Cognition, Computation, Communication and Perception (CCCP) Conference 2: “Theoretical and Neurobiological Bases of Higher Cognitive Functions” (Сознание, Вычисление, Коммуникация и Восприятие 2: «Теоретические и нейробиологические основы высших когнитивных функций»)

Cognition, Computation, Communication and Perception (CCCP) 2:

“Theoretical and Neurobiological Bases of Higher Cognitive Functions”

Сознание, Вычисление, Коммуникация и Восприятие 2: «Теоретические и нейробиологические основы высших когнитивных функций»

 Центр Нейроэкономики и Когнитивных Исследований

 Национальный Исследовательский Институт Высшая Школа Экономики, Москва, Россия

29-30 сентября 2015

Программа

Keynote presentations

The neurobiological basis of language Evelina Fedorenko Harvard Medical School, Massachusetts Institute of Technology, USA (evelina9@mit.edu)

Although many animal species have the ability to generate complex thoughts, only humans can share such thoughts with one another, via language.  My research aims to understand i) the system that supports our linguistic abilities, including its neural implementation, and ii) its interfaces with the rest of the human cognitive arsenal.  To tackle these questions, I use behavioral, fMRI, and genotyping methods in healthy adults, as well as intracranial recordings from the cortical surfaces in humans undergoing presurgical mapping (ECoG), and studies of patients with brain damage.

Attention and grammar: Event representations, linguistic representations, and language processing Russell Tomlin University of Oregon, USA (tomlin@uoregon.edu)

In my talk, I will discuss a theoretical and empirical framework for approaching how multiple attention systems are recruited during language production, considering both individual and dyadic protocols.  Congruent with Levelt’s (1989) blueprint for the speaker, this framework proposes a role for EVENT REPRESENTATION as a non-linguistic pre-cursor or alternative to conventional semantic representation and a model of FUNCTIONAL INTERACTION FOR LINGUISTIC REPRESENTATION that provides greater explicitness on how attentional processes do and do not map into the systemic detail of individual languages.

Interplay between abstract and concrete simulated representations. Andriy Myachykov Northumbria University, UK. (andriy.myachykov@northumbria.ac.uk)

 The question of the interplay between the domain-general and the domain-specific cognitive systems is at the heart of current psychological and neuroscientific research. This general question can be further subdivided into at least two more detailed questions. First, do mental representations that belong to different knowledge domains share similar organizational principles, resulting either from representational overlap or from the existence of higher-level representations shared between specific knowledge domains? Second, how do different domain-specific processes interface with the general systems of memory and attention? In my research, I pursue these two questions by conducting (1) cross-domain priming studies showing that similar organizational principles underlie representations from different abstract-knowledge systems (e.g. mental arithmetic and language syntax), and (2) studies that investigate the nature and properties of the attentional system subserving abstract (numbers and language) and concrete (manipulation affordances) mental operations. In my presentation, I will discuss results from my recent work in these two interrelated areas. 
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Poster presentations

1) “ Frequency-specific modulation of risk, certainty under gains and losses”

 Zachary A Yaple, Mario Martinez-Saito, Bhuvanesh Awasthi, Matteo Feurra, Anna Shestakova & Vasily Klucharev

 School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 Transcranial Alternating Current Stimulation (tACS) is a noninvasive stimulation technique that has been shown to enhance cognitive performance by means of entraining neural oscillations within adjacent cortical structures. For this study, we investigated whether it was possible to influence reward processing and cognitive control by frequency-specific tACS by targeting the bilateral prefrontal cortex. Stimulation was delivered online at 5, 10, 20, 40 Hz on the left and right lateral prefrontal cortex while respondents performed a modified volunteer task switching paradigm, in which gains and losses were granted depending on whether respondents chose to switch or repeat mental sets. This design allowed us to determine whether behavioural measures of cognitive control and risk versus certainty differed with respect to gain and loss domains. Preliminary results revealed a frequency specific modulation of 20Hz tACS delivered on the left prefrontal cortex significantly modulated reaction time of decisions associated with risk taking in the gain domain. We infer that this effect may underline frequency-specific and state-specific modulation of unexpected gains.

 Keywords: tACS, reward processing, cognitive control, prefrontal cortex, risk, task switching, gain promotion, loss prevention

 Support grant: This work is supported with a subsidy granted to the HSE by the government of the Russian Federation for the implementation of the Global Competitiveness Program.

2) “Memory for ads: influence of type of product, thematic congruence and typicality”

Beatriz Martin-Luengo (1), Karlos Luna (1,2) & Malen Migueles (3)

1. Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

2. Suleyman Sah University, Turkey

3. University of the Basque Country, Spain

 In this research, we studied how product interest, thematic congruence between advertisement and programme, and the typicality of the elements of an advertisement affect memory for new product ads in television, radio, and printed media. Three experiments were conducted with an ecological perspective, i.e., with realistic materials and an incidental exposure to the ads. Participants were exposed to a single type of media with two embedded ads. After a filler task, they completed a true/false recognition task. In television and radio, accuracy was higher for the interesting product ads. In three experiments, we found no effect of thematic congruence, and the standard effect of typicality. In printed media, where participants are free to read the ads or not, the differences in hits and false alarms in typicality were due to a change in the response criterion and not to an effect on memory. We conclude that different results can be obtained depending on the exposure to different media.

3)  "Pre-stimulus alpha oscillations and inter-subject variability of motor evoked potentials in paired pulse TMS paradigms"  

 Zafer Iscan, Maria Nazarova, Tommaso Fedele, Evgeny Blagoveshchensky & Vadim Nikulin

 There is an increasing interest in stimulating brain with different Transcranial Magnetic Stimulation (TMS) protocols to understand the short/long-term effects of the stimuli. Paired-pulse protocols gain interest as they provide cortical facilitation or inhibition. In this study, we aimed at finding a connection between prestimulus brain activity and the motor evoked potential (MEP) using paired and single pulse protocols to understand the effects that result from the stimuli. We calculated Spearman correlations between relative alpha power: (8-12) Hz / (4-16 Hz) of prestimulus multichannel EEG activity (1000 ms) with the motor evoked potentials (MEPs) during single pulse (SP) and paired-pulse TMS (ppTMS) protocols for intracortical facilitation (ICF) and short-interval intracortical inhibition (SICI) on 17 subjects. The application order of SP, ICF and SICI protocols was counterbalanced across subjects. Besides, we applied cluster statistics to capture the significant cluster channels. To check the differences between prestimulus EEG relative alpha power of SP, ICF and SICI protocols, we used Wilcoxon signed rank test with cluster statistics. Significant differences of SP, ICF and SICI relative alpha power in the prestimulus EEG give evidence that these protocols have distinct long lasting effects on the EEG activity.

4) "Classification using angle and radius of feature vector"

 Zafer Iscan

 School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 In this paper, use of angle and radius information for feature space classification is proposed. The performance of the classification using either angle or the radius was evaluated on two different feature spaces for three and four-class classification problems. The results were compared with the well-known K-Nearest Neighbor (K-NN) and Naïve Bayes (NB) algorithms in terms of the ability to classify the feature space and classification time. Results show that angle and radius-based classification could generate better classification performances, especially when there are few training vectors available. Moreover, proposed methods were computationally more efficient than K-NN and NB algorithms. However, optimum combination of angle and radius-based classification is needed for developing a general classifier which will perform well in classification of different feature patterns.

5) "Test–Retest Reliability of FreeSurfer Measurements Within and Between Sites: Effects of Visual Approval Process"  

 Zafer Iscan (1), Tony B. Jin, Alexandria Kendrick, Bryan Szeglin, Hanzhang Lu, Madhukar Trivedi, Maurizio Fava, Patrick J. McGrath, Myrna Weissman, Benji T. Kurian, Phillip Adams, Sarah Weyandt, Marisa Toups, Thomas Carmody, Melvin McInnis, Cristina Cusin, Crystal Cooper, Maria A. Oquendo, Ramin V. Parsey, Christine DeLorenzo

 1. School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 In the last decade, many studies have used automated processes to analyze magnetic resonance imaging (MRI) data such as cortical thickness, which is one indicator of neuronal health. Due to the convenience of image processing software (e.g., FreeSurfer), standard practice is to rely on automated results without performing visual inspection of intermediate processing. In this work, structural MRIs of 40 healthy controls who were scanned twice were used to determine the test–retest reliability of FreeSurfer-derived cortical measures in four groups of subjects—those 25 that passed visual inspection (approved), those 15 that failed visual inspection (disapproved), a combined group, and a subset of 10 subjects (Travel) whose test and retest scans occurred at different sites. Test–retest correlation (TRC), intraclass correlation coefficient (ICC), and percent difference (PD) were used to measure the reliability in the Destrieux and Desikan–Killiany (DK) atlases. In the approved subjects, reliability of cortical thickness/surface area/volume (DK atlas only) were: TRC (0.82/0.88/0.88), ICC (0.81/0.87/0.88), PD (0.86/1.19/1.39), which represent a significant improvement over these measures when disapproved subjects are included. Travel subjects’ results show that cortical thickness reliability is more sensitive to site differences than the cortical surface area and volume. To determine the effect of visual inspection on sample size required for studies of MRI-derived cortical thickness, the number of subjects required to show group differences was calculated. Significant differences observed across imaging sites, between visually approved/disapproved subjects, and across regions with different sizes suggest that these measures should be used with caution.

6) “The effect of economic competition on the neural mechanisms of decision-making”

M. Martinez-Saito (1), A. Shestakova, V (1). Klucharev1, B. Gutkin (1,2)

1. Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russia Federation

2. Ecole Normale Superieure, Paris, France

Behavioral economics has extensively studied how people make economic decisions in environments with different levels of supply and demand (i.e. with different levels of economic competition). However, the neural mechanisms underpinning such decisions remain unidentified. Here we study the neural mechanisms underlying decisions in different conditions of economic competition. Additionally, we aim to investigate the learning processes that lead to adaptive bargaining strategies and how these are modulated by the degree of economic competition. Fifteen subjects played the role of buyers in simultaneous games against different numbers of prerecorded buyers and sellers. We used a modified Ultimatum Game (double auctions) in 50-minute 3T functional magnetic resononace imaging (fMRI) scanning sessions. Overall, the game allowed us to identify the effects of competition (number of sellers and buyers) on subjects’ willingness to pay (the size of bids). Behavioral results demonstrated that subjects adjusted their trading price during the game based on the perceived competitiveness of the environment. We observed a progressive, yet incomplete convergence towards the optimal strategy predicted by a game-theoretic analysis. Intriguingly, the data hint at two separable learning processes involved: the subjects’ overall scales of bid values are mainly influenced by the market environment, whereas subjects' trial-by-trial adjustment of bid values instead display a skewed distribution modulated by the outcome of the previous trial. Preliminary fMRI data analysis showed significant differential activations and differential dynamics of the activity in the basal ganglia in the different competitive conditions. The results of the pilot study indicate that people learn to alter trading price based on the perceived competitiveness of the environment and suggest a profound role of the dopaminergic system in behavioral adaptations during economic competition.

7) “Executive control in automatic motor activations: Interference task leads to the inversion of the orientation affordance effect”

Nikolay Dagaev

 School of Psychology, National Research University Higher School of Economics, Russian Federation

 According to the notion of affordances, mere perception of familiar objects leads to automatic activation of related motor representations. However, the mechanisms that prevent automatic acting are still unclear. One possible mechanism is an inhibition by executive functions. In this study, participants were presented with photographs of graspable objects and asked to verify whether they are upright or inverted by making left-hand and right-hand responses; objects could be oriented with their graspable parts toward left or right hand. Participants had to simultaneously perform the backward-counting task (aimed to load the active monitoring mechanism): On each trial they were presented with a number and asked to subtract by three each time they hear a sound signal. The results of this condition turned out to be opposite to the classical (replicated in the control condition): RTs were slower on compatible trials than on incompatible ones. Thus, an inversion of the original effect was obtained. I propose the selfinhibitory account for these results, similar to the negative compatibility effect (Eimer & Schlaghecken, 1998). Usually active monitoring raises the threshold for the involvement of selfinhibition; but when the former is unavailable, this threshold drops again, and one can observe the inhibition of compatible response.

8) “Crosslinguistic phonological facilitation and cognitive control”

  Nikolay Novitskiy (1), Andriy Myachikov (1,2), Yury Shtyrov (1,3)

 1. Center for Cogntion and Decision Making, Higher School of Economics, Russia

 2. Department of Psychology, Northumbria University, Newcastle upon Tyne, UK

 3. Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark

  Modern linguistic theories suggest the words of all the languages of a multi-lingual person are stored in one lexicon in the brain and the selection takes place after word recognition (Dijkstra van Heuven, 1998, 2002). Thus living with two languages requires a substantial effort on executive control system. Indeed, a number of studies demonstrated the so-called “bilingual advantage” – higher performance of bilinguals in non-linguistic executive control tasks. Therefore, in the current study we aim at a balanced neurophysiological investigation of how a bilingual lexicon functions in the human brain as well as at understanding the influence of the degree of bilingualism on the functionality of the cognitive control system. The common lexicon for two languages is probed by using cross-linguistic homophones. We use a masked priming paradigm with Russian words (L1) as masked primes and English words (L2) as probes. In parallel, EEG is recorded and ERPs to the prime-target pair are calculated. The executive control is gauged by an established Attentional Network Task. The data of 11 Russian-English late unbalanced bilinguals recorded, including 10 subjects with EEG. Preliminary behavioral results suggest a trend for cross-linguistic facilitation due to both phonological and semantic similarities and for relation between inhibition and word perception.

9) “Reconstruction of handwriting with electromyography using the kalman filter”

  Elizaveta Okorokova (1), Mikhail Lebedev (3), Michael Linderman (4) and  Alex Ossadtchi (1,2)

 1. Centre for Cognition and Decision Making, National Research University Higher School of Economics, Moscow, Russia

 2. Laboratory of Control of Complex Systems, Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia

 3. Department of Neurobiology, Duke University, Durham, North Carolina, United States of America 

 4. Department of Biomedical Engineering, Norconnect Inc, Ogdensburg, New York, United States of America

  In recent years, several assistive devices have been proposed to reconstruct arm and hand movements from electromyographic (EMG) activity. Although simple to implement and potentially useful to augment many functions, such myoelectric devices still need improvement before they become practical. Here we considered the problem of reconstruction of handwriting from multichannel EMG activity. Previously, linear regression methods (e.g. the Wiener filter) have been utilized for this purpose with some success. To improve reconstruction accuracy, we implemented the Kalman filter, which allows to fuse two information sources: the physical characteristics of handwriting and the activity of the leading hand muscles, registered by the EMG. Applying the Kalman filter, we were able to convert eight channels of EMG activity recorded from the forearm and the hand muscles into smooth reconstructions of handwritten traces. The filter operates in a causal manner and acts as a true predictor utilizing the EMGs from the past only, which makes the approach suitable for real-time operations. Our algorithm is appropriate for clinical neuroprosthetic applications and computer peripherals. Moreover, it is applicable to a broader class of tasks where predictive myoelectric control is needed.

Key words:

 Handwriting, Electromyography, Pattern Recognition, Dynamical Modeling, the Kalman Filter, the Wiener Filter

 10) “Role of attention in sentence production”

 Mikhail Pokhoday and Andriy Myachykov

 Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 Understanding the determinants of syntactic choice in language production is one of the corner stones in psycholinguistic theories. Recent evidences (Myachykov and Tomlin, 2014 for review) suggest that syntactic choice is a result of interplay between different types of priming. These evidences however, come solely from visual attentional modality. In our research we address this issue by replicating visual cueing paradigm (Posner, 1980) experiments with auditory and motor modality cues. Additional factor of event orientation (Tversky, 2011) was also taken into account. Results suggest that cue location, as well as cue type and event orientation individually contribute to syntactic choice. Noteworthy the existence of a three-way interaction between factors opens new grounds for further research.

11)“The BDNF val66met polymorphism affects the Level of Processing effect of memory: A deep and shallow behavioral and rTMS study”

 Anna Shpektor (1), Nikola Vukovic (1), Enea Francesco Pavone (3), Matteo Feurra (1,3)

1. School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation.
2. Social and Cognitive Neuroscience Lab, IRCCS Santa Lucia Foundation, Rome, Italy
3. Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, Brain Investigation & NeuromodulationLab. (Si-BIN Lab), Azienda Ospedaliera Universitaria of Siena, Policlinico Le Scotte, Siena, Italy

  A polymorphism in the BDNF (BDNF val66met; rs6265) gene causing a valine (val)-to-methionine (met) substitution at codon 66 results in altered intracellular trafficking and packaging of BDNF, and in a reduction of its regulated secretion. BDNF-val/val carriers usually showed a better cognitive performance in terms of motor, attention and memory task with respect to those who are met-carriers. Not so far it has been shown that BDNFval66met genotype predicts variation in hippocampal anatomy as well as in human episodic memory function. So far it is still unclear if Val/Val subjects are susceptible to better plasticity and if their cognitive performance is a matter of better connectivity. Here we investigated how the BDNF val66met polymorphism affects cognitive memory performance in healthy young individuals. To do this we used a deep and shallow episodic memory task which is a classical paradigm to test the level of processing effect (LoP). Since val/val might be more susceptible to more stable plasticity change respect to Val/Met carriers, we used Repetitive Transcranial Magnetic Stimulation (rTMS) as interference approach to causally address the role of the left and right DLPFC during episodic memory retrieval with respect to the BDNF val66met polymorphism. To do this, we recruited two groups of healthy subjects (Val/Val and Val/Met carriers). Left and right DLPFC as well as a control site (Vertex) was targeted by time-locked rTMS at stimulus presentation during retrieval. Our findings indicated the causal involvement of the DLPFC in episodic memory by showing for the first time how rTMS at retrieval modulate the behavioral performance accordingly to the BDNF val66met.

 12) “State-dependent impact of Transcranial Alternating Current Stimulation of the motor mirror system”

  Maria Yurevich, Maria Nazarova, Evgeny Blagoveshchensky, Anna Lebedeva, Daria Pozdeeva, Vadim Nikulin, Matteo Feurra.

  School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

  Recent evidence showed that Transcranial Alternating Current Stimulation (tACS) entrains  the endogenous cortical oscillatory activity with a frequency and state-dependent specificity. In a previous study we showed state-dependent effects of tACS delivered on the primary motor cortex (M1) during a motor imagery task. The theta and alpha-tACS increase of corticospinal excitability, respectively indicated a reinforcement of working memory processes required to mentally process and “execute” the cognitive task and a synchronization of alpha oscillatory attentional patterns commonly associated with visual imagery. Here we adopted the same experimental setup to test state-dependent effects of tACS during action-observation, a cognitive task which produces the activation of the mirror motor system that simulates what would happen if the observer would execute himself a not goal-directed pinch-to grip action. Motor-evoked potentials (MEPs) were obtained by transcranial magnetic stimulation (TMS) of M1 by using an online-navigated TMS–tACS setup. Preliminary data showed that beta-tACS confirmed to increase M1 corticospinal excitability of subjects at rest. During action observation, the increase of corticospinal excitability was maximal with alpha-tACS, likely reflecting hypothesis that the mu rhythm in alpha range may specifically index downstream modulation of primary sensorimotor areas by mirror neuron activity and appear to reflect the translation of perception into action. Interestingly the absence of theta-tACS enhancement might reflect a lack of working memory engagement which is crucial for visual motor imagery. Our findings help to disentangle similarities and differences between motor imagery and action observation in terms of frequencies specificity and confirmed that tACS could be used to induce state-dependent enhancement effects.

13) “Long-Range Temporal Correlations in neuronal oscillations as predictors of TMS effects in paired-pulse paradigms”

  Evgeny Blagoveshchensky (1), Tommaso Fedele (1,2), Maria Nazarova (1,3), Zafer Iscan (1), Vadim Nikulin (1,4)

 1. Centre for Cognition and Decision Making, National Research University “Higher School of Economics”, Russian Federation,

 2. Neurosurgery Department, University Hospital Zurich, Zurich, Switzerland,

 3. Research Center of Neurology, Moscow, Russia, 

 4. Charité - University Medicine Berlin, Berlin, Germany

  In the present study we used Long-range Temporal Correlations in the amplitude dynamics of neuronal oscillations in order to predict and evaluate effects of intracortical facilitation (ICF) and short-interval intracortical inhibition (SICI) produced by paired-pulse TMS (ppTMS). LRTC in the alpha frequency range showed moderate intra-class correlation between the two rest sessions thus indicating a relative stability of the temporal dynamics between the sessions. Topographically, intra-class correlation was least pronounced over the stimulated areas thus demonstrating a potential long-lasting offline effect of TMS on neuronal activity. This was further confirmed by showing that there was a positive correlation between the magnitude of ICF and the magnitude of LRTC in 8–13 Hz range. Importantly, such correlation was regionally specific demonstrating strongest values over sensorimotor areas where TMS was applied. A less pronounced correlation was found between LRTC (in 10-12 Hz) and SICI. Neither LRTC before TMS nor the amplitude of alpha oscillations, however, were predictive of the strength of SICI/ICF.

 We showed that while effects of ppTMS can not be predicted from the neuronal dynamics at the resting state, recorded before the TMS experiments, ppTMS could sufficiently influence neuronal activity leading to the correlation between ICF/SICI and LRTC in the post-stimulation rest condition. Such correlations are most likely due to the fact that stronger ICF/SICI are likely to be associated with a more pronounced effect of ppTMS on the ongoing cortical activity

14) “Human motor cortex is functionally contributing to semantic processing of language: a combined Transcranial Magnetic Stimulation and behavioral study”

 Nikola Vukovic (1), Matteo Feurra (1), Anna Shpektor (1), Yury Shtyrov (1,2)

 1. Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation

 2. Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark

 The question of how linguistic meaning is represented in the brain stands as one of the foundational problems in cognitive science. Moving away from classical theories which studied language under the assumption of computational modularity, new research posits a tight link between “core” linguistic and sensorimotor brain structures. While new studies increasingly demonstrate early and parallel activation of these two systems, many still question whether this activity reflects functional links, or whether it is a mere epiphenomenon. TMS, with its ability to perturb neural processing online, is an ideal testing tool to investigate this question. Up to now, however, no TMS study directly investigated functional contributions of motor cortex to word semantics, as measured by changes in behavior during semantic and non-semantic tasks. Here, we tested 28 participants who performed a lexical decision, and a semantic decision task, while applying a 20Hz online interference TMS protocol. Our results demonstrate that stimulation of the Left M1 hand area leads to slower semantic processing of action targets, compared to abstract words, as revealed by reaction times. This effect was selectively observed only when participants made a semantic judgment, as opposed to a lexicality judgment, and was moreover, restricted to the left hemisphere of the brain. These findings show that previously observed motoric activity during word comprehension in EEG, MEG, and fMRI studies, is not simply a downstream phenomenon, but is reflective of functional contributions of motor cortex to semantic word representation.

15) “Artificial Stock Market via Neuroeconomic Multi-Agent System”

 Johann Lussange

 Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 We present here early results on a computational research work to study collective economic behavior via Multi-Agent System (MAS), where each agent is endowed with simple Hierarchical Reinforcement Learning (HRL) capabilities, together with cognitive and behavioral biases known to the field of neuroeconomics. The relevance of this study is based on the two fundamental hypotheses that these autonomous agents somewhat faithfully describe real traders (whether algorithmic or human) in stock markets, and that the trading transactions would also well fit those of actual stock markets. We describe the general architecture of this stock market simulator and show that it produces the stylized facts observed in real stock markets (e.g. bid-ask spread formation, volatility clustering, leptokurtic return distributions, etc...).

16) “Neural mechanisms of post-decisional spreading of alternatives: EEG study”

 Marco Colosio, Anna Shpektor, Anna Shestakova, Vasily Klucharev

 School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 Objective: Cognitive Dissonance (CD) theories state that preferences can be modulated by the mere act of choosing. According to CD theory (Festinger, 1957), a decision between two similarly valued alternatives creates a psychological tension (dissonance) that is reduced by  post-decisional re-evaluation of the alternatives, the chosen item being evaluated mor positively and the rejected item more negatively. Some neuroimaging studies (see Izuma 2013 for a review) suggested that activity of the medial prefrontal cortex (mPFC) underlies postdecisional spreading of alternatives, nevertheless the exact mechanism of CD remains unclear

 Methods: 10 right-handed hungry participants performed a free-choice paradigm (Izuma at al., 2010), in which participants were initially asked to rate their preference for food items (snack food) using 8-point Likert scale. Next, subjects made choices between pairs of foods (Self trials in the Choice task) which varied systematically so that choices were sometimes made between two equally liked items (Self-Difficult trials), and other times between one liked item and one disliked item (Self-Easy trial). In still other trials, choices were made randomly by a computer between two equally liked items (Computer trials, control condition). Next, participants were asked to rate the original set of food items again to detect post-decisional spreading. We also recorded response-locked event-related potentials (ERP) during Self-Difficult and Self-Easy trials.

Results: Our behavioral result clearly show post-decisional spreading of alternatives, i.e. items that were rejected during Self-Difficult trials were rated significantly more negative than those rejected during Self-Easy trials. Interestingly, decisions during Self-Difficult trials were accompanied by a stronger negative fronto-central ERP similar to the Error-Related Negativity (ERN).

Conclusion: ERN has been previously associated with incorrect responses and general performance monitoring mechanism (Young at al. 2004). Overall, our results suggest that CD can be mediated by the activity of the mPFC as a part of the general performance-monitoring circuitry.

17) “Test-retest reliability of nTMS mapping of direction and multimuscle representation in the human primary motor cortex (pilot study results)”

Darya Pozdeeva (1), Maria Nazarova (1,3), Pavel Novikov (2), Zafer Iscan (1), Evgeny Blagoveshchensky (1), Vadim Nikulin (1,4)
1 Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation 
2 Bauman Moscow State Technical University, Russian Federation
3 Research Center of Neurology, Moscow, Russian Federation 
4 Charité - University Medicine Berlin, Berlin, Germany

             Despite being one of the most studied brain structures primary motor cortex (M1) still remains an open question for researches. Rigid somatotopical organization of M1 which has been a dominant concept for many decades after the iconic works of H. Jackson and Penfield & Boldrey has been proven to be an oversimplified view. Primarily using micro-scale approaches like microstimulation it was shown that functional aspects of movement such as direction, velocity or joint angles could also be represented in the M1. At the macro-scale level one of the closest approaches to microstimulation is an approach of focal non-invasive brain stimulation such as transcranial magnetic stimulation (TMS), especially MRI navigated TMS (nTMS), which allows non-invasive motor cortex mapping with the accuracy of 1-2 mm. Being a routine practice in presurgical mapping nowadays it is still facing problems preventing it`s wider use for detailed investigation of the motor cortex organization. One of the main of them is a problem of nTMS motor maps stationarity in repeated measurements, without understanding of which the study of the changes in different experimental conditions is impossible. The aim of the present work is to explore the potential of the nTMS mapping methodology to examine the organization of the hand motor control at the cortical level. The idea is to assess the test-retest reliability of the nTMS motor maps of several hand muscles' cortical representations, their overlaps and of the directions of TMS-induced movements during rest and while isometric contraction of one of the investigated muscles. The study is currently ongoing, first part of the project includes probing of a test-retest reliability of multimuscular nTMS motor maps during rest. Sessions consists of multimuscular nTMS mapping of the cortical representation of the three upper limb muscles: abductor pollicis brevis (APB), abductor digiti mininmi (ADM) and extensor digitorum communis (EDC) in healthy right-handed male subjects (n=20). Two mapping sessions are repeated in 6-8 days. The results for the first five subjects including the repeatability of standard parameters like the size of the cortical muscle representation, hotspot and center of gravity location and additional parameters such as the volume of the representation, the shape of the area, the profile of the muscle cortical representation and the overlap between representations are presented. Between-sessions interval will include 5 sub-sessions with TMS pulses given in the same position using a grid.

For now, we already analysed the similarity of the binary images of the maps, which we consider as a reflexion of the similarity of the spatial distribution of cortical excitability in the hand area of the motor cortex on the first day of testing and after a week (analyzedin MATLAB, using Jaccard coefficient calculation)

 In our study we use individual MRI-navigated NBS eXimia Nexstim TMS setup, electromyography recordings from three muscles to obtain data for MEP-maps and the accelerometer attached to the distal phalanx of the thumb/index finger to obtain the data to construct the “movement directions maps”.

The study is currently ongoing, preliminary results were received for test/retest sessions for 5 subjects and processed MEP-data in the Superposition software to create MEP-maps of the three target muscles and also quantitatively evaluate the areas of their overlap in each session

Transcranial magnetic stimulation (TMS) allows noninvasive studies of cortical excitability in human. The method of MRI-navigated TMS (nTMS) in which the location of the magnetic coil is shown over the MRI reconstruction of the individual’s brain in real time made it possible to obtain reliable maps of cortical motor muscle’s representations with high spatial accuracy. It is well known that voluntary movements in hemiparetic stroke patients are restricted to the limb synergies which are marked by the inability to perform individual joint movements, so to perform precise muscles contractions. Thereby the problem of somatotopical mapping of the upper limb muscle’s cortical representations and their overlaps is very important for understanding of the process of neuroplasticity in patients after brain damage, like stroke.

18) "Multimodal assessment of the motor system for hand motor recovery prognosis in chronic ischemic stroke patients - fMRI-DTI-nTMS study”

 Maria Nazarova, Mikhail Piradov, Pavel Novikov, Konovalov, Vadim Nikulin.

 Hand motor recovery prognosis in chronic ischemic stroke patients is crucial to determine the extent of rehabilitation potential and therefore to develop a realistic individual rehabilitation plan. The aim of the study was to perform a multimodal assessment and compare a predictive role of different structural and functional biomarkers including cortical representation of upper limb muscles and their overlap measured by nTMS for hand motor recovery in chronic stroke patients. Total of 30 patie”nts with the only chronic (> 6 months) supratentorial ischemic stroke and various severity of hand paresis were enrolled. The assessment included investigation of structural parameters such as corticospinal tract (CST) integrity measured by diffusion tensor imaging (DTI) and TMS and functional assessment including analysis of BOLD response of the cortical areas induced by passive raising of the index finger of the paretic hand, cortical excitability level assessment in both affected (AH) and unaffected hemisphere (UH) reflected by short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) phenomena in the m. Abductor Pollicis Brevis (APB) muscle and nTMS motor mapping of one of the intrinsic hand muscles - APB and one of the extrinsic hand muscles - m. Extensor Digitorum Communis (EDC). A control group of 26 healthy () volunteers also completed the study. Hand motor function was analyzed by Fugl-Meyer assessment scale and Action Research Arm Test (ARAT). Main conclusions of the study are following:

 1. FA asymmetry in the internal capsule  may be considered as a clinically available measurement of CST integrity for hand motor prognosis in chronic ischemic stroke patients. Presence of MEPs in at least one of the hand muscles but not the level of RT may be used as a functional analogue of CST integrity in this group.

 2. Significantly higher disinhibition in the unaffected hemisphere in well recovered patients and normal SICI in patients of the unfavorable outcome group let to suppose that interhemispheric interaction is changing extensively during the process of recovery from subacute to chronic phase.

 3. fMRI activation for hand motor recovery should be analyzed independently in patients with pure subcortical vs patients cortical/cortico-subcortical ischemic stroke, interpretation of the ipsilesional primary sensorimotor cortex activation as a biomarker for hand motor recovery is not possible.

 4. Unaffected hemisphere RT may be viewed as a general measure of cortical excitability which is correlated with ipsilesional primary sensorimotor cortex activation in fMRI during affected passive motor paradigm.

 More information can be found here:

http://www.researchgate.net/publication/279175225_MULTIMODAL_ASSESSMENT_OF_THE_MOTOR_SYSTEM_FOR_HAND_MOTOR_RECOVERY_PROGNOSIS_IN_CHRONIC_ISCHEMIC_STROKE_PATIENTS_-_fMRI-DTI-nTMS_STUDY

19) “Software for quantitative assessment of the results of navigated TMS mapping”

Maria Nazarova (1,3), Pavel Novikov (2), Daria Pozdeeva (1), Vadim Nikulin (1,4)

1 Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation
2 Bauman Moscow State Technical University, Russian Federation
3 Research Center of Neurology, Moscow, Russian Federation
4 Charité - University Medicine Berlin, Berlin, Germany

Introduction.

Transcranial magnetic resonance (TMS) is a modern non-invasive approach to study brain organization in humans. Recently, navigation based on individual magnetic resonance images (MRI) became available for use during TMS resulted in the technique called navigated TMS (nTMS). Nowadays motor and speech nTMS mapping are routinely used for presurgical brain mapping in neurosurgery. However, wider use of nTMS mapping for research purposes, for example, to study motor cortex organization, is still facing important obstacles. First, there is no general agreement which parameters of nTMS motor  mapping should be assessed. Second, in nTMS motor mapping studies some well known principles of the motor cortex organization such as divergence and convergence are generally overlooked. Third, even for the most commonly used parameter - the size of the cortical representation area there is still no standard method for calculation.

 New method.

 We developed a software "Superposition" for quantative analysis of the results of motor nTMS mapping, which allows to consider not only standard parameters like the size of the cortical muscle representation and hotspot and center of gravity location, but as well the volume of the representation considering the amplitude of MEPs in each stimulation spot, the shape of the area, the profile/landscape of the muscle cortical representation and the overlap between representations.

 The software was written in C# on the Windows platform, it is totally independent and has graphical interface. The input data includes coordinates of the EF maximum and MEPs amplitude in each point of stimulation and individual MRI. The profile/landscape of the muscle representation is built using two approaches: 1) as a total of Gaussians in each stimulation spot depending on the amplitude of the MEP in the spot; 2) by finding of a smooth surface going though all stimulation points considering the amplitudes of the MEPs in each point (ABOS method).

 The results of area calculation were compared with results got using the method of spline interpolation, which was shown to have a good repeatability in the previous studies (Julkunen 2014).The software "Superposition" was used for the analysis of the nTMS mapping data for several upper extremity muscles in healthy volunteers and stroke patient with hand motor deficit.

 20) “TMS of non-literal language processing”

 Elena Kulkova, Yury Shtyrov, Andriy Myachykov

 School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation

 In accordance with the Embodied Cognition view, single words and sentences describing actions activate motor and premotor cortices (Aziz-Zadeh et al., 2006; Raposo et al., 2009; Desai et al., 2013). However, it is still under debate whether processing of abstract non-literal language leads to sensory-motor activations (Cacciari et al., 2010; Raposo et al., 2009; Cacciari and Pesciarelli, 2013) and whether the same mechanisms are employed for literal and figurative language processing (Hauk et al., 2004; Buccino et al., 2005).

 These questions are addressed in the current project, which is aimed at finding TMS evidence for the fact that motor involvement in sentence processing is  conditioned by the type of meaning (literal or figurative) and dependent on the number of additional factors. To provide support for the hypothesis that cognitive mechanisms of sentence processing and neural networks engaged in it are very sensitive to the context, single pulse TMS is going to be implemented during different stages of literal and figurative sentence processing.

 Variations of the motor cortex excitability, indexed by MEPs changes, are expected to be minimal across conditions in the first stimulation condition due to the lack of context information and significant in the second one, where the linear decrease in motor activation for literal-metaphoric-idiomatic-abstract sentences is hypothesized to be positively related to the increasing abstractness of the sentence meaning.

 To conclude with, the results of the research will shed more light on the neuroanatomical networks involved in idiom and metaphor comprehension.