scholarly journals Repeatability of decision-making behaviour in male threespine stickleback Gasterosteus aculeatus: Effects of dummy vs. live stimuli

2011 ◽  
Vol 57 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Teresa L. Dzieweczynski ◽  
Lindsay M. Forrette

Abstract Individuals select from a number of behaviours when responding to various situations and the decisions they make may affect their fitness. The costs and benefits of these responses vary among individuals causing them to differ even in identical situations. One example of this type of situation is when territorial males encounter both a male and female simultaneously, generating a trade-off that likely leads to individual differences due to differing costs of various actions among males. This situation commonly occurs in threespine stickleback, Gasterosteus aculeatus. However, for selection to act effectively, individuals must behave in a consistent manner and measuring repeatability can aid in understanding how selection may shape such trade-offs. Males of this species exhibit consistent individual differences in their response to dummy males and females but it is unknown if patterns are similar when feedback from the stimuli is present. To assess this, male threespine stickleback were tested with dummy and live male and female conspecifics, presented separately and simultaneously. While the same trends were found regardless of stimulus type, males were more aggressive towards the live conspecifics than to the dummies. Repeatability values were similar within a treatment regardless of whether live or dummy conspecifics were used, suggesting that individuals show the same level of consistency. This study adds to our understanding of consistent individual differences by demonstrating that feedback may not affect responses to conflicting stimuli and that male threespine stickleback respond in a consistent manner to both dummy and live stimuli.

2016 ◽  
Author(s):  
Miriam C Klein-Flügge ◽  
Steven W Kennerley ◽  
Karl Friston ◽  
Sven Bestmann

AbstractIntegrating costs and benefits is crucial for optimal decision-making. While much is known about decisions that involve outcome-related costs (e.g., delay, risk), many of our choices are attached to actions and require an evaluation of the associated motor costs. Yet how the brain incorporates motor costs into choices remains largely unclear. We used human functional magnetic resonance imaging during choices involving monetary reward and physical effort to identify brain regions that serve as a choice comparator for effort-reward trade-offs. By independently varying both options' effort and reward levels, we were able to identify the neural signature of a comparator mechanism. A network involving supplementary motor area (SMA) and the caudal portion of dorsal anterior cingulate cortex (dACC) encoded the difference in reward (positively) and effort levels (negatively) between chosen and unchosen choice options. We next modelled effort-discounted subjective values using a novel behavioural model. This revealed that the same network of regions involving dACC and SMA encoded the difference between the chosen and unchosen options' subjective values, and that activity was best described using a concave model of effort-discounting. In addition, this signal reflected how precisely value determined participants' choices. By contrast, separate signals in SMA and ventro-medial PFC (vmPFC) correlated with participants' tendency to avoid effort and seek reward, respectively. This suggests that the critical neural signature of decision-making for choices involving motor costs is found in human cingulate cortex and not vmPFC as typically reported for outcome-based choice. Furthermore, distinct frontal circuits ‘drive’ behaviour towards reward-maximization and effort-minimization.Significance StatementThe neural processes that govern the trade-off between expected benefits and motor costs remain largely unknown. This is striking because energetic requirements play an integral role in our day-to-day choices and instrumental behaviour, and a diminished willingness to exert effort is a characteristic feature of a range of neurological disorders. We use a new behavioural characterization of how humans trade-off reward-maximization with effort-minimization to examine the neural signatures that underpin such choices, using BOLD MRI neuroimaging data. We find the critical neural signature of decision-making, a signal that reflects the comparison of value between choice options, in human cingulate cortex, whereas two distinct brain circuits ‘drive’ behaviour towards reward-maximization or effort-minimization.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
M. Ammar Alzarrad ◽  
Gary P. Moynihan ◽  
Muhammad T. Hatamleh ◽  
Siyuan Song

As is often the case in project scheduling, when the project duration is shortened to decrease total cost, the total float is lost resulting in added critical or nearly critical activities. This, in turn, results in decreasing the probability of completing the project on time and increases the risk of schedule delays. To solve this problem, this research developed a fuzzy multicriteria decision-making (FMCDM) model. The objective of this model is to help project managers improve their decisions regarding time-cost-risk trade-offs (TCRTO) in construction projects. In this model, an optimization algorithm based on fuzzy logic and analytic hierarchy process (AHP) has been used to analyze the time-cost-risk trade-off alternatives and select the best one based on selected criteria. The algorithm was implemented in the MATLAB software and applied to two case studies to verify and validate the presented model. The presented FMCDM model could help produce a more reliable schedule and mitigate the risk of projects running overbudget or behind schedule. Further, this model is a powerful decision-making instrument to help managers reduce uncertainties and improve the accuracy of time-cost-risk trade-offs. The presented FMCDM model employed fuzzy linguistic terms, which provide decision-makers with the opportunity to give their judgments as intervals comparing to fixed value judgments. In conclusion, the presented FMCDM model has high robustness, and it is an attractive alternative to the traditional methods to solve the time-cost-risk trade-off problem in construction.


2019 ◽  
Author(s):  
Maria Moiron ◽  
Kate L. Laskowski ◽  
Petri Toivo Niemelä

Research focusing on among-individual differences in behaviour (“animal personality”) has been blooming for over a decade. One of the central theories explaining the maintenance of behavioural variation posits a trade-off between behaviour and survival with individuals expressing greater “risky” behaviours suffering higher mortality. Here, for the first time, we synthesize the existing empirical evidence for this key prediction. Our results did not support this prediction as there was no directional relationship between riskier behaviour and greater mortality; however there was a significant absolute relationship between behaviour and survival. In total, behaviour explained a significant, but small, portion (4.4%) of the variance in survival. We also found that risky (versus “shy”) behavioural types live longer in the wild, but not in the laboratory. This suggests that individuals expressing risky behaviours might be of overall higher quality but the lack of predation pressure and resource restrictions mask this effect in laboratory environments. Our work implies that individual differences in behaviour explain important differences in survival but not in the direction predicted by theory. Importantly, this suggests that the models predicting survival trade-offs may need revision and/or empiricists may need to reconsider their proxies of risky behaviours when testing such theory.


2012 ◽  
Vol 367 (1603) ◽  
pp. 2762-2772 ◽  
Author(s):  
Andrew Sih ◽  
Marco Del Giudice

With the exception of a few model species, individual differences in cognition remain relatively unstudied in non-human animals. One intriguing possibility is that variation in cognition is functionally related to variation in personality. Here, we review some examples and present hypotheses on relationships between personality (or behavioural syndromes) and individual differences in cognitive style. Our hypotheses are based largely on a connection between fast–slow behavioural types (BTs; e.g. boldness, aggressiveness, exploration tendency) and cognitive speed–accuracy trade-offs. We also discuss connections between BTs, cognition and ecologically important aspects of decision-making, including sampling, impulsivity, risk sensitivity and choosiness. Finally, we introduce the notion of cognition syndromes, and apply ideas from theories on adaptive behavioural syndromes to generate predictions on cognition syndromes.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Henrique Schneider

Abstract This paper investigates the trade-off between economics and ethics applying them to “lockdowns” as a policy measure to counter the Covid-19-pandemic. This is an academic research on the nature and mechanism of trade-offs in so far as they apply to decision making. In the course of the line of inquiry pursued here, several different ways of trading off are assessed. In applying them to the pandemics, each yield a different answer to the adequacy of lockdowns as measures against the pandemic. The economic trade-off found “optimalcy” conditions, the utilitarian-ethical trade-off failed to do so revealing that there is a problem using “scientific evidence” as basis for such a trade-off. The value-ethical trade-off found out that lockdowns do not pass the test of proportionality within the usual constitutional framework.


2020 ◽  
Author(s):  
Stephen P. De Lisle ◽  
Daniel I. Bolnick

AbstractParasites can mediate host fitness both directly, via effects on survival and reproduction, or indirectly by inducing host immune defense with costly side-effects. The evolution of immune defense is determined by a complex interplay of costs and benefits of parasite infection and immune response, all of which may differ for male and female hosts in sexual lineages. Here, we examine fitness costs associated with an inducible immune defense in a fish-cestode host-parasite system. Cestode infection induces peritoneal fibrosis in threespine stickleback (Gasterosteus aculeatus), constraining cestode growth and sometimes encasing and killing the parasite. Surveying two wild populations of stickleback, we confirm that the presence of fibrosis scar tissue is associated with reduced parasite burden in both male and female fish. However, fibrotic fish had lower foraging success and reproductive fitness (reduced female egg production and male nesting success), indicating strong costs of the lingering immunopathology. We show that these substantial sexually-concordant fitness effects of immune response act to align multivariate selection across the sexes, masking the signature of sexual antagonism that acted on morphology alone. Although both sexes experienced costs of fibrosis, the net impacts are unequal because in the two study populations females had higher cestode exposure. To evaluate whether this difference in risk should drive sex-specific immune strategies, we analyze a quantitative genetic model of host immune response to a trophically transmitted parasite. The model and empirical data illustrate how shared costs and benefits of immune response lead to shared evolutionary interests of male and female hosts, despite unequal infection risks across the sexes.


2020 ◽  
Author(s):  
Charly Jehan ◽  
Manon Chogne ◽  
Thierry Rigaud ◽  
Yannick Moret

Abstract Background: The disposable soma theory of ageing assumes that organisms optimally trade-off limited resources between reproduction and longevity to maximize fitness. Early reproduction should especially trade-off against late reproduction and longevity because of reduced investment into somatic protection, including immunity. Moreover, as optimal reproductive strategies of males and females differ, sexually dimorphic patterns of senescence may evolve. In particular, as males gain fitness through mating success, sexual competition should be a major factor accelerating male senescence. In a single experiment, we examined these possibilities by establishing artificial populations of the mealworm beetle, Tenebrio molitor, in which we manipulated the sex-ratio to generate variable levels of investment into reproductive effort and sexual competition in males and females. Results: As predicted, variation in sex-ratio affected male and female reproductive efforts, with contrasted sex-specific trade-offs between lifetime reproduction, survival and immunity. High effort of reproduction accelerated mortality in females, without affecting immunity, but high early reproductive success was observed only in balanced sex-ratio condition. Male reproduction was costly on longevity and immunity, mainly because of their investment into copulations rather than in sexual competition. Conclusions: Our results suggest that T. molitor males, like females, maximize fitness through enhanced longevity, partly explaining their comparable longevity.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jan Drugowitsch ◽  
Gregory C DeAngelis ◽  
Dora E Angelaki ◽  
Alexandre Pouget

For decisions made under time pressure, effective decision making based on uncertain or ambiguous evidence requires efficient accumulation of evidence over time, as well as appropriately balancing speed and accuracy, known as the speed/accuracy trade-off. For simple unimodal stimuli, previous studies have shown that human subjects set their speed/accuracy trade-off to maximize reward rate. We extend this analysis to situations in which information is provided by multiple sensory modalities. Analyzing previously collected data (<xref ref-type="bibr" rid="bib4">Drugowitsch et al., 2014</xref>), we show that human subjects adjust their speed/accuracy trade-off to produce near-optimal reward rates. This trade-off can change rapidly across trials according to the sensory modalities involved, suggesting that it is represented by neural population codes rather than implemented by slow neuronal mechanisms such as gradual changes in synaptic weights. Furthermore, we show that deviations from the optimal speed/accuracy trade-off can be explained by assuming an incomplete gradient-based learning of these trade-offs.


2017 ◽  
Vol 31 (2) ◽  
pp. 75-81
Author(s):  
Fakhra Aziz ◽  
Qudsia Kalsoom ◽  
Uzma Quraishi ◽  
Sibte Hasan

This descriptive, qualitative study aimed at identifying disparities in perceptions of males and females regarding gender-based differences in educational leadership. Data were gathered purposively from 20 renowned male and female educationists having a long experience of leadership in various institutes of Pakistan. An open-ended questionnaire was used as a research tool to express their perceptions. Data were thematically analyzed under pre-defined categories borrowed from different leadership theorists. The results showed that both male and female respondents perceive that males have more leadership qualities as compared to females. It is especially true about abilities of decision-making and empowering the employees.


2018 ◽  
Vol 34 (5) ◽  
pp. 414-418
Author(s):  
Logan A. Lucas ◽  
Benjamin S. England ◽  
Travis W. Mason ◽  
Christopher R. Lanning ◽  
Taylor M. Miller ◽  
...  

Lower-extremity musculoskeletal injuries are common in sports such as basketball and soccer. Athletes competing in sports of this nature must maneuver in response to the actions of their teammates, opponents, etc. This limits their ability to preplan movements. The purpose of this study was to compare impact accelerations during preplanned versus unplanned lateral cutting. A total of 30 subjects (15 males and 15 females) performed preplanned and unplanned cuts while the authors analyzed impact accelerations using an accelerometer secured to their tibia. For the preplanned condition, subjects were aware of the movement to perform before initiating a trial. For the unplanned condition, subjects initiated their movement and then reacted to the illumination of one of 3 visual stimuli which dictated whether they would cut, land, or land-and-jump. A mixed-model analysis of variance with a between factor of sex (male and female) and a within factor of condition (preplanned and unplanned) was used to analyze the magnitude and variability of the impact accelerations for the cutting trials. Both males and females demonstrated higher impact accelerations (P = .01) and a trend toward greater intertrial variability (P = .07) for the unplanned cutting trials (vs preplanned cuts). Unplanned cutting may place greater demands on the musculoskeletal system.


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