scholarly journals Re-thinking the role of the dorsal striatum in egocentric/response strategy

Author(s):  
Botreau
2018 ◽  
Author(s):  
Tiffany Bell ◽  
Angela Langdon ◽  
Michael Lindner ◽  
William Lloyd ◽  
Anastasia Christakou

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.


2021 ◽  
Author(s):  
Brendan Williams ◽  
Anastasia Christakou

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.


2019 ◽  
Vol 14 (1) ◽  
pp. 19-38 ◽  
Author(s):  
Nengzhi (Chris) Yao ◽  
Jiuchang Wei ◽  
Weiwei Zhu ◽  
Alexander Bondar

Purpose The conclusions on the importance of corporate response timing to a crisis have remained inconsistent. Some studies suggest that active response may reduce negative impacts, whereas managers argue that issuing official response frustrates stakeholders and thus decreases the firm value. The purpose of this paper is to investigate the role of external media in the response timing strategy and the consequent stock market reaction. Design/methodology/approach Based on 130 corporate crises that befell publicly listed firms in China from 2007 to 2014, this paper uses the Baidu News Search Engine and Chinese Lexical Analysis System to construct the variables of the media characteristics. A structural equation model is established to test the hypotheses. Findings The results of this paper suggest that media coverage drives response timing after a crisis. Although an official response is a burden for firms, the timing strategy has multidimensional benefits including effectively alleviating negative effects (defined as buffering effects) and repairing the market (defined as restoring effects). Moreover, the buffering effects of response timing are stronger when completeness of response is low. Originality/value This study mainly contributes to crisis communication literature by introducing the role of media in prompting managers to make timing decisions. The findings of this study provide empirical support for the importance of timing response strategy.


2016 ◽  
Vol 4 (4) ◽  
pp. 411-422 ◽  
Author(s):  
Nicholas A. Lusk ◽  
Dean V. Buonomano

Over the past decade advances in tracing and imaging techniques have spurred the development of increasingly detailed maps of brain connectivity. Broadly termed ‘connectomes’, these maps provide a powerful tool for systems neuroscience. As with most ‘maps’, connectomes offer a static spatial description of the brain’s circuits, whereas timing and temporal processing are inherently dynamic processes; nevertheless, the timing field stands to be a major beneficiary of these large-scale mapping projects. The recently reported ‘projectome’ of mouse cortico-striatal sub-networks is of particular interest because theoretical developments such as the striatal beat-frequency model emphasize the role of the striatum in temporal processing. The cortico-striatal projectome confirms that the dorsal striatum is ideally situated to sample patterns of activity throughout most of the cortex, but that it also contains a level of modularity previously not considered by integrative models of interval timing. Furthermore, the striatal projectome will allow for targeted studies of whether specific subdivisions of the dorsal striatum are differentially involved in timing and time perception as a function of task, stimulus modality, intensity, and valence.


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1018
Author(s):  
Caitlyn A. Mullins ◽  
Ritchel B. Gannaban ◽  
Md Shahjalal Khan ◽  
Harsh Shah ◽  
Md Abu B. Siddik ◽  
...  

Obesity prevalence is increasing at an unprecedented rate throughout the world, and is a strong risk factor for metabolic, cardiovascular, and neurological/neurodegenerative disorders. While low-grade systemic inflammation triggered primarily by adipose tissue dysfunction is closely linked to obesity, inflammation is also observed in the brain or the central nervous system (CNS). Considering that the hypothalamus, a classical homeostatic center, and other higher cortical areas (e.g. prefrontal cortex, dorsal striatum, hippocampus, etc.) also actively participate in regulating energy homeostasis by engaging in inhibitory control, reward calculation, and memory retrieval, understanding the role of CNS oxidative stress and inflammation in obesity and their underlying mechanisms would greatly help develop novel therapeutic interventions to correct obesity and related comorbidities. Here we review accumulating evidence for the association between ER stress and mitochondrial dysfunction, the main culprits responsible for oxidative stress and inflammation in various brain regions, and energy imbalance that leads to the development of obesity. Potential beneficial effects of natural antioxidant and anti-inflammatory compounds on CNS health and obesity are also discussed.


2015 ◽  
Vol 113 (1) ◽  
pp. 4-13 ◽  
Author(s):  
Elizabeth Tricomi ◽  
Karolina M. Lempert

For the consequences of our actions to guide behavior, the brain must represent different types of outcome-related information. For example, an outcome can be construed as negative because an expected reward was not delivered or because an outcome of low value was delivered. Thus behavioral consequences can differ in terms of the information they provide about outcome probability and value. We investigated the role of the striatum in processing probability-based and value-based negative feedback by training participants to associate cues with food rewards and then employing a selective satiety procedure to devalue one food outcome. Using functional magnetic resonance imaging, we examined brain activity related to receipt of expected rewards, receipt of devalued outcomes, omission of expected rewards, omission of devalued outcomes, and expected omissions of an outcome. Nucleus accumbens activation was greater for rewarding outcomes than devalued outcomes, but activity in this region did not correlate with the probability of reward receipt. Activation of the right caudate and putamen, however, was largest in response to rewarding outcomes relative to expected omissions of reward. The dorsal striatum (caudate and putamen) at the time of feedback also showed a parametric increase correlating with the trialwise probability of reward receipt. Our results suggest that the ventral striatum is sensitive to the motivational relevance, or subjective value, of the outcome, while the dorsal striatum codes for a more complex signal that incorporates reward probability. Value and probability information may be integrated in the dorsal striatum, to facilitate action planning and allocation of effort.


2008 ◽  
Vol 19 (11) ◽  
pp. 1131-1139 ◽  
Author(s):  
Jay J. Van Bavel ◽  
Dominic J. Packer ◽  
William A. Cunningham

Classic minimal-group studies found that people arbitrarily assigned to a novel group quickly display a range of perceptual, affective, and behavioral in-group biases. We randomly assigned participants to a mixed-race team and used functional magnetic resonance imaging to identify brain regions involved in processing novel in-group and out-group members independently of preexisting attitudes, stereotypes, or familiarity. Whereas previous research on intergroup perception found amygdala activity—typically interpreted as negativity—in response to stigmatized social groups, we found greater activity in the amygdala, fusiform gyri, orbitofrontal cortex, and dorsal striatum when participants viewed novel in-group faces than when they viewed novel out-group faces. Moreover, activity in orbitofrontal cortex mediated the in-group bias in self-reported liking for the faces. These in-group biases in neural activity were not moderated by race or by whether participants explicitly attended to team membership or race, a finding suggesting that they may occur automatically. This study helps clarify the role of neural substrates involved in perceptual and affective in-group biases.


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