Attentional deficits in cocaine-dependent patients: converging behavioral and electrophysiological evidence

Abstract

Although there are several reports of patients with cocaine dependence displaying cognitive deficits, the nature of their information processing deficits is not well characterized. In the present study, the attentional performance of cocaine-dependent patients (n=14) was examined and compared with that of healthy control individuals (n=15). Attention was assessed using an auditory oddball event-related task as well as the Continuous Performance Test (CPT, Identical Pairs version). The cocaine-dependent group displayed P300 amplitude reduction compared to controls. The group difference in P300 response latency did not reach significance. On the CPT, the cocaine-dependent patients displayed significantly poorer discriminability and greater errors of commission than the controls. There was a positive correlation between performance on the oddball event-related task and performance on the CPT. This investigation provides converging behavioral and electrophysiological evidence of attentional deficits in cocaine-dependent patients.

Figure 1. Grand Averaged Response to the Infrequent Stimuli

Grand averaged event-related potential waveform at Pz for the cocaine-dependent patient group (in red) and healthy control group (in blue) where the X-axis depicts the time in msec and Y-axis depicts μV.