Observing, performing, and understanding actions : revisiting the role of cortical motor areas in processing of action words

Language content and action/perception have been shown to activate common brain areas in previous neuroimaging studies. However, it is unclear whether overlapping cortical activation reflects a common neural source or adjacent, but distinct, sources. We address this issue by using multivoxel pattern analysis on fMRI data. Specifically, participants were instructed to engage in five tasks: (1) execute hand actions (AE), (2) observe hand actions (AO), (3) observe nonbiological motion (MO), (4) read action verbs, and (5) read nonaction verbs. A classifier was trained to distinguish between data collected from neural motor areas during (1) AE versus MO and (2) AO versus MO. These two algorithms were then used to test for a distinction between data collected during the reading of action versus nonaction verbs. The results show that the algorithm trained to distinguish between AE and MO distinguishes between word categories using signal recorded from the left parietal cortex and pre-SMA, but not from ventrolateral premotor cortex. In contrast, the algorithm trained to distinguish between AO and MO discriminates between word categories using the activity pattern in the left premotor and left parietal cortex. This shows that the sensitivity of premotor areas to language content is more similar to the process of observing others acting than to acting oneself. Furthermore, those parts of the brain that show comparable neural pattern for action execution and action word comprehension are high-level integrative motor areas rather than low-level motor areas

Adaptable Categorization of Hands and Tools in Prosthesis Users.

Some theories propose that tools become incorporated into the neural representation of the hands (a process known as tool embodiment; Maravita & Iriki, 2004). Others suggest that conceptual body representation is rigid and that experience with one’s own body is insufficient for adapting bodily cognition, as shown in individuals born without hands (Vannuscorps & Caramazza, 2016) and in amputees with persistent phantom hand representation (Kikkert et al., 2016). How sharp is the conceptual boundary between hands and tools? This question is particularly relevant for individuals who have lost one hand and use prosthetic hands as tools to supplement their missing hand function. Although both congenital one-handers (i.e., amelia patients) and one-handed amputees are encouraged to use prostheses, the former show a greater tendency than the latter to use prosthetic hands in daily tasks (Jang et al., 2011). One-handers have a fully functional remaining hand (allowing them to use handheld tools, etc.), which makes them less likely to show semantic distortions in hand and tool representation. However, their bodies and their interactions with their environment are fundamentally altered by their disability (Makin et al., 2013; Makin, Wilf, Schwartz, & Zohary, 2010). To determine how real-world experience shapes conceptual categorization of hands, tools, and prostheses, we recruited one-handers with congenital or acquired unilateral hand loss to take part in a study involving a priming task. We predicted that one-handers, particularly congenital one-handers, would show more conceptual blurring between hands and tools than control participants would, as a result of less experience with a hand and more reliance on prostheses (which are essentially tools) for typical hand functions. We further predicted that individual differences in prosthesis usage would be reflected in implicit categorization of hands, manual tools, and prostheses

Limits on prediction in language comprehension: A multi-lab failure to replicate evidence for probabilistic pre-activation of phonology

In current theories of language comprehension, people routinely and implicitly predict upcoming words by pre-activating their meaning, morpho-syntactic features and even their specific phonological form. To date the strongest evidence for this latter form of linguistic prediction comes from a 2005 Nature Neuroscience landmark publication by DeLong, Urbach and Kutas, who observed a graded modulation of article- and noun-elicited electrical brain potentials (N400) by the pre-determined probability that people continue a sentence fragment with that word ('cloze'). In a direct replication study spanning 9 laboratories (N=334), we failed to replicate the crucial article-elicited N400 modulation by cloze, while we successfully replicated the commonly-reported noun-elicited N400 modulation. This pattern of failure and success was observed in a pre-registered replication analysis, a pre-registered single-trial analysis, and in exploratory Bayesian analyses. Our findings do not support a strong prediction view in which people routinely pre-activate the phonological form of upcoming words, and suggest a more limited role for prediction during language comprehension

Large-scale replication study reveals a limit on probabilistic prediction in language comprehension

Do people routinely pre-activate the meaning and even the phonological form of upcoming words? The most acclaimed evidence for phonological prediction comes from a 2005 Nature Neuroscience publication by DeLong, Urbach and Kutas, who observed a graded modulation of electrical brain potentials (N400) to nouns and preceding articles by the probability that people use a word to continue the sentence fragment (‘cloze’). In our direct replication study spanning 9 laboratories (N=334), pre-registered replication-analyses and exploratory Bayes factor analyses successfully replicated the noun-results but, crucially, not the article-results. Pre-registered single-trial analyses also yielded a statistically significant effect for the nouns but not the articles. Exploratory Bayesian single-trial analyses showed that the article-effect may be non-zero but is likely far smaller than originally reported and too small to observe without very large sample sizes. Our results do not support the view that readers routinely pre-activate the phonological form of predictable words

Sickonomics : Diagnoses and remedies

Original article can be found at: http://www.tandfonline.com/ Copyright Taylor & FrancisIn their recent analysis of the alleged decay in modern economics, Ben Fine and Dimitris Milonakis claim to find its source and origin in the "marginal revolution" of the 1870s. They argue that this development led to "methodological individualism" and the detachment of economics from society and history. I contest their account of the marginal revolution and of the role of Alfred Marshall among others. They also fail to provide an adequate definition of methodological individualism. I suggest that neoclassical economics adopted a denuded concept of the social rather than removing these factors entirely. No such removal is possible in principle. It is also mistaken to depict neoclassical economics as the science of prices and the market. In truth, neoclassical economics fails to capture the true nature of markets. I consider some sketch an alternative explanation of the sickness of modern economics, which focuses on institutional developments since World War II.Peer reviewe

From North Africa to Latin America and back: comparative findings and theoretical reflections

Taking the different case studies of the book together, one general observation stands out: Key agents of socioeconomic contention, including movements by organized labor and the unemployed that were important in the run-up to the uprisings and that saw their political opportunities open up in the immediate aftermath of the revolutions, have since been effectively marginalized as political actors. The concluding chapter reflects on the causes of this weakness of socioeconomic contention by identifying comparative insights that emerge from the contributions to this volume and by situating them in the context of broader comparative and theoretical debates on the relationship between social movements and political change. More specifically, the chapter first discusses Egypt’s and Tunisia’s post-revolutionary trajectories from a comparative perspective. Second, it discusses these comparative findings in the light of experiences in Latin America. Third, drawing again on comparative scholarship on Latin America, the chapter offers a theoretical interpretation of some of the main dynamics observed in Egypt and Tunisia based on the notion of a popular-sector incorporation crisis. Fourth and finally, the chapter concludes with general implications and an outlook

Manipulable Objects Facilitate Cross-Modal Integration in Peripersonal Space

Previous studies have shown that tool use often modifies one's peripersonal space – i.e. the space directly surrounding our body. Given our profound experience with manipulable objects (e.g. a toothbrush, a comb or a teapot) in the present study we hypothesized that the observation of pictures representing manipulable objects would result in a remapping of peripersonal space as well. Subjects were required to report the location of vibrotactile stimuli delivered to the right hand, while ignoring visual distractors superimposed on pictures representing everyday objects. Pictures could represent objects that were of high manipulability (e.g. a cell phone), medium manipulability (e.g. a soap dispenser) and low manipulability (e.g. a computer screen). In the first experiment, when subjects attended to the action associated with the objects, a strong cross-modal congruency effect (CCE) was observed for pictures representing medium and high manipulability objects, reflected in faster reaction times if the vibrotactile stimulus and the visual distractor were in the same location, whereas no CCE was observed for low manipulability objects. This finding was replicated in a second experiment in which subjects attended to the visual properties of the objects. These findings suggest that the observation of manipulable objects facilitates cross-modal integration in peripersonal space

Can Historical Institutionalism be Applied to Political Regime Development in Africa?

Historical institutionalism has been used to explain the emergence of democracy and dictatorship in various regions of the world, but not applied to political development in Africa. Based on the recently refined concepts of historical institutionalism, the aim of this study is to provide a framework for the analysis of the various regime types that have been established in Africa during the last two decades: democratic, hybrid and authoritarian. Surprisingly little effort has been dedicated to a historically grounded explanation of these regime types. Against a common claim that African politics is mainly driven by informal institutions or behaviours, we argue that an institution-based examination of African politics is justified. We then provide a proposition of how to link up concepts of historical institutionalism with empirical cases in Africa, within a comparative approach. Our proposition for tracing specific development paths will not be based on the regimes as a 'whole', but on the deconstruction of a political regime into partial regimes and subsequently into selected formal and informal institutions. This will allow for an empirical analysis of the different components of a regime over long periods of time, and thus for path-dependent analyses of regime development

Liberalization, globalization and the dynamics of democracy in India

In the closing decades of the twentieth century there has been an almost complete intellectual triumph of the twin principles of marketization (understood here as referring to the liberalization of domestic markets and freer international mobility of goods, services, financial capital and perhaps, more arguably, labour) and democratization . A paradigm shift of this extent and magnitude would not have occurred in the absence of some broad consensus among policymakers and (sections of) intellectuals around the globe on the desirability of such a change. There seems to be a two-fold causal nexus between marketization and democracy. The first is more direct, stemming from the fact of both systems sharing certain values and attitudes in common. But there is also a second more indirect chain from marketization to democracy, which is predicated via three sub-chains (i) from marketization to growth, (ii) from growth to overall material development welfare and (iii) from material development to social welfare and democracy. We examine each of these sub-links in detail with a view to obtaining a greater understanding of the hypothesized role of free markets in promoting democracies. In the later part of the paper we examine the socio-economic outcomes governing the quality of democracy in a specifically Indian context