Investigating the processing architecture in memory intersection problems

Cues can be used to improve performance on memory recall tasks, and additional cues provide further benefit, presumably by narrowing the search space. Problems that require integration of two or more cues are referred to as memory intersections problems, or multiply constrained memory problems. The consideration of multiple cues in such problems can be done in parallel, when two (or more) cues are considered at the same time, or in serial, when one cue is considered after the other. The type of strategy, serial or parallel, is essential information for the development of theories of memory, yet evidence to date has been inconclusive. Using a novel application of the powerful Systems Factorial Technology (Townsend & Nozawa, 1995) we show participants use two cues in parallel in free recall tasks - a finding that contradicts two recent publications in this area. We then show that in a slightly modified variant of our method, constructed as a recognition task, most participants also use a parallel strategy but a reliable subset of participants used a serial strategy. Our findings provide important constrains for future theoretical development, point out strategy difference across recall- and recognition-based intersection memory tasks, and highlight the importance of tightly controlled methodological and analytic frameworks to overcome issues of serial/parallel model mimicry.