{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T04:56:36Z","timestamp":1790571396406,"version":"4.1.0"},"reference-count":53,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"vor","delay-in-days":20,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["SCHM 1092\/16\u20101"],"award-info":[{"award-number":["SCHM 1092\/16\u20101"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Psychophysiology"],"published-print":{"date-parts":[[2026,9]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    blenderFace is a highly precise marker\u2010based approach for measuring facial activity. Unlike most camera\u2010based automated facial expression recognition (AFER) systems, which rely on fixed natural landmarks, blenderFace flexibly tracks virtually any point of interest using painted markers. However, visible markers, like EMG electrodes, may alter appearance, increase self\u2010awareness, and affect spontaneous responding in face\u2010to\u2010face interactions. To address these limitations, we introduce blenderFaceUV, which uses sunscreen\u2010based markers that are visible only under ultraviolet (UV) light (365\u2009nm). In Study 1, we assessed UV\u2010marker tracking accuracy using parallel visible\u2010light and UV recordings from two participants. In Study 2, we examined the scalability of blenderFaceUV in\n                    <jats:italic>N<\/jats:italic>\n                    \u2009=\u200918 lay participants prompted to produce a broad range of facial movements using common emotion terms. We also compared identical facial movements measured with blenderFaceUV and OpenFace, a widely used AFER system based on a point distribution model (PDM). Study 1 showed that UV markers could be tracked with similarly high accuracy as visible markers (reprojection\/solve error &lt;\u20090.3 pixels). Across 10 markers and two participants, with more than 3800 measurement occasions per participant, the mean correlation between visible and UV marker movements across the x\u2010 and y\u2010coordinates was\n                    <jats:italic>r<\/jats:italic>\n                    \u2009=\u20090.957, while centered RMSE values indicated average deviations of approximately 1\u2009mm. Study 2 demonstrated the scalability of the method and revealed PDM\u2010related artifacts in OpenFace measurements, particularly during eye blinks and large mouth movements. PDM\u2010interpolated landmarks, such as upper\u2010lip markers, also deviated substantially from marker\u2010based blenderFaceUV measurements. Practical challenges remain, including the complexity of applying invisible markers and the relatively high cost of UV cameras (\u2248$2000\u2013$6000). We discuss technical requirements, limitations, and a recommended workflow for implementing blenderFaceUV.\n                  <\/jats:p>","DOI":"10.1111\/psyp.70394","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T04:34:07Z","timestamp":1790051647000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["blenderFaceUV: Toward Marker\u2010Based Precision and Flexibility in Facial Tracking With \u201cInvisible\u201d Markers"],"prefix":"10.1111","volume":"63","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0404-1195","authenticated-orcid":false,"given":"Axel","family":"Zinkernagel","sequence":"first","affiliation":[{"name":"University of Wuppertal  Wuppertal Germany"},{"name":"RPTU University of Kaiserslautern\u2010Landau  Landau Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9846-8936","authenticated-orcid":false,"given":"Rainer W.","family":"Alexandrowicz","sequence":"additional","affiliation":[{"name":"University of Klagenfurt  Klagenfurt Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8992-5648","authenticated-orcid":false,"given":"Dennis","family":"K\u00fcster","sequence":"additional","affiliation":[{"name":"University of Bremen  Bremen Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9978-8357","authenticated-orcid":false,"given":"Manfred","family":"Schmitt","sequence":"additional","affiliation":[{"name":"RPTU University of Kaiserslautern\u2010Landau  Landau Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4326-5127","authenticated-orcid":false,"given":"Tanja","family":"Lischetzke","sequence":"additional","affiliation":[{"name":"RPTU University of Kaiserslautern\u2010Landau  Landau Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,9,21]]},"reference":[{"key":"e_1_2_13_2_1","volume-title":"OpenFace: An Open Source Facial Behavior Analysis Toolkit","author":"Baltru\u0161aitis T.","year":"2016"},{"key":"e_1_2_13_3_1","doi-asserted-by":"publisher","DOI":"10.4304\/jmm.1.6.22\u201035"},{"key":"e_1_2_13_4_1","doi-asserted-by":"publisher","DOI":"10.3390\/s24010126"},{"key":"e_1_2_13_5_1","doi-asserted-by":"publisher","DOI":"10.1109\/CVPR52734.2025.00029"},{"key":"e_1_2_13_6_1","doi-asserted-by":"publisher","DOI":"10.1037\/0022\u20103514.50.2.260"},{"key":"e_1_2_13_7_1","doi-asserted-by":"publisher","DOI":"10.3389\/fnhum.2020.618985"},{"key":"e_1_2_13_8_1","doi-asserted-by":"publisher","DOI":"10.1037\/0033\u2010295X.99.3.550"},{"key":"e_1_2_13_9_1","volume-title":"Facial Action Coding System. 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