The Role of Visual Features in Text-Based CAPTCHAs: An fNIRS Study for Usable Security

<div>Mean HbO change observed for line and wave conditions at optode 13 for rotation 1 (a) and rotation 2 (b) cases. Error bars indicate %95 CI.</div>

Computational Intelligence and Neuroscience

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Figure 21

Figure 21: The Role of Visual Features in Text-Based CAPTCHAs: An fNIRS Study for Usable Security 