Sleep deprivation (SD) is increasingly prevalent due to contemporary lifestyles, shift work, and various psychological disorders, and has adverse effects on physical and psychological well-being. Behavioural research consistently shows reduced performance following SD; however, the mechanisms by which it affects perceptual processing remain unclear. Some studies suggest that SD selectively impairs recurrent processing while leaving the feedforward sweep intact, similar to effects observed in other attention and arousal manipulations. In contrast, other findings suggest more global effects, with both feedforward and recurrent stages being disrupted. Previous research has not implemented stimuli or methods that clearly dissociate these stages, limiting conclusions about which stage of perceptual processing SD affects. 

The present study addressed this gap by combining stimuli with features of increasing complexity and electroencephalography (EEG), allowing different perceptual processing stages to be dissociated. Contrary to expectations, SD did not significantly affect behavioural performance or classifier performance for any decoded feature contrast. Exploratory analyses, including temporal generalization, split-group decoding, prefrontal decoding, and time-frequency analyses, also did not provide evidence for SD-related differences. 

hese findings suggest that, in the present task, perceptual processing and behavioural performance were largely preserved following SD. However, this may reflect the study design rather than the absence of SD effects. Sleep was restricted to a maximum of four hours, which may not have produced robust impairment, and the visual 1-back task may have been too simple or engaging to reveal clear behavioural and neural differences. Future research should test whether stronger sleep manipulations or more demanding tasks reveal clearer effects on visual processing.