•A DRL method is designed to handle COLREGS collision avoidance path planning, which can ensure that each action of the USV is the optimal solution in the current state.•Simulated real-time sensor ...information is chosen as the input data of the DQN, which is used to simulate the practical navigation of the USVs.•The APF algorithm is utilized to improve the action space and reward function of the DQN to solve the sparse reward conundrum.
Improving the autopilot capability of ships is particularly important to ensure the safety of maritime navigation.The unmanned surface vessel (USV) with autopilot capability is a development trend of the ship of the future. The objective of this paper is to investigate the path planning problem of USVs in uncertain environments, and a path planning strategy unified with a collision avoidance function based on deep reinforcement learning (DRL) is proposed. A Deep Q-learning network (DQN) is used to continuously interact with the visually simulated environment to obtain experience data, so that the agent learns the best action strategies in the visual simulated environment. To solve the collision avoidance problems that may occur during USV navigation, the location of the obstacle ship is divided into four collision avoidance zones according to the International Regulations for Preventing Collisions at Sea (COLREGS). To obtain an improved DRL algorithm, the artificial potential field (APF) algorithm is utilized to improve the action space and reward function of the DQN algorithm. A simulation experiments is utilized to test the effects of our method in various situations. It is also shown that the enhanced DRL can effectively realize autonomous collision avoidance path planning.
Background
Pathological avoidance is a transdiagnostic characteristic of anxiety disorders. Avoidance conditioning re‐emerged as a translational model to examine mechanisms and treatment of ...avoidance. However, its validity for anxiety disorders remains unclear.
Methods
This study tested for altered avoidance in patients with anxiety disorders compared to matched controls (n = 40/group) using instrumental conditioning assessing low‐cost avoidance (avoiding a single aversive outcome) and costly avoidance (avoidance conflicted with gaining rewards). Autonomic arousal and threat expectancy were assessed as indicators of conditioned fear. Associations with dimensional symptom severity were examined.
Results
Patients and controls showed frequent low‐cost avoidance without group differences. Controls subsequently inhibited avoidance to gain rewards, which was amplified when aversive outcomes discontinued. In contrast, patients failed to reduce avoidance when aversive and positive outcomes competed (elevated costly avoidance) and showed limited reduction when aversive outcomes discontinued (persistent costly avoidance). Interestingly, elevated costly avoidance was not linked to higher conditioned fear in patients. Moreover, individual data revealed a bimodal distribution of costly avoidance: Some patients showed persistent avoidance, others showed little to no avoidance. Persistent versus low avoiders did not differ in other task‐related variables, response to gains and losses in absence of threat, sociodemographic data, or clinical characteristics.
Conclusions
Findings suggest that anxious psychopathology is associated with a deficit to inhibit avoidance in presence of competing positive outcomes. This offers novel perspectives for research on mechanisms and treatment of anxiety disorders.
Recent studies have shown that avoidance behavior may become excessive and inflexible (i.e., detached from its incentive value and resistant to extinction). On the other hand, prospective intolerance ...of uncertainty (P-IU) has been defined as a factor leading to excessive responding in uncertain situations. Thus, uncertain avoidance situations may be taken as a relevant scenario to examine the role of intolerance of uncertainty as a factor that facilitates excessive and inflexible avoidance behavior. In our experiment, we tested the hypothesis that P-IU is associated with excessive and inflexible avoidance in an outcome devaluation paradigm. Specifically, healthy participants learned in a free-operant discriminative task to avoid an aversive sound, and were tested in extinction to measure the sensitivity of avoidance responses to the devaluation of the sound aversiveness. The results showed that an increase in P-IU was positively associated to an increase in insensitivity to the devaluation. Moreover, P-IU was also related to an increase in the frequency of avoidance responses during the instrumental learning phase, and to resistance to extinction. Interestingly, these associations involving P-IU were still significant when trait anxiety was controlled for. The pattern of results suggests that P-IU may be a vulnerability factor for excessive and inflexible avoidance, which, in turn, has been found to be associated with several mental disorders.
•Prospective intolerance of uncertainty may be defined as a factor leading to excessive responding in uncertain situations.•Prospective intolerance of uncertainty is associated to insensitivity in an outcome devaluation paradigm.•Prospective intolerance of uncertainty is a vulnerability factor for excessive avoidance behaviors-related disorders.
On the ideal avoidance property Chen, Justin; Tarizadeh, Abolfazl
Journal of pure and applied algebra,
March 2024, 2024-03-00, Volume:
228, Issue:
3
Journal Article
Peer reviewed
Open access
In this article, we investigate the avoidance property of ideals and rings. Among the main results, a general version of the avoidance lemma is formulated. It is shown that every idempotent ideal ...(and hence every pure ideal) has avoidance. The avoidance property of arbitrary direct products of avoidance rings is characterized. It is shown that every overing of an avoidance domain is an avoidance domain. Next, we show that every avoidance N-graded ring whose base subring is a finite field is a PIR. It is also proved that the avoidance property is preserved under flat ring epimorphisms. Dually, we formulate a notion of strong avoidance, and show that it is reflected by pure morphisms.
Cognitive theories of depression and anxiety have traditionally emphasized the role of attentional biases in the processing of negative information. The dot-probe task has been widely used to study ...this phenomenon. Recent findings suggest that biased processing of positive information might also be an important aspect of developing psychopathological symptoms. However, despite some evidence suggesting persons with symptoms of depression and anxiety may avoid positive information, many dot-probe studies have produced null findings. The present review used conventional and novel meta-analytic methods to evaluate dot-probe attentional biases away from positive information and, for comparison, toward negative information, in depressed and anxious individuals. Results indicated that avoidance of positive information is a real effect exhibiting substantial evidential value among persons experiencing psychopathology, with individuals evidencing primary symptoms of depression clearly demonstrating this effect. Different theoretical explanations for these findings are evaluated, including those positing threat-processing structures, even-handedness, self-regulation, and reward devaluation, with the novel theory of reward devaluation emphasized and expanded. These novel findings and theory suggest that avoidance of prospective reward helps to explain the cause and sustainability of depressed states. Suggestions for future research and methodological advances are discussed.
Full text
Available for:
CEKLJ, FFLJ, NUK, ODKLJ, PEFLJ
The basolateral amygdala (BLA) plays essential roles in behaviors motivated by stimuli with either positive or negative valence, but how it processes motivationally opposing information and ...participates in establishing valence-specific behaviors remains unclear. Here, by targeting Fezf2-expressing neurons in the BLA, we identify and characterize two functionally distinct classes in behaving mice, the negative-valence neurons and positive-valence neurons, which innately represent aversive and rewarding stimuli, respectively, and through learning acquire predictive responses that are essential for punishment avoidance or reward seeking. Notably, these two classes of neurons receive inputs from separate sets of sensory and limbic areas, and convey punishment and reward information through projections to the nucleus accumbens and olfactory tubercle, respectively, to drive negative and positive reinforcement. Thus, valence-specific BLA neurons are wired with distinctive input-output structures, forming a circuit framework that supports the roles of the BLA in encoding, learning and executing valence-specific motivated behaviors.
Evolution of pathogen and parasite avoidance behaviours Sarabian, Cecile; Curtis, Val; McMullan, Rachel
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
07/2018, Volume:
373, Issue:
1751
Journal Article
Peer reviewed
Open access
All free-living animals are subject to intense selection pressure from parasites and pathogens resulting in behavioural adaptations that can help potential hosts to avoid falling prey to parasites. ...This special issue on the evolution of parasite avoidance behaviour was compiled following a Royal Society meeting in 2017. Here we have assembled contributions from a wide range of disciplines including genetics, ecology, parasitology, behavioural science, ecology, psychology and epidemiology on the disease avoidance behaviour of a wide range of species. Taking an interdisciplinary and cross-species perspective allows us to sketch out the strategies, mechanisms and consequences of parasite avoidance and to identify gaps and further questions. Parasite avoidance strategies must include avoiding parasites themselves and cues to their presence in conspecifics, heterospecifics, foods and habitat. Further, parasite avoidance behaviour can be directed at constructing parasite-retardant niches. Mechanisms of parasite avoidance behaviour are generally less well characterized, though nematodes, rodents and human studies are beginning to elucidate the genetic, hormonal and neural architecture that allows animals to recognize and respond to cues of parasite threat. While the consequences of infection are well characterized in humans, we still have much to learn about the epidemiology of parasites of other species, as well as the trade-offs that hosts make in parasite defence versus other beneficial investments like mating and foraging. Finally, in this overview we conclude that it is legitimate to use the word ‘disgust' to describe parasite avoidance systems, in the same way that ‘fear' is used to describe animal predator avoidance systems. Understanding disgust across species offers an excellent system for investigating the strategies, mechanisms and consequences of behaviour and could be a vital contribution towards the understanding and conservation of our planet's ecosystems.
This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours'.
Objective
Performance‐approach goals and performance‐avoidance goals are conceptually distinct, but they are often moderately or even highly positively correlated. The present research examines lay ...conceptions of approach and avoidance motivation as a moderator of this intergoal relation.
Method
Study 1 (N = 281) assessed whether participants considered norm‐based approach motivation as being the same or different from norm‐based avoidance motivation and tested these conceptions as a moderator of the performance goal correlation. Study 2 (N = 990) measured and experimentally manipulated lay conceptions.
Results
In both studies, individuals who viewed approach and avoidance motivation as different exhibited a smaller performance goal correlation and lower performance‐based goal adoption than those who viewed approach and avoidance goals as the same. Findings from experimentally manipulated conceptions provided further clarity regarding the precise nature of the relations and mean differences observed. Specifically, moderation was driven by the different condition (where the differences between approach and avoidance were highlighted).
Conclusions
This research sheds light on the nature and magnitude of the focal performance‐based goal correlation and highlights the value of attending to lay conceptions of approach and avoidance motivation as well as lay conceptions of ability.
Taking the 11th Five-Year Plan in China as a quasi-natural experiment, this paper explores the impact of environmental regulation on corporate tax avoidance based on firm-level data and the ...difference-in-difference-in-differences (DDD) method. We find that: (1) Environmental regulation has a significant positive effect on corporate tax avoidance, and several robustness checks confirm our findings; (2) Heterogeneity analysis show that this effects are more significant for private firms and for firms in the regions with less fiscal stress and that in the east part of China; (3) Two channels identified are the operating risks and financing constraints; (4) Further analysis show that the 11th Five-Year Plan has spillover effects on firms in low-emission industries. The increased tax avoidance of firms in high-emission industries contributes to a raised tax burden on firms in low-emission industries. Our study provides implications for the formulation of environmental policies in developing countries
•The impact of environmental regulation on corporate tax avoidance is explored.•Environmental regulation makes firms become more tax aggressive.•Two channels identified are the operating risks and the financing constraints.•Environmental regulation has spillover effects on firms in low-emission industries.
Avoidance behavior in clinical anxiety disorders is often a decision made in response to approach-avoidance conflict, resulting in a sacrifice of potential rewards to avoid potential negative ...affective consequences. Animal research has a long history of relying on paradigms related to approach-avoidance conflict to model anxiety-relevant behavior. This approach includes punishment-based conflict, exploratory, and social interaction tasks. There has been a recent surge of interest in the translation of paradigms from animal to human, in efforts to increase generalization of findings and support the development of more effective mental health treatments. This article briefly reviews animal tests related to approach-avoidance conflict and results from lesion and pharmacologic studies utilizing these tests. We then provide a description of translational human paradigms that have been developed to tap into related constructs, summarizing behavioral and neuroimaging findings. Similarities and differences in findings from analogous animal and human paradigms are discussed. Lastly, we highlight opportunities for future research and paradigm development that will support the clinical utility of this translational work.
•Analogous rodent and human behavioral tasks support translational research.•Approach-avoidance conflict is highly relevant for avoidance and decision-making.•Translational human approach-avoidance conflict tasks have recently been developed.•Translational human research has corroborated and extended animal research.•Future translational behavioral research could enhance understanding of anxiety.
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