Neurocognitive processing efficiency for non-alarm rather than alarm signaling in human scream calls

ABSTRACTAcross many species, scream calls signal the affective significance of events to other agents. Scream calls were often supposed to be of generic alarming and fearful nature to signal potential threats including their instantaneous, involuntary, and accurate recognition by perceivers. However, scream calls are more diverse in their affective signaling nature than being limited to fearfully alarm a threat, and thus the broader sociobiological relevance of various scream types is unclear. Here we used four different psychoacoustic, perceptual decision-making, and neuroimaging experiments in humans to demonstrate, first, the existence of at least six generic and psycho-acoustically distinctive types of scream calls of both an alarming and a non-alarming nature, rather than being limited to only screams caused by fear or aggression. Second, based on perceptual and processing sensitivity measures for decision-making during scream recognition, we found that alarming screams (with some exceptions) were overall discriminated the worst, were responded to the slowest and were associated with the lower perceptual sensitivity for their recognition compared with non-alarm screams. Third, the neural processing of alarm compared with non-alarm screams during an implicit processing task elicited only minimal neural signal and connectivity in perceivers, contrary to the frequent assumption of a threat processing bias of the primate neural system. These findings show that scream calls are more diverse in their signaling and communicative nature in humans and that especially non-alarming screams, and positive screams in particular, seem to have higher efficiency in the cognitive, neural, and communicative processing in humans.

Collision Prevention Algorithm for Fishing Vessels Using mmWAVE Communication

This study leveraged the millimeter wireless access in vehicular environments (mmWAVE) communication technology to reflect the maneuvering characteristics of small fishing vessels and constructed a collision prevention algorithm that can be applied relatively easily. The algorithm was verified through simulation and actual ship experiments. The algorithm had four components: detection of vessels within three miles; identification of dangerous vessels by applying the time to the closest point of approach (TCPA) and distance at the closest point of approach (DCPA) criteria; continuous monitoring of maritime traffic risk; and incremental alarm signaling. The simulations and experiments confirmed that the alarm was generated incrementally in accordance with the distance to a dangerous situation, with no false alarms. Thus, the proposed algorithm offers potential to enhance the safety of small fishing vessels.

Elimination of HSV-2 infected cells is mediated predominantly by paracrine effects of tissue-resident T cell derived cytokines

The mechanisms underlying rapid elimination of herpes simplex virus-2 (HSV-2) in the human genital tract despite low tissue-resident CD8+ T-cell density (TRM) are unknown. We analyzed shedding episodes during chronic HSV-2 infection: viral clearance always occurred within 24 hours of detection even if viral load exceeded 107HSV DNA copies; surges in granzyme B and interferon-γoccurred within the early hours after reactivation. We next developed a mathematical model of an HSV-2 genital ulcer to integrate mechanistic observations of TRMin situproliferation, trafficking, cytolytic effects and cytokine alarm signaling from murine studies with viral kinetics, histopathology and lesion size data from humans. A sufficiently high density of HSV-2 specific TRMpredicted rapid contact-mediated elimination of infected cells. At lower TRMdensities, TRMmust initiate a rapidly diffusing, polyfunctional cytokine response in order to eliminate of a majority of infected cells and eradicate briskly spreading HSV-2 infection.One Sentence SummaryControl of herpes simplex virus-2 is primarily mediated by rapidly diffusing cytokines secreted by tissue-resident T cells.

On-Line Tracking and Monitoring of Rolling Element Bearing Faults

Diagnostics of rolling element bearings is usually performed by the analysis of vibration signal using suitable signal analysis tools, such as the most used and simplest method, Envelope Analysis. This method is based on the identification of bearing damage frequency components in the so-called Square Envelope Spectrum. If the assessment of the bearing health is quite a simple task, the on-line monitoring and the real-time evaluation of the trend of a suitable damage index is a complex task to be performed in an automatic way. The damage index must be robust against variations of system operating conditions and external vibration sources to avoid misleading results. The damage index should be also simple to be evaluated in the case of real-time applications. In the paper, the case of a rolling element bearing in which the defect develops until a permanent failure is described as well as the algorithm implemented for alarm signaling.

Joint tail and vocal alarm signals of gray squirrels (Sciurus carolinensis)

Threat-specific vocalizations have been observed in primates and ground squirrels, but their contemporaneous usage with visible signals has not been experimentally analyzed for association with threat type. Here we examine the eastern gray squirrel, an arboreal squirrel that uses both vocal and tail signals as alarms. Squirrels were presented with cat and hawk models simulating natural terrestrial or aerial predator attacks and also with control objects that do not resemble predators but approach in a similar manner. Individuals responded with tail signals (twitches and flags) and vocalizations (kuks, quaas and moans), but only flags and moans are associated with predator type. Moans were elicited primarily by aerial stimuli and flags by terrestrial stimuli. Eastern gray squirrels use an alarm-signaling system in which signals in each modality potentially are associated with particular attributes of a threat or may be general alarms. Terrestrially-approaching stimuli yielded vocal and tail alarm signals regardless of whether the stimulus resembled a predator. With aerially-approaching stimuli, however, quaas were used more often when the stimulus resembled an aerial predator than when it did not. An approaching object’s physical appearance may therefore affect squirrels’ responses to aerial, but not terrestrial, objects. When the stimuli resembled real predators approaching in the natural manner (terrestrially or aerially), both tail flags and vocal moans were associated with predator type, so we also considered moans and flags together. The presence and absence of moans and flags in an alarm signaling bout yields a higher statistical index of predictive association as to whether the threat is aerial or terrestrial than does either component alone.

Multimodal alarm behavior in urban and rural gray squirrels studied by means of observation and a mechanical robot

Urbanization of animal habitats has the potential to affect the natural communication systems of any species able to survive in the changed environment. Urban animals such as squirrels use multiple signal channels to communicate, but it is unknown how urbanization has affected these behaviors. Multimodal communication, involving more than one sensory modality, can be studied by use of biomimetic mechanical animal models that are designed to simulate the multimodal signals and be presented to animal subjects in the field. In this way the responses to the various signal components can be compared and contrasted to determine whether the multimodal signal is made up of redundant or nonredundant components. In this study, we presented wild gray squirrels in relatively urban and relatively rural habitats in Western Massachusetts with a biomimetic squirrel model that produced tail flags and alarm barks in a variety of combinations. We found that the squirrels responded to each unimodal component on its own, the bark and tail flag, but they responded most to the complete multimodal signal, containing both the acoustic and the moving visual components, providing evidence that in this context the signal components are redundant and that their combination elicits multimodal enhancement. We expanded on the results of Partan et al. (2009) by providing data on signaling behavior in the presence and absence of conspecifics, suggesting that alarm signaling is more likely if conspecifics are present. We found that the squirrels were more active in the urban habitats and that they responded more to tail flagging in the urban habitats as compared to the rural ones, suggesting the interesting possibility of a multimodal shift from reliance on audio to visual signals in noisier more crowded urban habitats.