Theoretical positions lead to diverging predictions regarding the impact of control deprivation on subsequent performance. Learned helplessness research suggests that control deprivation impairs subsequent performance. This effect can be attributed either to a decrease in motivation or to a decrease in attentional resources. In contrast, control motivation hypothesis predicts that control deprivation increases careful processing of incoming information, and thus accuracy performance, unless the task is perceived as ego-threatening. In order to test these diverging predictions against each other, participants were exposed to zero, one, two, four, six or eight unsolvable (vs. solvable) problems and then asked to complete two letter cancellation tasks. This task allowed independent evaluation of effort expenditure (i.e., the number of letters scanned) and accuracy performance (i.e., percentage of letters correctly marked). Overall, the results were consistent with the predictions of the cognitive explanations of learned helplessness deficit as control deprivation at high levels reduced accuracy performance but not effort expenditure. Unexpectedly, effort expenditure was affected by problem solving activity. These results suggest that control deprivation could heighten motivation and, at the same time, deplete cognitive resources. Copyright © 2002 John Wiley & Sons, Ltd.