Modeling age-related differences in immediate memory using SIMPLE

In the SIMPLE model (Scale Invariant Memory and Perceptual Learning), performance on memory tasks is determined by the locations of items in multidimensional space, and better performance is associated with having fewer close neighbors. Unlike most previous simulations with SIMPLE, the ones reported here used measured, rather than assumed, dimensional values. The data to be modeled come from an experiment in which younger and older adults recalled lists of acoustically confusable and nonconfusable items. A multidimensional scaling solution based on the memory confusions was obtained. SIMPLE accounted for the overall difference in performance both between the two age groups and, within each age group, the overall difference between acoustically confusable and nonconfusable items in terms of the MDS coordinates. Moreover, the model accounted for the serial position functions and error gradients. Finally, the generality of the model’s account was examined by fitting data from an already published study. The data and the modeling support the hypothesis that older adults’ memory may be worse, in part, because of altered representations due to age-related auditory perceptual deficits

Positional uncertainty in the Brown-Peterson paradigm

Since McGeoch’s (1932) influential article, no accounts of long-term memory have invoked decay as a cause of forgetting. In contrast, multiple accounts of short-term memory (STM) invoke decay, with many appealing to results from the Brown-Peterson paradigm as offering support. Two experiments are reported that used a standard Brown-Peterson task but which scored the data in 2 ways. With traditional scoring (was the entire 3-letter consonant trigram recalled?) performance decreased with increasing delay. With immediate serial recall scoring (e.g., was the first letter recalled first, was the second letter recalled second?), standard position error gradients (Experiment 1), and protrusion gradients (Experiment 2) were observed. That is, when the first letter of the consonant trigram was not recalled first, it was more likely to be recalled second than last. In addition, if a letter from a previous list was mistakenly recalled in a later list, it most likely retained its original position. The presence of such gradients is inconsistent with claims of decay but is predicted by SIMPLE, a local distinctiveness model of memory. Moreover, the presence of such gradients is consistent with the claim that forgetting in the Brown-Peterson paradigm follows the same principles observed in other memory tasks

Serial position functions in general knowledge

Serial position functions with marked primacy and recency effects are ubiquitous in episodic memory tasks. The demonstrations reported here explored whether bow-shaped serial position functions would be observed when people ordered exemplars from various categories along a specified dimension. The categories and dimensions were: actors and age; animals and weight; basketball players and height; countries and area; and planets and diameter. In all cases, a serial position function was observed: People were more accurate to order the youngest and oldest actors, the lightest and heaviest animals, the shortest and tallest basketball players, the smallest and largest countries, and the smallest and largest planets, relative to intermediate items. The results support an explanation of serial position functions based on relative distinctiveness, which predicts that serial position functions will be observed whenever a set of items can be sensibly ordered along a particular dimension. The serial position function arises because the first and last items enjoy a benefit of having no competitors on 1 side and therefore have enhanced distinctiveness relative to mid-dimension items, which suffer by having many competitors on both sides

Backward recall and benchmark effects of working memory

Working memory was designed to explain four benchmark memory effects: the word length effect, the irrelevant speech effect, the acoustic confusion effect, and the concurrent articulation effect. However, almost all research thus far has used tests that emphasize forward recall. In four experiments, we examine whether each effect is observable when the items are recalled in reverse order. Subjects did not know which recall direction would be required until the time of test, ensuring that encoding processes would be identical for both recall directions. Contrary to predictions of both the primacy model and the feature model, the benchmark memory effect was either absent or greatly attenuated with backward recall, despite being present with forward recall. Direction of recall had no effect on the more difficult conditions (e.g., long words, similar-sounding items, items presented with irrelevant speech, and items studied with concurrent articulation). Several factors not considered by the primacy and feature models are noted, and a possible explanation within the framework of the SIMPLE model is briefly presented

From Brown-Peterson to continual distractor via operation span: A SIMPLE account of complex span

Three memory tasks—Brown-Peterson, complex span, and continual distractor—all alternate presentation of a to-be-remembered item and a distractor activity, but each task is associated with a different memory system, short-term memory, working memory, and long-term memory, respectively. SIMPLE, a relative local distinctiveness model, has previously been fit to data from both the Brown-Peterson and continual distractor tasks; here we use the same version of the model to fit data from a complex span task. Despite the many differences between the tasks, including unpredictable list length, SIMPLE fit the data well. Because SIMPLE posits a single memory system, these results constitute yet another demonstration that performance on tasks originally thought to tap different memory systems can be explained without invoking multiple memory systems

Express: additional evidence that valence does not affect serial recall

In immediate serial recall, a canonical short-term memory task, it is well established that performance is affected by several sublexical, lexical and semantic factors. One factor that receives a growing interest is valence, whether a word is categorized as positive (e.g., happy) or as negative (e.g., pain). However, contradictory findings have recently emerged. Tse and Altarriba (2022) in two experiments with one set of stimuli and fixed lists concluded that valence affects serial recall performance while Bireta et al. (2021) in three experiments with three sets of stimuli and randomized lists concluded that valence does not affect serial recall performance. Two experiments assessed the experimental discrepancy between Tse and Altarriba and Bireta et al. For both experiments, in one block every participant saw the exact same lists as those used in Tse and Altarriba and in the other block, each list was randomly constructed for each participant, as was done in Bireta et al. In Experiment 1, with concrete words varying in valence, we replicated the results of Tse and Altarriba with fixed lists and the results of Bireta et al. with randomized lists. In Experiment 2, with abstract words with both fixed and randomized lists we replicate the absence of effect valence like Tse and Altarriba and Bireta et al. Overall, we conclude that valence does not affect serial recall and the discrepancy was attributed to the peculiarity of the fixed lists used by Tse and Altarriba

Does Dynamic Visual Noise Eliminate the Concreteness Effect in Working Memory?

Dynamic visual noise (DVN), an array of squares that randomly switch between black and white, interferes with certain tasks that involve visuo-spatial processing. Based on the assumption that the representation of concrete words includes an imagistic code whereas that of abstract words does not, Parker and Dagnall (2009) predicted that DVN should disrupt visual working memory and selectively interfere with memory for concrete words. They observed a reversal of the concreteness effect in both a delayed free recall and a delayed recognition test. In six studies, we partially replicate and extend their work. In Experiments 1 (delayed free recall) and 2 (delayed recognition), DVN abolished, but did not reverse, the concreteness effect. Experiments 3 and 4 found no effect of DVN on a prototypical working memory task, immediate serial recall: concreteness effects were observed in both the control and DVN conditions. In contrast, Experiment 5 showed that DVN abolished the concreteness effect in an immediate serial recognition test. In the final experiment, subjects did not know whether they would receive an immediate serial recall or an immediate serial recognition test until after the list had been presented. Nonetheless, DVN had no effect on immediate serial recall but once again eliminated the concreteness effect on immediate serial recognition. The results (1) extend the effects of DVN on the concreteness effect to working memory tasks, (2) suggest that immediate serial recall and immediate serial recognition are more different than similar, and (3) have implications for theories of DVN, the concreteness effect, and models of memory

The orthographic/phonological neighbourhood size effect and set size

A growing number of studies have shown that on serial recall tests, words with more orthographic/phonological neighbours are better recalled than otherwise comparable words with fewer neighbours, the so-called neighbourhood size effect. Greeno et al. replicated this result when using a large stimulus pool but found a reverse neighbourhood size effect—better recall of words with fewer rather than more neighbours—when using a small stimulus pool. We report three registered experiments that further examine the role of set size in the neighbourhood size effect. Experiment 1 used the large pool from Greeno et al. and replicated their finding of a large-neighbourhood advantage. Experiment 2 used the small pool from Greeno et al. but found no difference in recall between the large and small neighbourhood conditions. Experiment 3 also used a small pool but the small pool was randomly generated for each subject from the large pool used in Experiment 1. This resulted in a typical large neighbourhood advantage. We suggest that set size is not critical to the direction of the neighbourhood size effect, with a large neighbourhood advantage appearing with both small and large pools

Set size and orthographic/phonological neighbourhood size effect in serial recognition: the importance of randomization

The neighbourhood size effect refers to the finding of better memory for words with more orthographic/phonological neighbours than otherwise comparable words with fewer neighbours. Although many studies have replicated this result with serial recall, only one has used serial recognition. Greeno et al. (2022) found no neighbourhood size effect when a large stimulus pool was used and a reverse effect—better performance for small neighbourhood words—when a small stimulus pool was used. We reexamined these results but made two methodological changes. First, for the large pool, we randomly generated lists for each subject rather than creating one set of lists that all subjects experienced. Second, for the small pool, we randomly generated a small pool for each subject rather than using one small pool for all subjects. In both cases, we observed a neighbourhood size effect consistent with results from the serial recall literature. Implications for methodology and theoretical accounts of both the neighbourhood size effect and serial recognition are discussed