Dynamic Social Adaptation of Motion-Related Neurons in Primate Parietal Cortex

Social brain function, which allows us to adapt our behavior to social context, is poorly understood at the single-cell level due largely to technical limitations. But the questions involved are vital: How do neurons recognize and modulate their activity in response to social context? To probe the mechanisms involved, we developed a novel recording technique, called multi-dimensional recording, and applied it simultaneously in the left parietal cortices of two monkeys while they shared a common social space. When the monkeys sat near each other but did not interact, each monkey's parietal activity showed robust response preference to action by his own right arm and almost no response to action by the other's arm. But the preference was broken if social conflict emerged between the monkeys—specifically, if both were able to reach for the same food item placed on the table between them. Under these circumstances, parietal neurons started to show complex combinatorial responses to motion of self and other. Parietal cortex adapted its response properties in the social context by discarding and recruiting different neural populations. Our results suggest that parietal neurons can recognize social events in the environment linked with current social context and form part of a larger social brain network

The effects of visual control and distance in modulating peripersonal spatial representation

In the presence of vision, finalized motor acts can trigger spatial remapping, i.e., reference frames transformations to allow for a better interaction with targets. However, it is yet unclear how the peripersonal space is encoded and remapped depending on the availability of visual feedback and on the target position within the individual’s reachable space, and which cerebral areas subserve such processes. Here, functional magnetic resonance imaging (fMRI) was used to examine neural activity while healthy young participants performed reach-to-grasp movements with and without visual feedback and at different distances of the target from the effector (near to the hand–about 15 cm from the starting position–vs. far from the hand–about 30 cm from the starting position). Brain response in the superior parietal lobule bilaterally, in the right dorsal premotor cortex, and in the anterior part of the right inferior parietal lobule was significantly greater during visually-guided grasping of targets located at the far distance compared to grasping of targets located near to the hand. In the absence of visual feedback, the inferior parietal lobule exhibited a greater activity during grasping of targets at the near compared to the far distance. Results suggest that in the presence of visual feedback, a visuo-motor circuit integrates visuo-motor information when targets are located farther away. Conversely in the absence of visual feedback, encoding of space may demand multisensory remapping processes, even in the case of more proximal targets

Structured bimanual actions and hand transfers reveal population-level right-handedness in captive gorillas

There is a common prevailing perception that humans possess a species-unique population-level right-hand bias that has evolutionary links with language. New theories suggest that an early evolutionary division of cognitive function gave rise to a left-hemisphere bias for behaviours underpinned by structured sequences of actions. However, studies of great ape handedness have generated inconsistent results and considerable debate. Additionally, the literature places a heavy focus on chimpanzees, revealing a paucity of handedness findings from other great ape species, and thus limiting the empirical evidence with which we can evaluate evolutionary theory. We observed handedness during spontaneous naturalistic bimanual actions in a captive, biological group of 13 western lowland gorillas, Gorilla gorilla gorilla. Our results demonstrated a significant group-level right-handed bias for bimanual actions as well as for a novel measure of handedness: hand transfer. The two measures revealed similar patterns of handedness, such that a right-hand bias for the majority of individuals was found across both measures. Our findings suggest that human population-level right-handedness is a behavioural trait linked with left-hemisphere dominance for the processing of structured sequences of actions, and was inherited by a common ancestor of both humans and apes

How does it feel to act together?

This paper on the phenomenology of joint agency proposes a foray into a little explored territory at the intersection of two very active domains of research: joint action and sense of agency. I explore two ways in which our experience of joint agency may differ from our experience of individual agency. First, the mechanisms of action specification and control involved in joint action are typically more complex than those present in individual actions, since it is crucial for joint action that people coordinate their plans and actions. I discuss the implications that these coordination requirements might have for the strength of the sense of agency an agent may experience for a joint action. Second, engagement in joint action may involve a transformation of agentive identity and a partial or complete shift from a sense of self-agency to a sense of we-agency. I discuss several factors that may contribute to shaping our sense of agentive identity in joint action

Triadic (ecological, neural, cognitive) niche construction: a scenario of human brain evolution extrapolating tool use and language from the control of reaching actions

Hominin evolution has involved a continuous process of addition of new kinds of cognitive capacity, including those relating to manufacture and use of tools and to the establishment of linguistic faculties. The dramatic expansion of the brain that accompanied additions of new functional areas would have supported such continuous evolution. Extended brain functions would have driven rapid and drastic changes in the hominin ecological niche, which in turn demanded further brain resources to adapt to it. In this way, humans have constructed a novel niche in each of the ecological, cognitive and neural domains, whose interactions accelerated their individual evolution through a process of triadic niche construction. Human higher cognitive activity can therefore be viewed holistically as one component in a terrestrial ecosystem. The brain's functional characteristics seem to play a key role in this triadic interaction. We advance a speculative argument about the origins of its neurobiological mechanisms, as an extension (with wider scope) of the evolutionary principles of adaptive function in the animal nervous system. The brain mechanisms that subserve tool use may bridge the gap between gesture and language—the site of such integration seems to be the parietal and extending opercular cortices

Tool-Use Training in a Species of Rodent: The Emergence of an Optimal Motor Strategy and Functional Understanding

Tool use is defined as the manipulation of an inanimate object to change the position or form of a separate object. The expansion of cognitive niches and tool-use capabilities probably stimulated each other in hominid evolution. To understand the causes of cognitive expansion in humans, we need to know the behavioral and neural basis of tool use. Although a wide range of animals exhibit tool use in nature, most studies have focused on primates and birds on behavioral or psychological levels and did not directly address questions of which neural modifications contributed to the emergence of tool use. To investigate such questions, an animal model suitable for cellular and molecular manipulations is needed.) to use a rake-like tool with their forelimbs to retrieve otherwise out-of-reach rewards. Eventually, they mastered effective use of the tool, moving it in an elegant trajectory. After the degus were well trained, probe tests that examined whether they showed functional understanding of the tool were performed. Degus did not hesitate to use tools of different size, colors, and shapes, but were reluctant to use the tool with a raised nonfunctional blade. Thus, degus understood the functional and physical properties of the tool after extensive training.Our findings suggest that tool use is not a specific faculty resulting from higher intelligence, but is a specific combination of more general cognitive faculties. Studying the brains and behaviors of trained rodents can provide insights into how higher cognitive functions might be broken down into more general faculties, and also what cellular and molecular mechanisms are involved in the emergence of such cognitive functions

Tool-use learning by common marmosets (Callithrix jacchus)

One of the most critical and common features of tool use is that the tool essentially functions as a part of the body. This feature is likely rooted in biological features that are shared by tool users. To establish an ideal primate model to explore the neurobiological mechanisms supporting tool-use behaviours, we trained common marmosets, a small New World monkey species that is not usually associated with tool use, to use a rake-shaped tool to retrieve food. Five naive common marmosets were systematically trained to manipulate the tool using a 4-stage, step-by-step protocol. The relative positions of the tool and the food were manipulated, so that the marmosets were required to (1) pull the tool vertically, (2) move the tool horizontally, (3) make an arc to retrieve a food item located behind the tool and (4) retrieve the food item. We found considerable individual differences in tool-use technique; for example, one animal consistently used a unilateral hand movement for all of the steps, whereas the others (n = 4) used both hands to move the tool depending on the location of the food item. After extensive training, all of the marmosets could manipulate the rake-shaped tool, which is reported in this species for the first time. The common marmoset is thus a model primate for such studies. This study sets the stage for future research to examine the biological mechanisms underlying the cognitive ability of tool use at the molecular and genetic levels

Pregnant women's awareness of sensitivity to cold (hiesho) and body temperature observational study: A comparison of Japanese and Brazilian women

<p>Abstract</p> <p>Background</p> <p>Sensitivity to cold (<it>hiesho</it>) is a serious health problem in Japan, yet it is minimally understood within Western cultures. The purpose of this study was to clarify the divergence between pregnant Japanese woman living in Japan and pregnant Brazilian women living in Brazil in awareness of <it>hiesho </it>and differences between core body and peripheral temperatures.</p> <p>Methods</p> <p>The subjects of this study were 230 pregnant Japanese women living in Japan and 200 pregnant Brazilian women living in Brazil. Data was collected in June/July and November 2005 in Japan and from October 2007 to February 2008 in Brazil. The survey methods consisted of measurement of deep body temperatures and questionnaires.</p> <p>Results</p> <p>67.0% of Japanese women and 57.0% of Brazilian women were aware of <it>hiesho</it>, which showed a significant difference between the Japanese and Brazilian women (p = 0.034). The difference between forehead and sole temperatures was 2.0°C among Japanese and 2.8°C among Brazilians in June-July (p = 0.01). But in November the difference between those temperatures was 5.2°C among Japanese and 2.8°C among Brazilians (p < 0.001).</p> <p>Conclusions</p> <p>There are differences between Japanese and Brazilians both in awareness of <it>hiesho </it>and in body temperatures.</p

Culture and Evolution

This chapter captures extensive discussions between people with different forms of expertise and viewpoints. It explores the relationships between language and music in evolutionary and cultural context. Rather than trying to essentialize either, they are characterized pragmatically in terms of features that appear to distinguish them (such as language’s compositional propositionality as opposed to music’s foregrounding of isochronicity), and those that they evidently share. Factors are considered that consti- tute proximate motivations for humans to communicate through language and music, ranging from language’s practical value in the organization of collective behavior to music’s significant role in eliciting and managing prosocial attitudes. Possible distal motivations are reviewed for music and language, in terms of the potentially adap- tive functions of human communication systems, and an assessment is made of the advantages which might accrue to flexible communicators in the light of ethological and archaeological evidence concerning the landscape of selection. Subsequently, the possible evolutionary relationships between music and language are explored, within a framework supplied by six possible models of their emergence. Issues of the roles of culture and of biology in the evolution of communication systems are then addressed within the framework of triadic niche construction, and the chapter concludes by sur- veying available comparative and phylogenetic issues that might inform the debate