A comparison of item and source forgetting

The purpose of the present research was to compare memory for an item with memory for the item’s source. Experiment 1 investigated discrimination between two external sources: each item in a list of words was spoken in either a male or a female voice. Subjects received a test of item recognition and a test of source monitoring at each of four delay intervals (immediate, 30 min, 48 h, 1 week). In contrast with previous research, no evidence of differential forgetting rates for item and source information was found. With delay intervals of 0 and 48 h, Experiment 2 replicated Experiment 1 while adding a reality monitoring condition that required discrimination between an internal (i.e., self-generated) and an external source. Subjects were better at making internal–external discriminations than at making external–external discriminations, but both types of source monitoring declined at the same rate as memory for the items themselves

Visual distinctiveness \u3ci\u3ecan\u3c/i\u3e enhance recency effects

Experimental efforts to meliorate the modality effect have included attempts to make the visual stimulus more distinctive. McDowd and Madigan (1991) failed to find an enhanced recency effect in serial recall when the last item was made more distinct in terms of its color. In an attempt to extend this finding, three experiments were conducted in which visual distinctiveness was manipulated in a different manner, by combining the dimensions of physical size and coloration (i.e., whether the stimuli were solid or outlined in relief). Contrary to previous findings, recency was enhanced when the size and coloration of the last item differed from the other items in the list, regardless of whether the “distinctive” item was larger or smaller than the remaining items. The findings are considered in light of other research that has failed to obtain a similar enhanced recency effect, and their implications for current theories of the modality effect are discussed