Jenna Kelly1,2 & Nestor Matthews2 Attentional Oblique Effect When Judging Simultaneity: A Perceptual Learning Study Jenna Kelly1,2 & Nestor Matthews2 1Center for Neural Science, New York University; 2Department of Psychology, Denison University Abstract # 53.455 Introduction Method Discussion Oblique effects have been observed in many visual tasks, even when making judgments about imaginary rather than physical components of stimuli1. Recently, we demonstrated an attentional oblique effect in a simultaneity judgment2. Performance at judging whether two precued targets changed orientation simultaneously was significantly worse for cardinally than for diagonally aligned targets. This oblique effect appears to result from inappropriate integration of temporal synchrony information from irrelevant spatial locations, rather than poor temporal acuity. Does this oblique effect disappear with practice? Does learning generalize to spatial frequency judgments under identical retinal stimulation? Oblique effect is not present for the spatial frequency judgment task, consistent with the idea that spatial and temporal attention are dissociable3. Practice attending diagonally aligned targets improved simultaneity judgments without eliminating the oblique effect, suggesting that the processes limiting performance on the simultaneity judgment are independent of those that generate the oblique effect. Learning on the simultaneity task did not generalize to the spatial frequency judgment task, suggesting different spatial integration windows for different attended features. Petrov, Dosher, & Lu (2005) offer the schematic below for interpreting the transfer of perceptual learning to novel tasks (A) and stimuli (B)4. One parsimonious account for the task-specific learning here and stimulus-specific learning shown in prior oblique effect studies5-8 is that training improves the SNR in the connections (arrows) between the sensory (bottom) and decision (top) stages. This could be achieved by channel reweighting4,9 for the left but not right arrow in configuration A. 2 tasks: judgments of simultaneity (“Target Timing?”) and spatial frequency (“Target Stripe Size?”) N=10: 5 sessions each Sessions 1, 2, 5: 360 trials divided across “horizontal,” “center,” and “diagonal” conditions; both tasks Sessions 3-4: 360 trials, all simultaneity judgments in diagonal condition only * Results References 1. Westheimer (2003). PMID: 12962986 2. Kelly & Matthews (2011).Attentional oblique effect when judging simultaneity. Journal of Vision, in press. 3. Aghdaee & Cavanagh (2007). PMID: 17574644 4. Petrov, Dosher & Lu (2005). PMID: 16262466 5. Vogels & Orban (1985). PMID: 3832592 6. Ball & Sekuler (1987). PMID: 3660656 7. Matthews & Welch (1997). PMID: 9038408 8. Strong, Kurosawa & Matthews (2006). PMID: 16881797 9. Dosher & Lu (1998). PMID: 9811913 Substantial learning on simultaneity judgment, oblique effect preserved Generalized across attentional conditions (horizontal, center, diagonal) but not tasks (simultaneity, spatial frequency) http://denison.edu/~matthewsn/vss2011kellymatthews.html