Attention Effects on the Auditory Event-related Potential

Abstract

Studies on selective-attention effects on the auditory event-related brain potential (ERP) are reviewed. Brainstem components of the ERP have not been shown to be sensitive to attention. On the other hand, attention effects in the middle-latency range (12–50 ms from stimulus onset) appear to occur under some conditions but it is not clear whether these effects are exogenous or endogenous. The predominant attention effect on the auditory ERP is the processing negativity, a slow endogenous negativity which often commences well before the exogenous (supratem-poral) NI component peaks (at about 100 ms post-stimulus), therefore giving the impression that this exogenous component is attention-sensitive. It is not yet settled, however, whether even these exogenous processes under some conditions might be modulated by selective attention.

CONCLUDING SUMMARY

The earliest selective-attention effects on the auditory ERP are not yet settled. Whereas it is quite clear that brainstem respones are not modulated by attention, effects at the middle-latency range under certain conditions seem to be quite firmly established. On the other hand, it is unclear whether they are of exogenous or endogenous nature although in the light of the available evidence, the latter alternative appears more likely. Puel et al.'s (13) data tentatively suggest that even the cochlear response might be sensitive to selective attention but an alternative interpretation in terms of a nonspecific effect should be ruled out.

PN appears to be the predominant, in many conditions even the only, effect of selective attention on auditory ERPs. However, the long controversy involving a possible selective-attention effect on some exogenous N1 component is not yet settled. Tentatively, it appears that the supratemporal N1 component is insensitive to attention (unless Giard et al.'s (25) effect originate as from an attentionally sensitive subpopulation of neurons generating this component). On the other hand, the negative component of the T-complex (maximal over the temporal sites) might be sensitive to intermodal selective attention.

Key Words:

• selective attention
• NI
• processing negativity