Information processing components of the auditory event related potential are reduced by cocaine

Abstract

The effects of cocaine on a human electroencephalographic event related potential (ERP) were measured. Forty-eight subjects received one of three IV doses (0.2, 0.4, or 0.6 mg/kg) and placebo. Thirty-three subjects received one of three oral doses (2, 3, or 4 mg/kg). All IV and oral doses reduced amplitude of the auditory ERP P200 and P300 components during the oddball task. P200 latency decreased. N100 amplitude was reduced only after IV administration. The changes in ERPs occurred during the period of peak cardiovascular and subjective effects. The amplitude reduction in ERP components occurring before the P300 component is consistent with decrements in attention, specifically selective attention. The P300 amplitude reduction after cocaine suggests a disruption of stimulus evaluation resources. The findings are inconsistent with the notion that stimulants affect only response selection and execution. The degree to which stimulants alter cognitive processes prior to response selection may depend on the magnitude of the cardiovascular, subjective, and probably other noncognitive effects.

Effects of Cocaine on P3B in Cocaine Abusers

“…The effects of cocaine on the ERPs of this group of heavier users of cocaine were different from our previous observations in less-frequent cocaine users [21], Specifi cally, we failed to replicate the immediate cocaineinduced reduction in P300 amplitude (P3B) observed in the oddball task [21], In the present study, cocaine blocked the decline observed over time in the P3B and SW amplitude observed on the placebo day. Specifically, P3B was significantly reduced from 150 to 210 min after the placebo; no such reduction was seen after the cocaine injection.…”

“…One possible explanation is that tolerance developed to the immediate effects of cocaine on P3B in these more frequent users of cocaine. In our original study, we attrib uted the cocaine-induced reduction in P3B to the disrup tive cardiovascular and subjective effects of cocaine [21]. We suggested that those infrequent users of cocaine were distracted form the auditory oddball tasks by the in creased cardiovascular effects and positive mood state produced by cocaine and as a result P3B was reduced.…”

“…Other stimulants such as amphetamine reduce the disruptive effects of repetition, boredom, fatigue and sleep deprivation on task performance [1][2][3][4][5][6][7][8][9][10][11][12][13]. Cocaine has also been reported to reverse the effects of fatigue and sleep deprivation [14][15][16], While cocaine has been shown to improve task performance in nonfatigued subjects [17][18][19], it has also been reported to be without any effects on similar tasks [19,20], Likewise, there is inconsistency in reports focusing on the effects of intravenous and oral doses of cocaine-altered event-related potentials (ERPs) elicited during cognitive tasks in nonfatigued subjects [21,22], Cocaine reduced the P3B component of auditory ERP elicited by the target tone in an auditory oddball tasks [21], Cocaine increased N100 amplitude and the contingent negative variation (CNV) elicited by the warn ing stimulus, but did not alter P3B amplitude elicited by the target stimuli in a continous performance task [22], It was thought that the lack of consistency might be due to the fact that most of these studies [18][19][20][21][22] had used individuals who use cocaine intermittently (once a week or less). Herein, we investigate the effects of cocaine in more frequent intravenous cocaine abusers (about 3 times a week) in order to determine whether the effects of cocaine on ERPs are similar to those observed in abusers who use cocaine less frequently.…”

Effects of Cocaine on Simple Reaction Times and Sensory Thresholds in Baboons

“…For example, cocaine users often experience hallucinations, with auditory hallucinations being most prominent (Brady, Lydiard, Malcolm, & Ballenger, 1991;Siegel, 1978). Cocaine can reduce the amplitude of some components of human auditory event-related potentials (Herning, Jones, Hooker, & Tulunay, 1985), although no changes in evoked potential sensitivity have been noted (Herning, Hooker, & Jones, 1987). In terms of visual function, it has been shown that d-methamphetamine can produce decrements in visual thresholds in nonhuman primates (Hienz et al, 1985).…”

Cocaine's effects on speech sound identification and reaction times in baboons

“…Previous studies have suggested that cocaine might adversely affect some aspects of auditory perception. For example, the latency and amplitude of auditory event-related potentials of humans are reduced following cocaine (Herning et al 1985;Robledo et al 1993), as are amplitude-intensity functions in the auditory nerve of guinea pigs (Shivapuja et al 1993). Behavioral demonstrations of auditory perceptual effects produced by cocaine, however, have been lacking.…”