Attention to local and global levels of hierarchical Navon figures affects rapid scene categorization.

John Brand,Aaron P Johnson

doi:10.3389/fpsyg.2014.01274

Abstract

In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images (i.e., images that contain low spatial frequency (LSF) content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks.

Highlights

The ability to perceive a scene under increased attentional load is often cited as evidence of pre-attentive scene perception
Observers in our study were sensitive to both sources of spatial frequency content and there was no significant interaction with presentation duration, observers were overall more sensitive to high spatial frequency (HSF) than low spatial frequency (LSF) in the hybrid images
Experiment 2 showed that observers preferred to categorize hybrid images based on LSF content, at both short and long durations

Summary

Introduction

The ability to perceive a scene under increased attentional load is often cited as evidence of pre-attentive scene perception. This evidence is typically indexed using dual-task paradigms in which a secondary scene categorization task is unaffected by a concurrent, cognitively demanding primary task. Cohen et al (2011) argued that previous studies falsely demonstrated pre-attentive scene perception because they failed to use sufficiently demanding primary tasks, thereby allowing attentional resources to be allocated to the scene stimuli. Together with previous research in which deficits in scene perception were indexed using attentional blink (Marois et al, 2004; Evans and Treisman, 2005; Slagter et al, 2010), inattentional blindness (Mack and Clarke, 2012), and dual task (Walker et al, 2008) paradigms, Cohen and colleagues concluded that conscious scene perception requires attention

Methods

Results

Conclusion