Sequence learning recodes cortical representations instead of strengthening initial ones
Fig 1
(A) Four Gabor patches (items used in this study) associated with four sequence positions and a matrix representation of the sequence. (B) Item-position associations in monkey prefrontal cortex as observed by Berdyyeva et al. [38]. Each subplot displays spiking activity for a particular neuron: the first one responds most to items at the beginning of a three-item sequence, the second for the ones in the middle, and the last one for items at the end of the sequence. Numbers on x-axis mark the onset of the stimulus events. (C) Visual representation of three sequences as position-item associations and the resulting frequency of associations. The frequency of associations can be learned as a model of the environment. (D) Dissociating between learning mechanisms in terms of similarity between novel and learned sequences: with associative learning (left) learned sequences share the same item codes with novel ones. Furthermore, learning reduces noise in learned sequence representations. Recoding (right) changes item representations so that novel and learned stimuli do not share representations.