Can electrical stimulation reduce brain activity in brain regions involved in reward responses linked to risk-taking behavior in people with bipolar disorder?

2019 ◽  
Author(s):  
Mary Phillips
2013 ◽  
Vol 19 (4) ◽  
pp. 474-482 ◽  
Author(s):  
Ceren Hıdıroğlu ◽  
Özlem Demirci Esen ◽  
Zeliha Tunca ◽  
Şehnaz Neslihan Gűrz Yalçìn ◽  
Lauren Lombardo ◽  
...  

AbstractRisk-taking behavior and impulsivity are core features of bipolar disorder. Whether they are part of the inherited aspect of the illness is not clear. We aimed to evaluate risk-taking behavior as a potential endophenotype for bipolar disorders, and its relationship with impulsivity and illness features. The Balloon Analogue Risk Task (BART) and Barratt Impulsiveness Scale-11 (BIS-11) were used to assess risk-taking behavior and impulsivity respectively in 30 euthymic bipolar I patients (BD), their 25 asymptomatic first-degree relatives (BD-R), and 30 healthy controls (HC). The primary BART outcome measure was the behavioral adjustment score (number of pumps after trials where the balloon did not pop minus the number of pumps after trials where the balloon popped). BD (p< .001) and BD-R (p= .001) had similar and significantly lower adjustment scores than HC. Only BD scored significantly higher on BIS-11 total (p= .01) and motor (p= .04) subscales than HC. Neither the BART, nor impulsivity scores associated with illness features. A limitation of this study is medicated patients and a heterogeneous BD-R were included. Riskiness may be a candidate endophenotype for bipolar disorder as it appears independently from illness features, presents similarly in BD and BD-R groups and differs from impulsivity. (JINS, 2013,19, 1–9)


2019 ◽  
Vol 8 (10) ◽  
pp. 1551 ◽  
Author(s):  
Trevor Steward ◽  
Asier Juaneda-Seguí ◽  
Gemma Mestre-Bach ◽  
Ignacio Martínez-Zalacaín ◽  
Nuria Vilarrasa ◽  
...  

Altered activity in decision-making neural circuitry may underlie the maladaptive food choices found in obesity. Here, we aimed to identify the brain regions purportedly underpinning risk-taking behavior in individuals with obesity. Twenty-three adult women with obesity and twenty-three healthy weight controls completed the Risky Gains Task during functional magnetic resonance imaging (fMRI). This task allows participants to choose between a safe option for a small, guaranteed monetary reward and risky options with larger rewards. fMRI analyses comparing losing trials to winning trials found that participants with obesity presented decreased activity in the left anterior insula in comparison to controls (p < 0.05, AlphaSim corrected). Moreover, left insula activation during losses vs. wins was negatively correlated with UPPS-P questionnaire sensation seeking scores. During safe vs. risky trials following a loss, the control group exhibited increased activation in the ventromedial prefrontal cortex (vmPFC) (p < 0.05, AlphaSim corrected) in comparison to the OB group. Moreover, vmPFC response in the obesity group during post-loss trials was negatively correlated with risky choices on the task overall. As a whole, our findings support that diminished tuning of the insula towards interoceptive signals may lead to a lack of input to the vmPFC when weighing the costs and benefits of risky choices.


Author(s):  
Peyman Ghobadi-Azbari ◽  
Asif Jamil ◽  
Fatemeh Yavari ◽  
Zeinab Esmaeilpour ◽  
Nastaran Malmir ◽  
...  

AbstractThe combination of non-invasive brain stimulation interventions with human brain mapping methods have supported research beyond correlational associations between brain activity and behavior. Functional MRI (fMRI) partnered with transcranial electrical stimulation (tES) methods, i.e., transcranial direct current (tDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation, explore the neuromodulatory effects of tES in the targeted brain regions and their interconnected networks and provide opportunities for individualized interventions. Advances in the field of tES-fMRI can be hampered by the methodological variability between studies that confounds comparability/replicability. In order to explore variability in the tES-fMRI methodological parameter space (MPS), we conducted a systematic review of 222 tES-fMRI experiments (181 tDCS, 39 tACS and 2 tRNS) published before February 1, 2019, and suggested a framework to systematically report main elements of MPS across studies. We have organized main findings in terms of fMRI modulation by tES. tES modulates activation and connectivity beyond the stimulated areas particularly with prefrontal stimulation. There were no two studies with the same MPS to replicate findings. We discuss how to harmonize the MPS to promote replication in future studies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sandra Chi Yiu Wong ◽  
Mary Chung Mun Ng ◽  
Joe Kwun Nam Chan ◽  
Martha Sin Ki Luk ◽  
Simon Sai Yu Lui ◽  
...  

Altered risk-taking propensity is an important determinant of functional impairment in bipolar disorder. However, prior studies primarily assessed patients with chronic illness, and risk-taking has not been evaluated in the early illness course. This study investigated risk-taking behavior in 39 euthymic early-stage bipolar disorder patients aged 16–40 years who were treated within 3 years from their first-episode mania with psychotic features and 36 demographically-matched healthy controls using the Balloon Analog Risk Task (BART), a well-validated risk-taking performance-based paradigm requiring participants to make responses for cumulative gain at increasing risk of loss. Relationships of risk-taking indices with symptoms, self-reported impulsivity, cognitive functions, and treatment characteristics were also assessed. Our results showed that patients exhibited significantly lower adjusted scores (i.e., average balloon pumps in unexploded trials) (p = 0.001), lower explosion rate (p = 0.007) and lower cumulative scores (p = 0.003) than controls on BART, indicating their suboptimal risk-taking performance with increased propensity for risk aversion. Risk-taking indices were not correlated with any symptom dimensions, self-reported impulsivity, cognitive functions or antipsychotic dose. No significant difference was observed between patients with and without antipsychotic medications on self-reported impulsivity or any of the BART performance indices. This is the first study to examine risk-taking behavior in early-stage bipolar disorder with history of psychosis and indicates that patients displayed altered risk-taking with increased risk aversion compared with controls. Further research is needed to clarify longitudinal trajectory of risk-taking propensity and its relationships with psychosis and functional outcome in the early stage of bipolar disorder.


CNS Spectrums ◽  
2007 ◽  
Vol 12 (S8) ◽  
pp. 13-16

AbstractBipolar disorder is a prevalent psychiatric disorder with a high rate of misdiagnosis and evidence of degenerative progression. Research indicates that the interval between bipolar episodes decreases steadily until the patient settles into a relatively frequent course of mania and depression. Various imaging techniques have been used in the understanding of the brain pathology underlying bipolar disorder through identification of patterns consistent with disruption of the normal brain activity in bipolar patients. These techniques have demonstrated evidence of abnormalities in the structure and function of the prefrontal cortex. In addition, the cerebellar vermis, which serves as an error-detection function to modulate the iterative network, appears to shrink with recurrent episodes. Functional imaging demonstrates that the anterior limbic network is overactivated and overresponsive in patients with bipolar disorder. In many patients, those deficits are often compensated for by activation of other brain areas. Ultimately, when the compensation fails, expression of bipolar symptoms arise. Using magnetic resonance spectroscopy, simple models can be constructed based on the hypothesis that mitochondrial function may be impaired in bipolar disorder. There is also increasing evidence that psychotropic medications can affect specific brain regions that are thought to be involved in the pathogenesis of psychiatric disorders. Glutamate levels appear to be elevated in untreated patients with bipolar disorder, which may cause glutamatergic neurotoxicity and negative therapeutic implications. Further advances in brain imaging may contribute to the improvement of available therapies and the understanding which treatments will be most suitable for specific patients.


2021 ◽  
Author(s):  
Aline Dantas ◽  
Peiran Jiao ◽  
Alexander Sack ◽  
Elisabeth Bruggen ◽  
Teresa Schuhmann

Abstract Recent research has shown that the gut microbiota can influence the interaction between the central and the enteric nervous systems via the gut-brain axis (GBA). Animal models and human neuroimaging studies have revealed that changes in the gut microbiota affect neural activity in brain regions linked to basic emotional and cognitive processes. Whether the gut microbiota also affect human decision-making and, more specifically, risk and time preferences, however, remains largely unknown. Here, we examine the role of the gut-brain axis in decision-making in the face of risk and intertemporal choices. In a placebo-controlled double-blinded design, with two sessions separated by 28 days, during which participants received daily doses of probiotics (or a placebo), we investigate whether the prolonged and controlled intake of probiotics affects risk-taking behavior and intertemporal choices using incentivised economic tasks. We found a significant decrease in risk-taking behavior and an increase in future-oriented choices in the probiotics group as compared to the placebo group. These findings provided the first direct experimental evidence suggesting a potential functional role on the part of the microbiota-gut-brain axis in decision-making, creating a path for potential clinical applications and allowing for a better understanding of the underlying neural mechanisms of risk-taking behavior and intertemporal choices.


2014 ◽  
Vol 28 (3) ◽  
pp. 148-161 ◽  
Author(s):  
David Friedman ◽  
Ray Johnson

A cardinal feature of aging is a decline in episodic memory (EM). Nevertheless, there is evidence that some older adults may be able to “compensate” for failures in recollection-based processing by recruiting brain regions and cognitive processes not normally recruited by the young. We review the evidence suggesting that age-related declines in EM performance and recollection-related brain activity (left-parietal EM effect; LPEM) are due to altered processing at encoding. We describe results from our laboratory on differences in encoding- and retrieval-related activity between young and older adults. We then show that, relative to the young, in older adults brain activity at encoding is reduced over a brain region believed to be crucial for successful semantic elaboration in a 400–1,400-ms interval (left inferior prefrontal cortex, LIPFC; Johnson, Nessler, & Friedman, 2013 ; Nessler, Friedman, Johnson, & Bersick, 2007 ; Nessler, Johnson, Bersick, & Friedman, 2006 ). This reduced brain activity is associated with diminished subsequent recognition-memory performance and the LPEM at retrieval. We provide evidence for this premise by demonstrating that disrupting encoding-related processes during this 400–1,400-ms interval in young adults affords causal support for the hypothesis that the reduction over LIPFC during encoding produces the hallmarks of an age-related EM deficit: normal semantic retrieval at encoding, reduced subsequent episodic recognition accuracy, free recall, and the LPEM. Finally, we show that the reduced LPEM in young adults is associated with “additional” brain activity over similar brain areas as those activated when older adults show deficient retrieval. Hence, rather than supporting the compensation hypothesis, these data are more consistent with the scaffolding hypothesis, in which the recruitment of additional cognitive processes is an adaptive response across the life span in the face of momentary increases in task demand due to poorly-encoded episodic memories.


Author(s):  
Thomas Plieger ◽  
Thomas Grünhage ◽  
Éilish Duke ◽  
Martin Reuter

Abstract. Gender and personality traits influence risk proneness in the context of financial decisions. However, most studies on this topic have relied on either self-report data or on artificial measures of financial risk-taking behavior. Our study aimed to identify relevant trading behaviors and personal characteristics related to trading success. N = 108 Caucasians took part in a three-week stock market simulation paradigm, in which they traded shares of eight fictional companies that differed in issue price, volatility, and outcome. Participants also completed questionnaires measuring personality, risk-taking behavior, and life stress. Our model showed that being male and scoring high on self-directedness led to more risky financial behavior, which in turn positively predicted success in the stock market simulation. The total model explained 39% of the variance in trading success, indicating a role for other factors in influencing trading behavior. Future studies should try to enrich our model to get a more accurate impression of the associations between individual characteristics and financially successful behavior in context of stock trading.


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