scholarly journals Selective Devaluation Affects the Processing of Preferred Rewards

Author(s):  
Dana M. Huvermann ◽  
Christian Bellebaum ◽  
Jutta Peterburs

AbstractThe present study investigated whether the representation of subjective preferences in the event-related potential is manipulable through selective devaluation, i.e., the consumption of a specific food item until satiety. Thirty-four participants completed a gambling task in which they chose between virtual doors to find one of three snack items, representing a high, medium, or low preference outcome as defined by individual desire-to-eat ratings. In one of two test sessions, they underwent selective devaluation of the high preference outcome. In the other, they completed the task on an empty stomach. Consistent with previous findings, averaged across sessions, amplitudes were increased for more preferred rewards in the time windows of P2, late FRN, and P300. As hypothesised, we also found a selective devaluation effect for the high preference outcome in the P300 time window, reflected in a decrease in amplitude. The present results provide evidence for modulations of reward processing not only by individual factors, such as subjective preferences, but also by the current motivational state. Importantly, the present data suggest that selective devaluation effects in the P300 may be a promising tool to further characterise altered valuation of food rewards in the context of eating disorders and obesity.

2020 ◽  
Author(s):  
Jorge Valdés Kroff ◽  
Patricia Roman ◽  
Paola E. Dussias

Prior studies using the event-related potential (ERP) technique show that integrating sentential code-switches in online processing lead to a broadly distributed late positivity component while processing semantically unexpected continuations instead lead to the emergence of an N400 effect. While the N400 is generally assumed to index lexico-semantic processing, the LPC has two different interpretations. One account suggests that it reflects the processing of an improbable or unexpected event while an alternative account proposes sentence-level reanalysis. To investigate the relative costs of semantic to language-based unexpectancies (i.e., code-switches), the current study tests 24 Spanish-English bilinguals in an ERP reading study. Semantically constrained Spanish frames either varied in their semantic expectancy (high vs low expectancy) and/or their language continuation (same language vs code-switch) while participants’ electrophysiological responses were recorded. The Spanish-to-English switch direction provides a more naturalistic test for integration costs to code-switching as it better approximates the code-switching practices of the target population. Analyses across three time windows show a main effect for semantic expectancy in the N400 time window and a main effect for code-switching in the LPC time window. Additional analyses based on the self-reported code-switching experience of the participants suggested an early positivity linked to less experience with code-switching. The results suggest that not all code-switches lead to similar integration costs and that prior experience with code-switching is an important additional factor that modulates online processing.


2020 ◽  
Author(s):  
Pablo Bernabeu

The engagement of sensory brain regions during word recognition is widely documented, yet its precise relevance is less clear. It would constitute perceptual simulation only if it has a functional role in conceptual processing. We investigated this in an Event-Related Potential (ERP) experiment implementing the conceptual modality switch paradigm. In each trial, participants verified the relation between a property word and a concept word. Orthogonally, we manipulated the conceptual modality of successive trials, and tested whether switching modalities incurred any processing costs at different stages of word recognition. Unlike previous studies, we time-locked ERPs to the first word of target trials, in order to measure the modality transitions from the beginning, and also to reduce confounds within the target trial. Further, we included different types of switch—one from auditory to visual modality, and one from haptic to visual—, which were compared to the non-switch—visual to visual. Also, one group of participants was asked to respond quickly (n = 21), and another group to respond self-paced (n = 21), whilst a few others received no constraints (n = 5). We found ERP effects in four typical time windows from 160 to 750 ms post word onset. The overall effect is characterized by a negativity for modality-switching relative to not switching, and it increases over time. Further, the effect arises with both types of switch, and influences both participant groups within anterior and posterior brain regions. The emergence of this effect in the first time window particularly suggests that sensory regions may have a functional role in conceptual processing. The increased effect later on converges with previous studies in supporting the compatibility of distributional and embodied processing. On a less conclusive note, more research may be necessary to ascertain the nature of the effect at late stages.


2021 ◽  
pp. 136700692199682
Author(s):  
Katarzyna Jankowiak ◽  
Marcin Naranowicz ◽  
Karolina Rataj

Aims and objectives: The study provides new insights into how bilingual speakers process semantically complex novel meanings in their native (L1) and non-native language (L2). Methodology: The study employs an EEG method with a semantic decision task to novel nominal metaphors, novel similes, as well as literal and anomalous sentences presented in participants’ L1 and L2. Data and analysis: In total, 29 native speakers of Polish (L1) who were highly proficient in English (L2) took part in the study. The collected EEG signal was analyzed in terms of an event-related potential analysis. The statistical analyses were based on behavioral data (reaction times and accuracy rates) as well as mean amplitudes for the four conditions in the two languages within the N400 and LPC time windows. Findings: The results revealed the N400 effect of utterance type modulated by language nativeness, where the brainwaves for anomalous sentences, novel nominal metaphors, and novel similes converged in L2, while in L1 a graded effect was observed from anomalous sentences to novel nominal metaphors, novel similes and literal sentences. In contrast, within the late time window, a more pronounced sustained negativity to novel nominal metaphors than novel similes was observed in both languages, thus indicating that meaning integration mechanisms might be of similar automaticity in L1 and L2 when bilingual speakers are highly proficient in their L2. Altogether, the present results point to a more taxing mechanisms involved in lexico-semantic access in L2 than L1, yet such an increased effort seems to be resolved within the meaning integration phase. Originality: The findings present novel insights into how bilinguals construct new unfamiliar meanings and show how and when cognitive mechanisms engaged in this process are modulated by language nativeness. Significance: The study might provide crucial implications for further research on bilingual semantic processing as well as human creativity.


SLEEP ◽  
2021 ◽  
Author(s):  
Jiefan Ling ◽  
Xuanyi Lin ◽  
Xiao Li ◽  
Ngan Yin Chan ◽  
Jihui Zhang ◽  
...  

Abstract Study Objectives Insomnia and depression are common comorbid conditions in youths. Emerging evidence suggests that disrupted reward processing may be implicated in the association between insomnia and the increased risk for depression. Reduced reward positivity (RewP) as measured by event-related potential (ERP) has been linked to depression, but has not been tested in youths with insomnia. Methods Twenty-eight participants with insomnia disorder and without any comorbid psychiatric disorders and 29 healthy sleepers aged between 15-24 completed a monetary reward task, the Cued Door task, whilst electroencephalographic activity was recorded. RewP (reward minus non-reward difference waves) was calculated as the mean amplitudes within 200ms to 300ms time window at FCz. Two analyses of covariance (ANCOVAs) were conducted with age as a covariate on RewP amplitude and latency, respectively. Results Participants with insomnia had a significantly lower RewP amplitude regardless of cue types (Gain, Control, and Loss) than healthy sleepers, F (1, 51) = 4.95, p = .031, indicating blunted reward processing. On the behavioural level, healthy sleepers were more prudential (slower reaction time) in decision making towards Loss/Gain cues than their insomnia counterparts. Trial-by-trial behavioural adjustment analyses showed that, compared with healthy sleepers, participants with insomnia were less likely to dynamically change their choices in response to Loss cues. Conclusions Dysfunctional reward processing, coupled with inflexibility of behavioural adjustment in decision-making, is associated with insomnia disorder among youth, independent of mood disorders. Future studies with long-term follow-up are needed to further delineate the developmental trajectory of insomnia-related reward dysfunctions in youth.


2020 ◽  
pp. 1-17
Author(s):  
Szczepan J. Grzybowski ◽  
Miroslaw Wyczesany ◽  
Jan Kaiser

Abstract. The goal of the study was to explore event-related potential (ERP) differences during the processing of emotional adjectives that were evaluated as congruent or incongruent with the current mood. We hypothesized that the first effects of congruence evaluation would be evidenced during the earliest stages of semantic analysis. Sixty mood adjectives were presented separately for 1,000 ms each during two sessions of mood induction. After each presentation, participants evaluated to what extent the word described their mood. The results pointed to incongruence marking of adjective’s meaning with current mood during early attention orientation and semantic access stages (the P150 component time window). This was followed by enhanced processing of congruent words at later stages. As a secondary goal the study also explored word valence effects and their relation to congruence evaluation. In this regard, no significant effects were observed on the ERPs; however, a negativity bias (enhanced responses to negative adjectives) was noted on the behavioral data (RTs), which could correspond to the small differences traced on the late positive potential.


Author(s):  
Hongguang Wu ◽  
Yuelin Gao ◽  
Wanting Wang ◽  
Ziyu Zhang

AbstractIn this paper, we propose a vehicle routing problem with time windows (TWVRP). In this problem, we consider a hard time constraint that the fleet can only serve customers within a specific time window. To solve this problem, a hybrid ant colony (HACO) algorithm is proposed based on ant colony algorithm and mutation operation. The HACO algorithm proposed has three innovations: the first is to update pheromones with a new method; the second is the introduction of adaptive parameters; and the third is to add the mutation operation. A famous Solomon instance is used to evaluate the performance of the proposed algorithm. Experimental results show that HACO algorithm is effective against solving the problem of vehicle routing with time windows. Besides, the proposed algorithm also has practical implications for vehicle routing problem and the results show that it is applicable and effective in practical problems.


OR Spectrum ◽  
2021 ◽  
Author(s):  
Christian Tilk ◽  
Katharina Olkis ◽  
Stefan Irnich

AbstractThe ongoing rise in e-commerce comes along with an increasing number of first-time delivery failures due to the absence of the customer at the delivery location. Failed deliveries result in rework which in turn has a large impact on the carriers’ delivery cost. In the classical vehicle routing problem (VRP) with time windows, each customer request has only one location and one time window describing where and when shipments need to be delivered. In contrast, we introduce and analyze the vehicle routing problem with delivery options (VRPDO), in which some requests can be shipped to alternative locations with possibly different time windows. Furthermore, customers may prefer some delivery options. The carrier must then select, for each request, one delivery option such that the carriers’ overall cost is minimized and a given service level regarding customer preferences is achieved. Moreover, when delivery options share a common location, e.g., a locker, capacities must be respected when assigning shipments. To solve the VRPDO exactly, we present a new branch-price-and-cut algorithm. The associated pricing subproblem is a shortest-path problem with resource constraints that we solve with a bidirectional labeling algorithm on an auxiliary network. We focus on the comparison of two alternative modeling approaches for the auxiliary network and present optimal solutions for instances with up to 100 delivery options. Moreover, we provide 17 new optimal solutions for the benchmark set for the VRP with roaming delivery locations.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Ilaria Izzo ◽  
Canio Carriero ◽  
Giulia Gardini ◽  
Benedetta Fumarola ◽  
Erika Chiari ◽  
...  

Abstract Background Brescia Province, northern Italy, was one of the worst epicenters of the COVID-19 pandemic. The division of infectious diseases of ASST (Azienda Socio Sanitaria Territoriale) Spedali Civili Hospital of Brescia had to face a great number of inpatients with severe COVID-19 infection and to ensure the continuum of care for almost 4000 outpatients with HIV infection actively followed by us. In a recent manuscript we described the impact of the pandemic on continuum of care in our HIV cohort expressed as number of missed visits, number of new HIV diagnosis, drop in ART (antiretroviral therapy) dispensation and number of hospitalized HIV patients due to SARS-CoV-2 infection. In this short communication, we completed the previous article with data of HIV plasmatic viremia of the same cohort before and during pandemic. Methods We considered all HIV-patients in stable ART for at least 6 months and with at least 1 available HIV viremia in the time window March 01–November 30, 2019, and another group of HIV patients with the same two requisites but in different time windows of the COVID-19 period (March 01–May 31, 2020, and June 01–November 30, 2020). For patients with positive viremia (PV) during COVID-19 period, we reported also the values of viral load (VL) just before and after PV. Results: the percentage of patients with PV during COVID-19 period was lower than the previous year (2.8% vs 7%). Only 1% of our outpatients surely suffered from pandemic in term of loss of previous viral suppression. Conclusions Our efforts to limit the impact of pandemic on our HIV outpatients were effective to ensure HIV continuum of care.


2014 ◽  
Vol 687-691 ◽  
pp. 5161-5164
Author(s):  
Lian Zhou Gao

As the development of world economy, how to realize the reasonable vehicle logistics routing path problem with time window constrain is the key issue in promoting the prosperity and development of modern logistics industry. Through the research of vehicle logistics routing path 's demand, particle swarm optimization with a novel particle presentation is designed to solve the problem which is improved, effective and adept to the normal vehicle logistics routing. The simulation results of example indicate that the algorithm has more search speed and stronger optimization ability.


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