of microsleeps that people experience. Subjective, self-reported psychological tests like the Karolinska Sleepiness Scale (KSS), though widely adopted and positively correlated to EEG, often have limited utility because individuals sometimes are not aware of their level of sleepiness. Future research needs to focus more on objective microstates (e.g. detailed electrical output in briefer intervals) that underlie microsleep events so that electrical events can be understood in terms of behavioral events with greater accuracy. Then microsleep events could be more seamlessly distinguished from other states of consciousness, such as silent consciousness experienced during meditation. Diseases, clinical studies, and pharmacology Microsleeps are often tied to diseases. Sleep apnea is by far the most significant disease tied to microsleeps in terms of prevalence, affecting roughly 10–15 million people. Other diseases that may be tied to microsleeps include narcolepsy, hypersomnia, schizophrenia, and other causes of excessive daytime sleepiness. Microsleep episodes are often neglected and are not used as a diagnostic indicator for these diseases. Instead, clinicians use instrumentation like PSG to do a sleep study on patients to assess overall sleep quality in a laboratory setting. Microsleeps that recur and negatively influence day-to-day living often are clustered into the category of excessive daytime sleepiness. Thus, most clinical studies related to microsleeps are in the context of reducing microsleeps in excessive daytime sleepiness through the use of pharmacological interventions. Particularly, modafinil has become a popular drug to reduce microsleeps due to its stimulant effect with little to no side effects, and new drugs are often compared to the results of modafinil and placebo to assess efficacy (e.g. methylphenidate in Parkinson's Disease). Modafinil is also being tested across a range of diseases such as schizophrenia, narcolepsy, cataplexy, and sleep apnea. Overall, the trajectory of clinical studies relating to negative symptom microsleeps seems to more thoroughly test modafinil across more diseases and compare new drugs to the efficacy of modafinil to reduce the negative effects of microsleeps on people across a spectrum of diseases. Microsleeps sometimes are a side effect of various drugs, particularly in reference to dopamine-stimulating drugs in Parkinson's Disease. Particularly, somnolence is a recognized adverse effect of dopamine agonists, pramipexole and ropinirole. These drugs are known to cause sudden-onset sleep spells in roughly 50% of patients with Parkinson's disease (PD) while they were driving. Therefore, clinical interventions pertaining to microsleeps may also encompass reducing excessive sleepiness as a side effect of drug administration. Methotrexate