Ear Movements Research Articles

Development of a training paradigm for voluntary control of the peri-auricular muscles: a feasibility study

BackgroundSpinal cord injury (SCI) can lead to severe and permanent functional deficits. In humans, peri-auricular muscles (PAMs) do not serve any physiological function, though their innervation is preserved in even high level SCI. Auricular control systems provide a good example of leveraging contemporary technologies (e.g., sEMG controlled computer games) to enable those with disabilities. Our primary objective is to develop and test the effectiveness of an auricular muscle training protocol to facilitate isolated and coordinated, bilateral voluntary control that could be used in individuals without volitional control of the vestigial PAMs.MethodsSeventeen non-disabled persons were screened; 13 were eligible and 10 completed the entire protocol. The facilitation phase, included one session of sub-motor threshold, sensory electrical stimulation followed by neuromuscular electrical stimulation paired with ear movement feedback for up to 8 additional sessions. Participants progressed to the skill acquisition phase where they dawned an auricular control device that used sEMG signals to control movements of a cursor through three levels of computer games, each requiring increasingly more complex PAM coordination.ResultsThe 10 who completed the protocol, finished the facilitation phase in 3 to 9 sessions and achieved some level of voluntary auricle movement that ranged between 1 and 5 mm. Qualitative analysis of longitudinal post-session auricular movement, revealed two subgroups of learners. Six successfully completed all 3 games—the “Learners”. Two were partially successful in game completion and two were unable to complete a single game--“Poor/Non-Learners”. Quantitative analysis revealed a significant group difference in auricular amplitude for both facilitation and skill phases (p < .05), and a significant relationship between performance in the two phases (R2 = 0.84, p = 0.004).ConclusionSixty percent of those who completed the facilitation phase were able to learn and demonstrate functional voluntary control of the vestigial PAMs. Those who progressed the fastest through facilitation were also those who were most proficient in skill acquisition with the device. There was considerable variability in progression through the two-phase protocol, with 20% deemed Poor/Non-Learners and unable to complete even the most basic game following training. There were no serious adverse events.Trial registrationClinicalTrials.gov Identifier: NCT02358915, first posted February 9, 2015.

Development of the interscutularis model as an outcome measure for facial nerve surgery

IntroductionAnimal models for the study of facial paralysis have been well developed, but concern has arisen regarding the accuracy of eye closure and whisker movement as outcome measures due to new data regarding interconnectivity between facial nerve branches and autonomic innervation. The posterior auricular nerve (PAN) is an isolated branch of the facial nerve which has been confirmed as the sole motor innervat or of the interscutularis muscle. This study was designed to develop a model for facial nerve palsy utilizing the PAN and interscutularis muscle. MethodsA custom-made automated video capture system was built into a poly methyl methacrylate cage using a high definition monochrome digital camera and image sensor to record the animal as it drank from a water feeder. A copper floor pad and copper collar around the water feeder were connected to an electrical circuit for automatic saving of the video recording 10 s prior to and 30 s following the drinking event. A pre-operative baseline recording of ear movement during drinking was captured. Female YFP-16 mice at 6 weeks were assigned to sham (Sh, n = 5), nerve excision (Ex, n = 10), or nerve crush (Cr, n = 10) groups with all interventions performed on the right PAN. Sh mice were irrigated with 10 ml normal saline as were the Ex and Cr mice following operative intervention. In Ex mice, a 3 mm section of the PAN was sharply excised and nerve gap was confirmed with fluorescent microscopy. In Cr mice, the PAN was crushed 3 mm from the origin of the facial nerve trunk with size 5 jeweler’s forceps for two periods of 20 s. Post-operative video recordings were collected on post-operative days (POD) 1, 10, 20, and 30. To determine the change in ear movement, the right ear was graphically compared to the left control side. ResultsSh animals exhibited a statistically significant reduction in ear movement at POD01 compared to other POD recordings (p < 0.05), but no significant change in right ear movement following POD05. Ex animals had a significant reduction in right ear movement at all PODs in comparison to the left ear (p < 0.05) with no significant change in right ear movement during the study period (p = 0.94). Cr animals showed a significant reduction in right ear movement compared to the left at POD01, POD10, and POD20 (p < 0.05). At POD30, there was no significant difference between ear movement on either side (p = 0.35). There was a significant change in right ear movement during the data collection period (p < 0.05). ConclusionThe results show that significant differences were demonstrated between the experimental groups and that significant changes within the crush group were identifiable making this an acceptable model to develop as an accurate outcome measure following rodent facial nerve surgery.

Correlated Evolution of White Spots on Ears and Closed Habitat Preferences in Felids

The pigmentation patterns of many carnivorous mammals comprise contrasting white patches of hair in different parts of the body whose evolution remains largely misunderstood. Some felids (Felidae) exhibit conspicuous white spots on the posterior part of the ears, while the ear color of others is uniform. On the basis that ear movement in felids has a role in intraspecific communication and that color contrast enhances detection, here it is hypothesized that white spots on ears may be particularly adaptive under conditions of poor visibility and thus be associated with the occupancy of closed habitats. This prediction was tested using phylogenetic logistic regression models with all species of extant felids. Results show a clear association between the occurrence of white spots on ears and preference for closed habitats, and this is independent of body size and whether species that occupy both closed and open habitats are considered as closed- or open-habitat specialists. Phylogenetic signal analyses indicate that the occurrence of white spots on ears is a highly conserved trait while habitat preferences are evolutionarily labile, suggesting that the presence of white spots may have partly contributed to the adaptation of felids to closed habitats. These findings indicate that some subtle pigment traits have fulfilled a significant role in determining the success of habitat occupancy by felids and possibly other mammals, which in turn has driven the evolutionary maintenance of such traits.

A soft robotic actuation system for a bat robot

A crucial development in the field of biomimicry is accurately recreating the kinematics of various organisms. In the example of a bat robot in development inspired by the greater horseshoe bat, Rhinolophus ferrumequinum, this takes the form of accurately recreating fast motions of the pinnae and noseleaf observed during echolocation. In order to accurately recreate these baffle shapes it is important to choose a material that is malleable but will retain its originally molded state. An actuation system was developed to replicate the ear movement seen in the bat when using biosonar. Several actuation designs were tested, including a physical motor connection, shape memory alloys, and soft-robotic pneumatics. In addition to the actuation system, a feedback system was developed in order to accurately control the robot and provide information which could be used to determine the effectiveness of the robot. Additionally, the final challenge to assemble all the components, i.e., the baffle shapes, actuator mechanism, and feedback control mechanism, in a way that recreates the baffle motions in an effective and accurate manner.

Technical note: Validation of an ear-tag accelerometer to identify feeding and activity behaviors of tiestall-housed dairy cattle

The objective of this study was to validate the CowManager SensOor ear-tag accelerometer (Agis Automatisering BV, Harmelen, the Netherlands) against visual observations of feeding, rumination, resting, and active behaviors of tiestall-housed dairy cows. Prior validation of the sensor has been published for freestall and grazing dairy herds. However, the behavioral differences that exist among these and a tiestall system necessitate additional validation. Lactating Holstein cows (n = 10) at different lactation stages and parities were included in the study. Cows were monitored both visually and with the sensor for 10 h/d for 4 consecutive days (10 cows × 10 h × 4 d = 400 h of observation total). A single trained observer classified each minute of visual observation into 1 of 13 behaviors and then summarized them into the 4 behavioral categories of eating, rumination, not active, or active. The sensor registered ear movements continuously and, based on a proprietary model, converted them into the behavioral categories. Multivariate mixed models were run to obtain covariance estimates, from which correlation coefficients were computed to assess agreement between visual observation and sensor data. The models included the percentage of time spent performing each behavior per day as the dependent variable and technology (visual observation versus sensor) and day as fixed effects. The models also included the random effects of technology and the repeated effects of technology and day. The correlation strength between visual observation and sensor data varied from poor to almost perfect by behavioral category (eating: r = 0.27; rumination: r = 0.69; eating-rumination: r = 0.83; not active: r = 0.95; and active: r = 0.89). The results suggest that the sensor can be used to accurately monitor active and not-active behaviors of tiestall-housed dairy cows. The results also suggest that although the sensor shows promise for identifying feeding behaviors in general, the independent classification of rumination and eating requires additional sensitivity.

Effects of straw provision, as environmental enrichment, on behavioural indicators of welfare and emotions in pigs reared in an experimental system

The present study aimed to investigate whether straw provision in pigs increases positive emotions, indicated by tail movement, and reduces poor welfare indicators (agonistic and displacement behaviours), including indicators of negative emotions (ear movement). Comparisons between Straw and Control sessions were analysed from video recording for all parameters. 15 mini-pigs participated in a three-week study. Depending on the week, animals were included in Straw or Control sessions. During Straw sessions, pigs were placed in their own pens where straw was introduced and continuously provided for one week. During Control sessions, pigs remained in their pens with no additional stimulus. Pig behaviours were video-recorded four times during each session and scored. Results showed that ear movement frequency was significantly lower in the Straw than in Control session (p = 0.005); agonistic behaviour frequency and duration were significantly lower in the Straw than in Control session (p = 0.013 and p = 0.0004, respectively), and displacement behaviour frequency and duration were significantly lower in the Straw than in Control session (p < 0.001 and p = 0.01, respectively). Results suggest that straw provision reduces poor welfare but does not modify indicators of positive emotions selected for this study (tail movement frequency and duration). Our study also provides information about potential indicators of welfare, and more precisely, about emotions, which could also be useful to improve animal welfare assessment in pigs, obtaining more information about feasible behavioural indicators which could show the emotional state of the animals.

Domestic horses (Equus caballus) discriminate between negative and positive human nonverbal vocalisations

The ability to discriminate between emotion in vocal signals is highly adaptive in social species. It may also be adaptive for domestic species to distinguish such signals in humans. Here we present a playback study investigating whether horses spontaneously respond in a functionally relevant way towards positive and negative emotion in human nonverbal vocalisations. We presented horses with positively- and negatively-valenced human vocalisations (laughter and growling, respectively) in the absence of all other emotional cues. Horses were found to adopt a freeze posture for significantly longer immediately after hearing negative versus positive human vocalisations, suggesting that negative voices promote vigilance behaviours and may therefore be perceived as more threatening. In support of this interpretation, horses held their ears forwards for longer and performed fewer ear movements in response to negative voices, which further suggest increased vigilance. In addition, horses showed a right-ear/left-hemisphere bias when attending to positive compared with negative voices, suggesting that horses perceive laughter as more positive than growling. These findings raise interesting questions about the potential for universal discrimination of vocal affect and the role of lifetime learning versus other factors in interspecific communication.

Tail and ear movements as possible indicators of emotions in pigs

A better understanding of animal emotions is an important goal in disciplines ranging from neuroscience to animal welfare science, but few reliable tools exist for measuring these emotions. Play behaviour is generally recognized as a trigger of positive emotions in mammals, and previous studies have suggested that tail movement (a behaviour often seen during play) may indicate positive emotions in pigs, while ear movements may indicate negative emotions, or a decrease in positive emotions. This study investigated whether the provision of toys to solicit play behaviour in pigs was associated with tail and ear movement changes, with the goal of confirming the use of these movements as indicators of different emotions in pigs. Sixteen mini-pigs were divided into two identical rooms of 8 individuals. During 4 consecutive days, each animal participated in the study for a total of two days in two different situations: one Control session and one Play session. Each animal served as its own control. During Play sessions, pigs were placed in their own pens of two individuals, where two medium-sized dog toys were introduced. During Control sessions, animals were placed in their own pens, but no toy was provided. Behaviours were scored from video using continuous recording with an ethogram, which also allows to confirm that pigs play during Play sessions. Results showed a significant difference in tail movement duration between sessions (DF = 15; t = −3.40; p < 0.01; Student t-test for paired sample) with longer durations during the Play session than during the Control session. Tail movement frequency also varied significantly between Play and Control sessions (DF = 15; t = 2.96; p = .01; Student t-test for paired samples) with significantly higher frequencies during the Control session. A significant difference between sessions was also observed for ear movement frequency (DF = 15; t = 4.69; p < 0.01; Student t-test for paired samples), which was significantly higher during the Control session. In addition, 69% of the pigs (11 of 16) performed displacement behaviours during the Control session, while none of the pigs displayed this behaviour during the Play session. Finally, during the Play session, a negative correlation was found between tail movement duration and tail movement frequency (rho = −0.79; N = 16; p < 0.001). In conclusion, tail and ear movement changes are linked to play behaviour: in a play situation, tail movement duration increases, and ear movement frequency and displacement behaviours decrease, compared to a control situation (without enrichment). These results could be useful for improving the analysis of emotions in pigs and assessing animal welfare.

Assessment of the Importance of Tympanic Membrane Mechanoreceptors on Eustachian Tube Function Based on Pressure Chamber Measurements.

Previously, it was demonstrated how the Eustachian tube (ET) opening function can be influenced by middle ear pressure and movement of the tympanic membrane via neural control. Mechanoreceptors on the tympanic membrane may be part of the afferent arc and could influence the middle ear pressure by activating the musculus veli palatini as part of a reflex. In a hypo and hyperbaric pressure chamber, 17 participants (34 ears) were twice exposed to a standardized pressure profile of pressure decrease and increase. The ET function reflecting parameters-ET opening pressure (ETOP), ET opening duration (ETOD), and ET opening frequency (ETOF)-were determined before and after local anesthesia of the right tympanic membrane. After pressure exposure by pressure increase (active induced equalization) and pressure decrease (passive equalization) there was no significant difference between the mean value of ETOP, ETOD, and ETOF before and after local anesthesia of the right tympanic membrane on the right (anesthetized) or left side (not anesthetized). These results may lead to the hypothesis that tympanic membrane mechanoreceptors may play a minor role in regulating the ET function in humans.

Analysis of corn ears movement within the threshing crescent using high-speed recording method

The main objective of the research was to establish movement of corn ears within the threshing crescent between the cylinder and the concave using high-speed recording method. Tangential threshing unit was used in the experimental trials. Cylinder rotation and linear velocity of rasp bars (11.00 m s-1, 14.14 m s-1 and 17.28 m s-1) were determined by using threshing cylinder covered with filler plates having 4 different shapes. During the trials, speed of corn ears within threshing crescent, number of impacts received by the corn ear, rising height of the corn ear after impact of rasp bar and time between two impacts of rasp bar to the corn ear, depending on the shape of filler plates of threshing cylinder were found. Video analysis of corn ear movement showed that the speed of corn ears movement in the threshing crescent highly depends on linear velocity of rasp bars. The average speed of corn ear within threshing crescent and number of impacts received by the corn ear were increased with increase of linear velocity of rasp bars irrespective of cylinder filler plates are used. Moreover, both above-mentioned parameters were larger in the second part of concave length than in the first one. A tendency of increase of the corn ear moving over the surface of the concave and decrease of number of impacts received by the corn ear was observable by reduction in the threshing crescent. Following reduction of linear velocity of rasp bars to 14.14 m s-1, it would be reasonable to cover the threshing cylinder with filler plates that can reduce the cross-section area between rasp bars and concave (to 94.26 cm2 in view of one gap between adjacent rasp bar). In this case, filler plates showed a substantial effect on behaviour of corn ears: they restrict a rising height of the corn ear, may be subject to additional rotational motion, deflect the corn ear to the clearance between the rasp bar and the concave bar as well as deflect threshed kernels towards concave grates.

Technical note: Validation of an ear-tag accelerometer sensor to determine rumination, eating, and activity behaviors of grazing dairy cattle

The objective of this study was to validate an ear-tag accelerometer sensor (CowManager SensOor, Agis Automatisering BV, Harmelen, the Netherlands) using direct visual observations in a grazing dairy herd. Lactating crossbred cows (n = 24) were used for this experiment at the University of Minnesota West Central Research and Outreach Center grazing dairy (Morris, MN) during the summer of 2016. A single trained observer recorded behavior every minute for 6 h for each cow (24 cows × 6 h = 144 h of observation total). Direct visual observation was compared with sensor data during August and September 2016. The sensor detected and identified ear and head movements, and through algorithms the sensor classified each minute as one of the following behaviors: rumination, eating, not active, active, and high active. A 2-sided t-test was conducted with PROC TTEST of SAS (SAS Institute Inc., Cary, NC) to compare the percentage of time each cow's behavior was recorded by direct visual observation and sensor data. For total recorded time, the percentage of time of direct visual observation compared with sensor data was 17.9 and 19.1% for rumination, 52.8 and 51.9% for eating, 17.4 and 11.9% for not active, and 7.9 and 21.1% for active. Pearson correlations (PROC CORR of SAS) were used to evaluate associations between direct visual observations and sensor data. Furthermore, concordance correlation coefficient (CCC), bias correction factors, location shift, and scale shift (epiR package of R version 3.3.1; R Foundation for Statistical Computing, Vienna, Austria) were calculated to provide a measure of accuracy and precision. Correlations between visual observations for all 4 behaviors were highly to weakly correlated (rumination: r = 0.72, CCC = 0.71; eating: r = 0.88, CCC = 0.88; not active: r = 0.65, CCC = 0.52; and active: r = 0.20, CCC = 0.19) compared with sensor data. The results suggest that the sensor accurately monitors rumination and eating behavior of grazing dairy cattle. However, active behaviors may be more difficult for the sensor to record than others.

Representations of speech signals recorded through a dynamic periphery inspired by horseshoe bat biosonar

Horseshoe bats have to navigate through complex environments such as dense forests and structure-rich vegetation relying on input from their highly sophisticated biosonar systems. One of the key components of these bats' ability to obtain high-quality acoustic information is to alter the shape of their outer ears rapidly. In prior work, the authors have shown that by mimicking the horseshoe bat rapid ear movements, a bat-inspired robotic dynamic periphery for recording speech signals could enhance speech recognition for limited dataset and also provide estimates for the speaker's direction along with speech recognition. In our current study, we continued to investigate how speech datasets processed by the dynamic periphery may be enhanced compared to a reference by extracting acoustical features through Mel frequency cepstral coefficient (MFCC) transform, Lyon's cochlear bandpass filters, and a neural spike representation, respectively. This study aims to characterize the detailed acoustical differences and quantify the improved speaker intelligence with noise robustness through the dynamic periphery. The ultimate goal of this research is to identify a signal representation that is well suited to capitalize on the time-variant properties of the biomimetic recording periphery and make the dynamic information-bearing features accessible for the classification stages.Horseshoe bats have to navigate through complex environments such as dense forests and structure-rich vegetation relying on input from their highly sophisticated biosonar systems. One of the key components of these bats' ability to obtain high-quality acoustic information is to alter the shape of their outer ears rapidly. In prior work, the authors have shown that by mimicking the horseshoe bat rapid ear movements, a bat-inspired robotic dynamic periphery for recording speech signals could enhance speech recognition for limited dataset and also provide estimates for the speaker's direction along with speech recognition. In our current study, we continued to investigate how speech datasets processed by the dynamic periphery may be enhanced compared to a reference by extracting acoustical features through Mel frequency cepstral coefficient (MFCC) transform, Lyon's cochlear bandpass filters, and a neural spike representation, respectively. This study aims to characterize the detailed acoustical differences a...

Echo-acoustic scanning with noseleaf and ears in phyllostomid bats.

The mammalian visual system is highly directional and mammals typically employ rapid eye movements to scan their environment. Both sound emission and hearing in echolocating bats are directional but not much is known about how bats use ear movements and possibly movements of the sound-emitting structures to scan space. Here, we investigated in a tightly controlled behavioural experiment how Phyllostomusdiscolor bats employ their echolocation system while being moved through differently structured environments: we monitored and reconstructed both a close-up of the facial structures in 3D, including the motile noseleaf and outer ears, and the sonar-beam of the bat while it was moved along reflectors. Despite the simple linear movement of the bats in the setup, the bats pointed their beam quite variably in azimuth with a standard deviation of about ±20deg. This variation arises from yaw-type head rotations. Video analyses show that the bat's noseleaf twitches with every echolocation call. Second, we show that the bat's ears are raised to a rather stereotypical head-centred position with every echolocation call. Surprisingly, P. discolor can adjust the timing and the magnitude of these ear movements to the distance of the reflectors with millisecond precision. Our findings reveal echolocation-specific specialisations as well as general principles of scanning and stabilisation of a directional remote sense. The call-correlated movements of the facial structures may lead to a higher directionality of the echolocation system and may enable the bats to adjust their echo-acoustic gaze to dynamic environments.

Relevance of Ear Movements in Dog's Emotional Expressions

In dog’s mimicry, ears movements are absolutely relevant. Dogs use them like humans using eyebrows: for a better communication. Using the DOGFACS maps,elative to the ears movement classification (EAD, Ears Action Units), we try to connect every EAD to a specific emotion. We consider just the fundamental emotion: fear, surprise, anger, happiness, disgust, sadness. Of course, dog communication is very complex, so just the ears movements are not enough to completely understand it, but, like for human eyebrows, they help very much in the comprehension. We analyzed the 6 emotions in 41 different dogs to have enough data.

Mimetic Muscles in a Despotic Macaque (Macaca mulatta) Differ from Those in a Closely Related Tolerant Macaque (M. nigra)

Facial displays (or expressions) are a primary means of visual communication among conspecifics in many mammalian orders. Macaques are an ideal model among primates for investigating the co-evolution of facial musculature, facial displays, and social group size/behavior under the umbrella of "ecomorphology". While all macaque species share some social behaviors, dietary, and ecological parameters, they display a range of social dominance styles from despotic to tolerant. A previous study found a larger repertoire of facial displays in tolerant macaque species relative to despotic species. The present study was designed to further explore this finding by comparing the gross morphological features of mimetic muscles between the Sulawesi macaque (Macaca nigra), a tolerant species, and the rhesus macaque (M. mulatta), a despotic species. Five adult M. nigra heads were dissected and mimetic musculature was compared to those from M. mulatta. Results showed that there was general similarity in muscle presence/absence between the species as well as muscle form except for musculature around the external ear. M. mulatta had more musculature around the external ear than M. nigra. In addition, M. nigra lacked a zygomaticus minor while M. mulatta is reported to have one. These morphological differences match behavioral observations documenting a limited range of ear movements used by M. nigra during facial displays. Future studies focusing on a wider phylogenetic range of macaques with varying dominance styles may further elucidate the roles of phylogeny, ecology, and social variables in the evolution of mimetic muscles within Macaca Anat Rec, 299:1317-1324, 2016. © 2016 Wiley Periodicals, Inc.

Evaluation of calving indicators measured by automated monitoring devices to predict the onset of calving in Holstein dairy cows

Dystocias are common in dairy cows and often adversely affect production, reproduction, animal welfare, labor, and economics within the dairy industry. An automated device that accurately predicts the onset of calving could potentially minimize the effect of dystocias by enabling producers to intervene early. Although many well-documented indicators can detect the imminence of calving, research is limited on their effectiveness to predict calving when measured by automated devices. The objective of this experiment was to determine if a decrease in vaginal temperature (VT), rumination (RT), and lying time (LT), or an increase in lying bouts (LB), as measured by 3 automated devices, could accurately predict the onset of calving within 24, 12, and 6h. The combination of these 4 calving indicators was also evaluated. Forty-two multiparous Holstein cows housed in tie-stalls were fitted with a temperature logger inserted in the vaginal cavity 7±2d before their expected calving date; VT was recorded at 1-min intervals. An ear-attached sensor recorded rumination time every hour based on ear movement while an accelerometer fitted to the right hind leg recorded cow position at 1-min intervals. On average, VT were 0.3±0.03°C lower, and RT and LT were 41±17 and 52±28min lower, respectively, on the calving day compared with the previous 4d. Cows had 2±1 more LB on the calving day. Of the 4 indicators, a decrease in VT≥0.1°C was best able to predict calving within the next 24h with a sensitivity of 74%, specificity of 74%, positive and negative predictive values of 51 and 89%, and area under the curve of 0.80. Combining the indicators enhanced the performance to predict calving within the next 24, 12, and 6h with best overall results obtained by combining the 3 devices for prediction within the next 24h (sensitivity: 77%, specificity: 77%, positive and negative predictive values: 56 and 90%, area under the curve: 0.82). These results indicate that a device that could simultaneously measure these 4 calving indicators could not precisely determine the onset of calving, but the information collected would assist dairy farmers in monitoring the onset of calving.

Reactions of sheep towards three sets of emotional stimuli: (In)Consistency in respect to stimulus valence and sheep identity

There is an increasing interest in affective states in applied animal behaviour science, because these states are thought to reflect welfare from the perspective of the animals. Also, it can be expected that individuals differ in how they consistently react to emotional challenges. Recently, we conducted three experiments in which the same sheep were repeatedly confronted with either physical, social or thermal stimuli that presumably varied in their valence. These sheep had been housed in either unpredictable, stimulus-poor or predictable, stimulus-rich housing conditions in order to manipulate their long-term mood. When the sheep were exposed to the stimuli, we measured general activity, ear movements, ear postures and frontal cortical haemodynamic changes as indicator variables for their emotional reaction. In the meta-analysis presented here, we searched for effects of the presumed valence and mood state on the indicator variables. Furthermore, we investigated the unexplained between- versus within-subject variability as an indicator of personality. Deoxy- [HHb] and oxy-haemoglobin concentrations [O2Hb] as well as general activity showed weak linear relationships with presumed valence. Sheep from the unpredictable, stimulus-poor housing conditions were generally more active and showed more ear movements, higher absolute [HHb], more transverse ears and less left-forward ears than sheep from the predictable, stimulus-rich housing conditions. However, these differences were small. The ratio of between- to within-individual variability was very low indicating little consistency in individual reactions. In conclusion, we found only weak evidence that presumed valence had a consistent effect on the indicator variables for emotional reactions in a given sheep, and these reactions were not modulated by presumed mood. Also, there was little indication that the sheep reacted in a way reflecting an individualised personality.

Technical note: Accuracy of an ear tag-attached accelerometer to monitor rumination and feeding behavior in feedlot cattle.

Early identification of sick cattle increases treatment success and decreases mortality. Continuous automated records of behavior can be used to identify sick cattle early in the disease process. The objective was to evaluate accuracy of an ear-attached accelerometer (SensOor) that quantified ear movements and estimated feeding and rumination time through a proprietary algorithm. Accelerometers were attached to the ear tag of 18 steers with an initial mean BW of 326 ± 46 kg. The manufacturer's proprietary software was used to determine time spent "feeding," "ruminating," "active," and "resting." Direct visual observation was used to validate the accelerometer. Sensitivity, specificity, and predictive values were calculated for rumination and feeding separately. Repeated measures were accounted for using mixed model logistic regression. Single minutes of either feeding or rumination in a run of other behavior minutes were changed to the preceding behavior. Accuracy and precision of hourly recorded feeding and rumination times were assessed using the concordance correlation coefficient adjusted for repeated measurements. Sensitivity and specificity were 95 and 76% for feeding and 49 and 96% for rumination, respectively. Concordance correlation between observations and the sensor were 0.79 (95% CI: 0.61 to 0.85) and 0.44 (95% CI: 0.23 to 0.60) for feeding and rumination, respectively. There was large variability among steers, with concordance correlations ranging from 0.09 to 0.98 for rumination time and from 0.58 to 0.96 for feeding time. We conclude that the accelerometer is a promising monitoring system for feeding behavior.

Frontal Brain Activity and Behavioral Indicators of Affective States are Weakly Affected by Thermal Stimuli in Sheep Living in Different Housing Conditions.

Many stimuli evoke short-term emotional reactions. These reactions may play an important role in assessing how a subject perceives a stimulus. Additionally, long-term mood may modulate the emotional reactions but it is still unclear in what way. The question seems to be important in terms of animal welfare, as a negative mood may taint emotional reactions. In the present study with sheep, we investigated the effects of thermal stimuli on emotional reactions and the potential modulating effect of mood induced by manipulations of the housing conditions. We assume that unpredictable, stimulus-poor conditions lead to a negative and predictable, stimulus-rich conditions to a positive mood state. The thermal stimuli were applied to the upper breast during warm ambient temperatures: hot (as presumably negative), intermediate, and cold (as presumably positive). We recorded cortical activity by functional near-infrared spectroscopy, restlessness behavior (e.g., locomotor activity, aversive behaviors), and ear postures as indicators of emotional reactions. The strongest hemodynamic reaction was found during a stimulus of intermediate valence independent of the animal’s housing conditions, whereas locomotor activity, ear movements, and aversive behaviors were seen most in sheep from the unpredictable, stimulus-poor housing conditions, independent of stimulus valence. We conclude that, sheep perceived the thermal stimuli and differentiated between some of them. An adequate interpretation of the neuronal activity pattern remains difficult, though. The effects of housing conditions were small indicating that the induction of mood was only modestly efficacious. Therefore, a modulating effect of mood on the emotional reaction was not found.

Evidence for a functional subdivision of Premotor Ear-Eye Field (Area 8B).

The Supplementary Eye Field (SEF) and the Frontal Eye Field (FEF) have been described as participating in gaze shift control. Recent evidence suggests, however, that other areas of the dorsomedial prefrontal cortex also influence gaze shift. Herein, we have investigated electrically evoked ear- and eye movements from the Premotor Ear-Eye Field, or PEEF (area 8B) of macaque monkeys. We stimulated PEEF during spontaneous condition (outside the task performance) and during the execution of a visual fixation task (VFT). In the first case, we functionally identified two regions within the PEEF: a core and a belt. In the core region, stimulation elicited forward ear movements; regarding the evoked eye movements, in some penetrations, stimulation elicited contraversive fixed-vectors with a mean amplitude of 5.14°; while in other penetrations, we observed prevalently contralateral goal-directed eye movements having end-points that fell within 15° in respect to the primary eye position. On the contrary, in the belt region, stimulation elicited backward ear movements; regarding the eye movements, in some penetrations stimulation elicited prevalently contralateral goal-directed eye movements having end-points that fell within 15° in respect to the primary eye position, while in the lateral edge of the investigated region, stimulation elicited contralateral goal-directed eye movements having end-points that fell beyond 15° in respect to the primary eye position. Stimulation during VFT either did not elicit eye movements or evoked saccades of only a few degrees. Finally, even though no head rotation movements were observed during the stimulation period, we viewed a relationship between the duration of stimulation and the neck forces exerted by the monkey's head. We propose an updated vision of the PEEF composed of two functional regions, core and belt, which may be involved in integrating auditory and visual information important to the programming of gaze orienting movements.