the absence of letters perceive illusory letters. This result means that there is still phenomenal consciousness, even when attention is diverted. Expectation creates illusory content that overwrites valid IM content. Taken together these findings suggest that the present experimental paradigm is not appropriate to make claims about IM content.