Local sleep, the intrusion of sleep-like slow waves (SLSW) into the wakeful cortex, is widely proposed as a mechanism linking sleep pressure to attentional lapses and degraded performance. This thesis examined whether experimentally induced sleep pressure increases SLSW, and whether SLSW occurrence is associated with reduced cortical information sharing and impaired task performance. In an existing within-subject dataset, 48 participants completed an auditory discrimination task with concurrent 64-channel EEG following a well-rested and a sleep-restricted night. Slow waves were detected trial by trial and related to weighted symbolic mutual information (wSMI), accuracy, reaction time, and response timeouts using mixed-effects models. Sleep restriction did not increase slow-wave occurrence, alter wave morphology or topography, or affect any behavioural or connectivity measure. Slow waves nevertheless occurred on approximately one fifth of trials in both conditions. At the trial level, wave occurrence was associated with reduced information sharing in nearly all participants and with a substantially elevated likelihood of response timeouts, alongside a small increase in reaction time; accuracy was unaffected, and information sharing predicted no behavioural outcome. Local sleep thus appears to be a spontaneous cortical phenomenon whose neural and behavioural correlates arise in parallel, rather than a mechanism by which sleep pressure degrades performance through disrupted information sharing.