This systematic review examines 76 studies that have utilised portable electroencephalographic (EEG) devices in naturalistic and semi-naturalistic contexts. The review considers themes, purposes, contexts, application populations, device characteristics, and data use. The results show a dominance of studies focused on attention, in technology-mediated semi-naturalistic situations, in which records are made individually, with university students using low-cost equipment with fewer than 15 channels. This review highlights an emerging field within educational research that has not yet been fully integrated into educational practice. However, these first experiences can gradually generate a body of knowledge that will facilitate future applications, together with the development of better and more accessible devices. The use of these devices in educational contexts raises ethical concerns, particularly the influence on teaching decisions by opaque commercial algorithms that may oversimplify assessments of specific cognitive processes and fail to adapt to individual student characteristics.
