A new form of human spatial attention: Automated symbolic orienting

Abstract

The control of human attention is typically conceptualized either in terms of exogenous automatic processes that are driven by external sensory stimulation or endogenous strategic processes that are driven by internal expectancies about events in the environment. However, this classic dichotomy has struggled to explain a wealth of new data demonstrating that behaviourally and biologically relevant visual stimuli, like arrow and eye direction, elicit shifts of spatial attention that on the one hand, appear exogenous, and on the other hand, endogenous. To address this issue, we used a double-cueing task that combined arrows with classic cues known to invoke either exogenous or endogenous orienting. Our data suggest that behaviourally relevant directional cues, like arrows, engage a new form of cortically mediated orienting—automated symbolic orienting—that operates independent of, and in parallel with, the two classic forms of exogenous and endogenous spatial attention.

Keywords:

• Behaviourally relevant cues
• Human attention
• Spatial orienting

Acknowledgements

Supported by NSERC (JR, AK), G. W. Stairs (JR), MSFHR (JR), and SSHRC (AK) funds.

Notes

¹Green and Woldorff (2012) recently argued that the early RT effects observed with central arrow cues cannot reflect reflexive orienting because (1) a RT effect is observed even when cue and target are simultaneous, suggesting impossibly fast reflexive orienting, and (2) flashing the cue at fixation delays the early RT effect, which should be unaffected by cue transients. Both conclusions should be taken with caution. The first conclusion disregards the fact that attentional orienting can occur from the time that a cue appears until a response is made. In Green and Woldorff’s study, overall response time exceeded 400 ms, meaning that participants had that long to shift attention from the arrow cue to the target even when cue and target were simultaneous. The second conclusion disregards the well established fact that flashing a stimulus at fixation will itself capture and delay attentional orienting to a peripheral location (e.g., Klein & Shore, 2000).