Looking into working memory through micro eye movements.

Understanding how humans select, rehearse, and transform internal representations 'in mind' is vital. Gaining access to these latent working-memory processes, however, is not trivial. Here, I review the recent discovery that working-memory processes 'leak' into spatial biases in minuscule eye movements known as microsaccades. I first unpack this central finding and position it alongside complementary findings from the literature on attention, memory, and eye movements. Next, I adopt a pragmatic perspective, showcasing how microsaccade biases can be leveraged as a versatile signal to 'track' working-memory processes, with benefits that complement traditional brain-imaging approaches. Finally, I outline opportunities and future avenues opened by this recently exposed and remarkably reliable association between externally accessible micro eye movements and internal working-memory processes.