Dissociating visuo-spatial and verbal working memory: It’s all in the features

Echoing many of the themes of the seminal work of Atkinson and Shiffrin (1968), this paper uses the Feature Model (Nairne, 1988, 1990; Neath & Nairne, 1995) to account for performance in working memory tasks. The Brooks verbal and visuo-spatial matrix tasks were performed alone, with articulatory suppression, or with a spatial suppression task; the results produced the expected dissociation. We used Approximate Bayesian Computation techniques to fit the Feature Model to the data and showed that the similarity-based interference process implemented in the model accounted for the data patterns well. We then fit the model to data from Guérard and Tremblay (2008); the latter study produced a double dissociation while calling upon more typical order reconstruction tasks. Again, the model performed well. The findings show that a double dissociation can be modelled without appealing to separate systems for verbal and visuo-spatial processing. The latter findings are significant as the Feature Model had not been used to model this type of dissociation before; importantly, this is also the first time the model is quantitatively fit to data. For the demonstration provided here, modularity was unnecessary if two assumptions were made: (1) the main difference between spatial and verbal working memory tasks is the features that are encoded; (2) secondary tasks selectively interfere with primary tasks to the extent that both tasks involve similar features. It is argued that a feature-based view is more parsimonious (see Morey, 2018) and offers flexibility in accounting for multiple benchmark effects in the field

Order Recall in Verbal Short-Term Memory is Influenced by Semantic Activation

It has recently been suggested that order recall in short-term memory tasks is influenced by the level of activation of items in the lexico-semantic network. According to the Activated Network view, increasing the level of activation of an item would increase the probability of observing a migration of the item toward the beginning of the list (Poirier et al., 2015). We tested this prediction by manipulating the orthographic neighbourhood of to-be-recalled items. In Experiment 1, the first three items of a 7-item list were orthographic neighbours of the target item in Position 5. As predicted, at recall, the target item migrated more toward the beginning of the list than control items. In Experiment 2, all list items were orthographic neighbours of the target item located on Position 4, 5, or 6. Compared to control items, the target item migrated more toward the beginning than the end of the list

Forward and backward recall: Different visuospatial processes when you know what’s coming

In an immediate memory task, when participants are asked to recall list items in reverse order, benchmark memory phenomena found with more typical forward recall are not consistently reproduced. These inconsistencies have been attributed to the greater involvement of visuospatial representations in backward than in forward recall at the point of retrieval. In the present study, we tested this hypothesis with a dual-task paradigm in which manual-spatial tapping and dynamic visual noise were used as the interfering tasks. The interference task was performed during list presentation or at recall. In the first four experiments, recall direction was only communicated at the point of recall. In Experiments 1 and 2, fewer words were recalled with manual tapping than in the control condition. However, the detrimental effect of manual tapping did not vary as a function of recall direction or processing stage. In Experiment 3, dynamic visual noise did not influence recall performance. In Experiment 4, articulatory suppression was performed on all trials and manual tapping was added on half of them. As in the first two experiments, manual tapping disputed forward and backward recall to the same extent. In Experiment 5, recall direction was known before list presentation. As predicted by the visuospatial hypothesis, when manual tapping was performed during recall, its detrimental effect was limited to backward recall. Overall, results can be explained by calling upon a modified version of the visuospatial hypothesis

A Curved Honulo improves your Short-Term and Long-Term Memory

During his distinguished career, Bill Hockley contributed to memory research in many ways, with work characterized by rigorous and innovative experimental designs. One of the areas he has explored is that of memory for associative information. We echo this interest here and attempt to emulate his careful experimental attitude. We report four experiments which examined how previously established links can support the development of new episodic associations. More specifically, we tested the idea that sound-symbolism links can support learning of new associations. Sound-symbolism links are relationships between phonemes and object characteristics that participants find natural − even if they have never encountered the items before. For instance, the nonword “honulo” is more readily seen to refer to a shape with curved contours than to a shape that has sharp angles. In Experiment 1, 70 participants studied three pairs and their memory for the associations between the members of each pair was tested in a paired-recognition task. Results demonstrate that sound-symbolism associations support the learning of new associations. Experiment 2 confirmed that the effect is replicated in a between-participants design. In Experiment 3, we replicated the findings with a 30-second filled interval between presentation and test, and in Experiment 4, we extended the delay to 2 minutes, establishing that the pattern is also found with a paradigm more typical of episodic memory. The results are discussed in terms of the importance of associative memory, while referring to some of the ideas Bill Hockley championed in his own work

The Production Effect Becomes Spatial

In the verbal domain, it is well established that words read aloud are better remembered than their silently read counterparts. It has been hypothesized that this production effect stems from the addition of distinctive features, with the caveat that the processing that generates added features interferes with rehearsal. Here, we tested the idea that a similar trade-off is found in the visuospatial domain. In all experiments, a short series of single dots sequentially appeared at various locations on a screen. Participants produced the items by clicking on them at presentation, watched the items appear quietly, or produced an irrelevant click after each item to better even out rehearsal opportunities between produced and control conditions. In Experiment 1, the dots appeared within a visible grid and an order reconstruction task was used. Experiment 2 also called upon reconstruction, but with the grid removed. In Experiments 3, a recall task was used. The results show that producing items hindered performance compared to the control condition. Conversely, production improved performance compared to the control condition where rehearsal was hindered. This is the first demonstration of a visuospatial production effect. The key findings were successfully modeled by the Revised Feature Model (RFM)

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

A Model of the Production Effect over the Short-Term: The Cost of Relative Distinctiveness

The production effect relates to the better memory of words read aloud during a study phase compared to silently read items. Here, we examined the production effect for memory over the short-term. In long-term memory tasks, the effect generates a complex pattern of results where production interacts with memory task and list composition. Within an immediate ordered recall paradigm, involving both item and order information, we tested the item-order account, recently called upon to explain the production effect. We also analysed results as a function of serial position. Results of the first five experiments were highly consistent, but hard to reconcile with the item-order account. Instead, we put forward an interpretation based on relative distinctiveness and the costs of the richer encoding associated with production. The predictions we derived from this interpretation were supported in the final experiment. Moreover, we tested the interpretation through a new version of the Feature Model. Overall, the work highlights the value of the production effect as a prototypical distinctiveness phenomenon illuminating the interaction of encoding and retrieval processes, the value of feature-rich representations, and the costs that can be associated with feature-generating distinctive processing

A new deep branch of eurasian mtDNA macrohaplogroup M reveals additional complexity regarding the settlement of Madagascar.

BACKGROUND: Current models propose that mitochondrial DNA macrohaplogroups M and N evolved from haplogroup L3 soon after modern humans left Africa. Increasingly, however, analysis of isolated populations is filling in the details of, and in some cases challenging, aspects of this general model. RESULTS: Here, we present the first comprehensive study of three such isolated populations from Madagascar: the Mikea hunter-gatherers, the neighbouring Vezo fishermen, and the Merina central highlanders (n = 266). Complete mitochondrial DNA genome sequences reveal several unresolved lineages, and a new, deep branch of the out-of-Africa founder clade M has been identified. This new haplogroup, M23, has a limited global distribution, and is restricted to Madagascar and a limited range of African and Southwest Asian groups. CONCLUSIONS: The geographic distribution, phylogenetic placement and molecular age of M23 suggest that the colonization of Madagascar was more complex than previously thought.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are