In effect, these paintings highlight the physical act of perception and challenge one's ability to read the picture plane in relation to its surrounding context. (museumpublicity.com)
There is in the living act of perception always something that glimmers and twinkles and will not be caught, and for which reflection comes too late. (religion-online.org)
This rules out causal explanations of perception such as (ii), if it be assumed that there is not immediate awareness of such causal mechanisms within an individual act of perception itself, if one does not have a perception and at the same time experience all the causes which produced it. (religion-online.org)