The effect of pain processing on attention capacity during visual search was examined in 2 experiments. In the first experiment, we investigated whether pain draws on the same limited resources as attentional task performance. It was hypothesized that pain would negatively affect task performance under different load manipulations. Low and high load conditions of a visual search task were presented in a mixed design combined with a painfully cold or neutral cold pressor test. Performance was not affected by pain. In experiment 2, low and high load conditions were separated in different blocks to study whether pain perception was affected when task load could be anticipated. Again, pain did not significantly affect task performance. In contrast, subjective pain intensity scores were significantly lower after performing the high load compared with the low load condition. Simultaneous recordings of event-related potentials indicated an increased negativity during the pain compared with the control condition. Also, in the early (350 to 450 msec) interval of event-related potentials, an increase in negativity was found for the high load compared with the low load condition. Topographic distributions suggested that pain and task load are mediated by qualitatively different resources.Perspective: Our findings indicate that highly demanding attentional task performance and pain processing interfere as a result of difficulties in allocating attention. The clinical relevance of this finding is that performing a highly demanding task might distract attention from pain. © 2006 by the American Pain Society Key words: Pain, cold pressor test, attention capacity, event-related potentials, distraction, visual search.I t has long been recognized that there are limitations to the capacity to allocate attention. 21,38 The resourcebased model of attention and pain processing suggests that pain and attentional tasks draw on the same limited attentional resources. 12 Results from studies investigating the role of attention in the processing of pain are, however, inconclusive. On the one hand, it has been shown that allocating attention to a cognitive task can modulate pain perception, ie, pain is perceived as less intense when distraction occurs, 12,45 although this has been challenged. 17,27 Performing an attention demanding cognitive task is hypothesized to displace attention available for the processing of pain. Moreover, a number of studies have shown that difficult tasks might be more successful in altering pain perception than easier tasks. 3,26,30,36 Hence, attention to a cognitive task might alter pain perception only when task load is sufficiently high.On the other hand, it has been hypothesized that pain perception can modulate attention demanding task performance. 9 Pain is a high-priority signal for danger and threat and therefore draws on limited capacity, which might lead to capacity limits being exceeded and there-