Friday, October 05, 2007

How Meaning Shapes Seeing

This is the title of an interesting article by Koivisto and Revonsuo in Psychological Science. They show that semantic meaning influences inattentional blindness. Here is their abstract:
Inattentional blindness refers to the failure to see an unexpected object that one may be looking at directly when one's attention is elsewhere. We studied whether a stimulus whose meaning is relevant to the attentional goals of the observer will capture attention and escape inattentional blindness. The results showed that an unexpected stimulus belonging to the attended semantic category but not sharing physical features with the attended stimuli was detected more often than a semantically unrelated stimulus. This effect was larger when the unexpected stimuli were words than when they were pictures. The results imply that the semantic relation between the observer's attentional set and the unexpected stimulus plays a crucial role in inattentional blindness: An unexpected stimulus semantically related to the observer's current interests is likely to be seen, whereas unrelated unexpected stimuli are unseen. Attentional selection may thus be driven by purely semantic features: Meaning may determine whether or not one sees a stimulus.

1 comment:

  1. This seems to imply there must be a "semantic threshold"--some measure of relevance or relatedness below which a stimulus fails to capture attention and/or awareness (I guess this is "directed attention" that's failing). Weird to think about measuring relevancy. Even if it's not measurable in the sense of being well-behaved or subject to pleasing math (like temperature), seemingly it's got to be measurable empirically, in that some physiological read-out must rate as above or below threshold. But even if strictly true in principle, I guess the reading might be represented somewhere or someway different in every test we might think of, which wouldn't be interesting.