Papers by Alexandra A de Sousa
Journal of Sex Research, Feb 16, 2023
Archives of Sexual Behavior, Apr 13, 2021
Cross-cultural research has repeatedly demonstrated sex differences in the importance of partner ... more Cross-cultural research has repeatedly demonstrated sex differences in the importance of partner characteristics when choosing a mate. Men typically report higher preferences for younger, more physically attractive women, while women typically place more importance on a partner's status and wealth. As the assessment of such partner characteristics often relies on visual cues, this raises the question whether visual experience is necessary for sex-specific mate preferences to develop. To shed more light onto the emergence of sex differences in mate choice, the current study assessed how preferences for attractiveness, resources, and personality factors differ between sighted and blind individuals using an online questionnaire. We further investigate the role of social factors and sensory cue selection in these sex differences. Our sample consisted of 94 sighted and blind participants with different ages of blindness onset: 19 blind/28 sighted males and 19 blind/28 sighted females. Results replicated well-documented findings in the sighted, with men placing more importance on physical attractiveness and women placing more importance on status and resources. However, while physical attractiveness was less important to blind men, blind women considered physical attractiveness as important as sighted women. The importance of a high status and likeable personality was not influenced by sightedness. Blind individuals considered auditory cues more important than visual cues, while sighted males showed the opposite pattern. Further, relationship status and indirect, social influences were related to preferences. Overall, our findings shed light on the availability of visual information for the emergence of sex differences in mate preference.
Proceedings of The Royal Society B: Biological Sciences, Oct 30, 2019
Communications biology, Jun 21, 2023
Alzheimer's disease (AD) is characterized by brain plaques, tangles, and cognitive impairment. AD... more Alzheimer's disease (AD) is characterized by brain plaques, tangles, and cognitive impairment. AD is one of the most common age-related dementias in humans. Progress in characterizing AD and other age-related disorders is hindered by a perceived dearth of animal models that naturally reproduce diseases observed in humans. Mice and nonhuman primates are model systems used to understand human diseases. Still, these model systems lack many of the biological characteristics of Alzheimer-like diseases (e.g., plaques, tangles) as they grow older. In contrast, companion animal models (cats and dogs) age in ways that resemble humans. Both companion animal models and humans show evidence of brain atrophy, plaques, and tangles, as well as cognitive decline with age. We embrace a One Health perspective, which recognizes that the health of humans is connected to those of animals, and we illustrate how such a perspective can work synergistically to enhance human and animal health. A comparative biology perspective is ideally suited to integrate insights across veterinary and human medical disciplines and solve long-standing problems in aging. O ne Health is the concept that cross-disciplinary approaches that bring humans, animals, and their shared environments together can synergistically resolve problems afflicting humans and animals 1. One Health recognizes that the health of humans is connected to those of animals and the environment. One Health is frequently discussed in the context of infectious diseases. For example, environmental degradation and ecological disruption can promote zoonotic diseases (i.e., diseases transmissible across species), which negatively impact human health. A One Health approach has much broader implications for human health than simply reducing zoonotic transmission 2-4. A One Health perspective can positively impact our understanding of non-transmissible diseases shared by humans and other species (Fig. 1a). The fields of evolutionary and comparative biology are ideally suited to bridge veterinary and human medicine disciplines to improve our understanding of diseases affecting humans and animals 3. Companion animals, which are domesticated dogs and cats maintained as household pets (Table 1 and Supplementary Data 1), suffer from many diseases also observed in humans. Like humans, companion animals suffer from cancer, aging, obesity, heart disease, diabetes, and kidney disease 5. Veterinary and human medicine are focused on identifying and treating similar diseases, but these two fields rarely interact. Nevertheless, there are groundbreaking examples where treatments developed for companion animals have yielded concrete benefits to human
Journal of Human Evolution, Apr 1, 2013
The neuronal composition of the insula in primates displays a gradient, transitioning from granul... more The neuronal composition of the insula in primates displays a gradient, transitioning from granular neocortex in the posterior-dorsal insula to agranular neocortex in the anterior-ventral insula with an intermediate zone of dysgranularity. Additionally, apes and humans exhibit a distinctive subdomain in the agranular insula, the frontoinsular cortex (FI), defined by the presence of clusters of von Economo neurons (VENs). Studies in humans indicate that the ventral anterior insula, including agranular insular cortex and FI, is involved in social awareness, and that the posterodorsal insula, including granular and dysgranular cortices, produces an internal representation of the body's homeostatic state. We examined the volumes of these cytoarchitectural areas of insular cortex in 30 primate species, including the volume of FI in apes and humans. Results indicate that the whole insula scales hyperallometrically (exponent = 1.13) relative to total brain mass, and the agranular insula (including FI) scales against total brain mass
Progress in Brain Research, 2023
Short-term memory is implicated in a range of cognitive abilities and is critical for understandi... more Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory ability, we tested 421 non-human primates across 41 species in a pre-registered, experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. However, interdependencies between phylogeny and socioecology of a given species present an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. The dataset corresponding to the study is freely accessible and constitutes an important resource for studying the ev...
Neuroscience & Biobehavioral Reviews, Mar 1, 2022
Research on the origin of vision and vision loss in naturally "blind" animal species can reveal t... more Research on the origin of vision and vision loss in naturally "blind" animal species can reveal the tasks that vision fulfills and the brain's role in visual experience. Models that incorporate evolutionary history, natural variation in visual ability, and experimental manipulations can help disentangle visual ability at a superficial level from behaviors linked to vision but not solely reliant upon it, and could assist the translation of ophthalmological research in animal models to human treatments. To unravel the similarities between blind individuals and blind species, we review concepts of 'blindness' and its behavioral correlates across a range of species. We explore the ancestral emergence of vision in vertebrates, and the loss of vision in blind species with reference to an evolution-based classification scheme. We applied phylogenetic comparative methods to a mammalian tree to explore the evolution of visual acuity using ancestral state estimations. Future research into the natural history of vision loss could help elucidate the function of vision and inspire innovations in how to address vision loss in humans.
Journal of comparative neurology, Jan 15, 2014
In this study, we describe an atypical neuroanatomical feature present in several primate species... more In this study, we describe an atypical neuroanatomical feature present in several primate species that involves a fusion between the temporal lobe (often including Heschl's gyrus in great apes) and the posterior dorsal insula, such that a portion of insular cortex forms an isolated pocket medial to the Sylvian fissure. We assessed the frequency of this fusion in 56 primate species (including apes, Old World monkeys, New World monkeys, and strepsirrhines) using either magnetic resonance images or histological sections. A fusion between temporal cortex and
Elsevier eBooks, 2007
We describe and evaluate the methods used to reconstruct the central nervous system (CNS) of exti... more We describe and evaluate the methods used to reconstruct the central nervous system (CNS) of extinct hominin taxa. Overviews of each hominin taxon are provided, focusing on evidence related to the evolution of the CNS. Trends in the evolution of the hominin CNS are investigated using these data. Encephalization in the hominin clade may have begun as early as Australopithecus afarensis and Au. africanus, but it is only with the appearance of Homo rudolfensis and H. habilis that both absolute and relative brain size have departed from a Pan-like condition. Brain size increase and the appearance of some aspects of modern humanlike brain morphology occur in at least two hominin lineages, Paranthropus and Homo, which have absolutely and relatively larger brains than Australopithecus. However, only fossil Homo taxa show a substantial increase in brain size and a shift to a modern humanlike brain morphology.
American Journal of Physical Anthropology, Mar 1, 2020
Cerebral Cortex, Sep 23, 2009
The visual cortex is the largest sensory modality representation in the neocortex of humans and c... more The visual cortex is the largest sensory modality representation in the neocortex of humans and closely related species, and its size and organization has a central role in discussions of brain evolution. Yet little is known about the organization of visual brain structures in the species closest to humans-the apes-thus, making it difficult to evaluate hypotheses about recent evolutionary changes. The primate visual cortex is comprised of numerous cytoarchitectonically distinct areas, each of which has a specific role in the processing of visual stimuli. We examined the histological organization of striate (V1) and 2 extrastriate (V2 and ventral posterior) cortical areas in humans, 5 ape species, and a macaque. The cytoarchitectural patterns of visual areas were compared across species using quantitative descriptions of cell volume densities and laminar patterns. We also investigated potential scaling relationships between cell volume density and several brain, body, and visual system variables. The results suggest that interspecific variability in the cytoarchitectural organization of visual system structures can arise independently of global brain and body size scaling relationships. In particular, species-specific differences in cell volume density seem to be most closely linked to the size of structures in the visual system.
Frontiers in Psychology, Mar 22, 2023
We sought to understand how the perception of personal space is influenced by different levels of... more We sought to understand how the perception of personal space is influenced by different levels of social density, spatial density, and type of window-view in South Korean and United Kingdom workplaces. We employed virtual reality to simulate shared and single occupancy offices. We obtained personal space estimations using a virtual disc around the participant which could be extended and retracted, inside the simulation, to indicate perceived amount of personal space, and compared this measure to questionnaire-based estimations. We found that in both cultures participants experienced greater perceived personal space (1) when in a sparse rather than dense office and (2) having a view of the city outside the office. However, British, but not Korean, participants had significantly higher personal space estimations in single occupancy offices than in shared offices. These results suggest subtle cross-cultural differences in workplace experience, that could only be investigated using virtual reality.
Visual-to-auditory sensory substitution devices (SSDs) provide improved access to the visual envi... more Visual-to-auditory sensory substitution devices (SSDs) provide improved access to the visual environment for the visually impaired by converting images into auditory information. Research is lacking on the mechanisms involved in processing data that is perceived through one sensory modality, but directly associated with a source in a different sensory modality. This is important because SSDs that use auditory displays could involve binaural presentation requiring both ear canals, or monaural presentation requiring only onebut which ear would be ideal? SSDs may be similar to reading, as an image (printed word) is converted into sound (when read aloud). Reading, and language more generally, are typically lateralised to the left cerebral hemisphere. Yet, unlike symbolic written language, SSDs convert images to sound based on visuospatial properties, with the right cerebral hemisphere potentially having a role in processing such visuospatial data. Here we investigated whether there is a hemispheric bias in the processing of visual-to-auditory sensory substitution information and whether that varies as a function of experience and visual ability. We assessed the lateralization of auditory processing with two tests: a standard dichotic listening test and a novel dichotic listening test created using the auditory information produced by an SSD, The vOICe. Participants were tested either in the lab or online with the same stimuli. We did not find a hemispheric bias in the processing of visualto-auditory information in visually impaired, experienced vOICe users. Further, we did not find any difference between visually impaired, experienced vOICe users and sighted novices in the hemispheric lateralization of visual-to-auditory information processing. Although standard dichotic listening is lateralised to the left hemisphere, the auditory processing of images in SSDs is bilateral, possibly due to the increased influence of right hemisphere processing. Auditory SSDs might therefore be equally effective with presentation to either ear if a monaural, rather than binaural, presentation were necessary.
Frontiers in computer science, Feb 13, 2023
Here we sought to understand how perceived personal space is influenced by a number of variables ... more Here we sought to understand how perceived personal space is influenced by a number of variables that could influence Indoor Environmental Quality (IEQ); specifically, we tested how di erent levels of social density, spatial density, noise presence, and type of view impact the appreciation of personal space in a shared o ce environment. We employed virtual reality (VR) to simulate shared and single occupancy o ces and devised a novel measure of personal space estimation. We also used a traditional personal space satisfaction score. Participants experienced greater perceived personal space when () in a sparsely populated rather than a dense o ce, () in a private o ce rather than an open plan o ce, and () having any view outside of the o ce. We did not find an e ect of the presence of noise or increased social density (with spatial density held constant) on the perception of personal space.
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Papers by Alexandra A de Sousa