Probing the orientation specificity of excitatory and inhibitory circuitries in the primary motor cortex with multi-channel TMS

Background: The electric field orientation is a crucial parameter for optimizing the excitation of neuronal tissue in transcranial magnetic stimulation (TMS). Yet, the effects of stimulus orientation on the short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) paradigms are poorly known, mainly due to significant technical challenges in manipulating the TMS-induced stimulus orientation within milliseconds. Objective: Our aim is to assess the effect of the TMS-induced stimulus orientation on the SICI and ICF paradigms and search for the optimal orientations to maximize the facilitation and suppression of the motor evoked potentials (MEP). Methods: We applied paired-pulse multi-channel TMS in healthy subjects to generate SICI and ICF with conditioning and test pulses in the same, opposite, and perpendicular orientations to each other. The conditioning- and test-stimulus intensities were 80% and 110% of the resting motor threshold, respectively. Results: Both SICI and ICF were significantly affected by the conditioning- and test-stimulus orientation. MEP suppression and facilitation were strongest with both pulses delivered in the same direction. SICI with a 2.5-ms and ICF with a 6.0-ms interstimulus interval (ISI) were more sensitive to changes in stimulus orientation compared with SICI at 0.5- and ICF at 8.0-ms ISIs, respectively. Conclusion: Our findings provide evidence that SICI and ICF at specific ISIs are mediated by distinct mechanisms. Such mechanisms exhibit a preferential orientation depending on the anatomical and morphological arrangement of inhibitory and excitatory neuronal populations. We also demonstrate that the SICI and ICF can be maximized by adjusting the TMS-induced electric field orientation.

Feature-based attention enables robust, long-lasting location transfer in human perceptual learning

Visual perceptual learning (VPL) is typically specific to the trained location and feature. However, the degree of specificity depends upon particular training protocols. Manipulating covert spatial attention during training facilitates learning transfer to other locations. Here we investigated whether feature-based attention (FBA), which enhances the representation of particular features throughout the visual field, facilitates VPL transfer, and how long such an effect would last. To do so, we implemented a novel task in which observers discriminated a stimulus orientation relative to two reference angles presented simultaneously before each block. We found that training with FBA enabled remarkable location transfer, reminiscent of its global effect across the visual field, but preserved orientation specificity in VPL. Critically, both the perceptual improvement and location transfer persisted after 1 year. Our results reveal robust, long-lasting benefits induced by FBA in VPL, and have translational implications for improving generalization of training protocols in visual rehabilitation.

Feature-based attention enables robust, long-lasting location transfer in human perceptual learning

Visual perceptual learning (VPL) is typically specific to the trained location and feature. However, the degree of specificity depends upon particular training protocols. Manipulating covert spatial attention during training facilitates learning transfer to other locations. Here we investigated whether feature-based attention (FBA), which enhances the representation of particular features throughout the visual field, facilitates VPL transfer, and how long such an effect would last. To do so, we implemented a novel task in which observers discriminated a stimulus orientation relative to two reference angles presented simultaneously before each block. We found that training with FBA enabled remarkable location transfer, reminiscent of its global effect across the visual field, but preserved orientation specificity in VPL. Critically, both the perceptual improvement and location transfer persisted after one year. Our results reveal robust, long-lasting benefits induced by FBA in VPL, and have translational implications for improving generalization of training protocols in visual rehabilitation.

Good for science, but which implications for business? An analysis of the managerial implications in high-impact B2B marketing articles published between 2003 and 2012

Purpose – This article aims to analyze a set of features in the managerial implications of the most-cited business-to-business (B2B) marketing articles which are related to their managerial relevance. The purpose is to further identify which are the most recurrent features of managerial implications, as well as the connections between such features. Finally, the articles aim to verify if these features of managerial implications vary depending on the scientific impact of the article. Design/methodology/approach – The 60 most-cited articles were selected from both generalist and specialized academic journals and a content analysis was conducted. Then the article assesses the formal features (e.g. dedicated space), the language (e.g. consulting or normative), the translation of scientific results (e.g. message efficacy) and such other features as time orientation, specificity and abstraction of the managerial implications in these high-impact articles. The article also analyses patterns and associations between the aforementioned dimensions across the 60 articles, also depending on their level of scientific impact (i.e. their number of citations). Findings – The results point that six out of nine features contributing to managerial relevance are the most frequently present in the implications (dedicated section easy to find, balance between academic and consulting language, partly scientific approach, overlap with scientific findings, message neither too complicated nor too simplistic, and long-term orientation). However, three other features reducing managerial relevance afflict nearly half of the articles: non-normative, generic and abstract implications. The ten articles lacking completely managerial implications are slightly more frequent among highest impact ones, which also often include overly complicated implications; while speculative and overly simplistic implications typically appear more among lowest impact articles which, however, also stand for very specific messages. There seems not to be any statistical correlation between the features contributing to managerial relevance and the scientific impact (number of citations) of an article. Instead, several of these features are correlated among each other, meaning that when one is missing, it is likely that the others also are. Finally, when implications are included in a dedicated section of the article, they tend to be specific and consequently also tend to have the other features favoring relevance. Originality/value – The article provides an empirically grounded assessment of features that influence the managerial relevance of scientific research in the areas of B2B marketing. Our results are, in fact, grounded in a detailed examination of the managerial implications of 60 high-impact articles in this disciplinary domain.