Social Primates Research Articles

Trump Trauma

It’s 2004 and, despite my best intentions, I’m a pop-culture junkie. While my one-year-old daughter is napping, I watch an episode of a new reality TV show, The Apprentice, hosted by New York real estate mogul, Donald Trump. The show’s premise: Sixteen to eighteen individuals, divided into two teams, test their business acumen by competing in a series of moneymaking challenges. At the end of each episode, Trump calls the losing team into an ersatz boardroom where he delivers his signature tag line, “You’re Fired!” to the individual he determines most guilty of gumming up the works.I remember noting what seemed to me an unprecedented televised celebration of US capitalism with its corresponding culture of authoritarianism and non-empathy. Before ordering contestants out of the boardroom, Trump denounced each one with epithets such as stupid, terrible, or loser, all while the camera zeroed in on the very face of human shame and vulnerability. After viewing a few harrowing instances of this, I turned the damn thing off.During the last decade or so, I’ve watched from afar as The Apprentice gave rise to Celebrity Apprentice, finally plopping Trump dead center in our political theater. When Trump won his run for the White House in 2016, I, along with most of the country, blinked in bewilderment, asking, How the f#%k did this happen?Shows like The Apprentice, along with toxic right wing radio and Fox News, did much to reflect and bolster a culture of Americans who see humanity as inherently greedy and who regard empathy as being for losers and wimps.If Trump excelled in reality TV, he is now shoring up to master what I’ll call reality by decree. In Trump’s world, truth is plastic and entirely relative; events and facts become true once they’re rubber-stamped—announced—by right-wing news outlets like Breitbart or Fox News. Each time Trump decrees a fake-fact such as Obama wire-tapping Trump Tower or “illegal immigrants” stealing the popular vote—each time he distorts reality and is not held accountable for doing so—he rules reality by decree.There are indeed psychological implications of Trump’s reality by decree. Since his presidential win, there has been ubiquitous discussion of the impact of a Trump presidency on survivors of social trauma: this is because social trauma rests on a distortion of reality.As social primates, we humans rely on a shared reality principle, a collective sense of what is factual or fictional, just or unjust. The fabric of our shared reality is unthreaded each time someone who has power over us abuses that power, destabilizing our reality by creating a world in which notions of truth are relative, mercurial, and unstable.Trump purposefully manipulates the truth like a street performer twists balloons into animals. With each new bizarre and menacing decree, trauma survivors feel unable to hold onto a vision of a rational and just world where people wielding tremendous authority and power are held accountable for their words and actions.We women wince upon hearing about Trump’s “locker room talk,” mortified even more when he decrees his own “tremendous respect for women.” Survivors feel gaslighted, driven into a world where everything is profoundly unpredictable and unsafe.Trump’s reality by decree—while common under dictators—is unprecedented in US history. Each day, we awaken into an Orwellian dystopia in which the “Ministry of Truth” controls not just the material and political conditions of life, but also the conditions of human perception.Perhaps it is we, survivors of rape, incest, and other abuses, who especially sense the steadily emerging danger associated with power-driven reality distortion. Maybe we of the the women’s and queer liberation movements have a key role to play in fighting against Trump’s blatant attempts to deny an objective ground for truth and justice.Maybe my once napping toddler—now a young woman of fourteen—will join a generation hungry for reality-based politics based on principles such as transparency, democracy, and accountability. I look forward to thousands taking to the streets in the coming months and years, organizing national strikes, consumer boycotts, as well as marches, protests, and revolutionary movement building. Our collective reality-based rallying cry? “Donald Trump, you f#%ked with our reality: You’re Fired!”

Macaques attend to scratching in others

Self-directed behaviours in primates as a response to increasing psychological or physiological stress are a well-studied phenomenon. There is some evidence that these behaviours can be contagious when observed by conspecifics, but the adaptive function of this process is unclear. The ability to perceive stress in others and respond to it could be an important part of sustaining cohesiveness in social primates, but spontaneously acquiring stress-related behaviours (and potentially emotional states) from all group mates via contagion could be maladaptive. To investigate this, a group of captive Barbary macaques, Macaca sylvanus, were presented with videos of conspecifics engaging in self-directed behaviour (scratching) and neutral behaviour. Behavioural responses as a result of exposure to the stimuli were compared (1) between familiar and unfamiliar individuals, and (2) within familiar individuals to consider the modulating effects of social relationships. Our results did not show contagious scratching in this species. However, there were differences in how individuals attended to the scratching stimuli. Subjects were more attentive to scratching videos than to neutral videos and familiar than unfamiliar individuals. Within the familiar individuals, subjects were more attentive to those to whom they were weakly bonded. We suggest that increased attention to scratching behaviours may be adaptive in order to monitor and avoid stressed group mates, whose subsequent behaviour may be unpredictable and aggressive. Monitoring group mates who are not allies may also be adaptive as they may pose the biggest risk. These findings will help increase our understanding of subtle cues that can be communicative in primates, and also the evolutionary steps towards understanding others.

Abstracts of the 29th conference of the SFDP: Sociality in primates (Rennes-Paimpont, France, 18-20 October, 2016)

Abstracts of the 29th conference of the SFDP: Sociality in primates (Rennes-Paimpont, France, 18-20 October, 2016)

Primate genotyping via high resolution melt analysis: rapid and reliable identification of color vision status in wild lemurs

Analyses of genetic polymorphisms can aid our understanding of intra- and interspecific variation in primate sociality, ecology, and behavior. Studies of primate opsin genes are prime examples of this, as single nucleotide variants (SNVs) in the X-linked opsin gene underlie variation in color vision. For primate species with polymorphic trichromacy, genotyping opsin SNVs can generally indicate whether individual primates are red-green color-blind (denoted homozygous M or homozygous L) or have full trichromatic color vision (heterozygous ML). Given the potential influence of color vision on behavior and fitness, characterizing the color vision status of study subjects is becoming commonplace for many primate field projects. Such studies traditionally involve a multi-step sequencing-based method that can be costly and time-consuming. Here we present a new reliable, rapid, and relatively inexpensive method for characterizing color vision in primate populations using high resolution melt analysis (HRMA). Using lemurs as a case study, we characterized variation at exons 3 and/or 5 of the X-linked opsin gene for 87 individuals representing nine species. We scored opsin genotypes and color vision status using both traditional sequencing-based methods as well as our novel melting-curve based HRMA protocol. For each species, the melting curves of varying genotypes (homozygous M, homozygous L, heterozygous ML) differed in melting temperature and/or shape. Melting curves for each sample were consistent across replicates, and genotype-specific melting curves were consistent across DNA sources (blood vs. feces). We show that opsin genotypes can be quickly and reliably scored using HRMA once lab-specific reference curves have been developed based on known genotypes. Although the protocol presented here focuses on genotyping lemur opsin loci, we also consider the larger potential for applying this approach to various types of genetic studies of primate populations.

Network centrality and seasonality interact to predict lice load in a social primate.

Lice are socially-transmitted ectoparasites. Transmission depends upon their host’s degree of contact with conspecifics. While grooming facilitates ectoparasite transmission via body contact, it also constrains their spread through parasite removal. We investigated relations between parasite burden and sociality in female Japanese macaques following two opposing predictions: i) central females in contact/grooming networks harbour more lice, related to their numerous contacts; ii) central females harbour fewer lice, related to receiving more grooming. We estimated lice load non-invasively using the conspicuous louse egg-picking behaviour performed by macaques during grooming. We tested for covariation in several centrality measures and lice load, controlling for season, female reproductive state and dominance rank. Results show that the interaction between degree centrality (number of partners) and seasonality predicted lice load: females interacting with more partners had fewer lice than those interacting with fewer partners in winter and summer, whereas there was no relationship between lice load and centrality in spring and fall. This is counter to the prediction that increased contact leads to greater louse burden but fits the prediction that social grooming limits louse burden. Interactions between environmental seasonality and both parasite and host biology appeared to mediate the role of social processes in louse burden.

Quantifying soluble carbohydrates in tropical leaves using a portable mid-infrared sensor: Implications for primate feeding ecology.

Identifying the nutritional composition of food items has significant ramifications for primate feeding ecology, which, in turn, influences investigations of primate sociality, cognition, and conservation. The aim of our study was to analyze water soluble carbohydrate (WSC) concentrations in the leaves of trees common to the Diani Forest of Kenya. Many of these leaves are consumed by black and white colobus monkeys (Colobus angolensis palliatus). We assessed whether the infrared spectral data collected using a portable spectrometer can be used to accurately predict WSC concentrations. WSC content was first quantified using the phenol-sulfuric acid method for young and mature leaves of 24 species and ranged from 1.15% to 9.16% dry weight. Spectral data were recorded with a spectrometer equipped with an attenuated total reflectance accessory (Agilent Cary 630) and analyzed using partial least squares regression. The spectral region from 1600 cm(-1) to 1000 cm(-1) gave unique polysaccharide bands associated with carboxyl, acetyl, and glycosidic linkages of sugar residues. The multivariate analysis gave excellent performance parameters with correlation coefficient (r(2) ) of 0.95 and standard error of cross-validation of 0.6% WSC. We found that IR spectroscopy provides a rapid and accurate technique for analyzing WSC concentrations and offers primatologists many advantages over wet chemistry methods for analyzing nutritional composition. Am. J. Primatol. 78:701-706, 2016. © 2016 Wiley Periodicals, Inc.

九寨沟自然保护区川金丝猴的分布及种群数量

PDF HTML阅读 XML下载 导出引用 引用提醒 九寨沟自然保护区川金丝猴的分布及种群数量 DOI: 10.5846/stxb201410031948 作者: 作者单位: 陕西省动物研究所,西华师范大学生命科学学院,陕西省动物研究所,陕西省动物研究所,四川省自然资源科学研究院野生动植物种质资源保护与可持续利用四川省重点实验室,四川省自然资源科学研究院野生动植物种质资源保护与可持续利用四川省重点实验室,九寨沟自然保护区管理局,陕西省动物研究所、西北大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学重点基金资助项目(31130061); 国家自然科学基金资助项目(31470214, 30900168); 陕西省科学院基金资助项目(2014K-12, 2013K-34, 2013K-35, 2012K-01); 西部之光人才培养计划资助项目(2011DF05); 日本Cosmo石油环保卡基金资助项目(2005-2015); 四川省科技计划项目(2014SZ0147) Distribution and population of Rhinopithecus roxellana in Jiuzhaigou National Nature Reserve, Sichuan Province, China Author: Affiliation: Institute of Zoology,Shaanxi Academy of Sciences,Xi’an,College of Life Sciences, China West Normal University, Nanchong,Institute of Zoology,Shaanxi Academy of Sciences,Xi’an,Institute of Zoology,Shaanxi Academy of Sciences,Xi’an,Sichuan Province Natural Resources Science Academy Wildlife Germplasm Resources Conservation and Sustainable Utilization Key Laboratory, Chengdu,Sichuan Province Natural Resources Science Academy Wildlife Germplasm Resources Conservation and Sustainable Utilization Key Laboratory, Chengdu,Jiuzhaigou National Nature Reserve Management, Abazhou,Institute of Zoology,Shaanxi Academy of Sciences,Xi’an;Northwest University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:2014年2月至5月,对四川省九寨沟自然保护区野生川金丝猴的种群分布、数量及其社会结构进行调查,初步探讨该种群与其他种群在外部形态和社会结构方面的差异性。采用"V"型路线法调查,发现九寨沟保护区共有川金丝猴4群。然后结合长时间的持续跟踪观察,证实家庭单元19个,全雄群3个,能区分不同个体296只。OMU大小平均为12.7只,其中OMU内的成年个体占38%,青少年个体占53%,幼仔占9%。成年与青少年比例为1:1.39,成年雌雄的比例为3.84:1。与秦岭种群的外部形态相比,该种群的成年雄性更为壮大,毛发弯曲程度明显;成年雌性毛发略显灰黑色,金黄色暗淡,大部分个体嘴角长有很小的肉瘤;青少年个体毛色泛白。亦发现九寨沟种群倾向于选择海拔偏高(2400-3550 m)的针叶林带活动。 Abstract:The Sichuan snub-nosed monkey (Rhinopithecus roxellana), a rare primate in China, has suffered rapid population decline over recent decades. This primate inhabits the temperate forests in the mountainous highlands of Sichuan, Shaanxi, Gansu, and Hubei Provinces in China, at 1500 m to 3400 m above sea level. Most of the previous studies on Rhinopithecus roxellana have been carried out in Shaanxi Province, and there have been fewer studies in Sichuan Province. A population survey conducted in Sichuan Province in 1994 showed that the species is widely distributed in the forests along the mountainsides of Minshan, Qionglai, and Liangshan, with the majority residing in the Minshan Mountain forests. Jiuzhaigou National Nature Reserve is located on the southern slope of the Minshan Mountains in northwest Sichuan Province. R. roxellana is a multi-level social primate with groups consisting of several units, each comprising a breeding male, several adult females, and their offspring. We sought the help of the local villagers to obtain information on the approximate distribution of the monkey population in the nature reserve. We used this information to select the study regions where the distribution, social structure, and population of R. roxellana were measured in an attempt to analyze their adaptability in the Jiuzhaigou National Nature Reserve, Sichuan Province. The data were collected from February to May 2014, and during the last 75 days of this period, we used a V-shaped transect for the survey. When a group was observed, we recorded the height at which the group members were observed, the location and time of encounter, direction of the group's movement, sex and age of all individuals, habitat structure at that location, and the plants species on which the group was feeding. Our survey results confirmed that 4 groups, 19 One Male Units (OMUs) and 3 All Male Units (AMUs), resided within the reserve. One of the 4 groups that we followed for 8 days ranged across areas from Jiuzhaigou to Baihe. We confirmed 296 individuals in the 4 groups, with the OMUs having an average of 12.7 members, of which 38% were adults, 53% were juveniles, and the remaining 9% were infants. The average ratio of adults to juveniles was 1:1.39, while the ratio of females to males was 3.84:1. The primary distribution of the social groups was in Zarugou in Jiuzhaigou Nature Reserve, an area on the southern face of the mountain that receives adequate sunlight and is near the Baihe Nature Reserve. The groups were observed to be the most active in coniferous forest, at heights between 2400 m and 3550 m. When compared to the Qinling golden monkeys, Jiuzhaigou monkeys showed the following differences in body size and color of the hair on their backs:adult Jiuzhaigou males seemed stronger than the Qinling monkeys and had longer hair; the hair on the backs of adult Jiuzhaigou females was less golden and more black, and most of them had caruncles at the corners of their mouths; and the hair of juvenile Jiuzhaigou monkeys was whiter than that of Qinling monkeys. Thus, these two groups may be different subspecies, based on their morphological differences. 参考文献 相似文献 引证文献

How Culture Makes Us Human: Primate Social Evolution and the Formation of Human Societies -- Preface and Chapter 1

The odyssey from the Old World monkeys to the great apes and then to the development of our unique forms of social organization is the overall theme of this book. The odyssey begins, as it must, with our biological roots as a primate and with change in social organization initially occurring through Darwinian evolution. The challenge, when coming forward to human societies as we know them, has been to connect our Darwinian beginnings to the current complexity of human social systems in which Darwinian evolution, with its focus on individual traits in the context of a population of interbreeding individuals, has been transformed into a new mode of evolution with change at the level of societal organization. It is the functionality of systems of organization, rather than the functionality of individual traits, that is critical to the evolutionary success of human societies. Ancestral hunter-gatherer societies developed cultural means for the expression and continuity over generations of societal practices from whose functionality individuals and families benefit. Through enculturation, individuals take on the properties, structure and features that are part of the cultural milieu that frames the way individuals and groups of individuals interact. More than a century ago, Edward B. Tylor (1924[1871]) referred to culture as “that complex whole,” a characterization that still stands today as a way to identify what is different about human societies in comparison to the societies of other social mammals. It is not an extra-somatic means of information transmission that is crucial to what constitutes culture, but rather that culture refers to conceptual systems such as the kinship systems central to the formation of human societies. The origin of kinship systems as the basis for social organization, hence as a conceptual system of relations, encompasses a transition to new forms of organization subject to change by the individuals embedded within those systems of organization. It is this capacity for self-modification that makes human societies unique.

Civilizing Humans with Shame: How Early Confucians Altered Inherited Evolutionary Norms through Cultural Programming to Increase Social Harmony

To say Early Confucians advocated the possession of a sense of shame as a means to moral virtue underestimates the tact and forethought they used successfully to mold natural dispositions to experience shame into a system of self, familial, and social governance. Shame represents an adaptive system of emotion, cognition, perception, and behavior in social primates for measurement of social rank. Early Confucians understood the utility of the shame system for promotion of cooperation, and they build and deploy cultural modules – e.g., rituals, titles, punishments – with this in mind. These policies result in subtle alterations to components of the evolved shame system that are detectable in data form contemporary cross-cultural psychology that show that populations in the Confucian diaspora have a unique shame profile compared to Western and non-Western populations. The status of Confucian diaspora populations as outliers in the context of shame is partially explained by appeal to the cultural transmission and historical endurance of relevant Early Confucian cultural modules.

Sex differences in human gregariousness.

Research on human sociality rarely includes kinship, social structure, sex, and familiarity, even though these variables influence sociality in non-human primates. However, cross-cultural ethnographic and observational studies with humans indicate that, beginning after age 5 years, males and females form differing social structures with unrelated individuals in a community. Specifically, compared with females, human males exhibit greater tolerance for and form larger, interconnected groups of peers which we term “gregariousness.” To examine sex differences in gregariousness early in life when children first interact with peers without adult supervision, 3- to 6-year-old children were given the choice to enter one of three play areas: an empty one, one with an adult, or one with a familiar, same-sex peer. More males than females initially chose the play area with the same-sex peer, especially after age 5 years. Sex differences in gregariousness with same-sex peers likely constitute one facet of human sociality.

Male-male affiliation and cooperation characterize the social behavior of the large-bodied pitheciids, Chiropotes and Cacajao: A review.

Cooperation and affiliation between males may be key to the evolution of large multimale-multifemale primate groups in some species. Cacajao and Chiropotes form multimale-multifemale groups larger than those of most other platyrrhines (Cacajao: over 150 and Chiropotes: up to 80 individuals), and groups exhibit a high degree of fission-fusion dynamics. In both genera, males engage in affiliative, sex-specific behaviors and form all-male parties. Males in both genera also have conspicuous genitalia but can demonstrate sexual crypsis, or mimicry, wherein testes are retracted, resembling labia. Observed egalitarian interactions among males suggest that there is scramble competition for access to females, and aggression between males is uncommon relative to other social primates. As of yet, there are no genetic data to clarify dispersal patterns, and while relatedness among males would in part explain their affiliative relationships, there is some limited evidence for dispersal by males in Cacajao. In this review of recent studies of male-male social interactions in Chiropotes and Cacajao, we posit that the ability to maintain large groups in these genera may be related to the affiliative and perhaps coalitionary relationships between males, who may or may not be related. Affiliative male-male relationships may allow for monopolization of groups of females and facilitate group cohesion by reducing intragroup aggression; however data on male-male interactions with identified individuals will be required to determine patterns of affiliation, while genetic studies may be the most practical way of determining dispersal patterns for these genera.

Do non-human primates cooperate? Evidences of motor coordination during a joint action task in macaque monkeys

Humans are intensively social primates, therefore many of their actions are dedicated to communication and interaction with other individuals. Despite the progress in understanding the cognitive and neural processes that allow humans to perform cooperative actions, in non-human primates only few studies have investigated the ability to interact with a partner in order to reach a common goal. These studies have shown that in naturalistic conditions animals engage in various types of social behavior that involve forms of mutual coordination and cooperation. However, little is known on the capacity of non-human primates to actively cooperate in a controlled experimental setting, which allows full characterization of the motor parameters underlying individual action and their change during motor cooperation. To this aim, we analyzed the behavior of three pairs of macaque monkeys trained to perform solo and joint-actions by exerting a force on an isometric joystick, as to move an individual or a common cursor toward visual targets on a screen. We found that during cooperation monkeys reciprocally adapt their behavior by changing the parameters that define the spatial and temporal aspects of their action, as to fine tune their joint effort, and maximize their common performance. Furthermore the results suggest that when acting together the movement parameters that specify each actor's behavior are not only modulated during execution, but also during planning. These findings provide the first quantitative description of action coordination in non-human primates during the performance of a joint action task.

What cortisol can tell us about the costs of sociality and reproduction among free-ranging rhesus macaque females on Cayo Santiago.

Research with the rhesus macaque population on Cayo Santiago can provide a unique perspective on the costs of sociality and reproduction in primates. Because the Cayo macaques live in unusually large groups and in a predator-free environment, in which their artificial food source lacks seasonal variation in abundance or quality, these monkeys constitute a semi-experimental study of the costs and benefits of group living. Here we review several long- and short-term studies that have focused on female life history and stress physiology. Long-term demographic data have shown that rhesus macaque females of middle- and low-ranking matrilines have lower adult survival probabilities than females of high-ranking matrilines. Costs of reproductive effort are also evident: adult females were more likely to die during the birth than during the mating season and they experienced higher cortisol levels when lactating. Lower-ranking females, in particular, experienced greater relative increase in cortisol production during lactation, in comparison to middle- and high-ranking females. Older high-ranking females had lower plasma cortisol levels than younger ones but cortisol levels were similarly high among young and old middle- and low-ranking females. Higher plasma cortisol levels and/or fecal glucocorticoid concentrations are associated with higher plasma concentrations of some proinflammatory cytokines. High cortisol, in turn, may be associated with chronic inflammation, and perhaps also with immunosuppression. In sum, the studies reviewed here provide multiple lines of evidence that sociality and reproductive effort impose measurable costs on female rhesus macaques. In line with socio-ecological theory, female dominance rank consistently emerges as an important modulator of variation in female life histories and physiology. The Cayo Santiago macaques are therefore a valuable model for elucidating the mechanisms by which within-group competition and reproduction impact health and survival in nonhuman primates and in humans.

Communication, Biology, and Physiology: An Introduction to the Special Issue

As perhaps the most social of all the social primates, humans have an undeniable stake in regulating their communicative behavior, from the intrapersonal level to the global level. Communication is...

Quaternary climate change and social behavior shaped the genetic differentiation of an endangered montane primate from the southern edge of the Tibetan Plateau.

Multiple factors, including climate change, dispersal barriers, and social behavior influence the genetic structure of natural populations. While the effects of extrinsic factors such as historical climatic change and habitat topography have been well studied, mostly in temperate habitats, the simultaneous effects of intrinsic factors such as social behavior on genetic structure have rarely been explored. Such simultaneous effect, however, may particularly be common in social mammals such as many primates. Consequently, we studied the population structure of a rare and endangered social primate, the Arunachal macaque Macaca munzala, endemic to the northeastern Indian state of Arunachal Pradesh, located on the subtropical southern edge of the Tibetan Plateau and forming part of the Eastern Himalayan biodiversity hotspot. We studied a 534 bp-long mitochondrial DNA sequence and 22 autosomal microsatellite loci in individuals from three populations, Tawang, Upper Subansiri, and West Siang. The mtDNA data revealed three major divergence events: that between the Arunachal and bonnet macaques (ca. 1.61 mya), the founding of the West Siang population and the ancestral population of the present-day bonnet macaques (ca. 1.32 mya), and the divergence between the Tawang and Upper Subansiri populations (ca. 0.80 mya) that coincided with the major glacial events in the region. Comparing mitochondrial DNA with autosomal microsatellites, we also found evidence for female philopatry and male-driven long-distance gene flow. Arunachal macaques thus appear to be characterized by groups of philopatric females separated by geographical barriers and harsh climate but with dispersing males exerting a homogenizing effect on the nuclear gene pool. Given that severe population differentiation is of major concern in species conservation, we suggest that our study populations represent significant conservation units of this rare, endangered primate but, more importantly, emphasize the complex interplay of extrinsic and intrinsic factors in shaping the population structure of a social mammalian species.

Neurons in the Monkey Amygdala Detect Eye Contact during Naturalistic Social Interactions

Primates explore the visual world through eye-movement sequences. Saccades bring details of interest into the fovea, while fixations stabilize the image. During natural vision, social primates direct their gaze at the eyes of others to communicate their own emotions and intentions and to gather information about the mental states of others. Direct gaze is an integral part of facial expressions that signals cooperation or conflict over resources and social status. Despite the great importance of making and breaking eye contact in the behavioral repertoire of primates, little is known about the neural substrates that support these behaviors. Here we show that the monkey amygdala contains neurons that respond selectively to fixations on the eyes of others and to eye contact. These "eye cells" share several features with the canonical, visually responsive neurons in the monkey amygdala; however, they respond to the eyes only when they fall within the fovea of the viewer, either as a result of a deliberate saccade or as eyes move into the fovea of the viewer during a fixation intended to explore a different feature. The presence of eyes in peripheral vision fails to activate the eye cells. These findings link the primate amygdala to eye movements involved in the exploration and selection of details in visual scenes that contain socially and emotionally salient features.

Amygdala: Eyes Wide Open

Summary A new study sheds light on how the amygdala contributes to social interactions by providing direct evidence for specialized visual neurons that selectively respond to seeing the eyes of another individual or making eye contact with them.

Probabilistic and single-subject retinotopic maps reveal the topographic organization of face patches in the macaque cortex.

Face perception is crucial to survival among social primates. It has been suggested that a group of extrastriate cortical regions responding more strongly to faces than to nonface objects is critical for face processing in primates. It is generally assumed that these regions are not retinotopically organized, as with human face-processing areas, showing foveal bias but lacking any organization with respect to polar angle. Despite many electrophysiological studies targeting monkey face patches, the retinotopic organization of these patches remains largely unclear. We have examined the relationship between cortical face patches and the topographic organization of extrastriate cortex using biologically relevant, phase-encoded retinotopic mapping stimuli in macaques. Single-subject fMRI results indicated a gradual shift from highly retinotopic to no topographic organization from posterior to anterior face patches in inferotemporal cortex. We also constructed a probabilistic retinotopic atlas of occipital and ventral extrastriate visual cortex. By comparing this probabilistic map to the locations of face patches at the group level, we showed that a previously identified posterior lateral temporal face patch (PL) is located within the posterior inferotemporal dorsal (PITd) retinotopic area. Furthermore, we identified a novel face patch posterior PL, which is located in retinotopically organized transitional area V4 (V4t). Previously published coordinates of human PITd coincide with the group-level occipital face area (OFA), according to a probabilistic map derived from a large population, implying a potential correspondence between monkey PL/PITd and human OFA/PITd. Furthermore, the monkey middle lateral temporal face patch (ML) shows consistent foveal biases but no obvious polar-angle structure. In contrast, middle fundus temporal (MF), anterior temporal and prefrontal monkey face patches lacked topographic organization.

Cool sperm: why some placental mammals have a scrotum.

Throughout the Cenozoic, the fitness benefits of the scrotum in placental mammals presumably outweighed the fitness costs through damage, yet a definitive hypothesis for its evolution remains elusive. Here, I present an hypothesis (Endothermic Pulses Hypothesis) which argues that the evolution of the scrotum was driven by Cenozoic pulses in endothermy, that is, increases in normothermic body temperature, which occurred in Boreotheria (rodents, primates, lagomorphs, carnivores, bats, lipotyphylans and ungulates) in response to factors such as cursoriality and climate adaptation. The model argues that stabilizing selection maintained an optimum temperature for spermatogenesis and sperm storage throughout the Cenozoic at the lower plesiomorphic levels of body temperature that prevailed in ancestral mammals for at least 163million years. Evolutionary stasis may have been driven by reduced rates of germ-cell mutations at lower body temperatures. Following the extinction of the dinosaurs at the Cretaceous-Palaeogene boundary 65.5mya, immediate pulses in endothermy occurred associated with the dramatic radiation of the modern placental mammal orders. The fitness advantages of an optimum temperature of spermatogenesis outweighed the potential costs of testes externalization and paved the way for the evolution of the scrotum. The scrotum evolved within several hundred thousand years of the K-Pg extinction, probably associated initially with the evolution of cursoriality, and arguably facilitated mid- and late Cenozoic metabolic adaptations to factors such as climate, flight in bats and sociality in primates.

Models of stress in nonhuman primates and their relevance for human psychopathology and endocrine dysfunction.

Stressful life events have been linked to the onset of severe psychopathology and endocrine dysfunction in many patients. Moreover, vulnerability to the later development of such disorders can be increased by stress or adversity during development (e.g., childhood neglect, abuse, or trauma). This review discusses the methodological features and results of various models of stress in nonhuman primates in the context of their potential relevance for human psychopathology and endocrine dysfunction, particularly mood disorders and dysregulation of the hypothalamic-pituitary-adrenocortical (HPA) system. Such models have typically examined the effects of stress on the animals' behavior, endocrine function (primarily the HPA and hypothalamic-pituitary-gonadal systems), and, in some cases, immune status. Manipulations such as relocation and/or removal of an animal from its current social group or, alternatively, formation of a new social group can have adverse effects on all of these outcome measures that may be either transient or more persistent depending on the species, sex, and other experimental conditions. Social primates may also experience significant stress associated with their rank in the group's dominance hierarchy. Finally, stress during prenatal development or during the early postnatal period may have long-lasting neurobiological and endocrine effects that manifest in an altered ability to cope behaviorally and physiologically with later challenges. Whereas early exposure to severe stress usually results in deficient coping abilities, certain kinds of milder stressors can promote subsequent resilience in the animal. We conclude that studies of stress in nonhuman primates can model many features of stress exposure in human populations and that such studies can play a valuable role in helping to elucidate the mechanisms underlying the role of stress in human psychopathology and endocrine dysfunction.