Effects of clean and soiled sawdust substrates and of different urine types upon aggressive behavior in male mice

The effects of sawdust taken from the cages of grouped or isolated male mice upon the aggressiveness of trained fighter mice toward castrated opponents were examined. The results indicate that (1) substrate soiled by stable groups of male mice does not provide aggression-promoting odors, (2) application of the urine of isolate male mice to castrate opponents increases the aggressiveness of fighters toward the castrates, and (3) application of isolate male urine to the test substrate inhibits the aggressive behavior of a fighter toward its castrated opponent. The concepts that male mouse urine possesses both aggression-promoting and aggression-inhibiting cues are not mutually exclusive, but the action of the urine depends upon whether it is placed onto a mouse or onto the substrate. The findings are discussed in relation to those of previous studies on soiled sawdust and aggression, and an attempt is made to relate these results to a territorial situation.     

Olfactory stimuli and intermale aggression in androgen-treated castrated sheep

The ability of olfactory stimuli to elicit aggression in male sheep was assessed in testosterone-treated castrates. Ablation of the olfactory bulbs (Exp. 1) did not reduce the capacity of sheep to participate in aggressive behaviour after testosterone treatment. Topical application of urine from castrates treated with propionated testosterone, 5α-dihydrotestosterone, 17β-oestradiol, or an oil vehicle to the fleeces of untreated castrates (Exp. 2) did not result in different levels of aggressive responsiveness in testosterone-treated castrates.     

Effects of olfactory bulb ablation and androgen on marking and agonistic behavior in male Mongolian gerbils (Meriones unguiculatus).

Male Mongolian gerbils, selected for high marking frequency, were paired with male opponents, and marking and fighting behavior were recorded. Animals then underwent castration, bilateral bulbectomy, unilateral bulbectomy, the combined operations, or a sham operation; and their behavior was again observed. All operated animals showed drastic reduction in both marking and aggressive encounters. Injections of testosterone propionate (TP) produced complete restoration of marking in castrates, but not in bilaterally or unilaterally bulbectomized animals or combined operates. The exhibition of aggression after injections of TP, however, was enhanced to supernormal levels in bulbectomized or bulbectomized-castrated animals. The results suggest the following: that removal of the olfactory bulbs may eliminate a critical neural input necessary for the normal expression of marking and agonistic; that although marking and fighting are influences by olfactory input and gonadal steroids, their regulatory mechanisms may not be identical; and that removal of the bulbs may sensitize a neural mechanism controlling aggression, thus potentiating its elicitation following administration of exogenous androgen.     

Affective matching of odors and facial expressions in infants: shifting patterns between 3 and 7 months

Recognition of emotional facial expressions is a crucial skill for adaptive behavior. Past research suggests that at 5 to 7 months of age, infants look longer to an unfamiliar dynamic angry/happy face which emotionally matches a vocal expression. This suggests that they can match stimulations of distinct modalities on their emotional content. In the present study, olfaction–vision matching abilities were assessed across different age groups (3, 5 and 7 months) using dynamic expressive faces (happy vs. disgusted) and distinct hedonic odor contexts (pleasant, unpleasant and control) in a visual‐preference paradigm. At all ages the infants were biased toward the disgust faces. This visual bias reversed into a bias for smiling faces in the context of the pleasant odor context in the 3‐month‐old infants. In infants aged 5 and 7 months, no effect of the odor context appeared in the present conditions. This study highlights the role of the olfactory context in the modulation of visual behavior toward expressive faces in infants. The influence of olfaction took the form of a contingency effect in 3‐month‐old infants, but later evolved to vanish or to take another form that could not be evidenced in the present study.     

Appetitive and aversive olfactory learning induce similar generalization rates in the honey bee

Appetitive and aversive learning drive an animal toward or away from stimuli predicting reinforcement, respectively. The specificity of these memories may vary due to differences in cost–benefit relationships associated with appetitive and aversive contexts. As a consequence, generalization performances may differ after appetitive and aversive training. Here, we determined whether honey bees show different rates of olfactory generalization following appetitive olfactory conditioning of the proboscis extension response, or aversive olfactory conditioning of the sting extension response. In both cases, we performed differential conditioning, which improves discrimination learning between a reinforced odor (CS+) and a non-reinforced odor (CS?) and evaluated generalization to two novel odors whose similarity to the CS+ and the CS? was different. We show, given the same level of discriminatory performance, that rates of generalization are similar between the two conditioning protocols and discuss the possible causes for this phenomenon.     

The role of attention in the localization of odors to the mouth

Odors can be perceived as arising from the environment or as part of a flavor located in the mouth. One factor that may dictate where an odor is perceived to be is concurrent gustatory stimulation in the mouth. A taste may impair the ability to attend to an odor, especially if they are perceptually similar. Alternatively, salient mouth-based features of a flavor might command attention at the expense of smell. Experiment 1 and 2, using different stimulus sets, explored the impact of perceptually similar and dissimilar pairings of tastes in the mouth and odors at the nose. In each case, these were followed by judgments of the odor's location (mouth vs. nose). Perceptual similarity had no impact on localization judgments. Experiment 3 then manipulated the salience of the olfactory and gustatory cues and showed that each could independently shift the perceived location of an odorant-salient olfactory cues toward the nose and gustatory cues toward the mouth. These findings suggest that the salient features of a flavor may command attention at the expense of olfaction and, thereby, contribute to oral localization, with implications for flavor binding.     

Agonistic behavior and social reactivity of LG/J mice in both an arena and a seminatural setting

In order to determine the relatively long-term effects of having been primed for agonistic behaviors in an arena setting, 28 male LG/J mice were observed for these behaviors in a seminatural environment for a period of 5 days following a 20 min arena test. The mice were first placed in an arena in which they were allowed either immediate physical contact with another strain (control condition) or were briefly separated from another strain by a transparent partition before being allowed physical access to them (priming condition). Subjects, recorded as either having fought or not fought in the arena, were then placed in a 101 cm square seminatural setting. Seven trials, using 8 LGs each (4 arenaexperienced males and 4 naive females), were made, and agonistic behaviors were recorded for the priming and control condition subjects. The results showed that the control condition fighters (CF) like the priming condition fighters (PF) fought in the arena situation, but different agonistic patterns in the seminatural setting were noted. While in the seminatural environment, both CF and PF mice were attacked frequently and submitted frequently, but PF mice attacked opponents more frequently than did CF subjects (p < 0.025) and elicited significantly more submissions from opponent mice than did CF mice (p < 0.025). It is concluded that: (1) there are more and different agonistic behavior patterns available in the more natural environment than in the arena setting, and more specifically (2) there is a greater effect on agonistic behaviors in a seminatural environment for mice that fought when exposed to the arena priming procedure as compared with mice having fought in the arena control condition.     

Group identification moderates attitudes toward ingroup members who confront discrimination

Three studies examined the hypothesis that group identification moderates African Americans’, Asian Americans’, and women’s attitudes toward fellow ingroup members who challenge an outgroup member’s discriminatory comments or who do not speak up about the comments. Highly identified racial minorities expressed more positive attitudes toward ingroup members who confronted discriminatory comments compared to those who did not confront; whereas weakly identified minorities did not express different attitudes across the two conditions. Among women, the weakly identified expressed more negative attitudes toward other women who confronted discrimination relative to those who did not confront; whereas highly identified women did not differentially evaluate ingroup members in the two conditions. The less women identified with their group, the more negatively they evaluated ingroup members who confronted sexism. This research highlights the important role of group identification in understanding how members of devalued groups respond toward ingroup members who take a stand against discrimination.     

Smelling objects

Objects are central to perception and our interactions with the world. We perceive the world as parsed into discrete entities that instantiate particular properties, and these items capture our attention and shape how we interact with the environment. Recently there has been some debate about whether the sense of smell allows us to perceive odours as discrete objects, with some suggesting that olfaction is aspatial and doesn’t allow for object-individuation. This paper offers two empirically tractable criteria for assessing whether particular objects are exhibited in perceptual experience—(1) susceptibility to figure-ground segregation and (2) perceptual constancies—and argues that these criteria are fulfilled by olfactory perception, and thus there are olfactory objects. I argue that there are, in fact, two different ways that olfaction allows for figure-ground segregation. First, I look at various Gestalt grouping principles, which are thought to govern when features are perceived as grouped into structured wholes, segregated from everything around them. I argue that these principles apply to olfactory experience, providing evidence of non-spatial figure-ground segregation. Second, I defend the contentious idea that a spatial variety of figure-ground segregation can also occur in olfaction. To see this, however, we need to look to empirical evidence showing that tactile stimulation and bodily movements play a crucial role in olfactory phenomenology. Finally, I draw on empirical evidence and olfactory phenomenology to argue that there are perceptual constancies in olfactory experience, allowing us to perceive odours as coherent objects that survive shifts in our perspectives on the world.

     

Context-dependent use of olfactory cues by foragers of Vespula germanica social wasps

Animal Cognition - Food search is guided by cues from different sensory modalities, such as olfactory and visual. In social wasps, olfaction plays a key role in locating new resources. However,...     

A Possible Protocognitive Role for Odor in Human Infant Development

Concepts relating to semiochemistry are now prevalent in the current literature on olfaction. Two fundamental tools of semiotics are metaphors, involving cognitive and verbal processes, and metonyms, involving nonverbal associations. By extending the concept of metonymy to non-linguistic transmission, we propose a possible explanation of how olfaction acts as a semiotic sense. Consideration of the sense of smell in animals and humans demonstrates its excellence for the formation of learned associations. In animals we find salient and complex information transmitted via biological odors. In this review, the olfactory dyadic relationship between mother and child is used for the theoretical proposal that the sense of smell plays an important protocognitive role in the genesis of cognition via mechanisms of in utero and postnatal nonlinguistic metonymic learning processes.     

The impact of mediodorsal thalamic lesions on olfactory attention and flavor perception

Olfactory attention may be important in generating odor-induced tastes - an arguably universal form of synesthesia - by ensuring that the taste concurrent is captured by the nose and olfaction, not by the mouth and gustation (oral-capture). To examine the role of olfactory attention in generating odor-induced tastes and oral capture we tested a small sample (n = 4) of participants with likely impairments in olfactory attention - individuals with mediodorsal thalamic nucleus (MDNT) lesions. These participants were compared to two sets of controls on tests of olfactory attention, oral capture, odor and flavor perception, and control tasks. MDNT participants demonstrated impaired olfactory attention and enhanced oral capture. Greater oral capture was associated with greater olfactory attentional impairment. These findings imply that olfactory attention may be important in attributing odor-induced tastes to the olfactory modality. However, unlike for visual binding and for the neurodevelopmental synesthesias, where attention may be necessary to demonstrate both phenomena, olfactory attention deficits did not impair flavor binding or the experience of odor-induced tastes.     

The role of Blacks’ discriminatory expectations in their prosocial orientations toward whites and blacks

The present research examined the role of discriminatory expectations in intergroup contact. In two experiments, Black participants who varied in discriminatory expectations were exposed to positive, negative, or racially neutral comments by a White person. Participants subsequently read about a different person-in-need and reported empathic concern for and prosocial attitudes/intentions toward that person. For participants with low discriminatory expectations, positive outgroup exposure increased and negative outgroup exposure decreased empathic concern for and prosocial attitudes/intentions toward a White person-in-need, relative to neutral exposure. Exposure had no effect on their reactions to a Black person-in-need. Findings were similar for participants with strong discriminatory expectations, except that positive exposure had no effect on prosocial attitudes/intentions toward a White person-in-need and negative exposure increased prosocial intentions toward a Black person-in-need. Empathic concern mediated the discriminatory expectations × outgroup exposure effect on prosocial attitudes/intentions. Findings highlight the role of discriminatory expectations in predicting contact outcomes.     

Odor memory: Review and analysis

We critically review the cognitive literature on olfactory memory and identify the similarities and differences between odor memory and visual-verbal memory. We then analyze this literature using criteria from a multiple memory systems approach to determine whether olfactory memory can be considered to be a separate memory system. We conclude that olfactory memory has a variety of important distinguishing characteristics, but that more data are needed to confer this distinction. We suggest methods for the study of olfactory memory that should make a resolution on the separate memory system hypothesis possible while simultaneously advancing a synthetic understanding of olfaction and cognition.     

Olfaction in autism spectrum disorders: A systematic review

Olfactory function is a well-known early biomarker for neurodegeneration and neural functioning in the adult population, being supported by a number of brain structures that could be dysfunctioning in neurodegenerative processes. Evidence has suggested that atypical sensory and, particularly, olfactory processing is present in several neurodevelopmental conditions, including autism spectrum disorders (ASDs). In this paper, we present data obtained by a systematic literature review, conducted according to PRISMA guidelines, regarding the possible association between olfaction and ASDs, and analyze them critically in order to evaluate the occurrence of olfactory impairment in ASDs, as well as the possible usefulness of olfactory evaluation in such conditions. The results obtained in this analysis suggested a possible involvement of olfactory impairment in ASDs, underlining the importance of olfactory evaluation in the clinical assessment of ASDs. This assessment could be potentially included as a complementary evaluation in the diagnostic protocol of the condition. Methods for study selection and inclusion criteria were specified in advance and documented in PROSPERO protocol #CRD42014013939.     

Dutch modality exclusivity norms: Simulating perceptual modality in space

Perceptual information is important for the meaning of nouns. We present modality exclusivity norms for 485 Dutch nouns rated on visual, auditory, haptic, gustatory, and olfactory associations. We found these nouns are highly multimodal. They were rated most dominant in vision, and least in olfaction. A factor analysis identified two main dimensions: one loaded strongly on olfaction and gustation (reflecting joint involvement in flavor), and a second loaded strongly on vision and touch (reflecting joint involvement in manipulable objects). In a second study, we validated the ratings with similarity judgments. As expected, words from the same dominant modality were rated more similar than words from different dominant modalities; but – more importantly – this effect was enhanced when word pairs had high modality strength ratings. We further demonstrated the utility of our ratings by investigating whether perceptual modalities are differentially experienced in space, in a third study. Nouns were categorized into their dominant modality and used in a lexical decision experiment where the spatial position of words was either in proximal or distal space. We found words dominant in olfaction were processed faster in proximal than distal space compared to the other modalities, suggesting olfactory information is mentally simulated as “close” to the body. Finally, we collected ratings of emotion (valence, dominance, and arousal) to assess its role in perceptual space simulation, but the valence did not explain the data. So, words are processed differently depending on their perceptual associations, and strength of association is captured by modality exclusivity ratings.     

Olfaction in Persons with Alzheimer's Disease

The need for low cost, noninvasive procedures for aiding in the diagnosis and understanding of Alzheimer's Disease (AD) has led to theories and procedures examining the role of olfactory disorders because of the finding that the brains of AD patients invariably exhibit neuropathology hi the hippocampus and entorhinal cortex. This loss correlates with the increase in the number of plaques and tangles and with the severity of dementia. Considered together, these findings suggest that brain structures closely related to the olfactory system demonstrate significant histopathology in AD. A comprehensive review of the literature pertaining to olfaction in persons with AD revealed that the olfactory identification ability of patients with memory disorders is impaired relative to controls. Consistency is lacking, however, when olfactory detection thresholds are investigated. Also, there is inconsistency in regards to severity of illness and olfactory function. In addition to differentiating AD patients from normals, the olfactory paradigm has shown some limited usefulness in differentiating AD patients from some other demented patients.     

Smelling lessons

Much of the philosophical work on perception has focused on vision. Recently, however, philosophers have begun to correct this ‘tunnel vision’ by considering other modalities. Nevertheless, relatively little has been written about the chemical senses—olfaction and gustation. The focus of this paper is olfaction. In this paper, I consider the question: does human olfactory experience represents objects as thus and so? If we take visual experience as the paradigm of how experience can achieve object representation, we might think that the answer to this question is no. I argue that olfactory experience does indeed represent objects—just not in a way that is easily read from the dominant visual case.     

Recall of odors: naming and autobiographical memories illustrate odor aftereffects

In the study phase, subjects had to encode either odors or the names there of by generating autobiographical memories, by judging the quality of the food source of the odors, or by labeling responses to odors. At the testing stage, explicit and implicit olfactory memory performance was assessed. With recognition testing, the provision of odors at study improved performance. Furthermore, recognition depended on elaborative encoding conditions with olfactory stimuli only. Implicit memory was measured by the correctness and speed of labeling responses at the testing stage. Old odors were named more correctly and faster than new ones, but only if subjects had encoded odors in the study phase. These results demonstrate that implicit memory in naming odors depends on olfactory stimulus processing and is not a purely verbal priming effect. As a further measure of implicit memory, the speed of autobiographical memory productions was assessed. We registered shorter reaction times for old versus new odors. But again, this effect of implicit memory was restricted to conditions of odor pre-experiences in the study phase. We conclude that olfactory memory is based on different types of memory traces. Implicit memory measures may prove to be useful in isolating sensory and other attributes of olfaction that seem to be interacting in making explicit memory judgments.