Modulating Attentional Load Affects Numerosity Estimation: Evidence against a Pre-Attentive Subitizing Mechanism.
, Article e3269. 10.1371/journal.pone.0003269.
Traditionally, the visual enumeration of a small number of items (1 to about 4), referred to as subitizing, has been thought of as a parallel and pre-attentive process and functionally different from the serial attentive enumeration of larger numerosities. We tested this hypothesis by employing a dual task paradigm that systematically manipulated the attentional resources available to an enumeration task. Enumeration accuracy for small numerosities was severely decreased as more attentional resources were taken away from the numerical task, challenging the traditionally held notion of subitizing as a pre-attentive, capacity-independent process. Judgement of larger numerosities was also affected by dual task conditions and attentional load. These results challenge the proposal that small numerosities are enumerated by a mechanism separate from large numerosities and support the idea of a single, attention-demanding enumeration mechanism.
|Title:||Modulating Attentional Load Affects Numerosity Estimation: Evidence against a Pre-Attentive Subitizing Mechanism|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||© 2008 Vetter et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This work was supported by a European Marie Curie Research Training Network grant to Butterworth, a Marie Curie Early Stage Research Fellowship to Vetter and a UCL Graduate School Research Scholarship and an Overseas Research Scholarship to Bahrami.|
|Keywords:||SELECTIVE ATTENTION, ENUMERATION, DISCRIMINATION, SEARCH, NUMBER|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Psychology and Language Sciences (Division of) > Institute of Cognitive Neuroscience
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
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