Select Indicators Research Articles

Evolutionary selection and morphological integration in the hand of modern humans.

To enhance our understanding of the evolutionary dynamics of the modern human hand by analyzing the degree of integration and ability to respond to selection pressures of each phalanx and metacarpal bone. The sample comprised 96 adult individuals, both female and male, from Euro-American, Afro-American, and European populations. We collected 10 linear measurements from the 19 metacarpals and proximal, middle, and distal phalanges that constitute the five digits of the hand. Using these data, we constructed variance/covariance matrices to quantify the degree of integration and assess the hand ability to respond to selective pressures. Distal phalanges are the most evolvable and flexible elements, while being the least integrated and constrained. The thumb is similarly integrated as the second and third rays, while medial rays (fourth and fifth digits) are more integrated. However, the thumb presents different integration and response to selection patterns. No significant relationship was found between functionality and the indices of selection and integration. Finally, the correlation between hand and foot indices yielded significant results for conditional evolvability and flexibility. The findings suggest different evolutionary trajectories for the metacarpal and distal phalanx in the modern human thumb, likely reflecting varying functional and developmental pressures. The first metacarpal, characterized by high flexibility and low evolvability, appears to have reached a stable, optimal morphology, under stabilizing selection. In contrast, the distal phalanx seems to have undergone directional evolution, suggesting specialization for a specific function. Comparisons between hands and feet suggest that these structures evolve differently under directional selection but similarly under stabilizing selection.

Synonymous codon usage influences the transmission of peste des petits ruminants (PPR) virus in camels.

Peste des petits ruminants virus (PPRV) is an infectious pathogen; causing highly contagious, acute febrile, and economically important disease of small ruminants. The virus is known to have intrinsic ability to adapt new hosts and to cross the species barrier. The incidence of PPR has already been reported in unusual host species such as camels, bovines, and wild animals from spill-over or natural infection. Still, there are elementary gaps in our knowledge of the extent of susceptibility of camel to PPRV and the adaptability of PPRV to camel. The present study delineates the potential role of preferential codon usage patterns responsible for adaptation, host immune evasion, and transmission of PPRV to unusual hosts like old world camel species namely, dromedary and bactrian camel. The results indicate codon usage of the PPRV genome is functioned by an interplay of mutational pressure and natural selection to exhort the adaptation and fitness of PPRV in probable hosts. The indices of natural selection like the relative codon deoptimization index (RCDI) and codon adaptation index (CAI) predict the ability of PPRV to adapt and evolve in camel species. The analysis also depicts the potential role of the CpG depletion mechanism employed by PPRV to evade host adaptive immune response. The report emphasizes the need for a comprehensive national PPR surveillance plan in unusual hosts like camels for the successful implementation of the PPR Global Eradication Programme (PPR- GEP).

Unifying quantification methods for sexual selection and assortative mating using information theory

Sexual selection plays a crucial role in modern evolutionary theory, offering valuable insight into evolutionary patterns and species diversity. Recently, a comprehensive definition of sexual selection has been proposed, defining it as any selection that arises from fitness differences associated with nonrandom success in the competition for access to gametes for fertilization. Previous research on discrete traits demonstrated that non-random mating can be effectively quantified using Jeffreys (or symmetrized Kullback-Leibler) divergence, capturing information acquired through mating influenced by mutual mating propensities instead of random occurrences. This novel theoretical framework allows for detecting and assessing the strength of sexual selection and assortative mating.In this study, we aim to achieve two primary objectives. Firstly, we demonstrate the seamless alignment of the previous theoretical development, rooted in information theory and mutual mating propensity, with the aforementioned definition of sexual selection. Secondly, we extend the theory to encompass quantitative traits. Our findings reveal that sexual selection and assortative mating can be quantified effectively for quantitative traits by measuring the information gain relative to the random mating pattern. The connection of the information indices of sexual selection with the classical measures of sexual selection is established.Additionally, if mating traits are normally distributed, the measure capturing the underlying information of assortative mating is a function of the square of the correlation coefficient, taking values within the non-negative real number set [0, +∞).It is worth noting that the same divergence measure captures information acquired through mating for both discrete and quantitative traits. This is interesting as it provides a common context and can help simplify the study of sexual selection patterns.

Using winter diet composition and forage plant availability to determine browse selection and importance for moose (Alces alces) in a landscape modified by industrial forestry

Abstract Between 2000 and 2015, moose (Alces alces L.) populations within some areas of north-central British Columbia, Canada declined by 70%. Such declines are occurring in other regions within the range of moose. One cause for mortalities of cow and calf moose in British Columbia was apparent starvation, implying a potential connection to food supply. To investigate possible connections between moose declines and industrial forestry, we examined moose winter diets relative to browse availability in six Biogeoclimatic Ecosystem Classification subzones within north-central British Columbia. In the spring of 2017, we collected moose winter pellets. To assess diet, pellets were analyzed using microhistology, a common technique for quantifying the diets of ungulates. In the summer of 2018, we used a modified point-intercept method to survey browse plant availability at pellet collection sites. We related diet composition to plant availability through indices of selection (use of a forage species relative to availability) and values of importance (the proportion of a species in the diet as a function of its occurrence in the environment) of various browse items to moose. Twenty-eight species of potential browse plants were identified in our browse availability surveys. Only 12 of these plants were found in moose pellets, with four plants [subalpine fir (Abies lasiocarpa Hooker), willow (Salix spp. Linnaeus), paper birch (Betula papyrifera Marshall), and trembling aspen (Populus tremuloides Michaux)] comprising the majority (93.3%) of the diet. We used mixed-model analyses to examine differences between these top four winter diet items, in relation to: (i) diet composition; (ii) plant availability; (iii) selection by moose; and (iv) importance to moose. Subalpine fir (mean: 45.7%) was a significantly larger diet component in pellets than aspen (5.7%) and willow (19.5%), but there was no significant difference in the proportions of subalpine fir and birch (22.4%). Birch and willow were found in significantly higher proportions than aspen, but proportions of birch and willow in pellets did not differ. The availability of the top four diet items was not significantly different between species. Subalpine fir, aspen, birch, and willow were the most selected diet items, but selection was not significantly different between them. The importance values of subalpine fir, birch, and willow were not significantly different from one another, but all three were significantly greater than the importance value for aspen. Diet composition, availability, selection, and importance did not vary between subzones surveyed. The high selection for and importance of subalpine fir, birch, willow, and aspen by moose in winter demonstrate the need to ensure these browse species are maintained on moose ranges, especially where moose populations are declining. Where industrial forestry impacts the abundance and species composition of winter browses for moose, we encourage forest planners and managers to examine browse availability in relation to moose diet, so that the browse plants important to and selected for by moose can be integrated into forest management objectives.

On the Utility of Indirect Methods for Detecting Faking.

Indirect indices for faking detection in questionnaires make use of a respondent's deviant or unlikely response pattern over the course of the questionnaire to identify them as a faker. Compared with established direct faking indices (i.e., lying and social desirability scales), indirect indices have at least two advantages: First, they cannot be detected by the test taker. Second, their usage does not require changes to the questionnaire. In the last decades, several such indirect indices have been proposed. However, at present, the researcher's choice between different indirect faking detection indices is guided by relatively little information, especially if conceptually different indices are to be used together. Thus, we examined and compared how well indices of a representative selection of 12 conceptionally different indirect indices perform and how well they perform individually and jointly compared with an established direct faking measure or validity scale. We found that, first, the score on the agreement factor of the Likert-type item response process tree model, the proportion of desirable scale endpoint responses, and the covariance index were the best-performing indirect indices. Second, using indirect indices in combination resulted in comparable and in some cases even better detection rates than when using direct faking measures. Third, some effective indirect indices were only minimally correlated with substantive scales and could therefore be used to partial faking variance from response sets without losing substance. We, therefore, encourage researchers to use indirect indices instead of direct faking measures when they aim to detect faking in their data.

Electrophysiological and behavioral evidence for the attention capture and suppression failure of irrelevant singleton in test anxiety

Attention bias (ABs) and inhibition deficits play crucial roles in the development, maintenance, and recurrence of test anxiety. However, whether test-anxious individuals will show ABs and inhibition deficits of general task-irrelevant stimuli in a complex visual display is unclear. Thus, we used the additional singleton task (AST) and recorded event-related potentials (ERPs) indices of attentional selection (the N2 posterior contralateral, N2pc), suppression (distractor positivity, PD), and maintenance of working memory (the sustained posterior contralateral negativity, SPCN) to explore this issue. Twenty-eight participants in the high test-anxious (HTA) group and twenty-eight participants in the low test-anxious (LTA) group attended the experiment and were required to search for a target and synchronously ignore a singleton distractor on some trials. Consequently, HTA and LTA individuals had poorer accuracies and longer response times in the distractor-present condition than in the distractor-absent condition. The HTA group got larger interferences from singleton distractors than the LTA group. Electrophysiological results revealed a distractor N2pc and SPCN in the HTA group. Moreover, target N2pc and SPCN in the HTA group were larger when the singleton distractor and target were on the same side than on the opposite side. These results indicated that HTA individuals were captured attention by singleton distractors and failed to expel them from working memory. Accordingly, the present findings extended previous work by providing direct evidence that test anxiety could increase the effects of stimulus-driven attention systems and impair the function of goal-directed attention systems.

General deficits of attentional inhibition in high trait anxiety: ERP evidence.

Behavioral evidence shows that individuals with high trait anxiety tend to be distracted by irrelevant stimulation not only for threat-related stimuli but also for non-emotional neutral stimuli. These findings suggest that there may be a general deficit of attentional control in trait anxiety. However, the neural mechanism underlying the anxiety-related deficit in attentional control, especially inhibition function, is still unclear. Here, we examined the attentional processing of the non-emotional neutral distractor on 66 young adults with different levels of trait anxiety, using the ERP indices of attentional selection (N2pc) and top-down inhibition (Pd) in a search task with geometric stimuli. We found that the distractor-evoked N2pc amplitude did not vary with anxiety levels, but increased anxiety was associated with smaller Pds (i.e. worse inhibition). Besides, delayed attentional selection of targets was associated with higher anxiety levels. These correlations of trait anxiety remained significant even after controlling for state anxiety, and state anxiety did not affect the attentional processing of distractors and targets, suggesting that trait anxiety, not current anxiety, affects attentional function. Our findings clarify the mechanism underlying the general attentional deficits in trait anxiety, e.g. reduced distractor inhibition and delayed target selection.

Efficacy of comparing coil behavior and distribution using the silicone aneurysm model: difference of coil distribution in the early filling stage.

This study sought to establish an experimental aneurysm model of visualizing coil insertion using radiolucent nylon coils. Moreover, this study aimed to clarify the characteristics and differences of each coil and use them clinically as indices of coil selection. The coil insertion test was performed on the 10 mm spherical silicone aneurysm model filled to a nylon coil volume embolization ratio of 11.8%. Five types of coil were randomly tested six times, and the distribution of the coils was analyzed by fluoroscopy imaging. Indices of "Area (mm2)," "Feret's diameter (mm)," and "Circularity" were calculated from the fluoroscopic images. Among the indices, only "Area" showed a significant difference between coils (p = 0.002). On multivariate analysis, "Area" of the ED Infini was larger than those of Target XL soft and Galaxy G3 (p = 0.018 and 0.026, respectively). Furthermore, the area of the 360 soft was larger than that of G3 (p = 0.049). Analysis of the correlation between these values and the coil configuration showed that "Area" was negatively correlated with the stock-wire diameter (r = -0.50; p = 0.004) and primary coil configuration (r = -0.65; p < 0.001). When inserting the coils in the early stage, although the difference between each coil is relatively difficult to obtain, knowledge on the proper use of the coils with differences in characteristics can help in selecting the coil most appropriate for the conditions.

Адаптивно‑многоиндексно‑кластерный алгоритм комплексной оценки воздействия химических загрязнений на лесные массивы по спутниковым фотоизображениям

An original adaptive-index-clustering algorithm is proposed: “Managed vegetation index”. An original adaptive-multi-index-cluster algorithm for comprehensive assessment of the impact of chemical pollution on forests using satellite photographs is proposed, which is distinguished by the use of an adaptive procedure for the formation of pixel clusters displaying a plurality of spectral channels of a photographic image of each type of vegetation state of a forest stand in the zones of chemical pollution of forest tracts, as well as using the procedure for calculating the weighted average values of complex vegetation indices for each zone of chemical pollution, which allows, based on the values of complex vegetation indices, to determine various biological, phytological and physico-chemical states of forest areas.It should be noted that in order to solve the complex problem of constructing complex indices linked to ecological zones, it is proposed to use the simple idea of increasing the quality of modeling and forecasting by expanding the amount of information. The proposed problem can be solved using a statistical analysis of data on the distribution of pixels whose belonging to ecological zones is known in advance. The development of the algorithm is based on the following prerequisites: (1) using a linear combination of individual classical vegetation indices of the state of forest areas, it is possible to create a new specialized complex vegetation index that makes it possible to identify ecological zones in forest areas according to the levels of impact on forests of chemical pollution of industrial enterprises; (2) the possibility of using specialized complex vegetation indices in the form of weighted average linear combinations of classical vegetation indices. Specialized complex vegetation indices of adaptive selection of weight coefficients are capable of displaying various biological, physicochemical and ecological characteristics of the state of forests based on clustering of satellite image pixels. The proposed algorithm makes it possible to calculate, as a result of clustering, more accurate estimates of the total areas of ecological zones of forest tracts, which can be used as a basis for assessing the degree of ecological degradation of forest tracts and environmental damage.

Effects of amikacin, polymyxin-B, and sulbactam combination on the pharmacodynamic indices of mutant selection against multi-drug resistant Acinetobacter baumannii.

Amikacin and polymyxins as monotherapies are ineffective against multidrug-resistant Acinetobacter baumannii at the clinical dose. When polymyxins, aminoglycosides, and sulbactam are co-administered, the combinations exhibit in vitro synergistic activities. The minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) were determined in 11 and 5 clinical resistant isolates of A. baumannii harboring OXA-23, respectively, in order to derive the fraction of time over the 24-h wherein the free drug concentration was within the mutant selection window (fTMSW) and the fraction of time that the free drug concentration was above the MPC (fT>MPC) from simulated pharmacokinetic profiles. The combination of these three antibiotics can confer susceptibility in multi-drug resistant A. baumannii and reduce the opportunity for bacteria to develop further resistance. Clinical intravenous dosing regimens of amikacin, polymyxin-B, and sulbactam were predicted to optimize fTMSW and fT>MPC from drug exposures in the blood. Mean fT>MPC were ≥ 60% and ≥ 80% for amikacin and polymyxin-B, whereas mean fTMSW was reduced to <30% and <15%, respectively, in the triple antibiotic combination. Due to the low free drug concentration of amikacin and polymyxin-B simulated in the epithelial lining fluid, the two predicted pharmacodynamic parameters in the lung after intravenous administration were not optimal even in the combination therapy setting.

Strategic Distractor Suppression Improves Selective Control in Human Vision.

Our visual environment is complicated, and our cognitive capacity is limited. As a result, we must strategically ignore some stimuli to prioritize others. Common sense suggests that foreknowledge of distractor characteristics, like location or color, might help us ignore these objects. But empirical studies have provided mixed evidence, often showing that knowing about a distractor before it appears counterintuitively leads to its attentional selection. What has looked like strategic distractor suppression in the past is now commonly explained as a product of prior experience and implicit statistical learning, and the long-standing notion the distractor suppression is reflected in α band oscillatory brain activity has been challenged by results appearing to link α to target resolution. Can we strategically, proactively suppress distractors? And, if so, does this involve α? Here, we use the concurrent recording of human EEG and eye movements in optimized experimental designs to identify behavior and brain activity associated with proactive distractor suppression. Results from three experiments show that knowing about distractors before they appear causes a reduction in electrophysiological indices of covert attentional selection of these objects and a reduction in the overt deployment of the eyes to the location of the objects. This control is established before the distractor appears and is predicted by the power of cue-elicited α activity over the visual cortex. Foreknowledge of distractor characteristics therefore leads to improved selective control, and α oscillations in visual cortex reflect the implementation of this strategic, proactive mechanism.SIGNIFICANCE STATEMENT To behave adaptively and achieve goals we often need to ignore visual distraction. Is it easier to ignore distracting objects when we know more about them? We recorded eye movements and electrical brain activity to determine whether foreknowledge of distractor characteristics can be used to limit processing of these objects. Results show that knowing the location or color of a distractor stops us from attentionally selecting it. A neural signature of this inhibition emerges in oscillatory alpha band brain activity, and when this signal is strong, selective processing of the distractor decreases. Knowing about the characteristics of task-irrelevant distractors therefore increases our ability to focus on task-relevant information, in this way gating information processing in the brain.

Spatially Guided Distractor Suppression during Visual Search.

Past work has demonstrated that active suppression of salient distractors is a critical part of visual selection. Evidence for goal-driven suppression includes below-baseline visual encoding at the position of salient distractors (Gaspelin and Luck, 2018) and neural signals such as the distractor positivity (Pd) that track how many distractors are presented in a given hemifield (Feldmann-Wüstefeld and Vogel, 2019). One basic question regarding distractor suppression is whether it is inherently spatial or nonspatial in character. Indeed, past work has shown that distractors evoke both spatial (Theeuwes, 1992) and nonspatial forms of interference (Folk and Remington, 1998), motivating a direct examination of whether space is integral to goal-driven distractor suppression. Here, we use behavioral and EEG data from adult humans (male and female) to provide clear evidence for a spatial gradient of suppression surrounding salient singleton distractors. Replicating past work, both reaction time and neural indices of target selection improved monotonically as the distance between target and distractor increased. Importantly, these target selection effects were paralleled by a monotonic decline in the amplitude of the Pd, an electrophysiological index of distractor suppression. Moreover, multivariate analyses revealed spatially selective activity in the θ-band that tracked the position of the target and, critically, revealed suppressed activity at spatial channels centered on distractor positions. Thus, goal-driven selection of relevant over irrelevant information benefits from a spatial gradient of suppression surrounding salient distractors.SIGNIFICANCE STATEMENT Past work has shown that distractor suppression is an important part of goal-driven attentional selection, but has not yet revealed whether suppression is spatially directed. Using behavioral data, event-related potentials (ERPs) of the EEG signal [N2pc and distractor positivity (Pd) component], as well as a multivariate model of EEG data [channel tuning functions (CTF)], we show that suppression-related neural activity increases monotonically as the distance between targets and distractors decreases, and that spatially-selective activity in the θ-band reveals depressed activity in spatial channels that index distractor positions. Thus, we provide robust evidence for spatially-guided distractor suppression, a result that has important implications for models of goal-driven attentional control.

Character association studies for morphological and quality characters in basmati rice (Oryza sativa L.)

The present study was undertaken to estimate correlation coefficients among 22 yield components and quality characters in thirty rice (Oriza sativa L.) genotypes. The genotypes were evaluated in RBD and ANOVA results revealed the highly significant mean sum of squares among the genotypes for all the characters. Highest significant positive genotypic as well as phenotypic correlation was found between traits 100 kernel weight and 100 grain weight whereas, highest significant negative genotypic correlation was found between characters water absorbed by 10gm kernel and 100 grain weight, whereas, highest significant negative phenotypic correlation was found between characters grain weight per plant and days to maturity. Highest significant positive phenotypic correlation was found between traits 100 kernel weight and 100 grain weight. Grain weight per plant showed highly significant positive correlation with hulling %, kernel breadth before cooking, kernel breadth after cooking, breadth increase ratio after cooking and water absorbed by 10 gm kernel; significant positive association with peduncle length and flag leaf length. These characters could be utilized as indices of selection for future breeding programme.

Designing a model for organizing volunteer personnel in disasters and emergencies in Tehran’s hospitals: an integrated approach of Fuzzy Delphi and interpretative structure modeling (ISM)

Organization of volunteer personnel and proper management of these enormous and valuable human resources to make that most of their scientific, experiential, physical, and expertise power is of paramount importance, so in disasters and emergencies, lack of proper planning for organizing volunteers in the health sector is one of the most critical issues in the Iranian health system. The primary objective of this study is designing a model for the organization of volunteer people in disasters and emergencies in Tehran’s hospitals, utilizing an integrated approach of Fuzzy Delphi and interpretative structure modeling. The present study is mixed research. This study was conducted during 2017–2018 using the Fuzzy Delphi method to identify and rank the indices. A total of 26 disaster management specialists and experts in the hospitals participated in two rounds in this designed Delphi study. After extracting the primary components through systematic studies and interviews with the experts, two rounds were conducted in the presence of the experts. A structural-interpretive modeling approach was used to interpret the data. The Fuzzy Delphi results after two rounds yielded 11 indices in the form of two criteria. Then, the internal relationships of the criteria were investigated using structural-interpretive modeling, according to which the criteria were classified into three levels. Based on the results of the research, individual characteristics, social characteristics, appropriate type of employment, information strategies in initial enrollment, participatory recruitment methods, information recording methods, type of natural disasters, hospital–volunteers communication system, pre-incident preparation measures of the volunteers, intra-incident and post-incident preparation measures were determined in two indices of selection and preparation using Fuzzy Delphi technique. The results indicated that most of the measures related to the organization of volunteer personnel are interrelated, and preparation indicators of pre-, during, and post-incidents and the individuals’ characteristics are all among the necessary operational measures which can be done by operational managers at the basic levels of organizations. This means that methods and strategies can provide a higher-level context. Ultimately, as expected, this means that other studied indicators influence participatory recruitment methods and the communication system between the hospital and the volunteers. In this regard, the researchers, managers, and policymakers can use the results of the research in policymaking in the field of health care. Organization of volunteer personnel can be of great help to the hospitals in the field of health care.

Circadian misalignment impairs ability to suppress visual distractions.

Evening-type individuals often perform poorly in the morning because of a mismatch between internal circadian time and external social time, a condition recognized as social jet lag. Performance impairments near the morning circadian (~24hr) trough have been attributed to deficits in attention, but the nature of the impairment is unknown. Using electrophysiological indices of attentional selection (N2pc) and suppression (PD ), we show that evening-type individuals have a specific disability in suppressing irrelevant visual distractions. More specifically, evening-type individuals managed to suppress a salient distractor in an afternoon testing session, as evidenced by a PD , but were less able to suppress the distractor in a morning testing session, as evidenced by an attenuated PD and a concomitant distractor-elicited N2pc. Morning chronotypes, who would be well past their circadian trough at the time of testing, did not show this deficit at either test time. These results indicate that failure to filter out irrelevant stimuli at an early stage of perceptual processing contributes to impaired cognitive functioning at nonoptimal times of day and may underlie real-world performance impairments, such as distracted driving, that have been associated with circadian mismatch.

Recommendation of Coffea arabica genotypes by factor analysis

Responsible for approximately 70% of the world’s coffee exports, Brazil is increasingly concerned about the quality of the coffees produced, given the growing demand for so-called specialty coffees. With this, the breeders need, besides the agronomic characteristics, to consider the physical and sensorial quality of the beans in the breeding programs. However, the greater the number of characteristics to be considered in the selection process, the higher the difficulty in selecting superior genotypes. In this context, multivariate analyzes can help to overcome this problem. In the light of the facts, the objective was to select Coffea arabica genotypes with a high simultaneous potential of variables of commercial interest, in three municipalities belonging to the Matas de Minas region—MG, Brazil, through factor analysis, using their scores as criteria or indices of selection for genotype identification. Multivariate analyzes were performed for each environment individually and, by commonality, three factors were established for each environment. The factors were interpreted as sensorial quality, sieve and vigor, in a similar way in the three environments. The interaction genotype by environment was maintained even after the summary of the variables in factorial complexes. The genotypes Catucai Amarelo 24/137 and H419-3-3-7-16-4-1 excelled in relation to the factorial complexes, besides showing good adaptability and stability, consequently, they present great potential to improve the coffee production performance in the region of Matas de Minas.

High Level of Trait Anxiety Leads to Salience-Driven Distraction and Compensation

Individuals with high levels of anxiety are hypothesized to have impaired executive control functions that would otherwise enable efficient filtering of irrelevant information. Pinpointing specific deficits is difficult, however, because anxious individuals may compensate for deficient control functions by allocating greater effort. Here, we used event-related-potential indices of attentional selection (the N2pc) and suppression (the PD) to determine whether high trait anxiety is associated with a deficit in preventing the misallocation of attention to salient, but irrelevant, visual search distractors. Like their low-anxiety counterparts (n = 19), highly anxious individuals (n = 19) were able to suppress the distractor, as evidenced by the presence of a PD. Critically, however, the distractor was found to trigger an earlier N2pc in the high-anxiety group but not in the low-anxiety group. These findings indicate that, whereas individuals with low anxiety can prevent distraction in a proactive fashion, anxious individuals deal with distractors only after they have diverted attention.

Hemispheric asymmetries in EEG alpha oscillations indicate active inhibition during attentional orienting within working memory

Working memory contents can be prioritized by retroactively deploying attention within memory. This is broadly interpreted as evidence of a concentration of memory resources to the attended, to-be-remembered stimulus. However, online attentional selection is known to additionally depend on distractor inhibition, raising the viable alternative that attentional deployment in working memory involves inhibitory control processes. Here, we demonstrate that active inhibition plays a central role in the deployment of attention in working memory. We do so using a retroactive cueing paradigm, where a briefly presented memory array is followed by a cue indicating a to-be-remembered target (Experiment 1) or a to-be-forgotten distractor (Experiment 2). We identify discrete indices of target selection and distractor inhibition in lateralized oscillatory activity over visual areas. When a retroactive cue identifies the location of a target, results show rapid decrease of lateral, target-elicited alpha band activity, representing attentional orienting toward the target. This is followed only later by emergence of an increase in distractor-elicited alpha activity, reflecting distractor inhibition. In contrast, when the retroactive cue identifies a distractor, evidence of distractor inhibition emerges first, only later followed by target selection. These results thus demonstrate that separate excitatory and inhibitory processes underlie the deployment of attention on the level of working memory representations.

Do extra-group fertilizations increase the potential for sexual selection in male mammals?

Fertilizations by males outside the social breeding group (extra-group paternity, EGP) are widespread in birds and mammals. EGP is generally proposed to increase male reproductive skew and thereby increase the potential for sexual selection, but the generality of this relationship is unclear. We extracted data from 27 mammals in seven orders and used phylogenetic comparative methods to investigate the influence of EGP and social mating system on measures of inequality in male fertilization success, which are indices of the potential for sexual selection. We find that EGP and social mating system can predict the potential for sexual selection in mammalian populations, but only when considered jointly and not individually. EGP appears to increase the potential for sexual selection but only when the degree of social polygyny is relatively low. When social polygyny is high, EGP appears to result in a more uniform distribution of reproduction and a decrease in the potential for sexual selection. A possible explanation to be investigated is that the phenotype of extra-group fathers differs systematically across social mating systems. Our findings have implications for the use of EGP and social mating system as indices of sexual selection in comparative analyses of trait evolution under sexual selection.

Electrophysiological indices of target selection and distractor suppression under varying perceptual load: Evidence for spreading suppression

Electrophysiological indices of target selection and distractor suppression under varying perceptual load: Evidence for spreading suppression