When co-action eliminates the Simon effect: Disentangling the impact of co-actor' s presence and task sharing on joint-task performance.

Thisstudyaimedatassessingwhetherthemerebeliefofperformingataskwithanotherperson,whoisinchargeofthecomplementarypartofthetask,issufficientfortheso-calledjointSimoneffecttooccur.Inallthreeexperimentsofthestudy,participantssataloneinaroomandunderwenttwoconsecutiveGo/NoGotasksthatwereidenticalexceptfortheinstructions.InExperiment1,participantsperformedthetaskfirstindividually(baselinetask),andtheneitherco-actingwithanotherpersonwhorespondedfromanunknownlocationtotheNoGostimuli(jointtask)orimagingthemselvesrespondingtotheNoGostimuli(imaginativetask).Relativetothebaseline,theinstructionsoftheimaginativetaskmadetheSimoneffectoccur,whilethoseofthejointtaskwereineffectiveinelicitingtheeffect.Thisresultsuggeststhatsharingataskwithapersonwhoisknowntobeinchargeofthecomplementarytask,butisnotphysicallypresent,isnotsufficienttoinducetherepresentationofanalternativeresponseabletoproduceinterference,whichhappensinsteadwhentheinstructionsexplicitlyrequiretoimaginesucharesponse.Interestingly,weobservedthatwhentheSimoneffectwasalreadypresentinthebaselinetask(i.e.,whentheresponsealternativetotheGoresponsewasrepresentedintheindividualtaskduetonon-socialfactors),itdisappearedinthejointtask.Weproposethat,whennoinformationabouttheco-actor’spositionisavailable,thedivisionoflaborbetweentheparticipantandco-actorallowsparticipantstofilteroutthepossible(incidental)representationofthealternativeresponsefromtheirtaskrepresentation,thuseliminatingpotentialsourcesofinterference.ThisaccountissupportedbytheresultsofExperiments2and3andsuggeststhatundercertaincircumstancestask-sharingmayreducetheinterferenceproducedbytheirrelevantinformation,ratherthanincreaseit

Evolutionary autonomous agents and the nature of apraxia

BACKGROUND: Evolutionary autonomous agents are robots or robot simulations whose controller is a dynamical neural network and whose evolution occurs autonomously under the guidance of a fitness function without the detailed or explicit direction of an external programmer. They are embodied agents with a simple neural network controller and as such they provide the optimal forum by which sensorimotor interactions in a specified environment can be studied without the computational assumptions inherent in standard neuroscience. METHODS: Evolutionary autonomous agents were evolved that were able to perform identical movements under two different contexts, one which represented an automatic movement and one which had a symbolic context. In an attempt to model the automatic-voluntary dissociation frequently seen in ideomotor apraxia, lesions were introduced into the neural network controllers resulting in a behavioral dissociation with loss of the ability to perform the movement which had a symbolic context and preservation of the simpler, automatic movement. RESULTS: Analysis of the changes in the hierarchical organization of the networks in the apractic EAAs demonstrated consistent changes in the network dynamics across all agents with loss of longer duration time scales in the network dynamics. CONCLUSION: The concepts of determinate motor programs and perceptual representations that are implicit in the present day understanding of ideomotor apraxia are assumptions inherent in the computational understanding of brain function. The strength of the present study using EAAs to model one aspect of ideomotor apraxia is the absence of these assumptions and a grounding of all sensorimotor interactions in an embodied, autonomous agent. The consistency of the hierarchical changes in the network dynamics across all apractic agents demonstrates that this technique is tenable and will be a valuable adjunct to a computational formalism in the understanding of the physical basis of neurological disorders

Enhancing communication through gesture and naming therapy

Purpose: This study investigated whether gesture, naming and strategic treatment improved the communication skills of 14 people with severe aphasia. Method: All participants received 15 hours of gesture and naming treatment (reported in a companion paper). Half the group received a further 15 hours of strategic therapy, while the remaining seven participants received no further input. The effects of therapy on communication were assessed with two novel measures. These required participants to convey simple messages and narratives to their communication partner. In both assessments a subset of the stimuli featured items that had been targets in gesture or naming treatment. Results: Performance on the communication measures was stable over two baseline assessments, but improved after gesture and naming treatment. Those who received additional strategic therapy made further gains on the message but not the narrative task. Communication gains were not specific to the stimuli featuring trained items. Conclusions: This study suggests that gesture and naming treatments can benefit interactive communication. The additional benefits of strategic therapy were less clear cut, but did impact on the transmission of simple messages. Gains seem to reflect the development of general communication skills, rather than the use of trained gestures and/or words

The Gender Congruency Effect across languages in bilinguals: A meta-analysis

In the study of gender representation and processing in bilinguals, two contrasting perspectives exist: integrated vs. the autonomous (Costa, Kovacic, Fedorenko, & Caramazza, 2003). In the former, cross-linguistic interactions during the selection of grammatical gender values are expected; in the latter, they are not. To address this issue, authors have typically explored the cross-linguistic Gender Congruency Effect (GCE: a facilitation on the naming or translation of second language [L2] nouns when their first language [L1] translations are of the same gender, in comparison to those of a different gender). However, the literature suggests that this effect is sometimes difficult to observe and might vary as a function of variables such as the syntactic structure produced to translate or name the target (bare nouns vs. noun phrases), the phonological gender transparency of both languages (whether or not they have phonological gender cues associated with the ending letter [e.g., “–a” for feminine words and “–o” for masculine words in Romance languages]), the degree of L2 proficiency, and task requirements (naming vs. translation). The aim of the present quantitative meta-analysis is to examine the robustness of the cross-linguistic GCE obtained during language production. It involves 25 experiments from 11 studies. The results support a bilingual gender-integrated view, in that they show a small but significant GC effect regardless of the variables mentioned above.This paper was funded through the state budget with reference IF / 00784/2013 / CP1158 / CT0013. The study has also been partially supported by the FCT and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). Government of Spain—Ministry of Education, Culture and Sports—through the Training program for Academic Staff (Ayudas para la Formación del Profesorado Universitario, FPU grant BOE-B-2017-2646), the research project (reference PSI2015-65116-P) granted by the Spanish Ministry of Economy and Competitiveness, and the grant for research groups (reference ED431B 2019/2020) from the Galician Government, as well as by the FCT (Foundation for Science and Technology, Portugal) through the state budget (reference IF / 00784/2013 / CP1158 / CT0013). Finally, the study has also been partially supported by the FCT and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653

Linguistic theory, linguistic diversity and Whorfian economics

Languages vary greatly in their words, sounds and sentence structures. Linguistic theory has shown that many aspects of variation are superficial and may not reflect underlying formal similarities between languages, which are relevant to how humans learn and process language. In this chapter, I show both how languages can vary and how the surface variations can be manifestations of underlying similarities. Economists have sometimes adopted a ‘Whorfian’ view that differences in languages can cause differences in how their speakers think and behave. Psychological experiments have shown both support for this hypothesis and evidence against it. Specific arguments that language causes thought, which have been made in recent economics papers, are examined in the light of what linguistics tells us about superficial and underlying variatio