Task-related modulation of event-related potentials does not reflect changes to sensory representations

Attention supports efficient perception by increasing the neural signals of targets while supressing those of distractors. Decades of work studying the event-related potentials of electroencephalography (EEG) recordings have established our understanding of attention in the human brain, but many aspects of this phenomenon remain unknown. Several recent studies suggest that multivariate analyses may provide new insights into how attention shapes the neural representations of stimuli; however, it is unclear whether the increased multivariate decoding accuracy associated with task relevance represents a change in the stimulus representation or an additional cognitive process. To understand what the change in multivariate information that is associated with task relevance reflects, here we used inverted encoding to characterize how task relevance shapes the neural representation of space and colour. For both spatial and feature-based tasks, we found that the change in the EEG recordings associated with task relevance is not related to the stimulus representation. Rather, our findings indicate that this phenomenon reflects an additional cognitive process, such as target recognition.