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The revelation effect is the tendency to call an item on a recognition test "old" if it is preceded by a different task interpolated between study and test. Seven experiments explored the generality of the revelation effect across a number of interpolated tasks. A revelation effect emerged when a variety of tasks preceded recognition test items; the effect was found for test items that followed a memory-span task, a synonym-generation task, and a letter-counting task. The compatibility between the test stimuli and the stimuli that composed the interpolated task was found to be a critical factor. With words as stimuli on a recognition test, a revelation effect was found when the stimuli in the interpolated task were words and letters. However, when numbers were the stimuli in the interpolated task, no revelation effect was found.

The Ranschburg effect refers to the finding of impaired serial recall of items repeated on a list. One account attributes this effect to the use of a strategy where subjects avoid using as guesses stimuli that they had recalled elsewhere on the list. Support for this interpretation is reported here. The Ranschburg effect is eliminated when subjects are instructed to avoid guessing. Also, the Ranschburg effect is found in partial report only when subjects are told that the crucial item occurred elsewhere on the list.

Substantial recency effects are found in immediate serial recall of auditory items. These recency effects are greatly reduced when an irrelevant auditory stimulus (a stimulus suffix) is presented. A number of accounts that have been proposed to explain these phenomena assume that auditory items are susceptible to masking or overwriting in memory. Later items overwrite earlier items, leading to an advantage for the last item, unless it is masked by a suffix. This assumption is called into question by evidence that presenting list items in two voices has no beneficial effect in immediate serial recall. In addition, it is shown that suffix effects on both terminal and preterminal list items are influenced by the physical similarity of the suffix to the terminal item and not by the physical similarity of the suffix to preterminal items.

Two experiments were designed to assess the relationship between task difficulty and arousal. Electrodermal measures of tonic and phasic arousal to four levels of task difficulty at stimulus onset and offset were studied in college students for intramodal and intermodal tasks. The students were presented for 18 trails with visual-auditory or visual-visual stimuli with either 2.0-, 0.2-, or 0.02-sec difference between stimuli onset or offset, and asked to judge which stimulus came on or went off first or merely to observe the stimuli. Both frequency and amplitude of skin conductance responses reliably differentiated the levels of task difficulty for both the intramodal and the intermodal task. None of the measures of tonic level of arousal was reliable. Electrodermal measures of phasic responses accurately reflected the task demands.