AbstractThe present study examined whether students' prior knowledge moderated the effects of their motivation compositions on learning performance (ie, retention and transfer) and interaction (ie, interpersonal brain synchronization (IBS) and behavioural pattern) in learning from video lectures. The results confirmed the benefits of the composition of two high motivation students on their knowledge transfer. The results also showed that students' prior knowledge had a moderating effect on interaction. For low prior knowledge students, high motivation composition increased their IBS in the temporoparietal junctionâinferior parietal lobule (TPJâIPL), temporoparietal junctionâsupplementary motor area (TPJâSMA), inferior parietal lobuleâsupplementary motor area (IPLâSMA) and anterior prefrontalâanterior prefrontal cortex (aPFCâaPFC) regions during coâexplaining and enhanced their regulatingârelated behavioural sequences and decreased disagreeârelated behavioural sequences. However, for high prior knowledge students, a high motivation dyad composition decreased their IBS in the supramarginal gyrusâanterior prefrontal cortex (SMGâaPFC) while coâviewing the video lecture, and in the TPJâIPL, TPJâSMA, IPLâSMA and SMGâaPFC during coâexplaining, cognitive communication, argumentationârelated and regulatingârelated behavioural sequences but enhanced offâtaskârelated behavioural sequences. Our findings suggest that instructors should encourage high motivation students to coâview video lectures, and scaffold students with low prior knowledge to enhance regulatingârelated behavioural sequences and scaffold students with high prior knowledge and high motivation to enhance cognitive communication, argumentationârelated and regulatingârelated behavioural sequences and decrease offâtaskârelated behavioural sequences. Practitioner notesWhat is already known about this topic Coâviewing video lectures is a common form of learning across a wide range of ages and topics. Students' motivation is essential for optimal learning in various settings (eg, faceâtoâface classroom and online learning). Students' prior knowledge moderates the effects of their motivations on learning from video lectures from the individual perspective. What this paper adds The composition of two high motivation students benefits their knowledge transfer. For low prior knowledge students, the composition of two high motivation students increased their IBS in the TPJâIPL, TPJâSMA, IPLâSMA and aPFCâaPFC regions, enhanced their regulatingârelated behavioural sequences and decreased their disagreeârelated behavioural sequences. For high prior knowledge students, the composition of two high motivation students decreased their IBS in multiple brain regions, as well as their cognitive communication, argumentationârelated and regulatingârelated behavioural sequences, but enhanced their offâtaskârelated behavioural sequences. Implications for practice and/or policy High motivation students are encouraged to coâview video lectures. Instructors should scaffold students with low prior knowledge to enhance regulatingârelated behavioural sequences. Instructors should scaffold students with high prior knowledge and high motivation to enhance cognitive communication, argumentationârelated and regulatingârelated behavioural sequences and decrease offâtaskârelated behavioural sequences.