scholarly journals Effects of prefrontal tDCS on dopamine-mediated behavior and psychophysiology

2019 ◽  
Author(s):  
Michael J. Imburgio ◽  
Hannah K. Ballard ◽  
Astin C. Cornwall ◽  
Darrell A. Worthy ◽  
Jessica A. Bernard ◽  
...  
Keyword(s):  
Dopamine Release ◽  
Basic Research ◽  
Effect Sizes ◽  
Blink Rate ◽  
Eye Blink ◽  
Non Invasive ◽  
Indirect Measures ◽  
Growing Body ◽  
Shed Light

AbstractThe ability to manipulate dopamine in vivo through non-invasive, reversible mechanisms has the potential to impact clinical, translational, and basic research. Recent PET studies have demonstrated increased dopamine release in the striatum after prefrontal transcranial direct current stimulation (tDCS). We sought to extend this work by examining whether prefrontal tDCS could demonstrate an effect on behavioral and physiological correlates of subcortical dopamine activity. We conducted a between-subjects study (n = 30) with active and sham tDCS and used spontaneous eye blink rate (EBR), facial attractiveness ratings, and greyscales orienting bias as indirect proxies for dopamine functioning. The initial design and analyses were pre-registered (https://osf.io/gmnpc). Stimulation did not significantly affect any of the three measures, though effect sizes were often moderately large and were all in the predicted directions. Additional exploratory analyses suggested that stimulation’s effect on EBR might depend on pre-stimulation dopamine levels. Our results shed light on the sensitivity of indirect measures of dopamine in humans and add to a growing body of work demonstrating the importance of examining individual differences in tDCS response.

scholarly journals Spontaneous Eye Blink Rate during the Working Memory Delay Period Predicts Task Performance

2021 ◽  
Author(s):  
Jefferson Ortega ◽  
Chelsea Reichert Plaska ◽  
Bernard A Gomes ◽  
Timothy M Ellmore
Keyword(s):  
Working Memory ◽  
Task Performance ◽  
Memory Task ◽  
Delay Period ◽  
Blink Rate ◽  
Indirect Measure ◽  
Eye Blink ◽  
Non Invasive ◽  
Relationship Of ◽  
The Relationship

Spontaneous eye blink rate (sEBR) has been found to be a non-invasive indirect measure of striatal dopamine activity. Dopamine (DA) neurons project to the prefrontal cortex (PFC) through the mesocortical dopamine pathway and their activity is implicated in a range of cognitive functions, including attention and working memory (WM). The goal of the present study was to understand how fluctuations in sEBR during different phases of a working memory task relate to task performance. Across two experiments, with recordings of sEBR inside and outside of a magnetic resonance imaging bore, we observed sEBR to be positively correlated with WM performance during the WM delay period. Additionally we investigated the non-linear relationship between sEBR and WM performance, and modeled a proposed Inverted-U-shape relationship between DA and WM performance. We also investigated blink duration, which is proposed to be related to sustained attention, and found blink duration to be significantly shorter during the encoding and probe periods of the task. Taken together, these results provide support towards sEBR as an important correlate of working memory task performance. The relationship of sEBR to DA activity and the influence of DA on the PFC during WM maintenance is discussed.

scholarly journals Now it’s your turn!: Eye blink rate in a Jenga task modulated by interaction of task wait times, effortful control, and internalizing behaviors

2021 ◽  
Author(s):  
Kelley Gunther ◽  
Xiaoxue Fu ◽  
Leigha A. MacNeill ◽  
Morgan Jones ◽  
Briana Ermanni ◽  
...  
Keyword(s):  
Effortful Control ◽  
Ecological Validity ◽  
Internalizing Behaviors ◽  
Task Demands ◽  
Blink Rate ◽  
Eye Blink ◽  
Non Invasive ◽  
Long Time ◽  
Midbrain Dopamine ◽  
Dopamine Signaling

Dopamine is a versatile neurotransmitter with implications in many domains, including anxiety and effortful control. Where high levels of effortful control are often regarded as adaptive, other work suggests that high levels of effortful control may be a risk factor for anxiety. Dopamine signaling may be key in understanding these relations. Eye blink rate is a non-invasive proxy metric of midbrain dopamine activity. However, much work with eye blink rate has been constrained to screen-based tasks which lack in ecological validity. We tested whether changes in eye blink rate during a naturalistic effortful control task differ as a function of parent-reported effortful control and internalizing behaviors. Children played a Jenga-like game with an experimenter, but for each trial the experimenter took an increasingly long time to take their turn. Blinks-per-second were computed during each wait period. Multilevel modeling examined the relation between duration of wait period, effortful control, and internalizing behaviors on eye blink rate. We found a significant 3-way interaction between effortful control, internalizing behaviors, and duration of the wait period. Probing this interaction revealed that for children with low reported internalizing behaviors (-1 SD) and high reported effortful control (+1 SD), eye blink rate significantly decreased as they waited longer to take their turn. These findings index task-related changes in midbrain dopamine activity in relation to naturalistic task demands, and that these changes may vary as a function of individual differences in effortful control and internalizing behaviors. We discuss possible top-down mechanisms that may underlie these differences.

scholarly journals Tracking Real-Time Changes in Working Memory Updating and Gating with the Event-Based Eye-Blink Rate

2017 ◽  
Author(s):  
Rachel Rac-Lubashevsky ◽  
Heleen A. Slagter ◽  
Yoav Kessler
Keyword(s):  
Working Memory ◽  
Cognitive Processes ◽  
Striatal Dopamine ◽  
Blink Rate ◽  
Eye Blink ◽  
Non Invasive ◽  
Working Memory Updating ◽  
Time Changes ◽  
Event Based ◽  
Gating Process

AbstractEffective working memory (WM) functioning depends on the gating process that regulates the balance between maintenance and updating of WM. The present study used the event-based eye-blink rate (ebEBR), which presumably reflects phasic striatal dopamine activity, to examine how the cognitive processes of gating and updating separately facilitate flexible updating of WM contents and the potential involvement of dopamine in these processes. Realtime changes in eye blinks were tracked during performance on the reference-back task, in which demands on these two processes were independently manipulated. In all three experiments, trials that required WM updating and trials that required gate switching were both associated with increased ebEBR. These results may support the prefrontal cortex basal ganglia WM model (PBWM) by linking updating and gating to striatal dopaminergic activity. In Experiment 3, the ebEBR was used to determine what triggers gate switching. We found that switching to an updating mode (gate opening) was more stimulus driven and retroactive than switching to a maintenance mode, which was more context driven. Together, these findings show that the ebEBR – an inexpensive, non-invasive, easy-to-use measure – can be used to track changes in WM demands during task performance and, hence, possibly striatal dopamine activity.

scholarly journals Eye Blink Rates and Eyelid Twitches as a Non-Invasive Measure of Stress in the Domestic Horse

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 562 ◽  
Author(s):  
Merkies ◽  
Ready ◽  
Farkas ◽  
Hodder
Keyword(s):  
Stress Responses ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Feed Restriction ◽  
Feeding Time ◽  
Stressful Situation ◽  
Blink Rate ◽  
Visual Contact ◽  
Eye Blink ◽  
Non Invasive

Physiological changes provide indices of stress responses, however, behavioural measures may be easier to determine. Spontaneous eye blink rate has potential as a non-invasive indicator of stress. Eyelid movements, along with heart rate (HR) and behaviour, from 33 horses were evaluated over four treatments: 1) control—horse in its normal paddock environment; 2) feed restriction—feed was withheld at regular feeding time; 3) separation—horse was removed from visual contact with their paddock mates; and 4) startle test—a ball was suddenly thrown on the ground in front of the horse. HR data was collected every five s throughout each three min test. Eyelid movements and behaviours were retrospectively determined from video recordings. A generalized linear mixed model (GLIMMIX) procedure with Sidak’s multiple comparisons of least squares means demonstrated that both full blinks (16 ± 12b vs. 15 ± 15b vs. 13 ± 11b vs. 26 ± 20a full blinks/3 min ± SEM; a,b differ p < 0.006) and half blinks (34 ± 15ab vs. 27 ± 14bc vs. 25 ± 13c vs. 42 ± 22a half blinks/3 min ± SEM; a,b,c differ p < 0.0001) decreased during feed restriction, separation and the startle test compared to the control, respectively. Eyelid twitches occurred more frequently in feed restriction (p < 0.0001) along with an increased HR (p < 0.0001). This study demonstrates that spontaneous blink rate decreases while eyelid twitches increase when the horse experiences a stressful situation.

scholarly journals Solid optical clearing agents based through-Intact-Skull (TIS) window technique for long-term observation of cortical structure and function in mice

2021 ◽  
Author(s):  
Dongyu Li ◽  
Zhengwu Hu ◽  
Hequn Zhang ◽  
Liang Zhu ◽  
Yin Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Basic Research ◽  
Neuron Activity ◽  
Optical Clearing ◽  
Non Invasive ◽  
Clearing Technique ◽  
Long Term Observation ◽  
And Function

In vivo cortical optical imaging needs to overcome the scattering of skull. Compared to the traditional transcranial surgery-based open-skull glass window and thinned-skull preparation, chemical tissue optical clearing techniques can provide a skull-remained optical access to the brain while maintaining its original environment. However, previously demonstrated skull optical clearing windows could only maintain transparency for a couple of hours and hardly capable for high-resolution monitoring of awake animals. Here, we developed a convenient and easy-handling chronic skull optical clearing technique, named "Through-Intact-Skull (TIS) window", which was compatible with long-term observation at high resolution, and yielded large imaging depth of 900 μm for cortical neurovascular visualization. In addition, our TIS window could monitor neuron activity in awake mice for a long term. Therefore, our bio-compatible and non-invasive TIS window is a new promising approach for intravital brain microscopy with great potential for basic research in neuroscience.

scholarly journals Spontaneous eye blink rate and dopamine synthesis capacity: Preliminary evidence for an absence of positive correlation

2017 ◽  
Author(s):  
Guillaume Sescousse ◽  
Romain Ligneul ◽  
Ruth J. van Holst ◽  
Lieneke K. Janssen ◽  
Femke de Boer ◽  
...  
Keyword(s):  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Negative Relationship ◽  
Region Of Interest ◽  
Preliminary Evidence ◽  
Striatal Dopamine ◽  
Dopamine Synthesis ◽  
Blink Rate ◽  
Eye Blink

AbstractDopamine is central to a number of cognitive functions and brain disorders. Given the cost of neurochemical imaging in humans, behavioral proxy measures of dopamine have gained in popularity in the past decade, such as spontaneous eye blink rate (sEBR). Increased sEBR is commonly associated with increased dopamine function based on pharmacological evidence and patient studies. Yet, this hypothesis has not been validated using in vivo measures of dopamine function in humans. In order to fill this gap, we measured sEBR and striatal dopamine synthesis capacity using [18F]DOPA PET in 20 participants (9 healthy individuals and 11 pathological gamblers). Our results, based on frequentist and Bayesian statistics, as well as region-of-interest and voxel-wise analyses, argue against a positive relationship between sEBR and striatal dopamine synthesis capacity. They show that, if anything, the evidence is in favor of a negative relationship. These results, which complement findings from a recent study that failed to observe a relationship between sEBR and dopamine D2 receptor availability, suggest that caution and nuance are warranted when interpreting sEBR in terms of a proxy measure of striatal dopamine.

Staring Down Death

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Thomas E. Joiner ◽  
Melanie A. Hom ◽  
Megan L. Rogers ◽  
Carol Chu ◽  
Ian H. Stanley ◽  
...  
Keyword(s):  
Suicide Risk ◽  
Clinical Utility ◽  
Blink Rate ◽  
Specific Task ◽  
Careful Planning ◽  
Eye Blink ◽  
Eye Blinks ◽  
Potential Clinical Utility ◽  
The Relationship

Abstract. Background: Lowered eye blink rate may be a clinically useful indicator of acute, imminent, and severe suicide risk. Diminished eye blink rates are often seen among individuals engaged in heightened concentration on a specific task that requires careful planning and attention. Indeed, overcoming one’s biological instinct for survival through suicide necessitates premeditation and concentration; thus, a diminished eye blink rate may signal imminent suicidality. Aims: This article aims to spur research and clinical inquiry into the role of eye blinks as an indicator of acute suicide risk. Method: Literature relevant to the potential connection between eye blink rate and suicidality was reviewed and synthesized. Results: Anecdotal, cognitive, neurological, and conceptual support for the relationship between decreased blink rate and suicide risk is outlined. Conclusion: Given that eye blinks are a highly observable behavior, the potential clinical utility of using eye blink rate as a marker of suicide risk is immense. Research is warranted to explore the association between eye blink rate and acute suicide risk.

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