Neuronal processes underlying the formation of new associations in the human brain are
not yet well understood. Here human participants, implanted with depth electrodes in the
brain, learned arbitrary associations between images presented in an ordered, predictable
sequence. During learning we recorded from medial temporal lobe (MTL) neurons that
responded to at least one of the pictures in the sequence (the preferred stimulus). We report
that as a result of learning, single MTL neurons show asymmetric shifts in activity and start …