Evaluating warning sound urgency with reaction times

It is well-established that subjective judgments of perceived urgency of alarm sounds can be affected by acoustic parameters. In this study, the authors investigated an objective measurement, the reaction time (RT), to test the effectiveness of temporal parameters of sounds in the context of warning sounds. Three experiments were performed using a RT paradigm, with two different concurrent visuomotor tracking tasks simulating driving conditions. Experiments 1 and 2 show that RT decreases as interonset interval (IOI) decreases, where IOI is defined as the time elapsed from the onset of one sound pulse to the onset of the next. Experiment 3 shows that temporal irregularity between pulses can capture a listener's attention. These findings lead to concrete recommendations: IOI can be used to modulate warning sound urgency; and temporal irregularity can provoke an arousal effect in listeners. The authors also argue that the RT paradigm provides a useful tool for clarifying some of the factors involved in alarm processing.     

The motion aftereffect reloaded

The motion aftereffect is a robust illusion of visual motion resulting from exposure to a moving pattern. There is a widely accepted explanation of it in terms of changes in the response of cortical direction-selective neurons. Research has distinguished several variants of the effect. Converging recent evidence from different experimental techniques (psychophysics, single-unit recording, brain imaging, transcranial magnetic stimulation, visual evoked potentials and magnetoencephalography) reveals that adaptation is not confined to one or even two cortical areas, but occurs at multiple levels of processing involved in visual motion analysis. A tentative motion-processing framework is described, based on motion aftereffect research. Recent ideas on the function of adaptation see it as a form of gain control that maximises the efficiency of information transmission at multiple levels of the visual pathway.     

Social mobbing calls in common marmosets (Callithrix jacchus): effects of experience and associated cortisol levels

We compared the mobbing response to model snakes of two groups of captive-born common marmosets (Callithrix jacchus) differing in genetic relatedness, age and past experience. Mobbing vocalisations (tsik calls), other mobbing behaviour and attention to the stimulus were recorded for 2 min. intervals pre-exposure, during exposure to various stimuli and post-exposure. Marmosets in one group were vocally reactive to all stimuli, although more so to one particular stimulus resembling rearing snakes and modified images of it, whereas the marmosets in a younger and genetically unrelated group attended to the stimuli but made very few mobbing calls. The parent stock of the first group had suffered stress in early life and had developed a phobic response to a specific stimulus, which they had transmitted to their offspring. A third group, matching the older group in age range but genetically unrelated, was also found to be unresponsive to the stimulus that elicited the strongest response in the first group. Cortisol levels in samples of hair were assayed and a significant negative correlation was found between the number of tsik calls made during presentation of the stimuli and the cortisol level, showing that mobbing behaviour/behavioural reactivity is associated with low levels of physiological stress.     

Infant transfer behavior in humans: A note on the exploitation of young

Human infant transfers filmed in West New Guinea and stored in the archives of Max-Planck Geselschaft are formally described and analyzed relative to reports of similar behavior from nonhuman primates in laboratory and field studies. Motor patterns directed from one individual to another were discriminated and grouped into five categories of behavior ordered according to their relative likelihoods of “damaging aggression” [Fagen, American Naturalist, 115:858–869, 1980]. Transfers generally occurred between two females of different reproductive conditions. Most interactions were directed from the holder of the infant to the infant, demonstrating that the infant is the recipient of most nondamaging as well as potentially damaging behavior. While transfers are characterized by “aggressive restraint,” the least damaging behavior is most likely to precede a transfer and may function to prolong the relative duration of infant holding. Behavior with a relatively high likelihood of damage to the infant by the infant holder is as likely to occur before as after transfer, suggesting that infant transfer behavior in this human society reflects competitive interactions among adult females.     

Robustness of the rule-learning effect in 7-month-old infants: A close,multicenter replication of Marcus et al. (1999)

We conducted a close replication of the seminal work by Marcus and colleagues from 1999, which showed that after a brief auditory exposure phase, 7-month-old infants were able to learn and generalize a rule to novel syllables not previously present in the exposure phase. This work became the foundation for the theoretical framework by which we assume that infants are able to learn abstract representations and generalize linguistic rules. While some extensions on the original work have shown evidence of rule learning, the outcomes are mixed, and an exact replication of Marcus et al.'s study has thus far not been reported. A recent meta-analysis by Rabagliati and colleagues brings to light that the rule-learning effect depends on stimulus type (e.g., meaningfulness, speech vs. nonspeech) and is not as robust as often assumed. In light of the theoretical importance of the issue at stake, it is appropriate and necessary to assess the replicability and robustness of Marcus et al.'s findings. Here we have undertaken a replication across four labs with a large sample of 7-month-old infants (N = 96), using the same exposure patterns (ABA and ABB), methodology (Headturn Preference Paradigm), and original stimuli. As in the original study, we tested the hypothesis that infants are able to learn abstract “algebraic” rules and apply them to novel input. Our results did not replicate the original findings: infants showed no difference in looking time between test patterns consistent or inconsistent with the familiarization pattern they were exposed to.     

Vocal indicators of facilitative interpersonal skills

The facilitative interpersonal skills (FIS) method uses simulations of difficult client moments as a test of helpers' ability to remain therapeutic in therapeutically stressful situations. A total of 135 participants completed the FIS task as part of a training in helping skills and provided verbal responses that were assessed by trained raters for interpersonal skills. Audio recordings of these verbal responses were then analysed acoustically for fundamental frequency (F0), spectral slope and F0 range. Mean F0 and F0 range were more highly associated with trained raters' ratings of FIS for female participants than for male participants, although F0 range was associated with FIS of both males and females. The results suggest that F0 is associated with FIS for females, especially the FIS items that are indicative of emotional expression and verbal fluency. Findings are discussed as possibly indicating that some expression of higher F0 in response to distressed client situations may be part of interpersonal skills, such that more skilled therapists respond to stressful client situations with a higher F0.