Alessandro Guida

How Chunks, Long-Term Working Memory and Templates Offer a Cognitive Explanation for Neuroimaging Data on Expertise Acquisition: A Two-Stage Framework.

Our review of research on PET and fMRI neuroimaging of experts and expertise acquisition reveals two apparently discordant patterns in working-memory-related tasks. When experts are involved, studies show activations in brain regions typically activated during long-term memory tasks that are not observed with novices, a result that is compatible with functional brain reorganization. By contrast, when involving novices and training programs, studies show a decrease in brain regions typically activated during working memory tasks, with no functional reorganization. We suggest that the latter result is a consequence of practice periods that do not allow important structures to be completely acquired: knowledge structures (i.e., Ericsson and Kintschs retrieval structures; Gobet and Simons templates) and in a lesser way, chunks. These structures allow individuals to improve performance on working-memory tasks, by enabling them to use part of long-term memory as working memory, causing a cerebral functional reorganization. Our hypothesis is that the two brain activation patterns observed in the literature are not discordant, but involve the same process of expertise acquisition in two stages: from decreased activation to brain functional reorganization. The dynamic of these two physiological stages depend on the two above-mentioned psychological constructs: chunks and knowledge structures.

Forgetting at short term: When do event-based interference and temporal factors have an effect?

Memory tasks combining storage and distracting tasks performed at either encoding or retrieval have provided divergent results pointing towards accounts of forgetting in terms of either temporal decay or event-based interference respectively. The aim of this study was to shed light on the possible sources of such a divergence that could rely on methodological aspects or deeper differences in the memory traces elicited by the different paradigms used. Methodological issues were explored in a first series of experiments by introducing at retrieval computer-paced distracting tasks that involved articulatory suppression, attentional demand, or both. A second series of experiments that used a similar design was intended to induce differences in the nature of memory traces by increasing the time allowed for encoding the to-be-remembered items. Although the introduction of computer-paced distracting tasks allowed for a strict control of temporal parameters, the first series of experiments replicated the effects usually attributed to event-based interference. However, deeper encoding abolished these effects while time-related effects remained unchanged. These findings suggest that the interplay between temporal factors and event-based interference in forgetting at short term is more complex than expected and could depend on the nature of memory traces.

The personalisation method applied to a working memory task: Evidence of long-term working memory effects

Ericsson and Kintsch (1995) proposed that, in situations of expertise, individuals can overcome working memory limitations by using long-term working memory. It allows a greater capacity than working memory thanks to long-term memory encoding and retrieving. To test this characteristic, an adaptation of Daneman and Carpenters (1980) reading span was used. To operationalise expertise, the personalisation method (Guida & Tardieu, 2005) was employed. In Experiment 1, a personalised group, which read reading span sentences that mentioned familiar locations, was compared to a nonpersonalised group, which read sentences with unfamiliar locations. In Experiment 2, a personalised group, which read reading span sentences with neutral locations, was encouraged to mentally personalise these locations by thinking about known locations. This group was compared to a nonpersonalised group, which was encouraged to think about unknown locations. The personalised groups were expected to store and retrieve information in long-term memory via long-term working memory more easily than the nonpersonalised groups, which had to count massively on working memory. The results showed that personalisation enhanced reading span and confirmed one implication of the long-term working memory theory: high- and low-reading-span differences could also be due to long-term memory retrieval. Finally, these results are interpreted in terms of interaction between working memory size and long-term memory knowledge, showing that participants with a lower reading span benefited more from high domain knowledge than participants with a higher reading span.

2011 space odyssey: Spatialization as a mechanism to code order allows a close encounter between memory expertise and classic immediate memory studies

In 2011 van Dijk and Fias with an innovative working memory paradigm showed for the first time that words to-beremembered, presented sequentially at the center of a screen acquired a new spatial dimension: the first words of the sequence acquired a left spatial value while the last words acquired a right spatial value. In this article, we argue that this spatialization which putatively underpins how order is coded in immediate memory 1 allows bridging the domain of memory expertise with classic immediate memory studies. After briefly reviewing the mechanisms for coding order in immediate memory and the recent studies pointing toward spatialization as an explanatory mechanism, we will pinpoint similar mechanisms that are known to exist in memory expertise, particularly in the method of loci. We will terminate by analyzing what these similarities can tell us about expertise.

Promoting the experimental dialogue between working memory and chunking: Behavioral data and simulation

Working memory (WM) is a cognitive system allowing short-term maintenance and processing of information. Maintaining information in WM consists, classically, in rehearsing or refreshing it. Chunking could also be considered as a maintenance mechanism. However, in the literature, it is more often used to explain performance than explicitly investigated within WM paradigms. Hence, the aim of the present paper was (1) to strengthen the experimental dialogue between WM and chunking, by studying the effect of acronyms in a computer-paced complex span task paradigm and (2) to formalize explicitly this dialogue within a computational model. Young adults performed a WM complex span task in which they had to maintain series of 7 letters for further recall while performing a concurrent location judgment task. The series to be remembered were either random strings of letters or strings containing a 3-letter acronym that appeared in position 1, 3, or 5 in the series. Together, the data and simulations provide a better understanding of the maintenance mechanisms taking place in WM and its interplay with long-term memory. Indeed, the behavioral WM performance lends evidence to the functional characteristics of chunking that seems to be, especially in a WM complex span task, an attentional time-based mechanism that certainly enhances WM performance but also competes with other processes at hand in WM. Computational simulations support and delineate such a conception by showing that searching for a chunk in long-term memory involves attentionally demanding subprocesses that essentially take place during the encoding phases of the task.

Distinctiveness as a function of spatial expansion in verbal working memory: comment on Kreitz, Furley, Memmert, and Simons (2015)

In a recent study, Kreitz et al. (Psychological Research 79:1034–1041, 2015) reported on a relationship between verbal working memory capacity and visuo-spatial attentional breadth. The authors hinted at attentional control to be the major link underlying this relationship. We put forward an alternative explanation by framing it within the context of a recent theory on serial order in memory: verbal item sequences entering in working memory are coded by adding a spatial context that can be derived from reading/writing habits. The observation by Kreitz et al. (Psychological Research 79:1034–1041, 2015) enriches this framework by suggesting that a larger visuo-spatial attentional breadth allows for internal coding of the verbal items in a more (spatially) distinct manner–thereby increasing working memory performance. As such, Kreitz et al. (Psychological Research 79:1034–1041, 2015) is the first study revealing a functional link between visuo-spatial attentional breadth and verbal working memory size, which strengthens spatial accounts of serial order coding in working memory.

Broca and Charcot’s Research on Jacques Inaudi:The Psychological and Anthropological Study of a Mental Calculator

In the nineteenth century, French scientific institutions became interested in young “mental calculators,” arithmetical prodigies able to quickly and accurately perform complex mental calculations. The first scientists to study mental calculators were phrenologists who sought to prove the existence of a calculating organ in the frontal lobe. Paul Broca introduced one such mental calculator, Jacques Inaudi, to the Anthropological Society of Paris in 1880. Broca attributed extraordinary faculty for mental calculation to memory functioning (the psychological hypothesis) rather than physiological difference (the phrenological hypothesis). In 1892, prominent French Academy of Sciences member Jean-Martin Charcot produced a noteworthy study of Inaudi on the organization’s behalf. Charcot observed that Inaudi called upon auditory memory rather than visual memory in his mental calculations, unlike most mental calculators who preceded him. Like Broca, Charcot was skeptical of the phrenological hypothesis, though he noted that Inaudi’s skull was markedly plagiocephalic. Interestingly, anthropological examination of Inaudi is consistent with the themes of modern cognitive neuroscience. Thus, Charcot seems to have anticipated present research on the localization of mental calculation and memory for numbers. 1. 1The Academy of Sciences, founded in 1666 by Louis XIV (1638–1715) with the goal of contributing to the advancement and application of the sciences in France, was one of the earliest European scientific institutions. As a prestigious society, it played an active role in defining scientific and technological research policy as well as drafting and publishing official reports.

Developmental Abilities to Form Chunks in Immediate Memory and Its Non-Relationship to Span Development

Both adults and children –by the time they are 2–3 years old– have a general ability to recode information to increase memory efficiency. This paper aims to evaluate the ability of untrained children aged 6–10 years old to deploy such a recoding process in immediate memory. A large sample of 374 children were given a task of immediate serial report based on SIMON®, a classic memory game made of four colored buttons (red, green, yellow, blue) requiring players to reproduce a sequence of colors within which repetitions eventually occur. It was hypothesized that a primitive ability across all ages (since theoretically already available in toddlers) to detect redundancies allows the span to increase whenever information can be recoded on the fly. The chunkable condition prompted the formation of chunks based on the perceived structure of color repetition within to-be-recalled sequences of colors. Our result shows a similar linear improvement of memory span with age for both chunkable and non-chunkable conditions. The amount of information retained in immediate memory systematically increased for the groupable sequences across all age groups, independently of the average age-group span that was measured on sequences that contained fewer repetitions. This result shows that chunking gives young children an equal benefit as older children. We discuss the role of recoding in the expansion of capacity in immediate memory and the potential role of data compression in the formation of chunks in long-term memory.

Charcot and the Mental Calculator Jacques Inaudi. Jean-Martin Charcot (1892): Procédés psychiques de fixation et de réviviscence des chiffres chez le calculateur Jacques Inaudi

In 1892, Jean Martin Charcot (1825-1893) was a member of the French Academie des Sciences (Academy of Sciences) and had the opportunity to examine a prodigious mental calculator named Jacques Inaudi (1867-1950). Charcot adopted the viewpoint of a neurologist and sought to develop a psycho-physiological explanation for the Inaudi case, presenting an extraordinary memory for numbers. Charcot’s official report was published in June 1892 and expressed the opinion of the members of the commission but not of himself alone. The manuscript found in Charcot’s archives and presented here is very informative. It exposes diverse elements already presented in the official report (Charcot, 1892) but it also expresses Charcot’s own opinion about Inaudi’s case and adds some new information about Charcot’s ideas about memory for digits and numbers.

Becoming an expert: Ontogeny of expertise as an example of neural reuse

In this commentary, we discuss an important pattern of results in the literature on the neural basis of expertise: (a) decrease of cerebral activation at the beginning of acquisition of expertise and (b) functional cerebral reorganization as a consequence of years of practice. We show how these two results can be integrated with the neural reuse framework.