title: Perception of successive targets presented in invariant-item streams.
abstract: When two successive, spatially overlapping, targets (S1 and S2) are presented on a blank background, S2 typically dominates in explicit perception. We tested whether S2 dominance is also found for the conditions of presenting S1 and S2 in a stream of irrelevant objects. Successive target letters were presented within a stream of invariant stimulus items (capital Is). The stream items were presented either as a perceptually continuous object where both type and token appeared invariant (60-Hz stream) or as a flickering stream of successive replicas of the invariant stationary object where the type appeared invariant but the token appearance seemed intermittent (20-Hz condition). Compared to the control condition where targets were presented on a blank background we found that (1) recognition rate was lower for targets embedded in a perceptually continuous type-and-token object (60 Hz), but was unchanged for targets in a perceptually flickering sequence of the invariant-object tokens (20 Hz); (2) S1 recognition rate was higher compared to S2 recognition rate within the first epoch of stream (0-150 ms) while within the later stream-epochs S2 dominated over S1 as usual; (3) the overall difference in recognition rates between S1 and S2 was decreased. The results are discussed in the theoretical context of visual masking and attentional blink.
authors.affiliation: Estonian Center of Behavioral and Health Sciences, Perception and Consciousness Research Group, University of Tartu, Kaarli puiestee 3, Tallinn 10119, Estonia. talis.b@lawinst.ee
authors.forename: Talis
authors.initials: T
authors.lastname: Bachmann
authors.forename: Pilleriin
authors.initials: P
authors.lastname: Sikka
mesh_terms: D000328:Adult; D000368:Aged; D001288:Attention; D001767:Blinking; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D010470:Perceptual Masking; D021641:Recognition, Psychology; D013028:Space Perception