Are Subitizing and Counting Implemented as Separate or Functionally Overlapping Processes?

@article{Piazza2002AreSA,
  title={Are Subitizing and Counting Implemented as Separate or Functionally Overlapping Processes?},
  author={Manuela Piazza and Andrea Mechelli and Brian Butterworth and Cathy J. Price},
  journal={NeuroImage},
  year={2002},
  volume={15},
  pages={435-446}
}
Enumeration of small groups of four or fewer objects is very fast and accurate (often called "subitizing"), but gets slower and more error prone for more than four items ("counting"). Many theories have been proposed to account for this dichotomy, most suggesting that "subitizing" and "counting" are two qualitatively different and separable processes. Others, in contrast, have proposed that the two operations reflect two different levels along a continuum of complexity. In this paper we present… 

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Cortical activation patterns during subitizing and counting
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It is found that, under conditions encouraging estimation, subitizing is an automatic process and may lead to the exact representation of small numbers, which contrasts with approximate representations for larger numerosities.
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