Extended Data Fig. 7. Decoding performance as a function of training data.
Decoders were trained on different amounts of data and evaluated on the perceived speech test story. (a) The fraction of significantly decoded time-points increased with the amount of training data collected from each subject but plateaued after 7 scanning sessions (7.5 h) and did not substantially increase up to 15 sessions (16 h). The substantial increase up to 7 scanning sessions suggests that decoders can recover certain semantic concepts after training on a small amount of data, but require much more training data to achieve consistently good performance across the test story. (b) The mean identification percentile rank increased with the amount of training data collected from each subject but plateaued after 7 scanning sessions (7.5 h) and did not substantially increase up to 15 sessions (16 h). For all results, black lines indicate the mean across subjects and error bars indicate the standard error of the mean ().