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Disentangling feedforward versus feedback processing in numerosity representation.

Michele Fornaciai1, Joonkoo Park2

  • 1Department of Psychological and Brain Sciences, University of Massachusetts Amherst, MA, USA.

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PubMed
Summary
This summary is machine-generated.

Numerosity perception relies on feedforward processing in the brain, not feedback. Even when masked, connected dots influence how we perceive the number of items in subsequent visual stimuli.

Keywords:
ConnectednessMaskingNumerosity perceptionSerial dependenceVisual processing

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Area of Science:

  • Cognitive Neuroscience
  • Visual Perception
  • Computational Neuroscience

Background:

  • Numerosity processing is crucial for effective behavior and involves temporal stages in early visual cortex.
  • Existing theories propose either feedforward processing followed by feedback, or multiple feedforward stages for numerosity perception.

Purpose of the Study:

  • To differentiate between feedforward and feedback models of numerosity perception.
  • To investigate the role of feedback signals in segmenting visual inputs for numerosity estimation.

Main Methods:

  • Utilized the connectedness illusion and backward masking to manipulate feedback signals.
  • Employed serial dependence to assess perceptual biases in numerosity representation.

Main Results:

  • The connectedness illusion biased numerosity representation even when masked, indicating feedback is not essential.
  • Perceptual segmentation for numerosity does not strictly require feedback processing.

Conclusions:

  • Feedforward processing stages, potentially carrying different spatial frequency information, are sufficient for numerosity representation in early visual areas.
  • This challenges the necessity of feedback for perceptual segmentation in numerosity processing.