scholarly journals Dissociable roles for the striatal cholinergic system in different flexibility contexts.

2021 ◽  
Author(s):  
Brendan Williams ◽  
Anastasia Christakou
Keyword(s):  
Reversal Learning ◽  
Cholinergic System ◽  
Dorsal Striatum ◽  
Resonance Spectroscopy ◽  
Prediction Errors ◽  
Behavioural Flexibility ◽  
Starting Point ◽  
Rate Of Learning ◽  
Striatal Cholinergic System

The production of behavioural flexibility requires the coordination and integration of information from across the brain, by the dorsal striatum. In particular, the striatal cholinergic system is thought to be important for the modulation of striatal activity. Research from animal literature has shown that chemical inactivation of the dorsal striatum leads to impairments in reversal learning. Furthermore, proton magnetic resonance spectroscopy work has shown that the striatal cholinergic system is also important for reversal learning in humans. Here, we aim to assess whether the state of the dorsal striatal cholinergic system at rest is related to flexible behaviour in reversal learning. We provide preliminary results showing that variability in choline in the dorsal striatum is significantly related to both the number perseverative and regressive errors that participants make, and their rate of learning from positive and negative prediction errors. These findings, in line with previous work, suggest the resting state of dorsal striatal cholinergic system has important implications for producing flexible behaviour. However, these results also suggest the system may have heterogeneous functionality across different types of tasks measuring behavioural flexibility. These findings provide a starting point for further interrogation into understanding the functional role of the striatal cholinergic system in flexibility.

scholarly journals Regional Striatal Cholinergic Involvement in Human Behavioural Flexibility

2018 ◽  
Author(s):  
Tiffany Bell ◽  
Michael Lindner ◽  
Angela Langdon ◽  
Paul Gerald Mullins ◽  
Anastasia Christakou
Keyword(s):  
Reversal Learning ◽  
Cholinergic System ◽  
Proton Magnetic Resonance ◽  
Dorsal Striatum ◽  
Resonance Spectroscopy ◽  
Prediction Errors ◽  
Behavioural Flexibility ◽  
Non Invasive ◽  
Negative Prediction ◽  
Striatal Cholinergic System

ABSTRACTAnimal studies have shown that the striatal cholinergic system plays a role in behavioural flexibility but, until recently, this system could not be studied in humans due to a lack of appropriate non-invasive techniques. Using proton magnetic resonance spectroscopy (1H-MRS) we recently showed that the concentration of dorsal striatal choline (an acetylcholine precursor) changes during reversal learning (a measure of behavioural flexibility) in humans. The aim of the present study was to examine whether regional average striatal choline was associated with reversal learning. 36 participants (mean age = 24.8, range = 18-32, 20 female) performed a probabilistic learning task with a reversal component. We measured choline at rest in both the dorsal and ventral striatum using 1H-MRS. Task performance was described using a simple reinforcement learning model that dissociates the contributions of positive and negative prediction errors to learning. Average levels of choline in the dorsal striatum were associated with performance during reversal, but not during initial learning. Specifically, lower levels of choline in the dorsal striatum were associated with a lower number of perseverative trials. Moreover, choline levels explained inter-individual variance in perseveration over and above that explained by learning from negative prediction errors. These findings suggest that the dorsal striatal cholinergic system plays an important role in behavioural flexibility, in line with evidence from the animal literature and our previous work in humans. Additionally, this work provides further support for the idea of measuring choline with 1H-MRS as a non-invasive way of studying human cholinergic neurochemistry.SIGNIFICANCE STATEMENTBehavioural flexibility is a crucial component of adaptation and survival. Evidence from the animal literature shows the striatal cholinergic system is fundamental to reversal learning, a key paradigm for studying behavioural flexibility, however, this system remains understudied in humans. Using proton magnetic resonance spectroscopy, we showed that choline levels at rest in the dorsal striatum are associated with performance specifically during reversal learning. These novel findings help to bridge the gap between animal and human studies by demonstrating the importance of cholinergic function in the dorsal striatum in human behavioural flexibility. Importantly, the methods described here can not only be applied to furthering our understanding of healthy human neurochemistry, but also to extending our understanding of cholinergic disorders.

scholarly journals Orbitofrontal and Thalamic Influences on Striatal Involvement in Human Reversal Learning

2018 ◽  
Author(s):  
Tiffany Bell ◽  
Angela Langdon ◽  
Michael Lindner ◽  
William Lloyd ◽  
Anastasia Christakou
Keyword(s):  
Reversal Learning ◽  
Animal Studies ◽  
Dorsal Striatum ◽  
Response Strategy ◽  
Cholinergic Interneurons ◽  
Learning Tasks ◽  
Initial Learning ◽  
Before And After ◽  
Psychophysiological Interaction

ABSTRACTCognitive flexibility is crucial for adaptation and is disrupted in neuropsychiatric disorders and psychopathology. Human studies of flexibility using reversal learning tasks typically contrast error trials before and after reversal, which provides little information about the mechanisms that support learning and expressing a new response. However, animal studies suggest a specific role in this latter process for the connections between the dorsal striatum and the centromedian parafascicular (CM-Pf) thalamus, a system which may recruit the striatal cholinergic interneurons, but which is not well understood in humans. This study investigated the role of this system in human probabilistic reversal learning, specifically with respect to learning a new response strategy, contrasting its function to that of the better understood orbitoftontal-striatal systems. Using psychophysiological interaction (PPI) analysis of functional magnetic resonance imaging (fMRI) data we show that connectivity between the striatum and both the lateral orbitofrontal cortex (lOFC) and CM-Pf pathways increased during reversal, but not initial learning. However, while the strength of lOFC-striatal connectivity was associated with the speed of the reversal, the strength of CM-Pf-striatal connectivity was associated specifically with the quality of the reversal (reduced regressive errors). These findings expand our understanding of flexibility mechanisms in the human brain, bridging the gap with animal studies of this system.

scholarly journals Cortical and thalamic influences on striatal involvement in instructed, serial reversal learning; implications for the organisation of flexible behaviour.

2021 ◽  
Author(s):  
Brendan Williams ◽  
Anastasia Christakou
Keyword(s):  
Functional Connectivity ◽  
Cognitive Flexibility ◽  
Reversal Learning ◽  
Orbitofrontal Cortex ◽  
Dorsal Striatum ◽  
Response Strategy ◽  
Flexible Control ◽  
The Right ◽  
Serial Reversal

Cognitive flexibility is essential for enabling an individual to respond adaptively to changes in their environment. Evidence from human and animal research suggests that the control of cognitive flexibility is dependent on an array of neural architecture. Cortico-basal ganglia circuits have long been implicated in cognitive flexibility. In particular, the role of the striatum is pivotal, acting as an integrative hub for inputs from the prefrontal cortex and thalamus, and modulation by dopamine and acetylcholine. Striatal cholinergic modulation has been implicated in the flexible control of behaviour, driven by input from the centromedian-parafascicular nuclei of the thalamus. However, the role of this system in humans is not clearly defined as much of the current literature is based on animal work. Here, we aim to investigate the roles corticostriatal and thalamostriatal connectivity in serial reversal learning. Functional connectivity between the left centromedian-parafascicular nuclei and the associative dorsal striatum was significantly increased for negative feedback compared to positive feedback. Similar differences in functional connectivity were observed for the right lateral orbitofrontal cortex, but these were localised to when participants switched to using an alternate response strategy following reversal. These findings suggest that connectivity between the centromedian-parafascicular nuclei and the striatum may be used to generally identify potential changes in context based on negative outcomes, and the effect of this signal on striatal output may be influenced by connectivity between the lateral orbitofrontal cortex and the striatum.

Operation of Conflict in Selective and Reversal Learning

1965 ◽  
Vol 16 (3_suppl) ◽  
pp. 1313-1322
Author(s):  
Leonard Worell ◽  
Thomas R. Schill ◽  
Norman D. Smith
Keyword(s):  
Reversal Learning ◽  
Choice Behavior ◽  
Y Maze ◽  
Rate Of Learning

Blocks of free and forced reinforced trials were combined to provide rats swimming underwater in a Y-maze with one of two levels of conflict. Strong conflict was induced by requiring animals to make 4 left and 3 right reinforced runs within each block; weak conflict by 4 left and 1 right per block. In reversal, all animals were given successive blocks of 6 reinforced rights and 1 reinforced left. Findings were that strong conflict reliably retarded rate of learning during acquisition and further significantly delayed reversal responding. The analyses also centered on the differential role of drive and conflict on temporal and choice behavior measures. Finally, both methodological and theoretical aspects of the results were discussed.

scholarly journals Functional neurochemical imaging of the human striatal cholinergic system during reversal learning

2018 ◽  
Vol 47 (10) ◽  
pp. 1184-1193 ◽  
Author(s):  
Tiffany Bell ◽  
Michael Lindner ◽  
Paul Gerald Mullins ◽  
Anastasia Christakou
Keyword(s):  
Reversal Learning ◽  
Cholinergic System ◽  
Striatal Cholinergic System

scholarly journals Dopamine waves as a mechanism for spatiotemporal credit assignment

2019 ◽  
Author(s):  
Arif A. Hamid ◽  
Michael J. Frank ◽  
Christopher I. Moore
Keyword(s):  
Activity Patterns ◽  
Dorsal Striatum ◽  
Functional Specialization ◽  
Prediction Errors ◽  
Credit Assignment ◽  
Reward Delivery ◽  
Instrumental Task ◽  
Propagating Waves ◽  
Instrumental Control

AbstractSignificant evidence supports the view that dopamine shapes reward-learning by encoding prediction errors. However, it is unknown whether dopamine decision-signals are tailored to the functional specialization of target regions. Here, we report a novel set of wave-like spatiotemporal activity-patterns in dopamine axons across the dorsal striatum. These waves switch between different activational motifs and organize dopamine transients into localized clusters within functionally related striatal subregions. These specific motifs are associated with distinct task contexts: At reward delivery, dopamine signals rapidly resynchronize into propagating waves with opponent directions depending on instrumental task contingencies. Moreover, dopamine dynamics during reward pursuit signal the extent to which mice have instrumental control and interact with reward waves to predict future behavioral adjustments. Our results are consistent with a computational architecture in which striatal dopamine signals are sculpted by inference about instrumental controllability and provide evidence for a spatiotemporally “vectorized” role of dopamine in credit assignment.

INTERPRETATION OF SINO-RUSSIAN CULTURE AND HUMANITIES COOPERATION IN THE NEW ERA

2020 ◽  
Vol 10 (3) ◽  
pp. 186-193
Author(s):  
REN YANYAN ◽  
Keyword(s):  
Current Status ◽  
Human Relations ◽  
New Era ◽  
Russian Culture ◽  
The People ◽  
Starting Point ◽  
Cooperative Partnership ◽  
Belt And Road ◽  
The Belt And Road

The friendship between nations lies in the mutual affinity of the people, and the people’s affinity lies in the communion of hearts. The cultural and humanities cooperation between China and Russia has a long history. In recent years, under the role of the“Belt and Road” initiative, the SCO, and the Sino-Russian Humanities Cooperation Committee, Sino-Russian culture and humanities cooperation has continued to deepen. Entering a new era, taking the opportunity to promote Sino-Russian relations into a “new era China-Russia comprehensive strategic cooperative partnership”, the development of human relations between the two countries has entered a new historical starting point, while also facing a series of problems and challenges. This article is based on the current status of Sino-Russian human relations in the new era, interprets the characteristics of Sino-Russian human relations in the new era, analyzes the problems and challenges of Sino-Russian human relations in the new era, and tries to propose solutions and solutions with a view to further developing Sino-Russian cultural and humanities relations in the new era. It is a useful reference, and provides a reference for future related research, and ultimately helps the Sino-Russian cultural and humanities relations in the new era to be stable and far-reaching.

Reward Prediction Errors Drive Declarative Learning Irrespective of Agency

2020 ◽  
Author(s):  
Kate Ergo ◽  
Luna De Vilder ◽  
Esther De Loof ◽  
Tom Verguts
Keyword(s):  
Learning Theory ◽  
Learning Effect ◽  
Steady Increase ◽  
Prediction Errors ◽  
Experimental Paradigm ◽  
Reward Prediction ◽  
Declarative Learning

Recent years have witnessed a steady increase in the number of studies investigating the role of reward prediction errors (RPEs) in declarative learning. Specifically, in several experimental paradigms RPEs drive declarative learning; with larger and more positive RPEs enhancing declarative learning. However, it is unknown whether this RPE must derive from the participant’s own response, or whether instead any RPE is sufficient to obtain the learning effect. To test this, we generated RPEs in the same experimental paradigm where we combined an agency and a non-agency condition. We observed no interaction between RPE and agency, suggesting that any RPE (irrespective of its source) can drive declarative learning. This result holds implications for declarative learning theory.

La conexión entre política de cohesión y gobernanza económica en la UE: Eficiencia del nuevo marco para abordar las consecuencias de la crisis

2015 ◽  
Vol 5 (3) ◽  
pp. 44-62
Author(s):  
Laura Gómez Urquijo
Keyword(s):  
Social Protection ◽  
Economic Governance ◽  
The European Union ◽  
Investment Funds ◽  
Current Economic Crisis ◽  
Starting Point ◽  
New Economic Governance ◽  
Social Protection Systems ◽  
New Instruments

The objective of this article is to contribute to the discussion on the validity of new instruments to enhance cohesion in the European Union (EU). First, we question to which extent cohesion policy is submitted to the new economic governance. Second, we discuss this subordination affects the fulfillment of cohesion aims. This question is especially relevant due to the increase of inequalities in the current economic crisis and the great diversity among State Members (including social protection systems and expenses). Thus, our starting point is the new economic governance framework and its impact on the fulfillment of cohesion objectives. Statistical data are considered with this aim. Next, we will assess the role of European Structural and Investment Funds to eventually compensate public expense cuts, as well as its subordination to the macroeconomic government. This aspect will be contrasted through the study of Country Specific Recommendations given by the European Semester. Spanish El objetivo de este artículo es contribuir a la discusión sobre la validez de los nuevos instrumentos para fomentar la cohesión en la Unión Europea. Nos preguntamos en qué modo queda sometida la política de cohesión a la nueva gobernanza económica y cómo afecta a la efectividad para cubrir susfines. Esta cuestión es particularmente relevante ante el incremento de las desigualdades suscitado en la crisis económica actual. Por ello, nuestro punto de partida es el nuevo marco de gobernanza económica y su impacto en el cumplimiento de los objetivos de cohesión, considerando para ello datos estadísticos. A continuación, valoraremos, el papel de los Fondos Estructurales y de Inversión Europeos como posibles compensadores de la reducción del gasto público así como su subordinación al gobierno macroeconómico. Esta cuestión será contrastada también a través del examen de las Recomendaciones Específicas por país dadas por el Semestre Europeo. French Le but de cet article est de contribuer à la discussion sur la validité de nouveaux instruments pour promouvoir la cohésion dans l'UE. Nous avons considéré, d'une part, en quoi la politique de cohésion est soumise à la nouvelle gouvernance économique et, d'autre part, la façon dont elle utilise l'efficacité pour répondre à ses fins.Cette question est particulièrement pertinente étant donnée l'augmentation de l'inégalité soulevée par la crise économique actuelle, dans un contexte de grande diversité d'États membres, notamment en ce qui concerne les systèmes de protection sociale et les dépenses publiques. Par conséquent, notre point de départ s'inscrit dans le nouveau cadre de gouvernance économique et son impact sur la mise en œuvre des objectifs de cohésion, à partir de la prise en compte de données statistiques. Pour ce faire, nous évaluons le rôle des Fonds Structurels Européens, leur capacité de compenser la réduction des dépenses publiques et leur subordination au gouvernement macroéconomique. Ce e question sera également abordée par l'examen des recommandations spécifiques par pays fournies par le Semestre Européen.

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