Reward learning and statistical learning independently influence attentional priority of salient distractors in visual search

Existing research demonstrates different ways in which attentional prioritization of salient nontarget stimuli is shaped by prior experience: Reward learning renders signals of high-value outcomes more likely to capture attention than signals of low-value outcomes, whereas statistical learning can produce attentional suppression of the location in which salient distractor items are likely to appear. The current study combined manipulations of the value and location associated with salient distractors in visual search to investigate whether these different effects of selection history operate independently or interact to determine overall attentional prioritization of salient distractors. In Experiment 1, high-value and low-value distractors most frequently appeared in the same location; in Experiment 2, high-value and low-value distractors typically appeared in distinct locations. In both experiments, effects of distractor value and location were additive, suggesting that attention-promoting effects of value and attention-suppressing effects of statistical location-learning independently modulate overall attentional priority. Our findings are consistent with a view that sees attention as mediated by a common priority map that receives and integrates separate signals relating to physical salience and value, with signal suppression based on statistical learning determined by physical salience, but not incentive salience.

Analysis of historical selection in winter wheat

Winter wheat is a major crop with a rich selection history in the modern era of crop breeding. Genetic gains across economically important traits like yield have been well characterized and are the major force driving its production. Winter wheat is also an excellent model for analyzing historical genetic selection. As a proof of concept, we analyze two major collections of winter wheat varieties that were bred in western Europe from 1916 to 2010, namely the Triticeae Genome (TG) and WAGTAIL panels, which include 333 and 403 varieties respectively. We develop and apply a selection mapping approach, Regression of Alleles on Years (RALLY), in these panels, as well as in simulated populations. RALLY maps loci under sustained historical selection by using a simple logistic model to regress allele counts on years of variety release. To control for drift-induced allele frequency change, we develop a hybrid approach of genomic control and delta control. Within the TG panel, we identify 22 significant RALLY quantitative selection loci (QSLs) and estimate the local heritabilities for 12 traits across these QSLs. By correlating predicted marker effects with RALLY regression estimates, we show that alleles whose frequencies have increased over time are heavily biased towards conferring positive yield effect, but negative effects in flowering time, lodging, plant height and grain protein content. Altogether, our results (1) demonstrate the use of RALLY to identify selected genomic regions while controlling for drift, and (2) reveal key patterns in the historical selection in winter wheat and guide its future breeding.

Learning to Expect the Predictable: The Role of Expectation in the Cognitive Control of Attention

<p>Some of the visual world is relevant to our goals and needs. Much more is not. A problem we face frequently in day-to-day living is that we are distracted by what is not relevant to our goals at the cost of attention towards what is. Emotional stimuli in particular have been shown to be very effective distractors, out-competing task-relevant stimuli for our attentional resources (Carretié, 2014; Pessoa, 2005; Pourtois et al., 2013). How often emotional distractors occur can alter our ability to ignore them and remain task focussed (Grimshaw et al., 2018; Schmidts et al., 2020). The Dual Mechanisms of Control framework (Braver et al., 2007; Braver, 2012) suggests that, because we can expect upcoming distractors when they occur frequently, we can effectively avoid distraction through proactive control; the use of effortful preparatory cognitive control strategies. That said, when distractors are frequent, we also become more experienced with them, and resolving the attentional conflict they create. The present investigation spanned two experiments assessing whether expectation of upcoming distractors would elicit proactive control while holding the experience of previous distractors constant. In Experiment 1 participants performed a simple perceptual task at fixation while neutral or negative task irrelevant images appeared peripherally on 25% of trials, either predictably in sequence (every fourth trial) or randomly. Expectation of distraction did not improve participants’ ability to avoid emotional distraction. A paradoxical expectation effect was also found wherein distraction was increased rather than decreased when distractors occurred predictably. In Experiment 2 distractors appeared either predictably (every fourth trial), on a random 25% of trials, or on a random 75% of trials. However, neutral and emotional images were now presented at fixation with the perceptual task presented above and below. Greater distractor frequency led to lower distraction and expectation of upcoming distractors again did not improve control, although a paradoxical increase in distraction was not replicated. Findings indicate that expectation of upcoming distractors alone is not sufficient to drive individuals to implement proactive control. Rather, distractor frequency is suggested to drive proactive control through implicit changes in top-down control settings based on experience. While the processes behind experience-driven proactive control are unclear, conflict adaptation and selection history are discussed as possible mechanisms of experience driven proactive control. Critically, present findings also indicate that emotional stimuli may present a unique challenge to our ability to control our attention.</p>

Learning to Expect the Predictable: The Role of Expectation in the Cognitive Control of Attention

<p>Some of the visual world is relevant to our goals and needs. Much more is not. A problem we face frequently in day-to-day living is that we are distracted by what is not relevant to our goals at the cost of attention towards what is. Emotional stimuli in particular have been shown to be very effective distractors, out-competing task-relevant stimuli for our attentional resources (Carretié, 2014; Pessoa, 2005; Pourtois et al., 2013). How often emotional distractors occur can alter our ability to ignore them and remain task focussed (Grimshaw et al., 2018; Schmidts et al., 2020). The Dual Mechanisms of Control framework (Braver et al., 2007; Braver, 2012) suggests that, because we can expect upcoming distractors when they occur frequently, we can effectively avoid distraction through proactive control; the use of effortful preparatory cognitive control strategies. That said, when distractors are frequent, we also become more experienced with them, and resolving the attentional conflict they create. The present investigation spanned two experiments assessing whether expectation of upcoming distractors would elicit proactive control while holding the experience of previous distractors constant. In Experiment 1 participants performed a simple perceptual task at fixation while neutral or negative task irrelevant images appeared peripherally on 25% of trials, either predictably in sequence (every fourth trial) or randomly. Expectation of distraction did not improve participants’ ability to avoid emotional distraction. A paradoxical expectation effect was also found wherein distraction was increased rather than decreased when distractors occurred predictably. In Experiment 2 distractors appeared either predictably (every fourth trial), on a random 25% of trials, or on a random 75% of trials. However, neutral and emotional images were now presented at fixation with the perceptual task presented above and below. Greater distractor frequency led to lower distraction and expectation of upcoming distractors again did not improve control, although a paradoxical increase in distraction was not replicated. Findings indicate that expectation of upcoming distractors alone is not sufficient to drive individuals to implement proactive control. Rather, distractor frequency is suggested to drive proactive control through implicit changes in top-down control settings based on experience. While the processes behind experience-driven proactive control are unclear, conflict adaptation and selection history are discussed as possible mechanisms of experience driven proactive control. Critically, present findings also indicate that emotional stimuli may present a unique challenge to our ability to control our attention.</p>

Systemic Effects of Selection History on Learned Ignoring

Despite our best intentions, physically salient but entirely task-irrelevant stimuli can sometimes capture our attention. With learning, it is possible to more efficiently ignore such stimuli, although specifically how the visual system accomplishes this remains to be clarified. Using a sample of young-adult participants, we examined the time course of eye movements to targets and distractors. We replicate a reduced frequency of eye movements to the distractor when appearing in a location at which distractors are frequently encountered. This reduction was observed even for the earliest saccades, when selection tends to be most stimulus-driven. When the distractor appeared at the high-probability location, saccadic reaction time was slowed specifically for distractor-going saccades, suggesting a slowing of priority accumulation at this location. In the event that the distractor was fixated, disengagement from the distractor was also faster when it appeared in the high-probability location. Both proactive and reactive mechanisms of distractor suppression work together to minimize attentional capture by frequently-encountered distractors.

Robust bacterial co-occurence community structures are independent of r- and K-selection history

Selection for bacteria which are K-strategists instead of r-strategists has been shown to improve fish health and survival in aquaculture. We considered an experiment where microcosms were inoculated with natural seawater and the selection regime was switched from K-selection (by continuous feeding) to r-selection (by pulse feeding) and vice versa. We found the networks of significant co-occurrences to contain clusters of taxonomically related bacteria having positive associations. Comparing this with the time dynamics, we found that the clusters most likely were results of similar niche preferences of the involved bacteria. In particular, the distinction between r- or K-strategists was evident. Each selection regime seemed to give rise to a specific pattern, to which the community converges regardless of its prehistory. Furthermore, the results proved robust to parameter choices in the analysis, such as the filtering threshold, level of random noise, replacing absolute abundances with relative abundances, and the choice of similarity measure. Even though our data and approaches cannot directly predict ecological interactions, our approach provides insights on how the selection regime affects the composition of the microbial community, providing a basis for aquaculture experiments targeted at eliminating opportunistic fish pathogens.

Anadolu-T Etlik Piliç Saf Hatlarının Gelişme ve Karkas Özellikleri

This study aimed to determine the growth and carcass traits of Anadolu-T broiler pure lines, which were kept breeding and selection over five generations from 2017 to 2021, in comparison with a commercial hybrid. After the selection process, pure lines (A1, A2, A3, B1, B2) and commercial hybrid (Ross-308) eggs were incubated and 120 female-male chicks were produced from each genotype in each generation. The broiler chickens were reared in broiler production standards for 6 weeks and carcass traits were determined by slaughtering at the end of this period. In this study, growth traits such as body weight (BW), feed conversion ratio (FCR), and livability; breast and thigh meat ratio were considered as carcass traits. The highest average BW (2961.2 to 3481.2 g) and best FCR (1.43 to 1.60) at 6 weeks of age over the five generations occurred in Ross-308 commercial hybrids; followed by sire (BW: 2633.8 to 3180.2 g; FCR: 1.65 to 1.77), dam lines (BW: 2307.7 to 2698.5 g; FCR: 1.65 to 1.78), respectively. Although there were some numerical differences in livability between generations in pure lines, it was generally at a similar level (96-100%) with commercial hybrids. The breast ratio was lower than commercial hybrid in both dam and sire lines, but it was determined that the thigh ratio was higher in pure lines. The fact that pure lines have a short selection history of five generations does not allow for detailed evaluation. We expect that the use of individual feed efficiency test in dam and sire lines, and additionally using body weight and breast

The natural adaptation and human selection history of African sheep genomes

African sheep manifest diverse but distinct physio-anatomical traits which are the outcomes of natural- and human-driven selection. Here, we generated 34.8 million variants from 150 indigenous African sheep genomes sequenced at an average depth of ∼54x for 130 samples (Ethiopia, Libya) and ∼10x for 20 samples (Sudan), representing sheep from diverse environments, tail morphology and post-Neolithic introductions to Africa. Phylogenetic and model-based admixture analysis provided evidence of four genetic groups that correspond to altitudinal geographic origins and tail morphotypes. Comparative genomic analysis identified targets of selection spanning conserved haplotype structures overlapping genes and gene families relating to hypoxia responses, caudal vertebrae and tail skeleton length, ear morphology, and tail fat-depot structure. Our findings provide novel insights underpinning variation and response to human selection and environmental adaptation, and possible pleiotropic gene interactions in indigenous African sheep genomes, which guaranteed the successful establishment of the species on the continent.

Blepharoplasty and Eyelid Reconstruction

A mastery of facial and eyelid anatomy is paramount to perform oculoplastic surgery safely and successfully. An understanding of periocular structures, vasculature, and innervation highlights the delicate relationship between form and function, which establishes the foundation for cosmetic and reconstructive procedures. This knowledge, coupled with an appreciation for the patient’s goals – both functional and aesthetic – and expectations for the outcome of surgery allows one to complete an effective, multidimensional pre-operative assessment encompassing patient selection, history, physical examination, and ancillary testing. Ultimately, the synthesis of these principles guides the selection and execution of appropriate and efficacious surgical technique for blepharoplasty and eyelid reconstruction. This review contains 15 figures and 28 references Keywords: Eyelid anatomy, Eyelid crease, Eyelid margin, Canthal tendons, Lacrimal system, Blepharoplasty, Tenzel flap, Hughes flap, Cutler-Beard procedure, Canthotomy and cantholysis