Dissociation of first- and second-order motion systems by perceptual learning

Abstract

Previous studies investigating transfer of perceptual learning between luminance-defined (LD) motion and texture-contrast-defined (CD) motion tasks have found little or no transfer from LD to CD motion tasks but nearly perfect transfer from CD to LD motion tasks. Here, we introduce a paradigm that yields a clean double dissociation: LD training yields no transfer to the CD task, but more interestingly, CD training yields no transfer to the LD task. Participants were trained in two variants of a global motion task. In one (LD) variant, motion was defined by tokens that differed from the background in mean luminance. In the other (CD) variant, motion was defined by tokens that had mean luminance equal to the background but differed from the background in texture contrast. The task was to judge whether the signal tokens were moving to the right or to the left. Task difficulty was varied by manipulating the proportion of tokens that moved coherently across the four frames of the stimulus display. Performance in each of the LD and CD variants of the task was measured as training proceeded. In each task, training produced substantial improvement in performance in the trained task; however, in neither case did this improvement show any significant transfer to the nontrained task.

Broad bandwidth of perceptual learning in second-order contrast modulation detection

“…On the other hand, we also show that the learning effect is specific to second-order processing. This result, together with previously reported asymmetry of transfer of learning between first-and second-order stimuli (Chen, Qiu, Zhang, & Zhou, 2009;Chung et al, 2008;Petrov & Hayes, 2010;Vaina & Chubb, 2012), indicates that perceptual learning in first-and second-order processing may occur at different stages of visual processing.…”

“…On the other hand, Chung, Li, and Levi (2008) trained observers with amblyopic vision to identify near-threshold luminancedefined (first-order) and contrast-defined (second-order) letters and found that the learning effect transferred from first-order to second-order tasks but not vice versa. Vaina and Chubb (2012) found no transfer between perceptual learning of luminance-defined (first-order) global motion and texture-contrast-defined (second-order) global motion tasks. Although the results on transfer of perceptual learning between first-and second-order processing are mixed, these previous studies suggest that first-and second-order perceptual learning might be at least partially independent.…”

“…Although several studies have evaluated the properties of perceptual learning with high-order stimuli (Chung, Li, & Levi, 2008;Dosher & Lu, 2006;McGovern, Webb, & Peirce, 2012;Petrov & Hayes, 2010;Vaina & Chubb, 2012;Zanker, 1999), the proposed models of first-order and second-order processing provide a valuable framework to test the level(s) of learning-induced plasticity. If perceptual learning only occurs in first-order tasks or occurs for both first-and second-order tasks but with different properties, it would imply different plasticity in the two processing systems and provide evidence for learning at different levels of the visual pathway.…”

The Role of Perceived Speed in Vection: Does Perceived Speed Modulate the Jitter and Oscillation Advantages?

“…This was used to argue that the oscillation advantage for vection may have a preconscious origin. However, an alternative explanation could be that first- and second-order motion systems do not interact in global motion perception [46] – [49] , although see [50] .…”

Orientation Discrimination in Periphery: Surround Suppression or Crowding?

“…This makes the transfer of perceptual learning in one visual system to the other a likelihood. Indeed, some studies confirmed the existence of such transfers (Chen, et al, 2009;Chung, Li, & Levi, 2008b;Petrov & Hayes, 2010;Zanker, 1999;Schofield, Ledgeway, & Hutchinson, 2007; but see Vaina & Chubb, 2012). However, it remains an open question whether this transfer is asymmetric (unidirectional, i.e., only from first-order to second-order or only from second-order to first-order) or symmetric (bidirectional, i.e, from first-order to second-order and vice versa).…”