Sneaking a peek: pigeons use peripheral vision (not mirrors) to find hidden food

A small number of species are capable of recognizing themselves in the mirror when tested with the mark-and-mirror test. This ability is often seen as evidence of self-recognition and possibly even self-awareness. Strangely, a number of species, for example monkeys, pigs and dogs, are unable to pass the mark test but can locate rewarding objects by using the reflective properties of a mirror. Thus, these species seem to understand how a visual reflection functions but cannot apply it to their own image. We tested this discrepancy in pigeons—a species that does not spontaneously pass the mark test. Indeed, we discovered that pigeons can successfully find a hidden food reward using only the reflection, suggesting that pigeons can also use and potentially understand the reflective properties of mirrors, even in the absence of self-recognition. However, tested under monocular conditions, the pigeons approached and attempted to walk through the mirror rather than approach the physical food, displaying similar behavior to patients with mirror agnosia. These findings clearly show that pigeons do not use the reflection of mirrors to locate reward, but actually see the food peripherally with their near-panoramic vision. A re-evaluation of our current understanding of mirror-mediated behavior might be necessary—especially taking more fully into account species differences in visual field. This study suggests that use of reflections in a mirrored surface as a tool may be less widespread than currently thought.     

Self-recognition: a study of a population without mirrors

The study of the influence of familiarity with mirrors on children's capacity to identify their reflected images permitted differentiation between two problems that confront the child in the mirror situation: (a) the identity of the image and (b) the capacity to relate mirror space to real space. Sixty children, 6 to 26 months old, without previous experience with mirrors, were observed systematically while discovering their mirror image and a reflected object. Their behavior was compared to a control group with habitual mirror familiarity. The results suggest that (a) self-recognition in the mirror is independent of the child's familiarity with reflecting surfaces and (b) the capacity to relate mirror to real space seems to be strongly influenced by previous experience with mirrors.     

Visual self-recognition in mirrors and live videos: Evidence for a developmental asynchrony

Three experiments (N = 123) investigated the development of live-video self-recognition using the traditional mark test. In Experiment 1, 24-, 30- and 36-month-old children saw a live video image of equal size and orientation as a control group saw in a mirror. The video version of the test was more difficult than the mirror version with only the oldest children's performance approaching ceiling. In Experiment 2, most 24-month-olds showed self-recognition when presented with a TV-set that featured a mirror in place of a screen. This finding does not substantiate the possibility that expectations about what appears on TV are responsible for the asynchrony. In Experiment 3, children were given a mark-test involving only their legs. Again, a video version was more difficult than previously reported performance with mirrors, suggesting that the impossibility of eye-contact in video cannot explain this developmental asynchrony. The findings suggest that self-recognition can be added to the growing list of contexts in which 2-year-olds display what has been called a “video deficit” [Anderson, D. R., & Pempek, T. A. (2005). Television and very young children. American Behavioral Scientist, 48, 505–532].     

Development of Visual Self-Recognition in Infancy

This research investigated the development of visual self-recognition in infancy. Prior research has investigated infants' self-perception in mirror or live video stimulation in which visual-proprioceptive contingency is available. No research, however, has addressed the young infants' ability to recognize his or her own face on the basis of featural information. Infants of 2, 3, 5, and 8 months of age viewed video films of their own face side by side with that of a peer. The faces were presented under both moving and still conditions. Results indicated that by the age of 3 months, infants discriminated the self from the peer and demonstrated a significant visual preference for the face of the peer. This suggests that infants already are familiar with their own visual appearance by 3 months of age. Given that most infants had received at least daily exposure to their mirror image, it was hypothesized that featural recognition of the self developed through mirror exposure. It was further suggested that viewing one's face in the context of the contingency provided by the mirror serves as a basis for perceiving the face as belonging to the self.     

Development of self-recognition in chimpanzees (Pan troglodytes).

Chimpanzees (Pan troglodytes) demonstrate the ability to recognize themselves in mirrors, yet investigations of the development of self-recognition in chimpanzees are sparse. Twelve young chimpanzees, grouped by age, were given mirror exposure and tested for self-recognition and contingent movement. All 6 juveniles, 4 and 5 years old, exhibited mirror-guided, mark-directed behavior and clear evidence of self-recognition. In contrast, among the infants, only the oldest group of 2 1/2-year-olds exhibited clear evidence of self-recognition. All chimpanzees exhibited both self-directed behaviors and contingent movements. These results suggest that self-recognition occurs at a slightly older age in chimpanzees than in human infants. In humans, self-recognition is linked with other cognitive abilities. The results conform to the general pattern that great apes exhibit many cognitive skills comparable to those of 2-year-old humans.     

Shadow recognition in human infants

Seventy-five children of five different age groups (ranging from 13–18 to 37–42 months of age) were tested using various nonverbal indices for (a) their ability to respond to shadowed information about objects other than themselves, (b) their ability to manipulate their own shadow, and (c) their ability to recognize their own shadow as evidenced by the explicit use of shadowed information about themselves to respond to themselves. The results show that although infants are aware of shadows and show signs of having mastered the concept of shadow permanence at a fairly early age, compelling evidence of shadow self-recognition is developmentally delayed relative to what has been reported for the onset of mirror self-recognition, with most infants failing to show positive evidence prior to 3 years of age. The results are discussed in light of psychological differences that may exist between shadows and mirrors. Prior involvement and/or tutoring by parents about shadows had no effect on the emergence of shadow recognition.     

The Alienating Mirror: Toward a Hegelian Critique of Lacan on Ego-Formation

This article brings out certain philosophical difficulties in Lacan’s account of the mirror stage, the initial moment of the subject’s development. For Lacan, the “original organization of the forms of the ego” is “precipitated” in an infant’s self-recognition in a mirror image; this event is explicitly prior to any social interactions. A Hegelian objection to the Lacanian account argues that social interaction and recognition of others by infants are necessary prerequisites for infants’ capacity to recognize themselves in a mirror image. Thus mutual recognition with another, rather than self-recognition in a mirror, is what makes possible subsequent ego-formation and self-consciousness. This intersubjective critique suggests that many of the psychoanalytic consequences that Lacan derives from the mirror stage (e.g., alienation, narcissism, and aggressivity) may need to be rethought.

A social cichlid fish failed to pass the mark test

Since the pioneering work in chimpanzees, mirror self-recognition (MSR), the ability to recognise oneself in a mirror, has been reported in great apes, Asian elephants, dolphins, and some social birds using the mark test, in which animals that possess MSR touch an imperceptible mark on their own bodies only when a mirror is present. However, giant pandas, which are solitary, failed to pass the mark test, suggesting that MSR evolved solely in highly social animals. In contrast to the increasing evidence of MSR in mammals and birds, little is known about MSR in fish. A Tanganyikan cichlid, Neolamprologus pulcher, is a good candidate for study because these fish live in highly social groups and recognise conspecifics about as rapidly as primates. We examined their responses to a mirror image and tested whether N. pulcher could pass the mark test. When the mirror was first exposed, they stayed in front of the mirror and exhibited aggressive behaviour towards the mirror image. These social behaviours suggested that the focal fish perceived the mirror image as an unfamiliar conspecific. The social responses decreased over the following days, as has generally been the case in animals with MSR. After mark injection, we found no increase in scraping behaviour or prolonged observation of the marked side. These results show a lack of contingency checking and mark-directed behaviours, meaning that N. pulcher failed to pass the mark test and did not recognise their self-image in the mirror.     

Tracking responses related to self-recognition: a frequency comparison of responses to mirrors, photographs, and videotapes by cotton top tamanins (Saguinus oedipus)

The frequency of responses cotton top tamarins (Saguinus oedipus) emitted indicative of self-recognition to a mirror was compared with the frequencies of responses emitted to digitized photographs of tamarins (Experiment 1) and to videotapes of real-time or prior tamarin action (Experiment 2). Results indicated more attentional responses toward the mirror in both studies, but behavioral indices of self-recognition were not consistently generated by the mirror. The 2 experiments confirmed that real-time self-reflection is a condition that generates heightened attention and rare examples of particular mirror-specific behaviors in tamarins.     

Social awareness and early self-recognition

Self-recognition by 86 children (14-52months) was assessed using the mirror mark test in two different social contexts. In the classic mirror task condition, only the child was marked prior to mirror exposure (Classic condition). In the social norm condition, the child, experimenter, and accompanying parent were marked prior to the child's mirror exposure (Norm condition). Results indicate that in both conditions children pass the test in comparable proportion, with the same increase as a function of age. However, in the Norm condition, children displayed significantly more hesitation while removing the mark, often touching it without removing it or, if so, promptly putting the mark back onto their forehead. In the Classic condition, only one child showed such hesitation. These results suggest that from the outset, mirror self-recognition can refer to social awareness. This link is interpreted as the trademark of human self-consciousness, a deeply rooted "looking glass" self-awareness.     

No evidence for infants’ contingency detection as a precursor of toddlers’ self-recognition

The aim of the present study was to assess the relationship between infants’ contingency preference and detection in the first year of life and toddlers’ mirror and video self-recognition in the second and third year of life in a longitudinal study (N = 113). Six- and 9-month-olds’ preference for a noncontingent over a perfect contingent view (contingency preference) and their differentiation between the two views – indicated by longer looking times to either view – (contingency detection) were assessed in two contingency tasks. A mirror-face-recognition task and a mirror-leg-recognition task were conducted at 18 months. A video-face-recognition task and a mirror-leg-recognition task were conducted at 26 months. Results revealed no predictive relationships between infants’ contingency preference and detection in the first year of life and their ability to recognize themselves in a mirror or on a video monitor in the second and third year of life. This finding supports the notion that self-recognition emerges independently from the experience of contingencies (Bischof-Köhler, 1991, 2012). Thus, a representation of the self seems to rely on more than a specific developmental pathway leading from contingency preference and detection to self-recognition.     

No evidence for self-recognition in a small passerine,the great tit (<Emphasis Type="Italic">Parus major</Emphasis>) judged from the mark/mirror test

Self-recognition is a trait presumed to be associated with high levels of cognition and something previously considered to be exclusive to humans and possibly apes. The most common test of self-recognition is the mark/mirror test of whether an animal can understand that it sees its own reflection in a mirror. The usual design is that an animal is marked with a colour spot somewhere on the body where the spot can only be seen by the animal by using a mirror. Very few species have passed this test, and among birds, only magpies have been affirmatively demonstrated to pass it. In this study, we tested great tits (Parus major), small passerines, that are known for their innovative foraging skills and good problem-solving abilities, in the mirror self-recognition test. We found no indication that they have any ability of this kind and believe that they are unlikely to be capable of this type of self-recognition.     

Responses to mirror image stimulation and assessment of self-recognition in mirror- and peer-reared stumptail macaques

Ten stumptail macaques (Macaca arctoides), varying in experience of conspecifics and mirrors from no experience to extensive experience throughout infancy, were tested for reactions to mirror image stimulation. Monkeys reared only with mirrors or only with one other monkey were highly responsive to their reflections, exhibiting mostly positive behaviour. Monkeys with experience of both a fully accessible cagemate and mirrors were intermediate in responsiveness, while monkeys reared with mirrors but given experience of a live conspecific behind a transparent partition responded least of all to the mirror. Monkeys reared with no experience of conspecifics at all were the most responsive. Rearing experiences influence reactions to social stimuli such as mirror image stimulation, and considerations of the novelty and complexity of the stimuli are important. Despite the most extensive exposure to mirrors yet reported, none of the monkeys showed any evidence of self-recognition.     

Self-recognition and self-regulation: the relationship with socialization trajectories and children's sex

The initial process of self development involves interaction with others and the establishment of relationships taking different paths depending on the socio-cultural context. Self-recognition and self-regulation are considered manifestations of this development between 18 and 24 months of age. This study aimed at analyzing the relationship between these two aspects, maternal beliefs about autonomy and relatedness, as well as identifying differences between boys and girls in this developmental stage. Participants were 94 mothers of different educational levels and their children of 17-22 months of age in two Brazilian cities. Socialization Goals Inventory and Parental Practices in the First Year Inventory were used to collect data on mothers' beliefs. Children performed tasks related to self-recognition (the mirror test) and self-regulation (compliance to requests). The group of mothers studied valued both autonomy and interdependence. Children's responses are consistent with a perspective of relational autonomy, which value both independence and interdependence. Differences were found in relation to sex in both self-recognition and self-regulation, and baby girls showed superior performance than boys in both tasks.     

A modified mark test for own-body recognition in pig-tailed macaques (Macaca nemestrina)

Classic mirror self-recognition mark tests involve familiarizing the subject with its mirror image, surreptitiously applying a mark on the subject’s eyebrow, nose, or ear, and measuring self-directed behaviors toward the mark. For many non-human primate species, however, direct gaze at the face constitutes an aggressive and threatening signal. It is therefore possible that monkeys fail the mark test because they do not closely inspect their faces in a mirror and hence they have no expectations about their physical appearance. In the current study, we prevented two pig-tailed macaques (Macaca nemestrina) from seeing their own faces in a mirror, and we adopted a modified version of the classic mark test in which monkeys were marked on the chest, a body region to which they normally have direct visual access but that in the current study was visible only via a mirror. Neither monkey tried to touch the mark on its chest, possibly due to a failure to understand the mirror as a reflective surface. To further the monkeys’ understanding of the mirror image, we trained them to reach for food using the mirror as the only source of information. After both monkeys had learned mirror-mediated reaching, we replicated the mark test. In this latter phase of the study, only one monkey scratched the red dye on the chest once. The results are consistent with other findings suggesting that monkeys are not capable of passing a mark test and imply that face and body recognition rely on the same cognitive abilities.     

"When did I learn and when shall I act?": The developmental relationship between episodic future thinking and memory

This study investigated the development of the ability to reflect on one’s personal past and future. A total of 64 4- to 6-year-olds received tasks of delayed self-recognition, source memory, delay of gratification, and a newly developed task of future-oriented action timing. Although children’s performance on delayed self-recognition, source memory, and action timing improved with age, their performance on delay of gratification did not. Children’s errors in source memory and action timing were solely and strongly associated with each other in older children (5–6 years) even after controlling for age and verbal ability. Results are discussed in terms of mental time travel underlying episodic memory and future thinking that includes both the projection of oneself into the past and future and the appreciation of events’ temporal relations.     

Observations on the behavior of gibbons (Hylobates leucogenys, H. gabriellae, and H. lar) in the presence of mirrors

Three captive gibbons (Hylobates leucogenys, H. gabriellae, and H. lar) were videotaped in the course of longitudinal exposure to mirrors introduced into their familiar cage or island housing situation. The gibbons, which differed in age, sex, species, and rearing condition, exhibited great individual differences in their behavioral reactions to mirrors, spanning from a minimal reaction dominated by social responses to a dramatic sequence of progressive behavioral change that featured a variety of contingency testing behaviors and included mirror-mediated, self-directed behavior. Additional information on the mirror competence of gibbons was provided by modified mark tests and a hidden object task. The results are discussed in relation to current criteria for self-recognition in primates and factors involved in individual and species differences in reactions to mirror exposure.     

Mirror self-recognition in ghost crab (Ocypode quadrata)

Animal Cognition - Mirror self-recognition has been examined primarily in vertebrate species, largely through the use of a mirror mark test. Recently, however, there has been growing interest in...     

Distinguishing three levels in explicit self-awareness

This paper focuses on the development of explicit self-awareness in children. Mirror self-recognition has been the most popular paradigm used to assess this ability in children. Nevertheless, according to Rochat (2003), there are, at least, three different levels of explicit self-awareness. We therefore designed three different self-recognition tasks, each corresponding to one of these levels (a mirror self-recognition task, a picture self-recognition task and a masked self-recognition task). We observed a decrease in performance across the three tasks. This supports a developmental scale in self-awareness. Besides, the masked self-recognition performance makes it possible to assess the final and the most sophisticated level of self-awareness, i.e. the external self. To our best knowledge, this task is the first attempt to evaluate the external self in preverbal children. Our results indicate that 22-month old children show awareness of their external self or, at least, that this ability is in the process of being acquired.     

自闭症幼儿的视觉性自我认知实验研究

通过对平均心理年龄为23个月的6名自闭症幼儿的实验研究．甄别他们是否能从视觉上进行自我与他人的分化认知并进一步探索自闭症幼儿对镜像自我认知与录像自我认知上的差异;以秒为单位．对实验结果和过程进行了编码分析。结果表明：这6名幼儿在看自己的录像时,比看同伴的表现出更多的关注和喜悦;对录像的自我进行认知寸表现出更大的关注和积极情绪。由此推断他们已具有初步的自我认知。