{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,10]],"date-time":"2026-01-10T01:41:48Z","timestamp":1768009308856,"version":"3.49.0"},"reference-count":31,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,4,14]],"date-time":"2024-04-14T00:00:00Z","timestamp":1713052800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Natural Sciences and Engineering Research Council of Canada"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This study presents phosphenotron, a device for enhancing the sensory spatial resolution of phosphenes in the visual field (VF). The phosphenotron employs a non-invasive transcranial alternating current stimulation (NITACS) to modulate brain activity by applying weak electrical currents to the scalp or face. NITACS\u2019s unique application induces phosphenes, a phenomenon where light is perceived without external stimuli. Unlike previous invasive methods, NITACS offers a non-invasive approach to create these effects. The study focused on assessing the spatial resolution of NITACS-induced phosphenes, crucial for advancements in visual aid technology and neuroscience. Eight participants were subjected to NITACS using a novel electrode arrangement around the eye orbits. Results showed that NITACS could generate spatially defined phosphene patterns in the VF, varying among individuals but consistently appearing within their VF and remaining stable through multiple stimulations. The study established optimal parameters for vibrant phosphene induction without discomfort and identified electrode positions that altered phosphene locations within different VF regions. Receiver Operating characteristics analysis indicated a specificity of 70.7%, sensitivity of 73.9%, and a control trial accuracy of 98.4%. These findings suggest that NITACS is a promising, reliable method for non-invasive visual perception modulation through phosphene generation.<\/jats:p>","DOI":"10.3390\/s24082512","type":"journal-article","created":{"date-parts":[[2024,4,15]],"date-time":"2024-04-15T08:08:12Z","timestamp":1713168492000},"page":"2512","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["A Phosphenotron Device for Sensoric Spatial Resolution of Phosphenes within the Visual Field Using Non-Invasive Transcranial Alternating Current Stimulation"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9615-3025","authenticated-orcid":false,"given":"Faraz","family":"Sadrzadeh-Afsharazar","sequence":"first","affiliation":[{"name":"Photonics Group, Department of Physics, Faculty of Science, Toronto Metropolitan University (Formerly Ryerson University), Toronto, ON M5B 2K3, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9948-9472","authenticated-orcid":false,"given":"Alexandre","family":"Douplik","sequence":"additional","affiliation":[{"name":"Photonics Group, Department of Physics, Faculty of Science, Toronto Metropolitan University (Formerly Ryerson University), Toronto, ON M5B 2K3, Canada"},{"name":"Institute for Biomedical Engineering, Science and Technology (iBEST), Keenan Research Centre of the Li Ka Shing (LKS) Knowledge Institute, St. Michael Hospital, Toronto, ON M5B 1T8, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,14]]},"reference":[{"key":"ref_1","unstructured":"Krames, E.S., Peckham, P.H., and Rezai, A.R. (2018). Neuromodulation, Academic Press. [2nd ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1038\/scientificamerican0270-82","article-title":"Phosphenes","volume":"222","author":"Oster","year":"1970","journal-title":"Sci. Am."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5092","DOI":"10.1038\/s41467-018-07233-7","article-title":"Immediate neurophysiological effects of transcranial electrical stimulation","volume":"9","author":"Liu","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"15247","DOI":"10.1038\/s41598-019-51792-8","article-title":"Human sensation of transcranial electric stimulation","volume":"9","author":"Zeng","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"023202","DOI":"10.1117\/1.OE.52.2.023202","article-title":"Electromechanical tactile stimulation system for sensory vision substitution","volume":"52","author":"Zalevsky","year":"2013","journal-title":"Opt. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1839","DOI":"10.1016\/j.cub.2008.10.027","article-title":"Frequency-Dependent Electrical Stimulation of the Visual Cortex","volume":"18","author":"Kanai","year":"2008","journal-title":"Curr. Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"7188","DOI":"10.1523\/JNEUROSCI.2896-16.2017","article-title":"Saturation in phosphene size with increasing current levels delivered to human visual cortex","volume":"37","author":"Bosking","year":"2017","journal-title":"J. Neurosci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"317","DOI":"10.3389\/fnhum.2013.00317","article-title":"Transcranial alternating current stimulation (tACS)","volume":"7","author":"Antal","year":"2013","journal-title":"Front. Hum. Neurosci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"8525706","DOI":"10.1155\/2018\/8525706","article-title":"Methods to compare predicted and observed phosphene experience in tACS subjects","volume":"2018","author":"Indahlastari","year":"2018","journal-title":"Neural Plast."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2173","DOI":"10.1152\/jn.00505.2012","article-title":"Transcranial electrical stimulation over visual cortex evokes phosphenes with a retinal origin","volume":"108","author":"Kar","year":"2012","journal-title":"J. Neurophysiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1016\/j.clinph.2010.01.029","article-title":"On the difficulties of separating retinal from cortical origins of phosphenes when using transcranial alternating current stimulation (tACS)","volume":"121","author":"Paulus","year":"2010","journal-title":"Clin. Neurophysiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.neuroimage.2015.09.067","article-title":"Cutaneous retinal activation and neural entrainment in transcranial alternating current stimulation: A systematic review","volume":"140","author":"Schutter","year":"2016","journal-title":"Neuroimage"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1080","DOI":"10.1016\/j.clinph.2009.10.038","article-title":"Retinal origin of phosphenes to transcranial alternating current stimulation","volume":"121","author":"Schutter","year":"2010","journal-title":"Clin. Neurophysiol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Granley, J., and Beyeler, M. (2021, January 1\u20135). A Computational Model of Phosphene Appearance for Epiretinal Prostheses. Proceedings of the 2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Guadalajara, Mexico.","DOI":"10.1109\/EMBC46164.2021.9629663"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.biosystems.2008.02.002","article-title":"Phosphene phenomenon: A new concept","volume":"92","year":"2008","journal-title":"BioSystems"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.preteyeres.2017.07.001","article-title":"Phosphenes, retinal discrete dark noise, negative afterimages and retinogeniculate projections: A new explanatory framework based on endogenous ocular luminescence","volume":"60","author":"Salari","year":"2017","journal-title":"Prog. Retin. Eye Res."},{"key":"ref_17","unstructured":"Tanie, K., and Tachi, S. (1981). Apparatus for Transmission of Information by Electrocutaneous Stimuli. (4,254,776), US Patent."},{"key":"ref_18","first-page":"275","article-title":"Both the cutaneous sensation and phosphene perception are modulated in a frequency-specific manner during transcranial alternating current stimulation","volume":"31","author":"Turi","year":"2013","journal-title":"Restor. Neurol. Neurosci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2181","DOI":"10.1016\/j.clinph.2015.03.015","article-title":"What do you feel if I apply transcranial electric stimulation? Safety, sensations and secondary induced effects","volume":"126","author":"Fertonani","year":"2015","journal-title":"Clin. Neurophysiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1493","DOI":"10.1016\/j.visres.2009.02.003","article-title":"Simulating prosthetic vision: I. Visual models of phosphenes","volume":"49","author":"Chen","year":"2009","journal-title":"Vis. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2783","DOI":"10.1016\/j.ajpath.2016.07.017","article-title":"Electrical Stimulation as a Means for Improving Vision","volume":"186","author":"Sehic","year":"2016","journal-title":"Am. J. Pathol."},{"key":"ref_22","first-page":"279","article-title":"Transcranial alternating current stimulation: A review of the underlying mechanisms and modulation of cognitive processes","volume":"14","author":"Herrmann","year":"2013","journal-title":"Front. Hum. Neurosci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"132","DOI":"10.2174\/1874364100802010132","article-title":"Transcutaneous electrical retinal stimulation therapy for age-related macular degeneration","volume":"2","author":"Shinoda","year":"2008","journal-title":"Open Ophthalmol. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1186\/s40779-019-0206-9","article-title":"Contemporary approaches to visual prostheses","volume":"6","author":"Mirochnik","year":"2019","journal-title":"Military Med Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"654","DOI":"10.1111\/ans.13616","article-title":"Advances in implantable bionic devices for blindness: A review","volume":"86","author":"Lewis","year":"2016","journal-title":"ANZ J. Surg."},{"key":"ref_26","unstructured":"Beck, S. (2024, April 04). The Phosphotron. Available online: http:\/\/www.vasulka.org\/archive\/4-30b\/Seno(9007).pdf."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.brainres.2015.08.038","article-title":"Electrical stimulation of the brain and the development of cortical visual prostheses: An historical perspective","volume":"1630","author":"Lewis","year":"2016","journal-title":"Brain Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1111\/j.1525-1594.2009.00878.x","article-title":"Estimation of phosphene spatial variability for visual prosthesis applications","volume":"34","author":"Obeid","year":"2010","journal-title":"Artif. Organs."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1228326","DOI":"10.3389\/fnins.2023.1228326","article-title":"Non-Invasive Transcranial Alternating Current Stimulation (NITACS) of Spatially Resolved Phosphenes","volume":"17","author":"Douplik","year":"2023","journal-title":"Front. Neurosci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1176\/appi.neuropsych.17110262","article-title":"Noninvasive Brain Stimulation: Challenges and Opportunities for a New Clinical Specialty","volume":"30","author":"Boes","year":"2018","journal-title":"J. Neuropsychiatry Clin. Neurosci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1016\/j.patrec.2005.10.010","article-title":"An introduction to ROC analysis","volume":"27","author":"Fawcett","year":"2006","journal-title":"Pattern Recognit. Lett."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/8\/2512\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:27:50Z","timestamp":1760106470000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/8\/2512"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,14]]},"references-count":31,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2024,4]]}},"alternative-id":["s24082512"],"URL":"https:\/\/doi.org\/10.3390\/s24082512","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,14]]}}}