28th International Congress of Psychology August 8 ... - U-netSURF

2074.5 Search asymmetries across feature dimensions, Jing Sun, Dingguo Gao, Hengyi Rao,
Debin Huang, Sun Yat-Sen University, Guangzhou, China
This study aimed to examine the search asymmetries of primitive features across feature
dimensions through manipulating terminators in three experiments. In Experiment 1, searching L
in Ss was faster than searching S in Ls, and the number of distractor affected searching S but not
searching L. In Experiment 2, when search targets shared same terminators but different curvature,
searching curve in line background was faster than searching line in curve background. Adopting
different stimuli, Experiment 3 replicated the effects obtained in Experiment 1. The above results
suggest terminator be more primitive than curvature in visual search.
2074.6 Recognition of rotated objects: Paying attention to orientation, Irina Harris, Paul Dux,
Macquarie University, Australia
Recognition costs incurred by rotated objects have been interpreted as evidence for
viewpoint-dependent recognition. We review findings which suggest that recognition is actually
mediated by orientation-invariant representations and that these costs reflect a post-recognition
process of determining the object’s orientation in space. We propose a two-stage theory of object
recognition. In Stage1, the object’s identity is retrieved from memory. Strictly speaking, this is the
recognition process, and is orientation-invariant. However, a second stage of processing is
necessary, in which identity is bound to orientation information, in order to deliver a conscious
percept anchored in space and time.
2074.7 Functional asymmetry between upper and lower visual fields revealed by an
event-related potential study, Zhe Qu 1 , Fan Silu 1 , Ding Yulong 2 , Song Yan 3 , Chen Lin 1 ,
1 2
Graduate School and Institute of Biophysics, Chinese Academy of Sciences; Sun Yat-Sen
University, China; 3 Beijing Normal University, China
To investigate the functional asymmetry between upper and lower visual fields (UVF and LVF),
we recorded event-related potentials from 16 subjects while they were performing a simple visual
discrimination task under sustained attention. The LVF stimuli elicited smaller P1, but larger N1
than UVF stimuli. The latency of N1 was earlier for LVF than UVF. Moreover, the attentional
effect on P1’s amplitude was smaller for LVF than UVF. These results, from visual perception and
sustained attention, showed clear evidence for the functional asymmetry between UVF and LVF,
suggesting LVF with more sensitivity of perception and less consumption of attentional resource.
2074.8 Neural correlates of fast and slow visual perceptual learning: An event-related potential
study, Yulong Ding 1 , Yan Song 2 , Zhe Qu 3 , Silu Fan 3 , 1 Sun Yat-Sen University, China; 2 Beijing
Normal University, China; 3 Graduate School and Institute of Biophysics, Chinese Academy of
Sciences, China
The present study investigated the time course of visual perceptual learning by recording
event-related potentials (ERPs) from adult subjects while they were trained with a visual
discrimination task. Behavioral data revealed both fast learning effect (occurred during daily
training) and slow learning effect (occurred between days) on reaction times. For ERPs, fast
learning effect was shown on decrement of N1 and increment of P2, while slow learning effect
was shown on increment of N1 and decrement of N2. These results provide clear evidence
supporting that different neural processes are involved in fast and slow visual perceptual learning.
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