Auditory Contact Research Articles

Auditory contact cues improve performance when grasping augmented and virtual objects with a tool

This experiment investigated the roles of haptic and auditory contact information for the control and execution of reaching to grasp augmented (physical plus graphic) and virtual (graphic only) objects of different sizes using a tool. Haptic contact information was present when grasping augmented objects only. In half of the trials, auditory cues were provided when contact was made between the tip of the tool and the target object. Transport and grasp kinematics, as well as on spatial errors at the end of the movement were examined. Providing auditory cues at contact led to faster movements; moreover, when haptic information was not available (when grasping virtual objects), auditory cues improved spatial accuracy. Movement times increased as the object size decreased for the augmented objects, when haptic information was available, and also for the virtual objects when auditory contact cues were provided, thus following Fitts' law. However, movement times were similar for all object sizes when neither haptic nor auditory contact information was provided. These results emphasize the importance of contact information when grasping with a tool, and the benefits of auditory contact cues for improving performance.

Projections from auditory cortex contact ascending pathways that originate in the superior olive and inferior colliculus

The superior olivary complex (SOC) and inferior colliculus (IC) are targets of cortical projections as well as sources of major ascending auditory pathways. This study examines whether the cortical projections contact cells in the SOC or IC that project to higher levels. First, we placed an anterograde tracer into the auditory cortex to label cortico-olivary axons and a retrograde tracer into the IC to label olivocollicular cells in guinea pigs. Cortical axons contacted many labeled cells in the ipsilateral SOC and fewer labeled cells in the contralateral SOC. Contacted cells projected to the ipsilateral or contralateral IC. In a second experiment, we labeled corticocollicular axons with an anterograde tracer and injected retrograde tracers into the medial geniculate (MG) to label colliculogeniculate cells. In the IC ipsilateral to the cortical injection, many cortical axons contacted colliculogeniculate cells in the dorsal cortex and external cortex of the IC. The contacted cells projected to the ipsilateral MG or, less often, to the contralateral MG. The results indicate that cortical projections are likely to contact cells in the SOC and IC that project to higher centers. This suggests that auditory cortex can modulate the ascending auditory pathways at multiple levels of the brainstem.

Response of dairy cows and calves to early separation: Effect of calf age and visual and auditory contact after separation

We evaluated how the behavioural and heart rate response of dairy cows and calves to mutual separation was affected by two factors: the age of the calf at separation (1, 4 and 7 days) and the presence or absence of visual and auditory contact between the mother and her calf after separation. In total, 46 cow–calf pairs were randomly allocated to one of six treatments according to a 3 × 2 factorial design. The cows’ behavioural response to separation was recorded at 0–1, 9–10, 25–26 and 50 and 51 h after separation. The calves’ behavioural response was recorded during the 24 h after separation. The heart rate was measured 60 min before and 60 min after separation. Cows from the later separation treatments spent more time standing ( p < 0.01), placed their heads outside the pen ( p < 0.001), vocalised ( p < 0.05) and sniffed both the air ( p < 0.01) and other animals ( p < 0.001) more frequently compared to cows separated from their calves on day 1. The behavioural response was also more intense when the cows could see and hear their calves: they placed their heads outside the pen ( p < 0.001), vocalised ( p < 0.001) and sniffed the air ( p < 0.01) more often than the no contact cows. Heart rate increased in all cows immediately after separation and was not influenced by the calf's age or by contact with the calf. After separation, older calves stood and moved more ( p < 0.001), placed their heads outside the pen more often ( p < 0.01) and showed more explorative behaviour (i.e. sniffing walls and bedding, p < 0.01; licking walls, p < 0.05) than the calves separated on day 1. Furthermore, the calves with visual and auditory contact with their mothers tended to place their heads outside the pen more often ( p < 0.1) than the calves from the no contact treatments. Heart rate increased rapidly in all calves after separation; however, the increase lasted longer in the later separated calves ( p < 0.05). At 3 weeks of age, the calves separated on day 7 habituated more quickly to the novel situation ( p < 0.001). Calves separated on day 4 were more likely to engage in social play than the calves separated on days 1 and 7 ( p < 0.05) and the calves denied post-separation contact with their dams also showed more social play compared to calves without this contact ( p < 0.05). The results indicate that the response of cows and calves to separation is more intense and lasts longer when separation is delayed and that this effect is prolonged and further intensified when they are allowed visual and auditory contact after separation. On the other hand, delayed separation influences later social behaviour of calves in a way that may enhance their coping abilities.

Hand‐rearing and reintroduction of an infant White‐crowned mangabeyCercocebus atys lunulatusat Flamingo Land Zoo, Malton, UK

A ♀ White‐crowned mangabeyCercocebus atys lunulatuswas born at Flamingo Land Zoo, Malton, UK, on 11 April 2005. On day of birth the infant was removed for hand‐rearing after it sustained injuries from rough handling by its mother. The infant was hand‐reared until 10 May when preliminary visual, olfactory, auditory and limited tactile contact was allowed with the adults. The infant continued to be hand‐reared in full view of the adults until 15 June when the process of reintroduction was initiated. Full reintegration occurred on 15 July 2005. The processes used to hand‐rear this infant White‐crowned mangabey and successfully reintroduce it to its natal group are described in this paper.

Display Behavior and Spatial Distribution of the White-Crowned Manakin in the Atlantic Forest of Brazil

AbstractAbstractWe studied the display behavior and spatial distribution of the White-crowned Manakin (Dixiphia pipra, formerly in the genus Pipra) in the Atlantic Forest of the state of Rio de Janeiro, Brazil. The study area included three leks, two apparently solitary display sites, and two “collective display sites,” where definitive-plumaged males, predefinitive-plumaged males, and birds of undetermined sex displayed. The average distance between display sites was 68.0 ± 24.4 m (n = 8, range = 41–113 m). Males occupied the same display sites among years. The dispersion pattern of males was typical of exploded or dispersed leks. Males did not display in auditory or visual contact, except at the two display sites that were closest to each other. Lekking White-crowned Manakins used 11 display behaviors and two vocalizations. Four of the 11 display behaviors were recorded only at the collective display sites. We only observed males displaying in the presence of other individuals, regardless of whether it was a collective or solitary display site. Definitive- and predefinitive-plumaged males and birds of indeterminate sex all displayed together. The White-crowned Manakin repertoire of 11 display behaviors indicates a more complex display behavior than previously described.

Grasping at ‘thin air’: multimodal contact cues for reaching and grasping

Two experiments investigated the effects of haptic, auditory and graphic contact cues on reaching to grasp augmented objects (physical and graphic) and virtual objects (graphic only) of various sizes. In Experiment 1, auditory contact cues were presented either to enhance or to replace natural haptic contact cues in grasping. In Experiment 2, graphic contact cues were presented alone or in combination with auditory cues, and were provided either to enhance or to replace haptic contact information. Visual information of the hand was not available. Experiment 1 showed that enhancing haptic contact information with redundant auditory cues (augmented object) led to faster movement times than haptic cues alone. When haptic information was not available (virtual object), it could be replaced to some extent by auditory contact cues. In Experiment 2 movement times were fastest when both auditory and graphic cues were provided, and slowest when no contact cues were provided. Further, movement times were scaled to target width when reaching to grasp augmented objects, thus following Fitts' law. In contrast, movement times showed a less pronounced decrease with increasing object size for virtual objects. However, even in the absence of haptic information, movement times showed a more pronounced scaling to object size when auditory contact cues were provided. These results emphasize the importance of contact information, especially haptic and auditory information, for planning and control of reaching and grasping.

DISPLAY BEHAVIOR AND SPATIAL DISTRIBUTION OF THE WHITE-CROWNED MANAKIN IN THE ATLANTIC FOREST OF BRAZIL

We studied the display behavior and spatial distribution of the White-crowned Manakin (Dixiphia pipra, formerly in the genus Pipra) in the Atlantic Forest of the state of Rio de Janeiro, Brazil. The study area included three leks, two apparently solitary display sites, and two “collective display sites,” where definitive-plumaged males, predefinitive-plumaged males, and birds of undetermined sex displayed. The average distance between display sites was 68.0 ± 24.4 m (n = 8, range = 41–113 m). Males occupied the same display sites among years. The dispersion pattern of males was typical of exploded or dispersed leks. Males did not display in auditory or visual contact, except at the two display sites that were closest to each other. Lekking White-crowned Manakins used 11 display behaviors and two vocalizations. Four of the 11 display behaviors were recorded only at the collective display sites. We only observed males displaying in the presence of other individuals, regardless of whether it was a collective or solitary display site. Definitive- and predefinitive-plumaged males and birds of indeterminate sex all displayed together. The White-crowned Manakin repertoire of 11 display behaviors indicates a more complex display behavior than previously described.

The effects of individual housing on mice and rats: a review

AbstractIsolating an animal refers to the situation where the animal is physically fully demarcated from conspecifics without physical, visual, olfactory and auditory contact. Animals housed in separate cages in the same room are, although deprived of physical and visual contact, still in olfactory and auditory contact, and thus not totally isolated. During the fifties and sixties several studies claimed to show physiological and behavioural differences between individually and group housed rats and mice. The so-called ‘Isolation Syndrome’ characterised by changes in corticosterone levels, metabolism, growth, and behaviour was introduced, rather as a model for psychoneurosis than through any concern for animal welfare. Today, it is often stated as common knowledge in laboratory animal science textbooks that individual housing as well as isolation of rats and mice has an effect on physiology and behaviour. It is, however, unclear whether this effect actually impairs animal welfare.The aim of this paper is to analyse studies on individual housing of mice and rats to evaluate whether there is documented proof that individual housing affects welfare, and, alternatively whether it is possible to house these animals individually without negative impact on welfare, eg by providing special housing improvements.A range of studies have shown that individual housing or isolation has effects on corticosterone, the open field behaviour, barbiturate sleeping time and the metabolism of different pharmaceuticals in the animals. However, this review of 37 studies in rats and 17 studies in mice showed divergence in test results difficult to explain, as many studies lacked basal information about the study, eg information on genetic strains and housing conditions, such as bedding, enrichment and cage sizes. Furthermore, test and control groups most frequently differed in cage sizes and stocking densities, and behavioural tests differed in ways which may very well explain the differences in results. Overall, there seemed to be an effect of individual housing, although it may be small, and it seems reasonable to assume that, through making small changes in the procedures and housing environments, the effects can be minimised or even eliminated. More well-controlled and standardised studies are needed to give more specific answers to the questions this issue poses.

Mobbing vocalizations as a coping response in the common marmoset

Using a non-invasive method of sampling saliva followed by assay for cortisol levels, we found that common marmosets ( Callithrix jacchus) show a decrease in cortisol levels after seeing a snake-model stimulus that reliably elicits mobbing (tsik) calls. In fact, there was a significant positive correlation between the number of tsik vocalizations made and the magnitude of the decrease in the cortisol concentrations. Furthermore, marmosets with higher levels of cortisol prior to being exposed to the stimulus produce more tsik calls than those with lower levels of cortisol. Subsequent experiments showed that, in response to 15 min of isolation with no visual or auditory contact with conspecifics (a traditional stressor), cortisol levels increased significantly. However, playback of the mobbing calls of a familiar conspecific to individual isolated marmosets not only prevented the rise in cortisol, but also actually caused a decrease in the levels of this hormone. This suggests that the mobbing calls serve to calm the marmoset after experiencing a stressful situation. This finding results in a greater understanding as to the role of physiological responses during communication in this species and could have implications for the welfare of marmosets in captivity.

Projections from auditory cortex contact cells in the cochlear nucleus that project to the inferior colliculus

Anterograde and retrograde tracing techniques were combined to determine whether auditory cortical axons contact cells in the cochlear nucleus that project to the inferior colliculus. FluoroRuby or fluorescein dextran was injected into auditory cortex to label cortical axons by anterograde transport. Different fluorescent tracers (Fast Blue, FluoroGold, FluoroRuby or fluorescein dextran) were injected into one or both inferior colliculi to label cells in the cochlear nucleus. After 12–15 days, the brain was processed for fluorescence microscopy and the cochlear nuclei were examined for apparent contacts between cortical axons and retrogradely labeled cochlear nucleus cells. The results suggest that axons from the ipsilateral or contralateral cortex contact fusiform and giant cells in the dorsal cochlear nucleus and multipolar cells in the ventral cochlear nucleus that project directly to the inferior colliculus. The contacts occur on cell bodies and dendrites. The target cells in the cochlear nucleus include cells that project ipsilaterally, contralaterally or bilaterally to the inferior colliculus. The results suggest that auditory cortex is in a position to exert direct effects on the monaural pathways that ascend from the cochlear nucleus.

Social mediation of vocal amplitude in a songbird, Taeniopygia guttata

Bird vocalizations are produced under various social contexts. It could therefore benefit birds, as social contexts change, to alter the amplitude of their signals. We tested this by recording male and female zebra finches, Taeniopygia guttata, when they were placed in isolation, in auditory contact, and in visual and auditory contact with each sex. The majority of females increased call amplitude only when in auditory contact with either sex. Most males increased both song and call amplitudes only when in visual and auditory contact with either sex. We found no changes in patterns of harmonic suppression (timbre) for males or females across social conditions. One explanation for the sex difference is that females increase amplitude for affiliative reasons, whereas males increase amplitude to advertise fitness.

Flexibility and context-sensitivity during the vocal exchange of coo calls in wild Japanese macaques (Macaca fuscata yakui)

AbstractThis study investigated the extent to which vocal production in wild Japanese macaques, Macaca fuscata yakui, is flexible. Japanese macaques frequently exchange coo calls with other group members to maintain auditory contact. When a coo call is emitted but no other members respond within a short interval, the same monkey often emits another call repeatedly. This study focused on these two successive coo call sequences. First, the sequences of eleven females in a free-ranging group were recorded and analyzed. Comparisons of the acoustic properties between the initial and repeated coo calls revealed that the repeated call was higher in fundamental frequency and longer in duration than the initial call. Next, playback experiments were conducted to examine the efficiency of the exaggerated acoustic features of these repeated coo calls. Eight pairs of initial and repeated coo calls were prepared from eight female monkeys as the playback stimuli, and played back to the eight subject females. Comparisons of subject responses to the initial and repeated coo call stimuli revealed that the repeated call stimuli elicited more frequent vocal responses. These field observation and playback results suggest that monkeys might be able to modify the acoustic properties of vocalizations according to the preceding context so as to elicit a more effective vocal response from other group members. The pattern of vocal interactions among wild Japanese macaques is therefore likely to be flexible and to some extent context-sensitive.

Effects of feeding level before and after calving, and restricted suckling frequency on postpartum reproductive and productive performance of Sarda and Charolais×Sarda beef cows

Two experiments were carried out on 48 Sarda (Sa) and 48 Charolais×Sarda (F1) grazing cows using a factorial design: 2 genotypes×2 feeding levels targeted to low (2, L) and high (3, H) body condition scores (BCS) at calving and in the following 3 months×2 suckling frequencies. These were ad libitum suckling (ADLIB) versus restricted (RESTR) to one suckling per day (45–90 days postpartum) in experiment 1 and ad libitum suckling (ADLIB) versus isolated (ISOL, one suckling daily between days 25 and 50 with no visual or auditory contacts between dams and calves outside the daily suckling period) in experiment 2. In experiment 1 postpartum anoestrus interval (PPI) was shorter in SaL than in F1L cows ( P<0.01). In experiment 2 BCS around calving exerted an overriding effect on PPI; Sa cows tended ( P<0.08) towards shorter PPI than F1 cows. Conception rate (CR) was higher in the 4th month postpartum in SaL than in F1L cows in experiment 1 (95 vs. 57%, P<0.01) and in H than in L cows (58 vs. 14%, P<0.001) in experiment 2. Suckling frequency affected CR of F1 cows by the 8th month postpartum in experiment 2: it was 90% in F1 ISOL cows and just 55% in F1 ADLIB cows ( P<0.02). It is concluded that in the less favoured areas of Sardinia, the Sarda breed gives better reproductive performance than F1 cows while maintained at low BCS during the calving period. Cross-bred, but not pure Sarda cows, can benefit from the implementation of suckling restriction with strict calf isolation.

Enhanced Cortical Extracellular Levels of Cholecystokinin-Like Material in a Model of Anticipation of Social Defeat in the Rat

The involvement of cholecystokinin (CCK) in the mechanisms of stress and/or anxiety was assessed by in vivo microdialysis in rats subjected to a social stress paradigm. During the initial 30 min period of each conditioning session, a male Sprague Dawley rat (intruder) was placed in a protective cage inside the cage of a male Tryon Maze Dull rat (resident), allowing unrestricted visual, olfactory, and auditory contacts but precluding close physical contact between them. During the following 15 min period, both the protective cage and the resident were removed (nondefeated intruders) or only the protective cage was removed allowing the resident to attack the intruder (defeated rats). This procedure was repeated once daily for 4 d. On the fifth day, a guide cannula was implanted into the prefrontal cortex of intruders. During a single 30 min test session, performed 4 d later, intruders were subjected to only the 30 min protected confrontation to the resident. Anxiety-like behavior (immobility, ultrasonic vocalizations, and defensive postures), associated with an increase (approximately +100% above baseline) in cortical outflow of CCK-like material (CCKLM), were observed in defeated intruders. Pretreatment with diazepam (5 mg/kg, i.p.), but not buspirone (0.5-2 mg/kg, i.p.), prevented both the anxiety-related behavior and CCKLM overflow. The selective CCK-B receptor antagonist CI-988 (2 mg/kg, i.p.) reduced the anxiety-like behavior without affecting the increase in CCKLM outflow. These data indicate that anticipation of social defeat induces a marked activation of cortical CCKergic neurons associated with anxiety-related behaviors in rats.

Can a Good Mother Help Response to Stress

Recent animal research has begun to uncover ways that parenting affects stress levels in offspring. These researchers investigated the acute effects of mother-child separation on 6 juvenile male rhesus monkeys exposed to 3 conditions: complete separation from the mother, separation with auditory and visual contact, and contact after brief separation …

Unusually extensive networks of vocal recognition in African elephants

Research on acoustic communication has often focused on signalling between territorial individuals or static neighbouring groups. Under these circumstances, receivers have the opportunity to learn to recognize the signals only of the limited number of conspecifics with which they are in auditory contact. In some mammals, however, social units move freely with respect to one another and range widely, providing individuals with opportunities to learn to recognize the signals of a wide range of conspecifics in addition to those of their immediate neighbours. We conducted playback experiments on African elephants,Loxodonta africana , in Amboseli National Park, Kenya, to determine the extent to which adult female elephants, which have a highly fluid social system, can recognize others in the population through infrasonic contact calls. Female elephants could distinguish the calls of female family and bond group members from those of females outside of these categories; moreover, they could also discriminate between the calls of family units further removed than bond group members, on the basis of how frequently they encountered them. We estimated that subjects would have to be familiar with the contact calls of a mean of 14 families in the population (containing around 100 adult females in total), in order to perform these discriminations. Female elephants thus appear to have unusually extensive networks of vocal recognition, which may prove to be typical of long-lived species that have both fluid social systems and the means for long-distance vocal communication.

Has predation shaped the social systems of arboreal primates

I studied antipredator behavior in two species of monkeys to elucidate the role of predation in shaping the social systems of arboreal primates. I compared the responses of monkeys to auditory and visual contact with predators to response elicited by sound playback experiments using the recorded calls of predators. Changes in vigilance and aggregation persisting up to 30 min after predator encounter occurred in both cases. Measures of vigilance shed light on individual perceptions of risk, while aggregation measures—intragroup spatial cohesion and polyspecific associations—permit direct inference about the protective benefits of grouping for the monkeys. They responded to real predator encounters and simulations in similar ways. Thus, sound playbacks of predator vocalizations are effective to simulate predator proximity. Contrary to predictions, predator encounters did not lead invariably to increased cohesion within groups or to increased time spent vigilant. Moreover, behavior in polyspecific associations was no different from that in single-species groups. Only red colobus encountering chimpanzees behaved as predicted by increasing vigilance and intragroup cohesion. The red colobus social system may have developed to protect against chimpanzee attack. In contrast, red-tailed monkey encounters with raptors and chimpanzees involved no change in time spent vigilant, coupled with decreases in intragroup cohesion. I conclude that predation is not a uniform selective pressure and patterns of social behavior within groups do not predict antipredator behavior.

Effects of chronic social separation on cardiovascular disease risk factors in female cynomolgus monkeys

A lack of social support is associated with increased risk of coronary heart disease morbidity and mortality in human beings. Similarly, chronic social separation (single cage housing) potentiates atherosclerosis in female monkeys. Under the hypothesis that autonomic arousal and/or ovarian impairment may mediate this effect (as both are associated with increased atherosclerosis), heart rate and luteal phase plasma progesterone concentrations were measured in 12 female cynomolgus monkeys that were first socially housed, then individually housed, and finally returned to their original social groups. Afternoon heart rates increased during social separation compared to the social groupings ( P<0.001). Increased heart rates could not be explained by activity levels, which were lower during social separation than in social groupings ( P<0.001). Ovarian function (i.e. luteal-phase progesterone concentrations) was not influenced by housing condition. Single caging reduced the extent of social signaling, even though animals were in visual and auditory contact. Rates of affiliative behaviors increased and time spent alone decreased in post-reunion social groups compared to pre-separation social groups ( P's<0.01). The results indicate that chronic social separation in this group-living species may exacerbate atherosclerosis via altered autonomic activity, as evidenced by higher heart rates during social separation.

Rearing with males accelerates onset of sexual maturity in female domestic fowl

Two experiments were conducted to investigate the effects of male presence on sexual maturation and sexual responses toward humans in laying strain females. In Experiment 1, two flocks of 50 medium-hybrid females were reared without males (separate-sex) and two flocks with males (mixed-sex) from 1 d of age. Mixed-sex females came into lay sooner and laid more eggs up to 22 wk of age than separate-sex females (P < 0.05). Comb size was also greater in mixed-sex females at 15 and 20 wk of age (P < 0.05). In Experiment 2, six replicate groups per treatment with n = 10 females per group were reared in separate-sex, mixed-sex, or adjacent to mixed-sex groups. Rearing adjacent to mixed-sex groups, which allowed visual and auditory contact with males, was just as effective for accelerating sexual maturation as was rearing in mixed-sex groups. Females reared in and adjacent to mixed-sex groups began to lay earlier (P < 0.05) and had larger combs (P < 0.05) than separate-sex females. However, after 22 wk of age, egg production rates of separate-sex females surpassed those of mixed-sex and adjacent females, resulting in similar numbers of eggs produced through 30 wk of age (P > 0.10). During tests for sexual responsiveness to humans, over 80% of females in separate-sex and adjacent to mixed-sex groups assumed a sexual crouch, whereas less than 20% of females in mixed-sex groups crouched (P < 0.001, chi-square). The degree of contact with males during rearing affected the females' physiological measures of reproductive function differently than behavioral measures.

Ultrastructural analysis of primary endings in deaf white cats: morphologic alterations in endbulbs of Held.

Changes in structure and function of the auditory system can be produced by experimentally manipulating the sensory environment, and especially dramatic effects result from deprivation procedures. An alternative deprivation strategy utilizes naturally occurring lesions. The congenitally deaf white cat represents an animal model of sensory deprivation because it mimics a form of human deafness called the Scheibe deformity and permits studies of how central neurons react to early-onset cochlear degeneration. We studied the synaptic characteristics of the endbulb of Held, a prominent auditory nerve terminal in the cochlear nucleus. Endbulbs arise from the ascending branch of the auditory nerve fiber and contact the cell body of spherical bushy cells. After 6 months, endbulbs of deaf white cats exhibit alterations in structure that are clearly distinguishable from those of normal hearing cats, including a diminution in terminal branching, a reduction in synaptic vesicle density, structural abnormalities in mitochondria, thickening of the pre- and postsynaptic densities, and enlargement of synapse size. The hypertrophied membrane densities are suggestive of a compensatory response to diminished transmitter release. These data reveal that early-onset, long-term deafness produces unambiguous alterations in synaptic structure and may be relevant to rehabilitation strategies that promote aural/oral communication.