scholarly journals The dopamine dip amplitude is a quantitative measure of disappointment

2021 ◽  
Author(s):  
Yu Shikano ◽  
Sho Yagishita ◽  
Kenji F Tanaka ◽  
Norio Takata
Keyword(s):  
Ventral Striatum ◽  
Fluorescent Protein ◽  
Lever Press ◽  
Fixed Ratio ◽  
Quantitative Measure ◽  
State Transitions ◽  
Task Completion ◽  
Great Expectations ◽  
Gpcr Activation ◽  
Set Up

Great expectations can lead to greater disappointment when the desired results are not achieved. Although it is well-documented that a better-than-expected reward is encoded quantitatively via midbrain dopaminergic (DA) activity, it has been less addressed experimentally whether disappointment, a worse-than-expected outcome is also expressed quantitatively by the DA signal. We show that the degree of disappointment is quantified by the magnitude of a transient decrease in the extracellular DA concentration (DA dip) in the ventral striatum of mice. We set up a lever press task on a fixed ratio (FR) schedule requiring five lever presses as an effort for a food reward (FR5). Mice occasionally checked the food magazine without a reward before completing the task. The percentage of this premature magazine entry (PME) increased as the number of lever presses approached five. This behavioral readout shows rising expectations with increasing proximity to task completion, leading to greater disappointment in the mice. Fiber photometry of the extracellular DA dynamics in the ventral striatum using a fluorescent protein (genetically encoded GPCR-activation-based-DA sensor: GRAB-DA2m) revealed that the amplitude of the DA dip following a PME was correlated with the percentage of the PME, demonstrating a monotonic relationship between the DA dip amplitude and the degree of disappointment. Computational modeling of the lever press task implementing temporal difference errors and state transitions replicated the positive correlation between the PME frequency and DA dip amplitude during improvement of the FR5 task. We propose that the degree of disappointment during making an effort for a goal is represented monotonically by the magnitude of the DA dip in the ventral striatum, which may guide behavioral adjustment.

scholarly journals The impact of translation modality on user experience: an eye-tracking study of the Microsoft Word user interface

2021 ◽  
Author(s):  
Ana Guerberof Arenas ◽  
Joss Moorkens ◽  
Sharon O’Brien
Keyword(s):  
User Interface ◽  
Eye Tracking ◽  
Cognitive Load ◽  
Task Completion ◽  
Eye Tracker ◽  
Software Products ◽  
Microsoft Word ◽  
Set Up ◽  
The Impact ◽  
The Given

AbstractThis paper presents results of the effect of different translation modalities on users when working with the Microsoft Word user interface. An experimental study was set up with 84 Japanese, German, Spanish, and English native speakers working with Microsoft Word in three modalities: the published translated version, a machine translated (MT) version (with unedited MT strings incorporated into the MS Word interface) and the published English version. An eye-tracker measured the cognitive load and usability according to the ISO/TR 16982 guidelines: i.e., effectiveness, efficiency, and satisfaction followed by retrospective think-aloud protocol. The results show that the users’ effectiveness (number of tasks completed) does not significantly differ due to the translation modality. However, their efficiency (time for task completion) and self-reported satisfaction are significantly higher when working with the released product as opposed to the unedited MT version, especially when participants are less experienced. The eye-tracking results show that users experience a higher cognitive load when working with MT and with the human-translated versions as opposed to the English original. The results suggest that language and translation modality play a significant role in the usability of software products whether users complete the given tasks or not and even if they are unaware that MT was used to translate the interface.

Operant Conditioning of Virginia Opossum

1970 ◽  
Vol 26 (1) ◽  
pp. 83-86 ◽  
Author(s):  
A. L. Cone ◽  
Donna M. Cone
Keyword(s):  
Operant Conditioning ◽  
Lever Press ◽  
Fixed Ratio ◽  
Fixed Interval ◽  
Response Style ◽  
Water Reinforcement ◽  
Deprivation Schedule ◽  
Limited Hold ◽  
Virginia Opossum

Laboratory-raised Virginia opossum have been found to readily acquire a lever-press response for water reinforcement. Fixed ratio behavior is comparable to that observed in other species. Fixed interval behavior, however, tends to move fairly rapidly toward an economical response style in which very few responses are emitted per reinforcement. Neither introduction of limited hold procedures nor lengthening of the deprivation schedule had any effect upon the FI responding.

scholarly journals Reducing effect of a Phaseolus vulgaris dry extract on operant self-administration of a chocolate-flavoured beverage in rats

2010 ◽  
Vol 104 (5) ◽  
pp. 624-628 ◽  
Author(s):  
Paola Maccioni ◽  
Giancarlo Colombo ◽  
Antonella Riva ◽  
Paolo Morazzoni ◽  
Ezio Bombardelli ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Phaseolus Vulgaris ◽  
Lever Press ◽  
Fixed Ratio ◽  
Rodent Models ◽  
Self Administration ◽  
Dry Extract ◽  
Reduce Body Weight ◽  
Derivatives Of

Extracts from or derivatives of Phaseolus vulgaris beans reduce body weight and food intake, including highly palatable foods and fluids, in multiple rodent models of overeating and obesity. The present study was designed to assess whether a standardised P. vulgaris dry extract was effective in reducing also the operant self-administration of a chocolate-flavoured beverage. To this end, rats were initially trained to lever-press for a chocolate-flavoured beverage under a fixed ratio 10 schedule of reinforcement in daily 60 min sessions. Once lever-responding reached stable levels, the effect of a P. vulgaris dry extract on the number of lever-responses for the chocolate-flavoured beverage was determined. Pretreatment with 50, 200 and 500 mg (intragastric) P. vulgaris dry extract per kg produced an approximate 15, 35 and 40 % reduction, respectively, in lever-responding for the chocolate-flavoured beverage. These results indicate the capacity of a P. vulgaris preparation to reduce the reinforcing properties of a highly palatable fluid in rats.

scholarly journals Effectiveness of Augmented Reality Guides for Blind Insertion Tasks

2020 ◽  
Vol 1 ◽  
Author(s):  
Nawel Khenak ◽  
Jeanne Vézien ◽  
Patrick Bourdot
Keyword(s):  
Augmented Reality ◽  
Academic Research ◽  
Potential Effect ◽  
Task Completion ◽  
Subjective Perception ◽  
Blind Insertion ◽  
Objective Performance Measures ◽  
Set Up ◽  
Two Stages ◽  
Assembly Tasks

Although many augmented reality (AR)-based assembly support systems have been proposed in academic research and industry, the effectiveness of AR to resolve the occlusion issue in the context of a blind assembly process remains an unexplored topic. Therefore, the present work investigates how AR can assist operators during the execution of blind manual assembly tasks. Specifically, an AR research set-up was designed to provide assistance in occlusion situations during a peg-in-hole task. The set-up featured a see-through device (HoloLens), which provides operators with two modes of visual augmentations that directly overlay on the assembly objects. The first mode referred to as the “wireframe overlay” displays the inner part of the objects, providing an inside view of the occluded parts, and the second one referred to as the “axes overlay,” displays the axes of the objects and their slots, indicating how to align the different parts during the assembly. The effectiveness of these AR visualizations was compared to a baseline augmentation-free situation in a controlled experiment. Thus, following a within-subject design, 30 participants performed a two-stages blind insertion task. Their performances represented by task completion time, insertion errors, and smoothness of the insertions were recorded. In addition, a post-questionnaire reported their subjective perception of task difficulty during the task and their preferences. Results indicated a strong acceptance of participants for AR visualizations that they rated as allowing them to perform the task more easily. However, no statistically significant differences in terms of objective performance measures were found. Yet, it was found that axes overlay produced smoother trajectories compared to the wireframe overlay, highlighting the potential effect of more abstract visualization aids.

Fatigue Delamination Growth in CFRP Composites: From Pure Mode I and Mode II to Mixed Mode I/II

2015 ◽  
Vol 825-826 ◽  
pp. 914-921 ◽  
Author(s):  
Steffen Stelzer ◽  
Gerald Pinter
Keyword(s):  
Mixed Mode ◽  
Fixed Ratio ◽  
Fatigue Tests ◽  
Mode I ◽  
Mode Ii ◽  
Pure Mode ◽  
Failure Envelope ◽  
Static Testing ◽  
Standard Procedures ◽  
Set Up

For composite design, it is desirable to have data covering the failure envelope from Mode I to Mode II. The existing standard procedures for quasi-static testing (ISO 15024 for Mode I and ISO DIS 15114 for Mode II) have recently been shown to be adaptable for the respective fatigue tests under displacement control. The Calibrated End-Loaded Split (C-ELS) test set-up developed for Mode II further allows performing a Fixed-Ratio Mixed Mode I/II (FRMM) test by simply inverting the loading direction compared to mode II.

scholarly journals Effectiveness of Light-Quality and Dark-White Growth Light Shifts in Short-Term Light Acclimation of Photosynthesis in Arabidopsis

2022 ◽  
Vol 12 ◽  
Author(s):  
Elisabeth Hommel ◽  
Monique Liebers ◽  
Sascha Offermann ◽  
Thomas Pfannschmidt
Keyword(s):  
Light Quality ◽  
Photosynthetic Performance ◽  
Light Acclimation ◽  
Photosynthetic Acclimation ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Dark Light ◽  
Light Shifts ◽  
Set Up ◽  
Photosynthetic Antenna

Photosynthesis needs to run efficiently under permanently changing illumination. To achieve this, highly dynamic acclimation processes optimize photosynthetic performance under a variety of rapidly changing light conditions. Such acclimation responses are acting by a complex interplay of reversible molecular changes in the photosynthetic antenna or photosystem assemblies which dissipate excess energy and balance uneven excitation between the two photosystems. This includes a number of non-photochemical quenching processes including state transitions and photosystem II remodeling. In the laboratory such processes are typically studied by selective illumination set-ups. Two set-ups known to be effective in a highly similar manner are (i) light quality shifts (inducing a preferential excitation of one photosystem over the other) or (ii) dark-light shifts (inducing a general off-on switch of the light harvesting machinery). Both set-ups result in similar effects on the plastoquinone redox state, but their equivalence in induction of photosynthetic acclimation responses remained still open. Here, we present a comparative study in which dark-light and light-quality shifts were applied to samples of the same growth batches of plants. Both illumination set-ups caused comparable effects on the phosphorylation of LHCII complexes and, hence, on the performance of state transitions, but generated different effects on the degree of state transitions and the formation of PSII super-complexes. The two light set-ups, thus, are not fully equivalent in their physiological effectiveness potentially leading to different conclusions in mechanistic models of photosynthetic acclimation. Studies on the regulation of photosynthetic light acclimation, therefore, requires to regard the respective illumination test set-up as a critical parameter that needs to be considered in the discussion of mechanistic and regulatory aspects in this subject.

Feasibility of EEG to monitor cognitive performance during venous cannulation: EEG Distracted Intravenous Access (E-DIVA)

2016 ◽  
Vol 2 (3) ◽  
pp. 68-72 ◽  
Author(s):  
David J Lowe ◽  
Scott A James ◽  
Adam Lloyd ◽  
Gareth R Clegg
Keyword(s):  
Cognitive Load ◽  
Clinical Performance ◽  
Educational Interventions ◽  
Task Completion ◽  
Cognitive Workload ◽  
Simple Arithmetic ◽  
Arithmetic Task ◽  
Significant Difference ◽  
Set Up ◽  
The Impact

BackgroundThe feasibility study aims to evaluate the use of EEG in measuring workload during a simulated intravenous cannulation task. Cognitive workload is strongly linked to performance, but current methods to assess workload are unreliable. The paper presents the use of EEG to compare the cognitive workload between an expert and novice group completing a simple clinical task.Methods2 groups of volunteers (10 final year medical students and 10 emergency medicine consultants) were invited to take part in the study. Each participant was asked to perform 3 components of the simulation protocol: intravenous cannulation, a simple arithmetic test and finally these tasks combined. Error rate, speed of task completion and an EEG-based measure of cognitive workload were recorded for each element.ResultsEEG cognitive workload during the combined cannulation and arithmetic task is significantly greater in novice participants when compared with expert operators performing the same task combination. EEG workload mean measured for novice and experts was 0.62 and 0.54, respectively (p=0.001, 95% CI 0.09 to 0.30). There was no significant difference between novice and expert EEG workload when the tasks were performed individually.ConclusionsEEG provides the opportunity to monitor and analyse the impact of cognitive load on clinical performance. Despite the significant challenges in set up and protocol design, there is a potential to develop educational interventions to optimise clinician's awareness of cognitive load. In addition, it may enable the use of metrics to monitor the impact of different interventions and select those that optimise clinical performance.

scholarly journals Correlation of in vivo tumor response and singlet oxygen luminescence detection in mTHPC-mediated photodynamic therapy

2015 ◽  
Vol 08 (01) ◽  
pp. 1540006 ◽  
Author(s):  
Brian C. Wilson ◽  
Michael S. Patterson ◽  
Buhong Li ◽  
Mark T. Jarvi
Keyword(s):  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Near Infrared ◽  
Tumor Tissue ◽  
Tumor Response ◽  
Fluorescent Protein ◽  
Normal Skin ◽  
Quantitative Measure ◽  
Clear Correlation

Excited-state singlet oxygen (1 O 2), generated during photodynamic therapy (PDT), is believed to be the primary cytotoxic agent with a number of clinically approved photosensitizers. Its relative concentration in cells or tissues can be measured directly through its near-infrared (NIR) luminescence emission, which has correlated well with in vitro cell and in vivo normal skin treatment responses. Here, its correlation with the response of tumor tissue in vivo is examined, using the photosensitizer meso-tetrahydroxyphenylchlorin (mTHPC) in an animal model comprising luciferase- and green fluorescent protein (GFP)-transduced gliosarcoma grown in a dorsal window chamber. The change in the bioluminescence signal, imaged pretreatment and at 2, 5 and 9 d post treatment, was used as a quantitative measure of the tumor response, which was classified in individual tumors as "non", "moderate" and "strong" in order to reduce the variance in the data. Plotting the bioluminescence-based response vs the 1 O 2 counts demonstrated clear correlation, indicating that 1 O 2 luminescence provides a valid dosimetric technique for PDT in tumor tissue.

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