Negative priming of unattended part primes: Implications for models of holistic and analytic processing in object recognition

Abstract

The “hybrid” model of object recognition (Hummel, 2001) proposes that unattended objects are processed holistically, while attended objects are processed both holistically and analytically. Supporting evidence for this claim was reported by Thoma, Hummel, and Davidoff (2004) who showed that, unlike whole object primes, unattended split object parts (presumed to require analytic processing) do not elicit repetition priming. Here we tested the generality of this finding by contrasting priming for whole and part prime stimuli as a function of prime informativeness and by modifying the design so that both unattended whole and part prime displays contained a single perceptual object. Unlike Thoma et al. (2004) the results showed negative (rather than an absence of) priming for unattended half object primes. These findings place new constraints on theoretical models of the role of attention in object recognition.

Keywords:

• Object recognition
• Negative priming
• Attention

Acknowledgments

The authors would like to thank John Hummel and two anonymous reviewers for their invaluable comments and suggestions on an earlier version of this manuscript.

Notes

¹ A further 12 participants were excluded due to high error rates in naming probe items (>60%). This may have been due to the relatively high proportion of bilingual English–Welsh speakers in the native population. For this reason a strict criterion for accuracy in probe naming was adopted in order to ensure consistency of responses across subject groups. To avoid ambiguity, and to ensure consistency, all responses where the exact English language target name was not given as the first utterance within the deadline were treated as errors (including synonyms).

² We are grateful to Volker Thoma (University of East London) for providing the original stimulus materials and E-Prime programs used in their original study for this purpose.

³ Against this “capacity limitation” account are findings of the absence of priming from single inverted whole unattended objects, rather than solely split parts (e.g., Thoma et al., 2007). However, other data have shown orientation invariant priming from unattended misoriented stimuli (e.g., Dux & Harris, 2007).

⁴ These contrasting priming effects in the unattended condition are also potentially relevant in the context of recent observations from other paradigms investigating object-based visual selection (e.g., Leek, Reppa, & Tipper, 2003; Vecera et al., 2001). For example, Leek et al. have shown how facilitation and inhibition are differentially constrained by occluding contour and internal part boundaries of objects in spatial cueing tasks. In the present task the observation of negative priming for half object primes is consistent with a differential distribution of inhibition and facilitation across object parts and wholes.

⁵ We are grateful to Steve Tipper and Paloma Mari-Beffa for their helpful discussions on this aspect of the data.