Processing Persuasive Arguments: 2. Discounting of Truth and Relevance as a Function of Agreement and Manipulated Activation Asymmetry

Abstract Previous research has demonstrated greater attention toward arguments with which one disagrees, increased recall and recognition for arguments with which one disagrees, and greater persuasibility during relative right than during relative left hemisphere activation of right-handers. Two experiments were performed to test whether these effects extend to the acceptance or rejection of persuasive arguments. Each experiment used induction of lateral orientation of attention as the means to selectively activate regions of the brain in normal subjects. Experiment 1 showed significantly greater discounting of arguments with which one disagrees during left- rather than during right-hemisphere activation, as measured by ratings of truth. Experiment 2 showed a similar significant agreement by lateral activation effect, but for ratings of relevance of the arguments. Both experiments supported the previously published research on cerebral asymmetries in the processing of persuasive arguments.