scholarly journals Neural Mechanisms in Eating Behaviors: A Pilot fMRI Study of Emotional Processing

2020 ◽  
Vol 17 (3) ◽  
pp. 225-236 ◽  
Author(s):  
Rosa M. Molina-Ruiz ◽  
T. García-Saiz ◽  
Jeffrey C.L. Looi ◽  
E. Via Virgili ◽  
M. Rincón Zamorano ◽  
...  

Objective Emotional processing dysfunction evident in eating disorders (ED) such as anorexia nervosa (AN) and bulimia nervosa (BN), is considered relevant to the development and maintenance of these disorders. The purpose of the current functional magnetic resonance imaging (fMRI) study was to pilot a comparison of the activity of the fronto-limbic and fronto-striatal brain areas during an emotion processing task in persons with ED.Methods 24 women patients with ED were scanned, while showing emotionally stimulating (pleasant, unpleasant) and neutral images from the International Affective Picture System (IAPS).Results During the pleasant condition, significant differences in Dorsolateral Prefrontal Cortex (DLPFC) activations were found with AN participants presenting greater activation compared to BN and ED comorbid groups (EDc) and healthy controls also showing greater activation of this brain area compared to BN and EDc. Left putamen was less activated in EDc compared to both controls (C) and AN. During the unpleasant condition, AN participants showed hyperactivation of the Orbito-frontal Cortex (OFC) when compared to EDc.Conclusion This study highlights the potential functional relevance of brain areas that have been associated with self-control. These findings should help advance understanding the neural substrate of ED, though they should be considered as preliminary and be cautiously interpreted.

2019 ◽  
Author(s):  
Angus Inkster ◽  
Fraser Milton ◽  
Charlotte E R Edmunds ◽  
Abdelmalek Benattayallah ◽  
Andy Wills

The Inverse Base Rate effect (IBRE; Medin & Edelson, 1988) is a non-rational behavioral phenomenon in predictive learning. Canonically, participants learn that the AB stimulus compound leads to one outcome and that AC leads to another outcome, with AB being presented three times as often as AC. When subsequently presented with BC, the outcome associated with AC is selected preferentially, in opposition to the underlying base rates of the outcomes. While many potential explanations of the effect exist, an error-driven learning account (Kruschke, 2001b) is particularly influential. A key component of this account is prediction error, a concept previously linked to a number of brain areas including the anterior cingulate, the striatum and the dorsolateral prefrontal cortex. The present study is the first fMRI study to directly examine the IBRE. Activations were noted in the brain areas linked to prediction error, including the caudate body, the anterior cingulate cortex and the middle frontal gyrus. Analysing the difference in activations for singular key stimuli (B and C), as well as frequency matched controls, supports the predictions made by the error-driven learning account.


2022 ◽  
Vol 15 ◽  
Author(s):  
Ehsan Rezayat ◽  
Kelsey Clark ◽  
Mohammad-Reza A. Dehaqani ◽  
Behrad Noudoost

Neural signatures of working memory (WM) have been reported in numerous brain areas, suggesting a distributed neural substrate for memory maintenance. In the current manuscript we provide an updated review of the literature focusing on intracranial neurophysiological recordings during WM in primates. Such signatures of WM include changes in firing rate or local oscillatory power within an area, along with measures of coordinated activity between areas based on synchronization between oscillations. In comparing the ability of various neural signatures in any brain area to predict behavioral performance, we observe that synchrony between areas is more frequently and robustly correlated with WM performance than any of the within-area neural signatures. We further review the evidence for alteration of inter-areal synchrony in brain disorders, consistent with an important role for such synchrony during behavior. Additionally, results of causal studies indicate that manipulating synchrony across areas is especially effective at influencing WM task performance. Each of these lines of research supports the critical role of inter-areal synchrony in WM. Finally, we propose a framework for interactions between prefrontal and sensory areas during WM, incorporating a range of experimental findings and offering an explanation for the observed link between intra-areal measures and WM performance.


Author(s):  
T. Pattyn ◽  
L. Schmaal ◽  
F. Van Den Eede ◽  
L. Cassiers ◽  
BW Penninx ◽  
...  

2006 ◽  
Vol 18 (8) ◽  
pp. 1331-1342 ◽  
Author(s):  
Andrea Kübler ◽  
Veronica Dixon ◽  
Hugh Garavan

The ability to exert control over automatic behavior is of particular importance as it allows us to interrupt our behavior when the automatic response is no longer adequate or even dangerous. However, despite the literature that exists on the effects of practice on brain activation, little is known about the neuroanatomy involved in reestablishing executive control over previously automatized behavior. We present a visual search task that enabled participants to automatize according to defined criteria within about 3 hr of practice and then required them to reassert control without changing the stimulus set. We found widespread cortical activation early in practice. Activation in all frontal areas and in the inferior parietal lobule decreased significantly with practice. Only selected prefrontal (Brodmann's areas [BAs] 9/46/8) and parietal areas (BAs 39/40) were specifically reactivated when executive control was required, underlining the crucial role of the dorsolateral prefrontal cortex in executive control to guide our behavior.


2007 ◽  
Vol 13 (11) ◽  
pp. 1011-1020 ◽  
Author(s):  
R Norbury ◽  
C E Mackay ◽  
P J Cowen ◽  
G M Goodwin ◽  
C J Harmer

1889 ◽  
Vol 35 (149) ◽  
pp. 23-44 ◽  
Author(s):  
Francis Warner

(1) Movement in mau has long been a subject of profitable study. Visible movement in the body is produced by muscular contraction following upon stimulation of the muscles by efferent currents passing from the central nerve-system. Modern physiological experiments have demonstrated that when a special brain-area discharges nerve-currents, these are followed by certain visible movements or contraction of certain muscles corresponding. So exact are such reactions, as obtained by experiment upon the brain-areas, that movements similar to those produced by experimental excitation of a certain brain-area may be taken as evidence of action in that area, or as commencing in discharge from that area (see Reinforcement of Movements, 35; Compound Series of Movements, 34).


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
P. Šimko ◽  
M. Pupíková ◽  
M. Gajdoš ◽  
I. Rektorová

Enhancing cognitive functions through noninvasive brain stimulation is of enormous public interest, particularly for the aging population in whom processes such as working memory are known to decline. In a randomized double-blind crossover study, we investigated the acute behavioral and neural aftereffects of bifrontal and frontoparietal transcranial direct current stimulation (tDCS) combined with visual working memory (VWM) training on 25 highly educated older adults. Resting-state functional connectivity (rs-FC) analysis was performed prior to and after each stimulation session with a focus on the frontoparietal control network (FPCN). The bifrontal montage with anode over the left dorsolateral prefrontal cortex enhanced VWM accuracy as compared to the sham stimulation. With the rs-FC within the FPCN, we observed significant stimulation × time interaction using bifrontal tDCS. We found no cognitive aftereffects of the frontoparietal tDCS compared to sham stimulation. Our study shows that a single bifrontal tDCS combined with cognitive training may enhance VWM performance and rs-FC within the relevant brain network even in highly educated older adults.


2020 ◽  
Author(s):  
Sihai Li ◽  
Christos Constantinidis ◽  
Xue-Lian Qi

ABSTRACTThe dorsolateral prefrontal cortex plays a critical role in spatial working memory and its activity predicts behavioral responses in delayed response tasks. Here we addressed whether this predictive ability extends to categorical judgments based on information retained in working memory, and is present in other brain areas. We trained monkeys in a novel, Match-Stay, Nonmatch-Go task, which required them to observe two stimuli presented in sequence with an intervening delay period between them. If the two stimuli were different, the monkeys had to saccade to the location of the second stimulus; if they were the same, they held fixation. Neurophysiological recordings were performed in areas 8a and 46 of the dlPFC and 7a and lateral intraparietal cortex (LIP) of the PPC. We hypothesized that random drifts causing the peak activity of the network to move away from the first stimulus location and towards the location of the second stimulus would result in categorical errors. Indeed, for both areas, when the first stimulus appeared in a neuron’s preferred location, the neuron showed significantly higher firing rates in correct than in error trials. When the first stimulus appeared at a nonpreferred location and the second stimulus at a preferred, activity in error trials was higher than in correct. The results indicate that the activity of both dlPFC and PPC neurons is predictive of categorical judgments of information maintained in working memory, and the magnitude of neuronal firing rate deviations is revealing of the contents of working memory as it determines performance.SIGNIFICANCE STATEMENTThe neural basis of working memory and the areas mediating this function is a topic of controversy. Persistent activity in the prefrontal cortex has traditionally been thought to be the neural correlate of working memory, however recent studies have proposed alternative mechanisms and brain areas. Here we show that persistent activity in both the dorsolateral prefrontal cortex and posterior parietal cortex predicts behavior in a working memory task that requires a categorical judgement. Our results offer support to the idea that a network of neurons in both areas act as an attractor network that maintains information in working memory, which informs behavior.


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