Developmental prosopagnosia in Poland: an analysis of online-conducted population based study

Background and aim of the study: Developmental prosopagnosia (DP) is defi ned asimpaired face recognition in the absence of brain injury or intellectual defi cit. Becauseof the complexity of validated face memory and perception tests, its online distributiongreatly improves the effectiveness and convenience of conducting research. Assessmentof DP occurrence in the Polish population concerning study sample collection andcharacteristics.Material and methods: An online questionnaire consisting of the 20-item ProsopagnosiaIndex (PI20) was administered to assess self-reported problems with face recognition.Cambridge Face Memory Test (CFMT) and Glasgow Face Matching Test (GFMT)were applied to assess respondents’ face memory and perception. Additional data onrespondents’ gender, age and handedness were also obtained. All of the components werearranged together using Google Forms tool. Respondents were recruited via social mediaannouncements. The study was conducted from 1st January to 31st March 2019. Each ofthe respondents was provided with personalised results analysis, which was sent with ane-mail. They were also able to stay in contact with research authors, asking additional questionsand giving remarks.Results: During the study, a total of 1349 questionnaires were collected, out of which1276 met inclusion criteria and were enrolled in the study. 66.1% of the respondent groupwere females and 33.9% males. The mean age was 28.3 ± 9.5 years (range: 14-75). Themean PI20 score was 49.6 ± 18 (range: 20-99). In 11.8% of respondents PI20 result indicatedself-reported mild, in 8.3% moderate and in 3.9% severe DP. The mean CFMT totalscore was 58.1 (median: 59, range: 26-72) and mean GFMT score was 33.9 (median: 34,range: 18-40). According to the cutoff values from original papers, 81 (6.3%) of respondentsscored below threshold in CFMT, 27 (2.4%) in GFMT. Out of 50 respondents whoself-reported symptoms indicating severe DP, only 15 (30%) scored below the cutoff inCFMT and 6 (12%) in GFMT. On the contrary, 30 (3.1%) and 16 (1.4%) out of 970 respondentsreporting no problems with face recognition had total scores below the cutoff inCFMT and GFMT, respectively.Conclusions: The estimated prevalence of developmental prosopagnosia in Polishpopulation is higher than in normative data. These discrepancies may result from specifi cdemographics of participant group more than an online-character of the study. It is important to focus on experiment design and methodology in order to maintain high quality ofcollected data. Development of country-specifi c norms and stimuli for face-recognitiontests should also be considered .