Automatic memory search and the effects of information load and irrelevant information

Palmer, J., & Jonides, J. (1988). Automatic memory search and the effects of information load and irrelevant information. Journal of Experimental Psychology: Learning, Memory, and Cognition, 14(1), 136-144.

Abstract:
If automaticity is identified with both light capacity usage and little attentional selectivity, then an automatic process should be symptomatized by both small effects of concurrent information load and large susceptibility to interference by similar but irrelevant information. Several experiments are reported that test this prediction for memory search among sets of words. For well-learned memory sets, a small effect of information load co-occurs with a large effect of irrelevant information. By contrast, for arbitrary sets, a large effect of information load co-occurs with a small effect of irrelevant information. These results do confirm the correlation between effects of information load and irrelevant information as a hallmark for identifying automatic processes.

Note:
Both information load (defined by the number of memory set) which is related to the capacity and irrelevant information co-occur in the memory search.

After a fixation, memory items (set-size was varied) were presented. All the memory items were form name category (well-learned category) or from both name and no-name category (arbitrary category). A prime which may be corresponding to or conflicting to the category of memory items was manipulated. The prime was required to be focused (Exp 1) or ignored (Exp2). And then, participants were required to judge if the probe item was presented in the memory set.

Results showed that large information load effect in the arbitrary category, and participants may automatically process the irrelevant information (prime) in the well-learned category. Whether the prime was attended or ignored did not matter the result.