Biology subjects

Semple, S.

Publications and source records attributed to Semple, S..

5 recordsLinked to original sources

bioRxiv2023

Do Goats Recognise Humans Cross-Modally?

Recognition plays a key role in the social lives of gregarious species, enabling animals to distinguish among social partners and tailor their behaviour accordingly. As domesticated animals regularly interact with humans, as well as members of their own species, we might expect mechanisms used to discriminate between conspecifics to also apply to humans. Given that goats can combine visual and vocal cues to recognize one another, we investigated whether this cross-modal recognition extends to discriminating among familiar humans. We presented 28 goats with facial photographs of familiar people and two repeated playbacks of a voice, either congruent (from the same person) or incongruent with that photograph (from a different person). When cues were incongruent, violating their expectations, we expected goats to respond faster and for longer after playbacks and show increases in physiological arousal (increased heart rate and/or decreased heart rate variability). We found the increase in latency that goats took to respond as the playback series progressed was greater when the face and voice were incongruent. As differences were not as predicted and only observed in one response measured, our evidence is tentative, but the variation in latency to look between congruency conditions suggests goat cross-modal recognition extends to humans. If this is the case, not only would this further demonstrate the flexibility of complex recognition systems to discriminate among members of a very different species, but indicates goats can produce mental representations for familiar people, a key component of individual recognition.

animal behavior and cognition↗

bioRxiv2023

Goat Discrimination of Emotional Valence in the Human Voice

Reading another animals emotional state can enable receivers to anticipate their behavioural motivations, which is important in guiding interactions with that individual. For species living closely alongside humans, the emotional cues that people express can be almost as informative as those of conspecifics. Goats can discriminate differences in emotional valence present in another goats calls, and we investigated whether this ability extends to human speech. We presented goats with a habituation-dishabituation-rehabituation paradigm, where they experienced multiple playbacks of a familiar or unfamiliar human voice conveying a single emotional valence (e.g., angry; habituation phase), before the valence of the voice changed (e.g., happy; dishabituation phase) and then reversed again in-line with the habituation phase (e.g., angry; rehabituation phase). Over the habituation phase, goat behavioural responses decreased, showing evidence of having habituated to the playback stimuli presented. Following a change in emotional valence (dishabituation phase), although goats were overall less likely to respond, those that did looked for longer, suggesting they had perceived the shift in emotional content conveyed in human voice playbacks. We found no changes in physiological arousal (heart rate or heart rate variability) with shifts in playback valence. Goats, as a domesticated species, may have developed a sensitivity to our cues over their long association with humans, but the differences in individual behaviour towards the playback paradigm could highlight a role for learning and individual experience in particular on interspecific emotional communication.

animal behavior and cognition↗

bioRxiv2023

Observing Aggression Increases Aggression In Semi-Free Ranging Barbary Macaques

In many social living species, seeing conspecifics interacting can alter the behaviour of bystanders, leading to social contagion - the spread of behaviour or emotion among group members. Among primates, studies of a small number of species have explored bystanders responses to observing aggressive interactions, finding evidence that individuals that see such interactions are more likely to subsequently engage in aggressive behaviours themselves. To increase the taxonomic breadth of this body of research, working with semi-free ranging adult female Barbary macaques (Macaca sylvanus) at the Trentham Monkey Forest, Stoke-on-Trent, UK, we assessed bystanders responses to observing naturally occurring aggressive interactions. Data were collected under two conditions: (i) after observing an aggressive interaction between conspecifics and (ii) during a matched-control period, before which individuals did not observe aggression. Bystanders were significantly quicker to initiate an aggressive interaction themselves after observing an aggressive interaction than if they had not, providing evidence of behavioural contagion. There was no effect of observing aggression on the rates of self-directed behaviour (an indicator of anxiety), suggesting the negative emotional states associated with involvement in aggressive interactions did not spread to bystanders. The results of this study provide new insight into the nature and importance of visual contagion of behaviour among primates.

animal behavior and cognition↗

bioRxiv2020

Traffic-derived particulate matter and angiotensin-converting enzyme 2 expression in human airway epithelial cells

Background The mechanism for the association between traffic-derived particulate matter less than 10 microns (PM10) and cases of COVID-19 disease reported in epidemiological studies is unknown. To infect cells, the spike protein of SARS-CoV-2 interacts with angiotensin-converting enzyme 2 (ACE2) on host airway cells. Increased ACE2 expression in lower airway cells in active smokers, suggests a potential mechanism whereby PM10 increases vulnerability to COVID-19 disease.Objective To assess the effect of traffic-derived PM10 on human airway epithelial cell ACE2 expression in vitro.Methods PM10 was collected from Marylebone Road (London) using a kerbside impactor. A549 and human primary nasal epithelial cells were cultured with PM10 for 2 h, and ACE2 expression (median fluorescent intensity; MFI) assessed by flow cytometry. We included cigarette smoke extract as a putative positive control. Data were analysed by either Mann-Whitney test, or Kruskal-Wallis with Dunn’s multiple comparisons test.Results PM10 at 10 μg/mL, and 20 μg/mL increased ACE2 expression in A549 cells (P<0.05, 0.01 vs. medium control, respectively). Experiments using a single PM10 concentration (10 μg/mL), found increased ACE2 expression in both A549 cells (control vs. PM10, median (IQR) MFI; 470 (0.1 to 1114) vs 6217 (5071 to 8506), P<0.01), and in human primary epithelial cells (0 (0 to 591) vs. 4000 (2610 to 7853), P<0.05). Culture of A549 cells with 5% cigarette smoke extract increased ACE2 expression (n=4, 0 (0 to 28) vs. 9088 (7557 to 15831, P<0.05).Conclusion Traffic-related PM10 increases the expression of the receptor for SARS-CoV-2 in human respiratory epithelial cells.Competing Interest StatementThe authors have declared no competing interest.View Full Text

pharmacology and toxicology↗

bioRxiv2017

Experimental evidence that female rhesus macaques (Macaca mulatta) perceive variation in male facial masculinity

Among many primate species, face shape is sexually dimorphic, and male facial masculinity has been proposed to influence female mate choice and male-male competition by signalling competitive ability. However, whether conspecifics pay attention to facial masculinity has only been assessed in humans. In a study of free-ranging rhesus macaques, Macaca mulatta, we used a two-alternative look-time experiment to test whether females perceive male facial masculinity. We presented 107 females with pairs of images of male faces - one with a more masculine shape and one more feminine - and recorded their looking behaviour. Females looked at the masculine face longer than at the feminine face in more trials than predicted by chance. Although there was no overall difference in average look-time between masculine and feminine faces across all trials, females looked significantly longer at masculine faces in a subset of trials for which the within-pair difference in masculinity was most pronounced. Additionally, the proportion of time subjects looked toward the masculine face increased as the within-pair difference in masculinity increased. This study provides evidence that female macaques perceive variation in male facial shape, a necessary condition for intersexual selection to operate on such a trait. It also highlights the potential impact of perceptual thresholds on look-time experiments.

animal behavior and cognition↗