Abstract: The goal of this paper was to assess whether there were systematic trade-offs between attention and stimulus quality in determining awareness. The approach was based on the qualitative differences in performance across perception with and without awareness, which had been shown to occur when stimulus quality was varied or the level of attention was varied. Qualitative differences in performance were established across perception with and without awareness, based on a phenomenon: false recognition, which is defined as an "old" response to a new item on an old! new recognition test. This means, the subjects said "old" to new test characters more often on match (context characters were the same as test characters) than nonmatch trials (context characters were different from test characters) when context characters perceived unconsciously, whereas they said "old' to new test characters less often on match than nonmatch trials when context characters perceived consciously. The results of the two experiments showed that there were systematic trade-offs between attention and stimulus quality in determining whether a stimulus was perceived with or without awareness. In Experiment 1, a stimulus that was perceived without awareness when presented with poor quality (short duration), could be perceived with awareness either by increasing stimulus quality (long duration) or by increasing the level of attention; and correspondently, in Experiment 2, a stimulus that was perceived without awareness under a condition of divided-attention, could be perceived with awareness either by focusing attention on it or by increasing stimulus quality. It seemed that attention and stimulus quality can supplement each other in determining whether a stimulus is perceived with or without awareness. Discussion focused on the interrelations between awareness, attention and stimulus quality.

Key words: false recognition, awareness, attention, stimulus quality