Cattle discriminate between familiar and unfamiliar conspecifics by using only head visual cues

Faces have features characteristic of the identity, age and sex of an individual. In the context of social communication and social recognition in various animal species, facial information is relevant for discriminating between familiar and unfamiliar individuals. Here, we present two experiments aimed at testing the ability of cattle (Bos taurus) to visually discriminate between heads (including face views) of familiar and unfamiliar conspecifics represented as 2D images. In the first experiment, we observed the spontaneous behaviour of heifers when images of familiar and unfamiliar conspecifics were simultaneously presented. Our results show that heifers were more attracted towards the image of a familiar conspecific (i.e., it was chosen first, explored more, and given more attention) than towards the image of an unfamiliar one. In the second experiment, the ability to discriminate between images of familiar and unfamiliar conspecifics was tested using a food-rewarded instrumental conditioning procedure. Eight out of the nine heifers succeeded in discriminating between images of familiar and unfamiliar conspecifics and in generalizing on the first trial to a new pair of images of familiar and unfamiliar conspecifics, suggesting a categorization process of familiar versus unfamiliar conspecifics in cattle. Results of the first experiment and the observation of ear postures during the learning process, which was used as an index of the emotional state, provided information on picture processing in cattle and lead us to conclude that images of conspecifics were treated as representations of real individuals.     

Effect of anosmia on reproduction in male and female wolves (Canis lupus)

Anosmia was produced in two female and three male wolves by transection of the olfactory peduncle and was confirmed by their inability to detect meat, urine, feces, anal-gland secretions, and fish emulsion. All operated animals continued to investigate the environment with their noses, to interact normally with other pack members, and to feed at levels which maintained presurgical body weights. No effect was found on reproductive physiology (females: estradiol or progesterone concentrations, ovulation, pregnancy or parturition; males: testosterone, testicular recrudescence or sperm numbers, motility or maturation). One anosmic female became dominant and although she urine-marked with a flexed leg, the rate was lower than typical for dominant females and perhaps contributed to her failure to pair-bond with the dominant male. One anosmic male raised-leg-urinated while competing for pack dominance and when kenneled away from other males. Precopulatory, copulatory, and maternal behavior were observed for one anosmic female and appeared normal. However, neither male that was sexually naive before surgery showed interest in proestrous or estrous females. The possibility that secondary degeneration of brain regions mediating sexual behavior was responsible for the failure of these males to respond was not supported. Not only was the lack of male sexual response the only serious deficit following transection, but the male which was sexually experienced prior to surgery did copulate successfully during his second postoperative breeding season despite continued anosmia. Chemosensory priming from female urine during the protracted proestrous phase, as well as urinary and vaginal odors during estrus, appear to be critical for induction of full sexual potency in sexually naive males. The importance of urine and vaginal secretions in the sexual response of experienced males is uncertain.     

Evidence that rats discriminate between familiar and unfamiliar putative urinary odorants of adult male conspecifics

Adam [1976; Lehman and Adams, 1977] suggested that a resident rat makes an olfactory comparison of cage odor and other rat odor prior to attacking an unfamiliar conspecific intruder. The findings of the present study are consistent with the notion that rats discriminate between familiar and unfamiliar putative urinary odorants Adult male albino rats were tested for preferences between areas treated with familiar urine (11 hours pretest exposure), unfamiliar urine (no pretest exposure), and untreated areas. Subjects (N = 12) preferred areas treated with familiar urine over ones treated with unfamiliar urine (p < 0.05). Also, they (N = 12 per preference-test group) preferred areas treated with either urine over untreated ones (familiar versus clean, p < 0.01; unfamiliar versus clean, p < 0.05).     

Phenomenological differences between familiar and unfamiliar odours

Unfamiliar odours are harder to discriminate than familiar odours. We explored the phenomenal basis of this difference. In experiments la and 1b, participants profiled odour quality for two sets of familiar and unfamiliar odours. In both cases unfamiliar odours were redolent of more odour qualities than familiar stimuli. In experiment 2, participants received (i) a set of familiar and unfamiliar odours and learnt their names, and (ii) a further set of familiar and unfamiliar odours to which they were exposed. Participants then profiled these stimuli as well as a further unexposed set of familiar and unfamiliar odours. Exposure, but not naming, led to a significantly smaller difference between the familiar and unfamiliar stimuli, in terms of their redolence to other odours, when compared to unexposed control stimuli. Unfamiliar exposed odours were also judged as less redolent than unexposed unfamiliar odours. These observations are consistent with a mnemonic basis for odour-quality perception.     

Recognizing familiar and unfamiliar faces

These experiments addressed why, in episodic-memory tests, familiar faces are recognized better than unfamiliar faces. Memory for faces of well-known public figures and unfamiliar persons was tested, not only with old/new recognition tests, in which initially viewed faces were discriminated from dis tractors, but also with tests of memory for specific information. These included: detail recall, in which a masked feature had to be described; orientation recognition, in which discrimination between originally seen faces and mirror-image reversals was required; and recognition and recall of labels for the public figures. Experiments 1 and 2 showed that memory for orientation and featural details was not robustly related either to facial familiarity or to old/new recognition rates. Experiment 3 showed that memory for labels was not the exclusive determinant of the famous-face advantage in recognition, since famous faces were highly recognizable even they were not labelable or when labels were forgotten. These results suggest that the familiarity effect, and face recognition in general, may reflect a nonverbal memory representation that is relatively abstract.     

熟悉面孔与陌生面孔识别的差异

摘 要：面孔识别包括熟悉面孔识别和陌生面孔识别,两者之间的差异已经得到了多方面的证明。神经生理学的研究发现,识别陌生面孔和熟悉面孔所激活的脑区存在差异,与识别陌生面孔相比,识别熟悉面孔的脑区活动范围更大,包括双侧前额叶、单侧颞叶、海马回、杏仁核、后扣带回和右下额叶。并且也存在脑电的差异,比如 N400和P600的差异。对陌生面孔和熟悉面孔识别具有相同影响的因素有：遮挡、倒置等;具有不同影响的因素有：视角、表情、内外部特征等。文章也探讨了陌生面孔变成熟悉面孔的过程,以及在这一过程中起主要作用的编码形式等。     

Domestic dogs (Canis lupus familiaris) are sensitive to the correlation between pitch and timbre in human speech

Animal Cognition - The perceived pitch of human voices is highly correlated with the fundamental frequency (f0) of the laryngeal source, which is determined largely by the length and mass of the...     

Canine responses to familiar and unfamiliar humans

Dogs were observed during controlled approaches by their owners and by strangers. Significant differences between the dogs' responses to their owners and their responses to strangers were found. These results supported the popular belief that dogs respond differently to different persons, and not merely to different situations in which persons are usually encountered.     

Food quantity discrimination in puppies (Canis lupus familiaris)

Animal Cognition - There is considerable evidence that animals are able to discriminate between quantities. Despite the fact that quantitative skills have been extensively studied in adult...     

Matching familiar and unfamiliar faces on identity and expression

Summary Subjects were asked to decide whether or not simultaneously presented photographs of pairs of faces were pictures of the same person or of different people (identity matching), or to decide whether or not the pairs of face showed the same expressions or different expressions (expression matching). Faces of familiar and unfamiliar people were used as stimuli. For identity matching, reaction times to familiar faces were faster than reaction times to unfamiliar faces, but there was no difference between familiar and unfamiliar faces for expression matching. These results support the view derived from neuropsychological and neurophysiological studies that analyses of facial expressions proceed independently from processes involved in establishing the person's identity.This research was supported by the ESRC (Grant C 0023 2075)     

Verbal and behavioral responses to familiar and unfamiliar music

Thirty adult subjects completed an Operant Music Listening Recorder (OMLR) task with two unfamiliar and two familiar music channels (one “popular” and one “classical” in each case), then rated the music on each channel on seven-point scales for liking, quality, and familiarity. The two familiar music channels received significantly higher ratings than the two unfamiliar channels on all three rating scales, and there were no significant main effects or interactions involving musical style. The predictions (a) that subjects would spend more time listening to the familiar channels on the OMLR task, and (b) that measures of listening time would display higher correlations with ratings of liking than with those of quality both received weak support from the direction of the results, but neither was confirmed by statistical significance tests. The results are discussed in terms of the fragmentation between the affective and evaluative components of attitudes toward music.     

Allocation of attention in familiar and unfamiliar traffic scenarios

Increased travel worldwide has led to an escalation of road traffic accidents, particularly among tourists driving in unfamiliar, opposite traffic flow driving scenarios. Ability to allocate attention to driving-relevant information and regions is predicted to be the main cause of tourist accidents, with a lack of attention directed to areas of space that are inhibited in familiar traffic conventions but relevant in overseas driving. This study investigated the influence of habit and expectancy on driver behaviour and allocation of attention in familiar (left-hand traffic; LHT) and unfamiliar (right-hand traffic; RHT) contexts. Twenty-eight drivers from the UK were presented with video clips of driving taken in the UK and in Poland and asked to judge whether it was safe to enter a roundabout in each clip. Half were given information about differences in LHT and RHT situations prior to the task. Judgement performance was not influenced by this information, however accuracy was higher for LHT and the RHT task was rated more difficult, supporting the notion that driving in unfamiliar surroundings is more effortful. In LHT both groups made more fixations to the right side of each roundabout, however in RHT, whilst the control group allocated attention in the same way, the intervention group made significantly more fixations to the left. Pre-drive preparatory information can therefore increase attention to the most relevant areas of space in unfamiliar driving contexts. This has implications for drive tourism and it is suggested that such information is made more explicit to drivers.     

Orangutans (Pongo abelii) and a gorilla (Gorilla gorilla gorilla) match features in familiar and unfamiliar individuals

Great apes can perceive images as representative of corresponding real-life objects. Coupled with the potential advantages of identifying specific members of one’s species and mounting evidence for individual recognition in other non-humans, it seems likely that great apes would have the ability to identify conspecifics in photographs. The ability of four orangutans and a gorilla to match images of individuals of their own and a closely related but unfamiliar species was examined here for the first time. First, the subjects matched photographs of familiar conspecifics taken at various time points in a delayed matching-to-sample procedure (Experiment 1). Second, they matched different photographs of unfamiliar individuals of a different species (Experiment 2) at above chance levels. These results suggest that the subjects matched photographs by matching physical features, not necessarily by recognizing the identity of the individuals depicted. However, they also quickly learned to select photographs of familiar individuals when these photographs were paired with photographs of unfamiliar individuals of their own species (Experiment 3), and three subjects showed transfer to novel images of familiar and unfamiliar individuals. Thus, the findings support the idea that subjects attended to physical features to identify individuals that they could categorize on the basis of familiarity.     

Order of feature recognition in familiar and unfamiliar faces

Three experiments measured order of processing for single faces presented to the left or right visual field (VF) using a same-different matching task. In contrast to earlier studies, the stimuli in the present experiments were carefully matched for overall similarity prior to the actual experiments. Experiments 1 and 2 showed that a significant top-to-bottom order of processing occurred for line drawings of unfamiliar faces but not for line drawings of familiar faces. Experiment 3 found evidence supporting top-to-bottom processing for unfamiliar photographic face stimuli. The photographic stimuli in Experiment 3 were matched more quickly when presented in the left VF (right hemisphere); however, this VF asymmetry was not related to previously reported differences in order of processing. It is suggested that under some conditions faces presented to the right hemisphere may be processed more like familiar faces than faces presented to the left hemisphere; however, this difference is not critical for the left VF (right hemisphere) superiority often found in face recognition tasks.     

Commonsense beliefs and the identification of familiar voices

Two experiments are reported in which participants attempted to reject the tape‐recorded voice of a stranger and identify by name the voices of three personal associates who differed in their level of familiarity. In Experiment 1 listeners were asked to identify speakers as soon as possible, but were not allowed to change their responses once made. In Experiment 2 listeners were permitted to change their responses over successive presentations of increasing durations of voice segments. Also, in Experiment 2 half of the listeners attempted to identify speakers who spoke in normal‐tone voices, and the remainder attempted to identify the same speakers who spoke in whispers. Separate groups of undergraduate students attempted to predict the performance of the listeners in both experiments. Accuracy of performance depended on the familiarity of speakers and tone of speech. A between‐subjects analysis of rated confidence was diagnostic of accuracy for high familiar and low familiar speakers (Experiment 1), and for moderate familiar and unfamiliar normal‐tone speakers (Experiment 2). A modified between‐subjects analysis assessed across the four levels of familiarity yielded reliable accuracy‐confidence correlations in both experiments. Beliefs about the accuracy of voice identification were inflated relative to the significantly lower actual performance for most of the normal‐tone and whispered‐speech conditions. Forensic significance and generalizations are addressed. Copyright © 2001 John Wiley & Sons, Ltd.     

Children's haptic and cross-modal recognition with familiar and unfamiliar objects

Five-year-old children explored multidimensional objects either haptically or visually and then were tested for recognition with target and distractor items in either the same or the alternative modality. In Experiments 1 and 2, haptic, visual, and cross-modal recognition were all nearly with familiar objects; haptic and visual recognition were also excellent with unfamiliar objects, but cross-modal recognition was less accurate. In Experiment 3, cross-modal recognition was also less accurate than within-mode recognition with familiar objects that were members of the same basic-level category. The results indicate that children's haptic recognition is remarkably good, that cross-modal recognition is otherwise constrained, and that cross-modal recognition may be accomplished differently for familiar and unfamiliar objects.