The process of verifying affirmative and negative sentences against pictures

Experiments 1 and 2 investigated sentence context effects on picture encoding in a sentence-picture verification and a picture naming task, respectively. The results showed that a picture following a sentence was encoded faster when the two were congruent than when they were incongruent. Experiment 3 compared two conditions: Under one condition, true affirmatives, false affirmatives, true negatives, and false negatives were mixed in each block of presentation. Under the other condition, different sentence types were presented in different blocks. The results showed (l) that errors committed in verification were largely negation errors, but seldom falsification errors, and (2) that there was a decrease of falsification time, but a resistance to change in negation time from the mixed to the blocked presentation. These results were interpreted to mean that falsification time results from a longer time to encode the picture and to confirm or disconfirm the truth index value by the polarity of the sentence in false affirmatives and true negatives than in true affirmatives and false negatives, whereas negation time and negation errors result from a response-suppression operation.