When two limbs are weaker than one: Sensorimotor syncopation with alternating hands

This study addresses the demands of alternating bimanual syncopation, a coordination mode in which the two hands move in alternation while tapping in antiphase with a metronomic tone sequence. Musically trained participants were required to engage in alternating bimanual syncopation and five other coordination modes: unimanual syncopation where taps are made (with the left or right hand) after every tone; unimanual syncopation where taps are made after every other tone; bimanual synchronization with alternating hands; unimanual synchronized tapping with every tone; and unimanual tapping with every other tone. Variability in tap timing was greatest overall for alternating bimanual syncopation, indicating that it is the most difficult. This appears to be due to instability arising from the simultaneous presence of two levels of antiphase coordination (one between the pacing sequence and the hands, the other between the two hands) rather than factors relating to movement frequency or dexterity limits of the nonpreferred hand.     

How infant-directed actions enhance infants’ attention,learning, and exploration: Evidence from EEG and computational modeling

When teaching infants new actions, parents tend to modify their movements. Infants prefer these infant-directed actions (IDAs) over adult-directed actions and learn well from them. Yet, it remains unclear how parents’ action modulations capture infants’ attention. Typically, making movements larger than usual is thought to draw attention. Recent findings, however, suggest that parents might exploit movement variability to highlight actions. We hypothesized that variability in movement amplitude rather than higher amplitude is capturing infants’ attention during IDAs. Using EEG, we measured 15-month-olds’ brain activity while they were observing action demonstrations with normal, high, or variable amplitude movements. Infants’ theta power (4–5 Hz) in fronto-central channels was compared between conditions. Frontal theta was significantly higher, indicating stronger attentional engagement, in the variable compared to the other conditions. Computational modelling showed that infants’ frontal theta power was predicted best by how surprising each movement was. Thus, surprise induced by variability in movements rather than large movements alone engages infants’ attention during IDAs. Infants with higher theta power for variable movements were more likely to perform actions successfully and to explore objects novel in the context of the given goal. This highlights the brain mechanisms by which IDAs enhance infants’ attention, learning, and exploration.     

Free-operant avoidance in the pigeon using a treadle response

A free-operant avoidance schedule was used to establish and maintain foot-treadle responding by two Homing, one White King, and two Carneaux pigeons. In the absence of responding, the interval between shocks equaled 10 sec. Each time a treadle response occurred the shock was postponed for 32 sec. Pigeons appear to learn the treadle response more quickly and use it to avoid shock more successfully than do rats bar pressing on similar schedules. The treadle response becomes highly stereotyped and interresponse time distributions obtained from terminal behavior appear very similar to data obtained from rats. It is concluded that the difficulty in training pigeons to avoid electric shock is not in establishing avoidance behavior but in attempting to evaluate such behavior with the key-peck response.     

Social Comparisons and Absenteeism: A Structural Modeling Approach1

In this study a social comparison model is constructed that predicts objectively recorded absence frequency among male Dutch blue-collar workers from a metal factory in the Netherlands. By employing LISREL, the model is developed (tested and revised) in Plant North (N = 254), and successfully cross-validated in Plant South (N= 199). The study demonstrates the impact of two social comparison processes upon absenteeism. Absenteeism is the result of: (a) the perception that one is less well-off than one's colleagues on several job aspects, and (b) the adjustment of one's personal absence norm to that of the work group. In addition, our study reveals that, rather than being absent or having tolerant absence norms, employees may develop feelings of resentment in response to perceived inequity and a tolerant group absence norm. It is concluded that social comparison theory enhances our understanding of absenteeism.     

You'll Never Believe This: Irony and Hyperbole in Expressing Surprise

Three experiments compared how people comprehend irony and hyperbole as expressing surprise. Experiment 1 demonstrated that, when irony and hyperbole are used together, they express more surprise than if either is used alone. There was no difference between the degree of surprise expressed by hyperbole and irony, although both expressed more surprise than literal commentary. Experiment 2 revealed that, when a speaker has exaggerated about some unexpected event, as much surprise is expressed by very slight, realistically possible hyperbole as by outlandish, impossible hyperbole. In a third experiment the range of possible levels of hyperbole tested in Experiment 2 was shown to cause differences in how easy it was to determine that a speaker was surprised at some turn of events. The results are discussed in terms of theories of irony and hyperbole comprehension.