Plot 99 : towards a feminine semiotic : spiritual and sexual emergence(y) in women's puppetry and visual performance

Includes bibliographical references.This thesis explores how a multidisciplinary Feminine Semiotics may find expression through the cross-disciplinary medium of puppetry and visual performance. It investigates puppetry's relevance to the developing academic field of Practice as Research in performance. It considers the theoretical and creative applications of this multidisciplinary art form in the innovative Feminine Semiotics of emergence(y) in the production Plot 99

Psychophysical measures of sensitivity to facial expression of emotion.

We report the development of two simple, objective, psychophysical measures of the ability to discriminate facial expressions of emotion that vary in intensity from a neutral facial expression and to discriminate between varying intensities of emotional facial expression. The stimuli were created by morphing photographs of models expressing four basic emotions, anger, disgust, happiness, and sadness with neutral expressions. Psychometric functions were obtained for 15 healthy young adults using the Method of Constant Stimuli with a two-interval forced-choice procedure. Individual data points were fitted by Quick functions for each task and each emotion, allowing estimates of absolute thresholds and slopes. The tasks give objective and sensitive measures of the basic perceptual abilities required for perceiving and interpreting emotional facial expressions

Maladamatjuate and the theatre of difference : staging the female body in South Africa

Includes bibliographical references (p. 90-92).In this paper, I investigate contemporary alternative staging strategies that critically and creatively explore representations of women in South African theatre. I interrogate representations of the female body of' difference' and the theatrical interpretation of complex identity in South Africa. Imperative questions are raised around the renegotiation of perceptions of division and stereotype (especially regarding women) in performance in South Africa. I raise crucial questions regarding the empowerment of representations of difference on the stage. Theatre of Difference requires representations that are as critically interrogatory of the socio-political circumstances of female identity as they are intimately concerned with the personal processes of the psyches of individual women

Olfactory communication of the white rhinoceros (Ceratotherium simum)

Doctor of Philosophy in Ecology. University of KwaZulu-Natal, Pietermaritzburg, 2017.Many mammal species communicate olfactorily via specialised scent glandular secretions, urine and/or dung. Despite a large body of work on olfactory communication, the extent to which mammals communicate via dung odours, and what information is transmitted, is unknown. White rhinos (Ceratotherium simum) have poor eyesight but an acute sense of smell and therefore rely heavily on olfactory signals. Moreover, white rhinos of all ages and sex defecate communally in middens, thus it is possible that these middens act as olfactory information centres for male-male, female-male, male-female and female-female communication. To explore these possibilities, I first analysed the odours emitted from the dung of free-ranging white rhinos. In doing so, I identified distinct odour profiles that indicated an individual’s sex, age, male territorial status, and female oestrous state. Once I had identified the information transmitted, I then explored how long these signals lasted. In order for an olfactory signal to be effective it must persist in the environment for an extended period. To determine signal longevity I analysed the temporal changes of white rhino dung odours. I found that over a short period male dung odours had shorter longevity than female odours. Within males, territorial odours had shorter longevity than non-territorial, while non-oestrous female odours had a shorter longevity than oestrous odours. The high temperature and humidity of the wet season decreased the longevity of all adult dung odours. However, white rhinos did not adjust their visitation or defecation frequency during the wet season to counteract this decrease in longevity. Having identified the odours and how long they lasted, I then investigated the behaviour of white rhinos at middens to determine which individuals were primarily transmitting information and who were the intended targets. I found that middens were utilised predominately by adults. Moreover, the primary function of middens was for territorial males to transmit and obtain information (male-male and female-male communication), with secondary functions for non-territorial males to also assess female reproductive state, and females to assess the quality and number of potential mates (male-female communication). In addition to olfactory signals there was a spatial aspect to defecating in middens, where territorial males defecated in the centre of the midden and other individuals around the periphery. Further, territorial males regulated their dung output, with a higher defecation frequency and smaller dung volume than any other adult. Finally, I conducted an experiment to investigate the purpose of territorial male dung kicking. Using non-territorial adult male dung as a surrogate, I found that the dispersal of male white rhino dung caused olfactory signal amplification by increasing the emission of hydrocarbon acids. However, despite the benefits of odour amplification, dung dispersal also carried a cost of decreased odour longevity, ultimately decreasing signal longevity. Territorial males likely counteract this by defecating in middens during peak visitation times by other individuals. Ultimately, my results highlight the mechanism behind olfactory communication in white rhinos and the importance of middens in this communication system. Moreover, as many other mammal species defecate communally, olfactory communication via dung odours is likely a widespread phenomenon

Representational neural mapping of dexterous grasping before lifting in humans

Corrected by: Erratum: Marneweck and Grafton, “Representational Neural Mapping of Dexterous Grasping Before Lifting in Humans, in 41(2) 390; DOI: https://doi.org/10.1523/JNEUROSCI.2479-20.2020. An important detail was left out of the legend of Figure 2. The online version has been updated to include the following sentence: “All cortical regions (including those on the medial wall) are projected to the lateral surface.”The ability of humans to reach and grasp objects in their environment have been the mainstay paradigm for characterizing the neural circuitry driving object-centric actions. While much is known about hand shaping, a persistent question is how the brain orchestrates and integrates the grasp with lift forces of the fingers in a coordinated manner. The objective of the current study was to investigate how the brain represents grasp configuration and lift force during a dexterous object-centric action in a large sample of male and female human subjects. BOLD activity was measured as subjects used a precision-grasp to lift an object with a center of mass (CoM) on the left or right with the goal of minimizing tilting the object. The extent to which grasp configuration and lift force varied between left and right CoM conditions was manipulated grasping the object collinearly (requiring a non-collinear force distribution) or non-collinearly (requiring more symmetrical forces). Bayesian variational representational similarity analyses on fMRI data assessed the evidence that a set of cortical and cerebellar regions were sensitive to grasp configuration or lift force differences between CoM conditions at differing timepoints during a grasp to lift action. In doing so, we reveal strong evidence that grasping and lift force are not represented by spatially separate functionally specialized regions, but by the same regions at differing timepoints. The coordinated grasp to lift effort is shown to be under dorsolateral (PMv and AIP) more than dorsomedial control, and under SPL7, somatosensory PSC, ventral LOC and cerebellar control. Signficance Statement: Clumsy disasters like spilling, dropping, and crushing during our daily interactions with objects are a rarity rather than the norm. These disasters are avoided in part as a result of our orchestrated anticipatory efforts to integrate and coordinate grasping and lifting of object interactions, all before the lift of an object even commences. How the brain orchestrates this integration process has been largely neglected by historical approaches independently and solely focusing on reaching and grasping and the neural principles that guide them. Here we test the extent to which grasping and lifting are represented in a spatially or temporally-distinct manner and identified strong evidence for the consecutive emergence of sensitivity to grasping, then lifting within the same region.Michelle Marneweck and Scott T. Grafto

Neural substrates of anticipatory motor adaptation for object lifting

Anticipatory force control is a fundamental means by which humans stave off slipping, spilling, and tilting disasters while manipulating objects. This control must often be adapted due to changes in an object's dynamics (e.g. a lighter than expected mug of coffee) or its relation with involved effectors or digits (e.g. lift a mug with three vs. five digits). The neural processes guiding such anticipatory and adaptive control is understudied but presumably operates along multiple time scales, analogous to what has been identified with adaptation in other motor tasks, such as perturbations during reaching. Learning of anticipatory forces must be ultrafast to minimize tilting a visually symmetric object towards its concealed asymmetric center of mass (CoM), but slower when the CoM is explicitly and systematically switched from side to side. Studying the neural substrates of this latter slower learning process with rapid multiband brain imaging, in-scanner kinematics and Bayesian pattern component modelling, we show that CoM-specific pattern distances increase with repeated CoM switching exposures and improved learning. The cerebellum showed the most prominent effects, fitting with the idea that it forms a stored internal model that is used to build and update anticipatory control. CoM-specific pattern distances were present 24 h later, in line with the presence of consolidation effects.Michelle Marneweck, Scott T. Grafto

Visual Cues of Object Properties Differentially Affect Anticipatory Planning of Digit Forces and Placement

Studies on anticipatory planning of object manipulation showed initial task failure (i.e., object roll) when visual object shape cues are incongruent with other visual cues, such as weight distribution/density (e.g., symmetrically shaped object with an asymmetrical density). This suggests that shape cues override density cues. However, these studies typically only measured forces, with digit placement constrained. Recent evidence suggests that when digit placement is unconstrained, subjects modulate digit forces and placement. Thus, unconstrained digit placement might be modulated on initial trials (since it is an explicit process), but not forces (since it is an implicit process). We tested whether shape and density cues would differentially influence anticipatory planning of digit placement and forces during initial trials of a two-digit object manipulation task. Furthermore, we tested whether shape cues would override density cues when cues are incongruent. Subjects grasped and lifted an object with the aim of preventing roll. In Experiment 1, the object was symmetrically shaped, but with asymmetrical density (incongruent cues). In Experiment 2, the object was asymmetrical in shape and density (congruent cues). In Experiment 3, the object was asymmetrically shaped, but with symmetrical density (incongruent cues). Results showed differential modulation of digit placement and forces (modulation of load force but not placement), but only when shape and density cues were congruent. When shape and density cues were incongruent, we found collinear digit placement and symmetrical force sharing. This suggests that congruent and incongruent shape and density cues differentially influence anticipatory planning of digit forces and placement. Furthermore, shape cues do not always override density cues. A continuum of visual cues, such as those alluding to shape and density, need to be integrated

Overt and Covert Object Features Mediate Timing of Patterned Brain Activity during Motor Planning

11 pagesHumans are seamless in their ability to efficiently and reliably generate fingertip forces to gracefully interact with objects. Such interactions rarely end in awkward outcomes like spilling, crushing, or tilting given advanced motor planning. Here we combine multiband imaging with deconvolution- and Bayesian pattern component modeling of functional magnetic resonance imaging data and in-scanner kinematics, revealing compelling evidence that the human brain differentially represents preparatory information for skillful object interactions depending on the saliency of visual cues. Earlier patterned activity was particularly evident in ventral visual processing stream-, but also selectively in dorsal visual processing stream and cerebellum in conditions of heightened uncertainty when an object’s superficial shape was incompatible rather than compatible with a key underlying object feature

Generalization of Dexterous Manipulation Is Sensitive to the Frame of Reference in Which It Is Learned

Studies have shown that internal representations of manipulations of objects with asymmetric mass distributions that are generated within a specific orientation are not generalizable to novel orientations, i.e., subjects fail to prevent object roll on their first grasp-lift attempt of the object following 180° object rotation. This suggests that representations of these manipulations are specific to the reference frame in which they are formed. However, it is unknown whether that reference frame is specific to the hand, the body, or both, because rotating the object 180° modifies the relation between object and body as well as object and hand. An alternative, untested explanation for the above failure to generalize learned manipulations is that any rotation will disrupt grasp performance, regardless if the reference frame in which the manipulation was learned is maintained or modified. We examined the effect of rotations that (1) maintain and (2) modify relations between object and body, and object and hand, on the generalizability of learned two-digit manipulation of an object with an asymmetric mass distribution. Following rotations that maintained the relation between object and body and object and hand (e.g., rotating the object and subject 180°), subjects continued to use appropriate digit placement and load force distributions, thus generating sufficient compensatory moments to minimize object roll. In contrast, following rotations that modified the relation between (1) object and hand (e.g. rotating the hand around to the opposite object side), (2) object and body (e.g. rotating subject and hand 180°), or (3) both (e.g. rotating the subject 180°), subjects used the same, yet inappropriate digit placement and load force distribution, as those used prior to the rotation. Consequently, the compensatory moments were insufficient to prevent large object rolls. These findings suggest that representations of learned manipulation of objects with asymmetric mass distributions are specific to the body- and hand-reference frames in which they were learned

Food, family and female age affect reproduction and pup survival of African wild dogs

Understanding factors that affect the reproductive output and growth of a population of endangered carnivores is key to providing information for their effective conservation. Here, we assessed patterns in reproduction for a small population of endangered African wild dogs (Lycaon pictus) over 90 pack years. We tested how availability of prey, pack size, pack density, rainfall, temperature and female age affected the age of first litter, litter size and pup survival. We found that females bred younger when pack density, availability of prey and pack size were large.We also found that fecundity increased significantly with age while the population was male biased only for 1-, 2- and 4-year olds. Larger litters were produced by larger packs, suggesting strong reproductive benefits of grouping related to cooperative hunting and food provisioning for helpers and alpha females. We also found an interaction between breeding female age and pack size where older females in large packs raised a high proportion of pups. Additionally, large litters and large packs were important for raising a greater number of pups to 6 and 12 months, respectively, suggesting that while litter size is important for pup survival, the benefits of a large pack are only realised when pups are older and mobile with the pack. Collectively, these results illustrate the novel finding that prey availability is critically important in initiating reproduction inwild dogs and that the number of non-breeding helpers, female age and litter size is essential to pup survival