Daniel Bajic

The temporal dynamics of strategy execution in cognitive skill learning

The transition from algorithmic to memory-based performance is a core component of cognitive skill learning. There has been debate about the temporal dynamics of strategy execution, with some models assuming a race (i.e., independent, capacity unconstrained parallel processing) between algorithm and retrieval, and others assuming a choice mechanism. The authors investigated this issue using a new approach that allows the latency of each algorithm step to be measured, in turn providing new insight into (a) whether there is slowing of 1 or more algorithm steps on trials immediately preceding the 1st retrieval trial for an item, as might be expected if there is a competitive strategy execution process of some type other than a race, and (b) whether there is partial algorithm completion on retrieval trials, as would be expected if the 2 strategies are executed in parallel. Results are uniquely consistent with a strategy choice mechanism involving a competition between the retrieval strategy and the 1st step of the algorithm.

Cued recall from image and sentence memory: a shift from episodic to identical elements representation.

The applicability of the identical elements (IE) model of arithmetic fact retrieval (T. C. Rickard, A. F. Healy, & L. E. Bourne, 1994) to cued recall from episodic (image and sentence) memory was explored in 3 transfer experiments. In agreement with results from arithmetic, speedup following even minimal practice recalling a missing word from an episodically bound word triplet did not transfer positively to other cued recall items involving the same triplet. The shape of the learning curve further supported a shift from episode-based to IE-based recall, extending some models of skill learning to cued recall practice. In contrast with previous findings, these results indicate that a form of representation that is independent of the original episodic memory underlies cued-recall performance following minimal practice.

Major memory for microblogs

Online social networking is vastly popular and permits its members to post their thoughts as microblogs, an opportunity that people exploit, on Facebook alone, over 30 million times an hour. Such trivial ephemera, one might think, should vanish quickly from memory; conversely, they may comprise the sort of information that our memories are tuned to recognize, if that which we readily generate, we also readily store. In the first two experiments, participants’ memory for Facebook posts was found to be strikingly stronger than their memory for human faces or sentences from books—a magnitude comparable to the difference in memory strength between amnesics and healthy controls. The second experiment suggested that this difference is not due to Facebook posts spontaneously generating social elaboration, because memory for posts is enhanced as much by adding social elaboration as is memory for book sentences. Our final experiment, using headlines, sentences, and reader comments from articles, suggested that the remarkable memory for microblogs is also not due to their completeness or simply their topic, but may be a more general phenomenon of their being the largely spontaneous and natural emanations of the human mind.

Automatic mediation or absence of mediation? Commentary on Crutcher and Ericsson (2000)

R. J. Crutcher and K. A. Ericsson (2000; see record 2000-05419-014) showed that subjects stopped reporting mnemonic mediation in a recall task after sufficient practice. They concluded that subjects continued to use the mediator indefinitely but that its execution eventually became automatic and no longer required access to working memory. Their article thus supports the more general hypothesis that multistep cognition can take place without awareness. In this article the authors evaluate that conclusion on both conceptual and empirical grounds and report results of a new experiment that indicate that a qualitative shift to direct, unmediated recall can occur for at least some tasks.

Specificity of learning through memory retrieval practice: The case of addition and subtraction

The identical elements (IE) model (Rickard, Healy, & Bourne, Learning, Memory, and Cognition 32:734–748, 1994) of fact representation predicts that, in both verbal and numerical domains, performance gains with retrieval practice on multielement items will be specific to the practiced stimulus–response combinations, failing to transfer even to altered stimulus–response mappings of practiced items. In the case of arithmetic, the model predicts no transfer across either complementary operations (e.g., 4 × 7 to 28 / 4) or complementary division or subtraction problems (e.g., 28 / 4 to 28 / 7). Although that model has successfully described transfer effects in the domains of multiplication–division and episodic cued recall, it is challenged by a recent demonstration of positive cross-operation transfer for addition and subtraction (Campbell & Agnew, Psychonomic Bulletin & Review 16:938–944, 2009). We report results of a new addition–subtraction transfer experiment, the design of which closely matched that of a prior multiplication–division experiment that supported the model. The transfer results were consistent with the IE model. A two-component model of memory retrieval practice effects is proposed to account for the discrepant experimental results for addition and subtraction and to guide future work.

Specificity of children's arithmetic learning.

Among adults, arithmetic training-transfer studies have documented a high degree of learning specificity. Provided that there is a delay of at least 1day between training and testing, performance gains do not transfer to untrained problems, nor do they transfer to complement operation-inverted problems (e.g., gains for 4+7=__ do not transfer to the complement subtraction problem, 11-4=__, or vice versa). Here we demonstrate the same degree of learning specificity among 6- to 11-year-old children. These results appear to rule out, for the current training paradigm, operation-level procedural learning as well as any variant of complement problem mediation that would predict transfer. Results are consistent with either or both of two types of learning: (a) item-level procedural learning and (b) a shift to memory-based performance as predicted by the elemental elements model. These results suggest a developmental pattern such that specificity of learning among children is similar to that among adults. Educational implications are noted.

Toward a generalized theory of the shift to retrieval in cognitive skill learning

Prior research on cognitive skill learning has shown that algorithmic and direct memory retrieval strategies are not executed in parallel if the algorithm entails a series of long-term memory (LTM) retrieval steps (as in the case, for example, of mental arithmetic). This phenomenon has been hypothesized to reflect a bottleneck in LTM retrieval processes that forces a strategy choice during an early stage of processing. Here, we investigate simple perceptual–motor algorithms that involve no memory retrieval steps, a largely unexplored case in which parallel strategy execution models remain viable. Pronounced strategy interference was again observed, albeit interference that was different in important respects from that observed for LTM retrieval algorithms. It appears that neither parallel nor choice models, as developed to date, are sufficient as a generalized theory of this skill learning phenomenon. Issues central to the development of a more comprehensive theory are discussed.

In Search of Cross-Talk Facilitation in a Dual-Cued Recall Task

Despite earlier evidence that the presence of 2 redundant cues can facilitate activation of a common response, T. C. Rickard and D. Bajic (2004) found no dual-cue facilitation in the case of cued recall, provided that each cue-response association was learned independently. In this study the authors investigated the generality of their results using a dual-task cross-talk design. There was no evidence of dual-cue facilitation for compatible cue trials in the case of associative independence. Race models as well as at least some limited capacity parallel retrieval accounts can be eliminated by these and related results. It appears instead that a preretrieval stage performance bottleneck precludes cued recall through more than 1 independently represented cue-response association at a time.