An atypical social touch system in Anorexia Nervosa? Towards a novel non-invasive brain stimulation intervention

As outlined in Chapter 1, affective touch is a pleasant interoceptive stimulus facilitated by the activation of a specialised system of mechanosensitive cutaneous afferents C-tactile afferents (CTs), which respond when an individual receives gentle touch to the skin. The purpose of CTs is to encode the rewarding sensation of the touch that has been received. This type of touch is important for communication, bonding, and typical development. Numerous investigations have outlined that this process is associated with the activation of the Insula Cortex. In particular, the anterior and posterior regions respond when an individual receives affective touch to their hairy skin. In addition to this region, other brain regions specifically involved in social perception and social cognition, such as the medial Prefrontal Cortex (mPFC), have been implicated in affective touch processing. Furthermore, the role of the primary Somatosensory Cortex (S1), a key brain region for discriminatory touch processing, has been debated in terms of affective touch processing. More recently, investigations have shifted their focus from the general population to atypical responses to affective touch in clinical populations, specifically Anorexia Nervosa (AN). AN is an eating pathology characterised by restricted eating, body image distortions and impaired socio-cognitive abilities. It has been suggested that altered responses to affective touch may contribute to the aetiology and maintenance of this disorder. Based on this evidence, study 1 (Chapter 3) aimed to examine whether women with high and low EDs risk differed in their responses to third-party vicarious social touch, delivered to various body regions at CT-optimal vs. non-CT optimal velocities. Forty-five women reporting high EDs risk symptoms vs. 40 women reporting low EDs risk symptoms viewed a sequence of video clips depicting one individual being touched by another, which was delivered to five body sites (cheek, back, ventral forearm, upper arm vs. palm). Participants were asked to rate how pleasant they perceived the touch to be when delivered at CT-optimal (5 cm/s) vs. CT non-optimal velocities (0 cm/s and 30 cm/s) for self-directed and other-directed touch. Self-report measures of body image concerns, interoceptive awareness and touch experiences and attitudes were also collected (outlined in Chapter 2). Surprisingly, touch pleasantness did not differ between both groups for both self-directed and other-directed touch. For high EDs risk females, eating disorder traits and specific interoceptive awareness facets impacted pleasantness of touch for both the upper arm and back. Findings suggest that EDs traits and body awareness negatively affect ratings of social touch for specific body sites. However, results should be handled cautiously, given that women in this investigation did not have a clinical diagnosis of AN. Therefore, given that women in study 1 did not have a formal AN diagnosis, study 2 (Chapter 4) investigated whether women with a current diagnosis of AN, recovered from AN (RAN) and Healthy Controls (HCs) responded differently to vicarious social touch also delivered at CT-optimal vs. non-CT optimal velocities. Thirty-five HCs, 27 AN and 29 RAN provided third-party pleasantness evaluations for two different tasks, one concerning self (self-directed touch) and one focused on touch to another person (other-directed touch). As in study 1, measures of body image concerns, interoceptive awareness and touch experiences and attitudes were administered through various questionnaires (outlined in Chapter 2). Results from this investigation revealed that both AN and RAN did not differ to HCs in their evaluations of touch directed to another person. However, both clinical populations rated self-directed CT-optimal touch as less pleasant compared to HCs. Thus, suggesting that both clinical groups display atypical responses to affective touch, when this touch is directed towards the self and not another person. In particular, that a learnt experience may contribute towards pleasantness responses to other-directed touch, as individuals with AN or RAN may be aware through experience that touch is pleasantly experienced by another, even if this is not the case for them. Moreover, given that in study 2 individuals with AN demonstrated atypical responses to self-directed touch, study 3 (Chapter 5) examined whether this type of touch is mediated by the social relationship of that touch. Specifically, whether individuals with high and low levels of Body Image Disturbances (BIDs) differed in their responses to ‘imagined’ social touch. This was achieved through the use of an interactive mobile application, the ‘Virtual Touch Toolkit’ (See Chapter 2 for details). Sixty-nine high vs. low levels of BIDs completed heatmaps of front and back full body avatars, to indicate the intimate and social regions they find soothing/unpleasant to receive touch from a loved one vs. an acquaintance. In addition to this, various self-reports of interoceptive awareness and dysmorphic concerns were also collected. The results from this study revealed that both groups rated touch from a loved one as soothing, compared to touch from an acquaintance which was rated as unpleasant. For the high levels of BIDs group, greater emotional awareness predicted higher soothing ratings for touch provided from a loved one. Thus, findings support the idea that pleasantness responses to social touch are mediated by the relationships shared between the touch provider and receiver. Lastly, study 4 (Chapter 6) aimed to understand the neural underpinnings related to atypical responses to social touch in AN. This study explored whether the primary somatosensory cortex (S1) and the ventromedial prefrontal cortex (mPFC) are involved in affective touch processing. In order to investigate this, 18 healthy control participants received offline continuous theta burst Transcranial Magnetic Stimulation (cTBS), a form of repetitive transcranial magnetic stimulation (rTMS) to the right vmPFC, S1 and Vertex (control). After this, participants provided ratings of self-directed vicarious touch and other-directed touch. In addition, self-report measures of interoception, body image concerns and touch experiences and attitudes were collected (Detailed in Chapter 2). Findings from this study revealed that vmPFC-cTBS reduced pleasantness ratings for other directed touch but not for self-directed touch. S1-cTBS increased pleasantness ratings for self-directed touch but had no effect on pleasantness ratings for other-directed touch. The reduction in pleasantness for other-directed touch and the increase in pleasantness for self-directed touch was not CT-specific. Overall, results from this study imply that both S1 and vmPFC have distinctive roles in social touch processing and the processing of CT-optimal touch occurs outside of these social brain regions. This study offers important consideration for future non-pharmacological intervention which could improve touch processing in individuals with AN regardless of CT-optimality (Chapter 6). Taken together, findings from these investigations suggest that women with AN and recovered from AN display comparable intact evaluations when comparing touch for another person, similar to HCs. However, atypical responses to affective touch occur when asked to make judgements for touch to the self, with both clinical groups rating this touch as less pleasant than HCs (Chapter 4). These results do not extend to high EDs risk, who display typical and comparable responses to self and other-directed touch to HCs (Chapter 3). Overall, responses to social touch have been found to be modulated by the relationship shared with the touch provider, with more familiar individuals being more positive and more distant being more unpleasant (Chapter 5). Furthermore, although there is some distinctive involvement of vmPFC and S1 in social touch processing, it is evident that the processing of CT-optimal touch occurs outside of these regions, such as the orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC). Overall, results from these investigations offer valuable insight into responses to vicarious social touch in women at risk of EDs, women with AN and recovered from AN (Chapters 3 and 4). Based on this, results offer the potential for future pilot studies to be developed, incorporating both TMS and mobile applications as an intervention for atypical responses to self-directed touch in individuals with AN (discussed in Chapter 7)

Alien versus native species as drivers of recent extinctions

Native plants and animals can rapidly become superabundant and dominate ecosystems, leading to claims that native species are no less likely than alien species to cause environmental damage, including biodiversity loss. We compared how frequently alien and native species have been implicated as drivers of recent extinctions in a comprehensive global database, the 2017 International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Alien species were considered to be a contributing cause of 25% of plant extinctions and 33% of animal extinctions, whereas native species were implicated in less than 5% and 3% of plant and animal extinctions, respectively. When listed as a putative driver of recent extinctions, native species were more often associated with other extinction drivers than were alien species. Our results offer additional evidence that the biogeographic origin, and hence evolutionary history, of a species are determining factors of its potential to cause disruptive environmental impacts

Societal attention toward extinction threats : a comparison between climate change and biological invasions

Public attention and interest in the fate of endangered species is a crucial prerequisite for effective conservation programs. Societal awareness and values will largely determine whether conservation initiatives receive necessary support and lead to adequate policy change. Using text data mining, we assessed general public attention in France, Germany and the United Kingdom toward climate change and biological invasions in relation to endangered amphibian, reptile, bird and mammal species. Our analysis revealed that public attention patterns differed among species groups and countries but was globally higher for climate change than for biological invasions. Both threats received better recognition in threatened than in non-threatened species, as well as in native species than in species from other countries and regions. We conclude that more efficient communication regarding the threat from biological invasions should be developed, and that conservation practitioners should take advantage of the existing attention toward climate change.Peer reviewe

An integrated concurrency and core-ISA architectural envelope definition, and test oracle, for IBM POWER multiprocessors

Funding: Scottish Funding Council (SICSA Early Career Industry Fellowship)Weakly consistent multiprocessors such as ARM and IBM POWER have been with us for decades, but their subtle programmer-visible concurrency behaviour remains challenging, both to implement and to use; the traditional architecture documentation, with its mix of prose and pseudocode, leaves much unclear. In this paper we show how a precise architectural envelope model for such architectures can be defined, taking IBM POWER as our example. Our model specifies, for an arbitrary test program, the set of all its allowable executions, not just those of some particular implementation. The model integrates an operational concurrency model with an ISA model for the fixedpoint non-vector user-mode instruction set (largely automatically derived from the vendor pseudocode, and expressed in a new ISA description language). The key question is the interface between these two: allowing all the required concurrency behaviour, without overcommitting to some particular microarchitectural implementation, requires a novel abstract structure. Our model is expressed in a mathematically rigorous language that can be automatically translated to an executable test-oracle tool; this lets one either interactively explore or exhaustively compute the set of all allowed behaviours of intricate test cases, to provide a reference for hardware and software development.Postprin

Role of medial prefrontal cortex and primary somatosensory cortex in self and other-directed vicarious social touch: a TMS study

Conflicting evidence points to the contribution of several key nodes of the 'social brain' to the processing of both discriminatory and affective qualities of interpersonal touch. Whether the primary somatosensory cortex (S1) and the medial prefrontal cortex (mPFC), two brain areas vital for tactile mirroring and affective mentalizing, play a functional role in shared representations of C-tactile (CT) targeted affective touch is still a matter of debate. Here, we used offline continuous theta-burst Transcranial Magnetic Stimulation (cTBS) to mPFC, S1 and Vertex (control) prior to participants providing ratings of vicarious touch pleasantness for self and others delivered across several body sites at CT-targeted velocities. We found that S1-cTBS led to a significant increase in touch ratings to the self, with this effect being positively associated to levels of interoceptive awareness. Conversely, mPFC-cTBS reduced pleasantness ratings for touch to another person. These effects were not specific for CT-optimal (slow) stroking velocities, but rather they applied to all types of social touch. Overall, our findings challenge the causal role of the S1 and mPFC in vicarious affective touch and suggest that self- vs. other-directed vicarious touch responses might crucially depend on the specific involvement of key social networks in gentle tactile interactions

Recent developments in Diversity and Distributions and trends in the field

This is the final version. Available on open access from Wiley via the DOI in this recordDiversity and Distributions, which was founded as Biodiversity Letters in 1993, is a leading journal in the Web of Science (WOS) categories of Ecology and Biodiversity Conservation. In this editorial, we want to address the revised scope of the journal, the impact of the Open Access transition and associated waiver policy on the journal progress, and the recently established data accessibility policy

Patterns and drivers of climatic niche dynamics during biological invasions of island-endemic amphibians, reptiles, and birds

Shifts between native and alien climatic niches pose a major challenge for predicting biological invasions. This is particularly true for insular species because geophysical barriers could constrain the realization of their fundamental niches, which may lead to underestimates of their invasion potential. To investigate this idea, we estimated the frequency of shifts between native and alien climatic niches and the magnitude of climatic mismatches using 80,148 alien occurrences of 46 endemic insular amphibian, reptile, and bird species. Then, we assessed the influence of nine potential predictors on climatic mismatches across taxa, based on species' characteristics, native range physical characteristics, and alien range properties. We found that climatic mismatch is common during invasions of endemic insular birds and reptiles: 78.3% and 55.1% of their respective alien records occurred outside of the environmental space of species' native climatic niche. In comparison, climatic mismatch was evident for only 16.2% of the amphibian invasions analyzed. Several predictors significantly explained climatic mismatch, and these varied among taxonomic groups. For amphibians, only native range size was associated with climatic mismatch. For reptiles, the magnitude of climatic mismatch was higher for species with narrow native altitudinal ranges, occurring in topographically complex or less remote islands, as well as for species with larger distances between their native and alien ranges. For birds, climatic mismatch was significantly larger for invasions on continents with higher phylogenetic diversity of the recipient community, and when the invader was more evolutionarily distinct. Our findings highlight that apparently common niche shifts of insular species may jeopardize our ability to forecast their potential invasions using correlative methods based on climatic variables. Also, we show which factors provide additional insights on the actual invasion potential of insular endemic amphibians, reptiles, and birds

How biological invasions affect animal behaviour: A global, cross-taxonomic analysis

In the Anthropocene, species are faced with drastic challenges due to rapid, human-induced changes, such as habitat destruction, pollution and biological invasions. In the case of invasions, native species may change their behaviour to minimize the impacts they sustain from invasive species, and invaders may also adapt to the conditions in their new environment in order to survive and establish self-sustaining populations. We aimed at giving an overview of which changes in behaviour are studied in invasions, and what is known about the types of behaviour that change, the underlying mechanisms and the speed of behavioural changes. Based on a review of the literature, we identified 191 studies and 360 records (some studies reported multiple records) documenting behavioural changes caused by biological invasions in native (236 records from 148 species) or invasive (124 records from 50 species) animal species. This global dataset, which we make openly available, is not restricted to particular taxonomic groups. We found a mild taxonomic bias in the literature towards mammals, birds and insects. In line with the enemy release hypothesis, native species changed their anti-predator behaviour more frequently than invasive species. Rates of behavioural change were evenly distributed across taxa, but not across the types of behaviour. Our findings may help to better understand the role of behaviour in biological invasions as well as temporal changes in both population densities and traits of invasive species, and of native species affected by them