We assessed the transfer effects of training working memory strategies to a novel problem-solving task. Previous WM training studies have produced little evidence for transfer across contexts. In the ...current study, 64 6- to 9-year-olds were randomly assigned to one of four training conditions: semantic and rehearsal training, semantic training only, rehearsal training only, and treated control group. All training groups performed significantly better on the transfer task than the control group, but training groups did not differ significantly from each other. Implications of the findings for cognitive interventions and future WM training studies are discussed.
Flavescence dorée (FD) is a quarantine disease of grapevine, involving interactions between the plants, leafhopper vectors, and FD phytoplasma. Characterizing the susceptibility of vine varieties ...could limit disease propagation. After extensive surveys in vineyards, we showed that Cabernet Sauvignon (CS) is highly susceptible, with a high proportion of symptomatic branches and phytoplasma titers, in contrast to Merlot (M). Localized insect transmissions and grafting showed that phytoplasma circulate in the whole plant in the CS cultivar, but in M they are restricted to the transmission point. Insect-mediated transmission under high confinement mimicking natural conditions confirmed these phenotypes and allowed the classification of 28
accessions into three distinct categories, according to the percentage of infected plants and their phytoplasma titers. Reduced symptoms, low phytoplasma titers, and low percentages of infected plants were found to be associated in the
cultivars tested. Interestingly, the low susceptibility of M was observed for one of its parents, i.e., Magdeleine Noire des Charentes. Rootstocks and their
parents, although having high percentages of infected plants and intermediate to high phytoplasma titers, shared a symptomless response. This is troubling, because rootstocks can constitute a silent reservoir of contamination in mother plants or when they grow wild nearby vineyards. Altogether, data suggest distribution of genetic traits within the
genus involved in insect-mediated phytoplasma transmission, multiplication, circulation, and symptom development.
This article sets the stage for a debate, played out in two subsequent articles in this issue by Glenberg and by Mahon, regarding the role of embodied conceptual representations in cognitive ...operations such as language understanding and object identification. On an embodied view of cognition, championed by Glenberg, conceptual knowledge and thought are necessarily grounded in sensorimotor representations. The contrary position, advocated by Mahon, is that symbolic thought is the foundation for cognition and is independent of such representations, although it may coincidentally evoke them. I review a few of the many available demonstrations showing that cognition is influenced by sensorimotor representations. Then, taking Mahon's perspective, I illustrate how examples from various classes of these demonstrations can be explained by mechanisms other than embodiment of conceptual representations. I close with an example of what can be taken as evidence for the representation of a behavioural goal that is abstract in the sense that it is not coded directly as an embodied action.
Cet article ouvre la porte à un débat, mené dans deux articles subséquents du présent numéro par Glenberg et Mahon, traitant du rôle des représentations conceptuelles incarnées dans les opérations cognitives telles la compréhension du langage et l'identification d'objets. Dans une perspective incarnée de la cognition, avancée par Glenberg, les connaissances et pensées conceptuelles sont obligatoirement ancrées dans les représentations sensorimotrices. La position contraire, défendue par Mahon, stipule que la pensée symbolique est à la base de la cognition et indépendante de telles représentations, bien qu'elles puissent, par pure coincidence, les évoquer. J'examine une sélection des nombreuses démonstrations disponibles illustrant que la cognition est influencée par les représentations sensorimotrices. Ensuite, en utilisant la perspective de Mahon, je montre comment des exemples de diverses classes de ces représentations s'expliquent par des mécanismes autres que l'incarnation de représentations conceptuelles. Je conclus avec un exemple de ce qui pourrait être considéré comme preuve pour la représentation d'un but comportemental qui est abstrait dans le sens où il n'est pas codé directement comme une action incarnée.
Additive and interactive effects of word frequency, stimulus quality, and semantic priming have been used to test theoretical claims about the cognitive architecture of word-reading processes. ...Additive effects among these factors have been taken as evidence for discrete-stage models of word reading. We present evidence from linear mixed-model analyses applied to 2 lexical decision experiments indicating that apparent additive effects can be the product of aggregating over- and underadditive interaction effects that are modulated by recent trial history, particularly the lexical status and stimulus quality of the previous trial's target. Even a simple practice effect expressed as improved response speed across trials was powerfully modulated by the nature of the previous target item. These results suggest that additivity and interaction between factors may reflect trial-to-trial variation in stimulus representations and decision processes rather than fundamental differences in processing architecture.
Two classes of hand action representations are shown to be activated by listening to the name of a manipulable object (e.g., cellphone). The functional action associated with the proper use of an ...object is evoked soon after the onset of its name, as indicated by primed execution of that action. Priming is sustained throughout the duration of the word's enunciation. Volumetric actions (those used to simply lift an object) show a negative priming effect at the onset of a word, followed by a short-lived positive priming effect. This time-course pattern is explained by a dual-process mechanism involving frontal and parietal lobes for resolving conflict between candidate motor responses. Both types of action representations are proposed to be part of the conceptual knowledge recruited when the name of a manipulable object is encountered, although functional actions play a more central role in the representation of lexical concepts.
Switching between competing grasp postures incurs costs on speeded performance. We examined switch costs between lift versus use actions under task conditions that required subjects to identify ...familiar objects. There were no asymmetrical interference effects, though reliable costs occurred when the same object required a different action on consecutive trials. In addition, lift actions were faster to objects targeted for a prospective use action than objects irrelevant to this intended goal. The benefit of a lift-then-use action sequence was not merely due to the production of two different actions in short order on the same object; use actions to an object marked for the distal goal of a lift action were not faster than use actions applied to another object. We propose that the intention to use an object facilitates the prior action of lifting it because the motor sequence lift-then-use is habitually conscripted to enact the proper function of an object.
We demonstrate that constituents of motor actions associated with handled objects play a role in identifying such objects. Subjects held in working memory action plans for reaching movements; these ...action plans specified both the hand to be used (left or right) and a wrist orientation (vertical or horizontal). Speeded object identification was impaired when a pictured object matched the action on only one of these two categorical dimensions (e.g., a beer mug with its handle facing left, an action plan involving the right hand and vertical wrist orientation), relative to when the object matched the action on both dimensions or neither dimension. This result implies that identification of a manipulable object leads to automatic retrieval of matching features of a planned action along with nonmatching features to which they are bound. These discrepant features conflict with those of the target object, which results in delayed identification.
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