scholarly journals Investigating self-recognition in bonobos: mirror exposure reduces looking time to self but not unfamiliar conspecifics

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9685
Author(s):  
Gladez Shorland ◽  
Emilie Genty ◽  
Jean-Pascal Guéry ◽  
Klaus Zuberbühler

The question of whether animals have some sort of self-awareness is a topic of continued debate. A necessary precondition for self-awareness is the ability to visually discriminate the self from others, which has traditionally been investigated through mirror self-recognition experiments. Although great apes generally pass such experiments, interpretations of results have remained controversial. The aim of this study was to investigate how bonobos (Pan paniscus) respond to different types of images of themselves and others, both before and after prolonged mirror exposure. We first presented presumably mirror-naive subjects with representations of themselves in three different ways (mirror image, contingent and non-contingent video footage) as well as representations of others (video footage of known and unknown conspecifics). We found that subjects paid significantly less attention to contingent images of themselves (mirror image, video footage) than to non-contingent images of themselves and unfamiliar individuals, suggesting they perceived the non-contingent self-images as novel. We then provided subjects with three months of access to a large mirror centrally positioned in the enclosure. Following this manipulation, subjects showed significantly reduced interest in the non-contingent self-images, while interest in unknown individuals remained unchanged, suggesting that the mirror experience has led to a fuller understanding of their own self. We discuss implications of this preliminary investigation for the on-going debate on self-awareness in animals.

2018 ◽  
Author(s):  
Masanori Kohda ◽  
Takashi Hotta ◽  
Tomohiro Takeyama ◽  
Satoshi Awata ◽  
Hirokazu Tanaka ◽  
...  

AbstractThe ability to perceive and recognise a reflected mirror image as self (mirror self-recognition, MSR) is considered a hallmark of cognition across species. Although MSR has been reported in mammals and birds, it is not known to occur in any other major taxon. A factor potentially limiting the ability to test for MSR is that the established assay for MSR, the mark test, shows an interpretation bias towards animals with the dexterity (or limbs) required to touch a mark. Here, we show that the cleaner wrasse fish, Labroides dimidiatus, passes through all phases of the mark test: (i) social reactions towards the reflection, (ii) repeated idiosyncratic behaviours towards the mirror (contingency testing), and (iii) frequent observation of their reflection. When subsequently provided with a coloured tag, individuals attempt to remove the mark in the presence of a mirror but show no response towards transparent marks, or to coloured marks in the absence of a mirror. This remarkable finding presents a challenge to our interpretation of the mark test – do we accept that these behavioural responses in the mark test, which are taken as evidence of self-recognition in other species, mean that fish are self-aware? Or do we conclude that these behavioural patterns have a basis in a cognitive process other than self-recognition? If the former, what does this mean for our understanding of animal intelligence? If the latter, what does this mean for our application and interpretation of the mark test as a metric for animal cognitive abilities?


1997 ◽  
Vol 84 (2) ◽  
pp. 355-370 ◽  
Author(s):  
Ethel Tobach ◽  
Alexander J. Skolnick ◽  
Isobel Klein ◽  
Gary Greenberg

Reports on self-recognition in great apes have been mostly derived from experimental studies of mirror behavior (mark test) requiring anesthetization of the animals. We investigated a relatively noninvasive technique to study this behavior. In two experiments with a group of captive orangutans (1 adult male, 3 adult females, 1 juvenile male, and 1 juvenile female), we presented combinations of blank posters, life-size portraits of each individual in the group, a mirror, and videos. Durations of viewing and patterns of viewing were recorded. The prominent features of the viewing were the differences among the individuals in frequency, duration, and pattern of viewing. Some evidence of mirror-based self-referent behavior (behavior in which the activity of the animal with its body was related to the activity of the image in the mirror) was seen in the juvenile female, but more was seen in one adult female. This adult female spent the most time viewing the mirror and was the only animal to view her own portrait more than the other portraits in one session. In addition, she moved from one portrait to another, and back to the first, and to her own portrait and the mirror in a pattern resembling comparison of the two portraits as well as of her portrait and her mirror image. It is suggested that data based on self-referent behavior of the same animal during self-viewing in a mirror and during viewing of its self-portrait and on behavior observed in the mark test are worth further investigation.


1952 ◽  
Vol 98 (411) ◽  
pp. 326-329 ◽  
Author(s):  
Asenath Petrie

Three years ago at the last International Congress of Psychology I reported on a preliminary investigation of personality changes after the usual standard prefrontal leucotomy. This investigation was carrried out on 20 neurotic patients before and three months after the operation performed by Mr. McKissock (McKissock, 1943). An extensive group of objective personality tests were chosen to define the factors of “Neuroticism” and “Introversion” as described by Eysenck (1947), which to all intents and purposes are equivalent to Cattell's (1950) factors C and F. In addition, the following intelligence tests were used: the Wechsler Scale, Porteus Mazes, and the proverbs from the Stanford Binet. The changes found provided us with some evidence in support of the hypothesis with which the investigation had been planned. This was that as a result of this type of incision in the frontal lobe there was a decrease in “Neuroticism,” a decrease in “Introversion” and a decrease in certain aspects of intelligence (Petrie, 1949a).Since then a further 50 patients have been examined before and after operations on the frontal lobes, bringing the total to 70. Most of these were severe neurotics attending the psychiatric department of Dr. Desmond Curran at St. George's Hospital, London. Only those changes will be referred to as an alteration in personality where the probability is less than one in twenty that they could have occurred by chance.


2021 ◽  
Vol 8 (3) ◽  
pp. 391-404
Author(s):  
Kathrin S. Kopp ◽  
Sonja J. Ebel ◽  
Roman M. Wittig ◽  
Daniel B. M. Haun ◽  
Catherine Crockford

Mirror self-recognition (MSR) is considered an indicator of self-awareness. Standardized mirror tests reveal compelling evidence for MSR in a few non-human species, including all great apes. However, substantial inter-individual variation of MSR within species resulted in an ongoing methodological controversy, questioning the appropriateness of standard MSR tests for cross-species comparisons. Lack of motivation, in particular, is discussed as one possible cause for false negative results. Here, we compare the spontaneous behavioral response of 47 zoo-housed chimpanzees (Pan troglodytes) to (i) standard body-sized, stationary mirrors and (ii) small, portable hand mirrors. We predicted that the monopolizability and maneuverability of small mirrors increase the chances of identifying MSR across a larger proportion of individuals. Chimpanzees both revealed a substantially higher frequency of general mirror-related behaviors and engaged in significantly more and longer behaviors specifically indicating MSR when provided with small mirrors compared to a large mirror. Handheld mirrors provide a more sensitive measure for MSR within and likely between primate species than the traditional large mirrors, and thereby are a potentially valuable tool for studying self-awareness across species.


2019 ◽  
Vol 38 (2) ◽  
pp. 406-416 ◽  
Author(s):  
Marcel Mikeska ◽  
Jan Najser ◽  
Václav Peer ◽  
Jaroslav Frantík ◽  
Jan Kielar

Gas from the gasification of pellets made from renewable sources of energy or from lower-quality fuels often contains a number of pollutants. This may cause technical difficulties during the gas use in internal combustion gas engines used for energy and heat cogeneration. Therefore, an adequate system of gas cleaning must be selected. In line with such requirements, this paper focuses on the characterization and comparison of gases produced from different types of biomass during gasification. The biomass tested was wood, straw, and hay pellets. The paper gives a detailed description and evaluation of the measurements from a fix-bed gasifier for the properties of the produced gases, raw fuels, tar composition, and its particle content before and after the cleaning process. The results of elemental composition, net calorific value, moisture, and ash content show that the cleaned gases are suitable for internal combustion engine-based cogeneration systems, but unsuitable for gas turbines, where a different cleaning technology would be needed.


2021 ◽  
Vol 11 (5) ◽  
pp. 590
Author(s):  
Raeghan L. Mueller ◽  
Jarrod M. Ellingson ◽  
L. Cinnamon Bidwell ◽  
Angela D. Bryan ◽  
Kent E. Hutchison

In recent years of expanding legalization, older adults have reported the largest increase in cannabis use of any age group. While its use has been studied extensively in young adults, little is known about the effects of THC in older adults and whether the risks of cannabis might be different, particularly concerning intoxication and cognition. The current study investigated whether age is associated with the deleterious effects of THC on cognitive performance and other behavioral measures before and after ad libitum self-administration of three different types of cannabis flower (THC dominant, THC + CBD, and CBD dominant). Age groups consisted of young adults (ages 21–25) and older adults (ages 55–70). Controlling for pre-use scores on all measures, the THC dominant chemovar produced a greater deleterious effect in younger adults compared with older adults in tests of learning and processing speed, whereas there were no differences between old and young in the effects of the other chemovars. In addition, the young group reported greater cannabis craving than the older group after using the THC chemovar. Consistent with some reports in the preclinical literature, the findings suggest that older adults may be less sensitive to the effects of THC on cognitive and affective measures.


Author(s):  
Bing Song ◽  
Xiao-Yong Yan ◽  
Suoyi Tan ◽  
Bin Sai ◽  
Shengjie Lai ◽  
...  

Understanding the spatial interactions of human mobility is crucial for urban planning, traffic engineering, as well as for the prevention and control of infectious diseases. Although many models have been developed to model human mobility, it is not clear whether such models could also capture the traveling mechanisms across different time periods (e.g. workdays, weekends or holidays). With one-year long nationwide location-based service (LBS) data in China, we investigate the spatiotemporal characteristics of population movements during different time periods, and make thorough comparisons for the applicability of five state-of-the-art human mobility models. We find that population flows show significant periodicity and strong inequality across temporal and spatial distribution. A strong “backflow” effect is found for cross-city movements before and after holidays. Parameter fitting of gravity models reveals that travels in different type of days consider the attractiveness of destinations and cost of distance differently. Surprisingly, the comparison indicates that the parameter-free opportunity priority selection (OPS) model outperforms other models and is the best to characterize human mobility in China across all six different types of days. However, there is still an urgent need for development of more dedicated models for human mobility on weekends and different types of holidays.


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