Response priming in a go/nogo task: do we have to explain the go/nogo N2 effect in terms of response activation instead of inhibition?

OBJECTIVES: In the present study, we examined the effects of response priming on the event-related potentials (ERPs) evoked by target stimuli in a go/nogo task. METHODS: In each trial, subjects were presented a cue and a target stimulus. The cue informed subjects about the following target in that trial, and therefore, also about the kind of response (right-hand response, left-hand response, no overt response) potentially to be given in that trial. RESULTS: The traditional N2 and P3 go/nogo effects were replicated: the ERPs to nogo targets were negative compared to the ERPs evoked by go targets in the N2 latency range at frontal electrode sites, and the nogo P3s were more anteriorly distributed than the go P3s. Comparing the ERPs evoked by nogo targets, we found the P3, but not the N2, to be modulated by response priming. CONCLUSIONS: These results seem to indicate that the P3, but not the N2, is associated with response inhibition, or with an evaluation/decision process with regard to the expected and/or given response. It could be speculated that the traditional go/nogo N2 effect has to be explained in terms of response activation instead of response inhibition.

African-American physicians and smoking cessation counseling.

While African American physicians can play a key role in encouraging black patients who smoke to quit, little is known about the views and activities of these physicians with respect to antitobacco programming. In the process of developing a protocol for encouraging physicians' smoking cessation intervention, 96 African-American physicians completed a survey indicating their knowledge, attitudes, and practices relating to stop smoking counseling. Few physicians reported patient help-seeking behavior and 47.9% cited lack of patient motivation as a key barrier to intervention. Only 46.8% believed that it is possible to accomplish a lot of cessation help in a few minutes time, and 34.4% believed that setting up and maintaining an office protocol would require a great deal of effort. Explaining health risks (71.9%) and enrolling patients in programs (66.6%) were perceived as keys to patient cessation; fewer than half of the physicians surveyed discuss specific strategies for quitting with their patients. Physicians indicated a willingness to offer more counseling in the future and were open to a range of strategies for learning more about effective approaches. Our findings support the need for dissemination of such information, particularly among specialists, to support antitobacco efforts among African-American physicians.