Decisional space determines saccadic reaction times in healthy observers and acquired prosopagnosia

ABSTRACT

Determining the familiarity and identity of a face have been considered as independent processes. Covert face recognition in cases of acquired prosopagnosia, as well as rapid detection of familiarity have been taken to support this view. We tested P.S. a well-described case of acquired prosopagnosia, and two healthy controls (her sister and daughter) in two saccadic reaction time (SRT) experiments. Stimuli depicted their family members and well-matched unfamiliar distractors in the context of binary gender, or familiarity decisions. Observers’ minimum SRTs were estimated with Bayesian approaches. For gender decisions, P.S. and her daughter achieved sufficient performance, but displayed different SRT distributions. For familiarity decisions, her daughter exhibited above chance level performance and minimum SRTs corresponding to those reported previously in healthy observers, while P.S. performed at chance. These findings extend previous observations, indicating that decisional space determines performance in both the intact and impaired face processing system.

KEYWORDS:

• Acquired prosopagnosia
• face recognition
• minimum saccadic reaction times
• personal familiarity
• visual categorization

Acknowledgements

We thank Mattia Moggio for assistance during stimulus preparation. We are greatly indebted to P.S. and her family for their continued support and cooperation.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Meike Ramon http://orcid.org/0000-0001-5753-5493

Notes

1 Note that the procedural parameters used in both experiments paralleled those used by Visconti di Oleggio Castello & Gobbini (2015), with exception of stimulus presentation duration (600 ms instead of 400 ms), as initial pilot testing revealed that slightly longer presentation durations were necessary for acceptable performance levels (Ramon, Sokhn, et al., 2017; Ramon et al., 2018a).