Dissociation of the mismatch negativity and processing negativity attentional waveforms with nitrous oxide

Abstract

In Näätänen's model of early attention, the role of arousal in influencing the permanent feature detection system (indexed by mismatch negativity [MMN]) and the temporary feature-detection system (indexed by processing negativity [PN]) is unclear. To address this question, we investigated the effects of the anesthetic gas nitrous oxide (N2O) on the MMN and PN. Ten subjects performed a dichotic listening task in which discrimination difficulty and breathing mixture (air or 25% N2O) were manipulated factorially. MMN, PN, N1 and P300 at Fz, Cz, and Pz, as well as reaction time (RT), were measured. N2O had no effect on the PN, but decreased MMN amplitude. As expected, N2O decreased the amplitude of the N1 and P300 and increased the latency of the P300 and RT. The dissociation of MMN and PN by N2O suggests that this agent decreases the ability to detect automatic stimulus change without affecting voluntary selective attention. We interpret these results as indicating that arousal has multidimensional effects on early attentional mechanisms. These dimensions can be differentiated chemically by neurotransmitters in the reticular formation of the brain.

The late Nd reflects a memory trace containing amodal spatial information

“…The third hypothesis, reception by the frontal mechanisms of a match with the attentional trace, is not ruled out on present evidence but at best is a contributing factor. The fourth hypothesis, transient arousal, is ruled out because Pang and Fowler (1999) observed that nitrous oxide, an anesthetic gas that decreases arousal, failed to influence either the early or late Nd, although this gas decreased the amplitude of the mismatch negativity (MMN), an ERP component that reflects an automatic stimulus change detector within the auditory attention system (Na¨a¨ta¨nen, 1990). It can also be noted that the MMN is unaffected by an interfering visual task (Singhal et al, 2002).…”

Attentional Lapses Under Decision-Making: An Event-Related Potential Study

“…The two components can be dissociated [Pang, Fowler, 1999]. Since the mismatch negativity is seen when there is a clear difference between the physical features of the presented stimuli, for example, in frequency [Näätänen et al, 2007], and mismatch negativity is unaffected by the voluntary processes, this is unlikely to be the cause of the observed differences in P2 amplitude.…”

Subhypnotic Doses of Isoflurane Impair Auditory Discrimination in Rats

“…27 There are no previous studies on the effects of isoflurane or other volatile agents on attention, but other anesthetic agents, such as ketamine, lorazepam, and diazepam, have been shown to impair performance on sensory tasks requiring selective attention, 28 -30 although evidence suggests that this is not the case for nitrous oxide. 31,32 There are no previous psychophysical studies of the effect of anesthetic agents on auditory sensory processing, and few studies in other sensory modalities. In addition to the aforementioned studies on ketamine, nitrous oxide, and benzodiazepines, there are two studies on humans that investigated the effect of low doses of isoflurane on performance in visual sensory tasks.…”