Whose Input Matters? The influence of socially-differentiated input sources in adult Lx phonetic learning

Input is a necessary condition for language acquisition, and in the language classroom, input may come from a variety of sources, including the teacher and student peers. Here we ask whether adult Lx learners are sensitive to the social roles of teachers and students such that they exhibit a preference for input from the teacher. We conducted an experiment wherein adult English speakers heard words in an artificial language. During an exposure phase, in one condition a “teacher” produced words with 25 ms of VOT on initial stop segments and a “student” produced the same words with 125 msec, and in another condition the VOT durations were reversed. At test, participants judged productions by a different “student” and demonstrated a preference for the productions that matched the VOT durations of the teacher during exposure, providing evidence for an influence of social factors in differentiating input in Lx acquisition.

Lack of neophobic responses to color in a jumping spider that uses color cues when foraging (Habronattus pyrrithrix)

Chemically defended prey often advertise their toxins with bright and conspicuous colors. To understand why such colors are effective at reducing predation, we need to understand the psychology of key predators. In bird predators, there is evidence that individuals avoid novelty—including prey of novel colors (with which they have had no prior experience). Moreover, the effect of novelty is sometimes strongest for colors that are typically associated with aposematic prey (e.g., red, orange, yellow). Given these findings in the bird literature, color neophobia has been argued to be a driving force in the evolution of aposematism. However, no studies have yet asked whether invertebrate predators respond similarly to novel colors. Here, we tested whether naive lab-raised jumping spiders (Habronattus pyrrithrix) exhibit similar patterns of color neophobia to birds. Using color-manipulated living prey, we first color-exposed spiders to prey of two out of three colors (blue, green, or red), with the third color remaining novel. After this color exposure phase, we gave the spiders tests where they could choose between all three colors (two familiar, one novel). We found that H. pyrrithrix attacked novel and familiar-colored prey at equal rates with no evidence that the degree of neophobia varied by color. Moreover, we found no evidence that either prey novelty nor color (nor their interaction) had an effect on how quickly prey was attacked. We discuss these findings in the context of what is known about color neophobia in other animals and how this contributes to our understanding of aposematic signals.

ACQUIRING L2 PRONOUN INTERPRETATION BIASES

Learners of a nonnull subject language (e.g., English) whose first language (L1) is a null subject language (e.g., Spanish) can show some optionality in the interpretation of overt subject pronouns in the second language (L2). By exposing L2 learners to nativelike interpretations of pronouns in discourse, we aim at understanding how exposure can promote implicit learning of pronoun comprehension biases in a L2. A sentence comprehension task was used with intermediate-proficiency English L2 speakers (L1 Spanish) that included a pretest, an exposure phase using the priming technique, an immediate posttest, and a delayed posttest administered 6–10 days later. English learners showed a significant increase in nativelike pronoun interpretations both in the immediate posttest and in the delayed posttest, in comparison to the pretest. The results show that exposure through priming can be effective in changing L2 participants’ interpretations and that effects of exposure are persistent and may aid in the successful acquisition of pronoun resolution biases.

Responses to Auditory Feedback Manipulations in Speech May Be Affected by Previous Exposure to Auditory Errors

Purpose Speakers use auditory feedback to guide their speech output, although individuals differ in the magnitude of their compensatory response to perceived errors in feedback. Little is known about the factors that contribute to the compensatory response or how fixed or flexible they are within an individual. Here, we test whether manipulating the perceived reliability of auditory feedback modulates speakers' compensation to auditory perturbations, as predicted by optimal models of sensorimotor control. Method Forty participants produced monosyllabic words in two separate sessions, which differed in the auditory feedback given during an initial exposure phase. In the veridical session exposure phase, feedback was normal. In the noisy session exposure phase, small, random formant perturbations were applied, reducing reliability of auditory feedback. In each session, a subsequent test phase introduced larger unpredictable formant perturbations. We assessed whether the magnitude of within-trial compensation for these larger perturbations differed across the two sessions. Results Compensatory responses to downward (though not upward) formant perturbations were larger in the veridical session than the noisy session. However, in post hoc testing, we found the magnitude of this effect is highly dependent on the choice of analysis procedures. Compensation magnitude was not predicted by other production measures, such as formant variability, and was not reliably correlated across sessions. Conclusions Our results, though mixed, provide tentative support that the feedback control system monitors the reliability of sensory feedback. These results must be interpreted cautiously given the potentially limited stability of auditory feedback compensation measures across analysis choices and across sessions. Supplemental Material https://doi.org/10.23641/asha.14167136

Odor-taste interactions in food perception: Exposure protocol shows no effects of associative learning

Repeated exposure can change the perceptual and hedonic features of flavor. Associative learning during which a flavor’s odor component is affected by co-exposure with taste is thought to be central in this process. However, changes can also arise due to exposure to the odor in itself. The aim of this study was to dissociate effects of associative learning from effects of exposure without taste by repeatedly presenting one odor together with sucrose and a second odor alone. Sixty individuals attended two testing sessions separated by a five-day exposure phase during which the stimuli were presented as flavorants in chewing gums that were chewed three times daily. Ratings of odor sweetness, odor pleasantness, odor intensity enhancement by taste, and odor referral to the mouth were collected at both sessions. Consistent with the notion that food preferences are modulated by exposure, odor pleasantness increased between the sessions independently of whether the odor (basil or orange flower) had been presented with or without sucrose. However, we found no evidence of associative learning in any of the tasks. In addition, exploratory equivalence tests suggested that these effects were either absent or insignificant in magnitude. Taken together, our results suggest that the hypothesized effects of associative learning are either smaller than previously thought or highly dependent on the experimental setting. Future studies are needed to evaluate the relative support for these explanations and, if experimental conditions can be identified that reliably produce such effects, to identify factors that regulate the formation of new odor-taste associations.

Non-invasive Neurologic Assessment in Recovery and Treatment Phase Acrylamide Exposure in Ageing Wistar Rats

Acrylamide is a chemical that naturally forms in starchy food products during every day high temperature cooking. The ingredients, storage and processing conditions greatly influence acrylamide formation in food. Home-cooking choices can have a substantial impact on the level of acrylamide humans are exposed to through the diet. This study scientifically determined the neurologic impact of acrylamide treatment and recovery in male wistar rats of different ages. A total of 20 male wistar rats were randomly sampled into 4 groups aged 45, 60, 75 and 90 days. The treatment dose was 50 mg/kg of acrylamide for 7 days. The study duration was 15 days with 2 phases; day 1 to 7 for exposure phase and day 8 to 14 as recovery phase after acrylamide exposure. Neurologic tests performed include open field test (OFT), buried reward test (BRT) and hand grip test (HGT). The study data was statistically significant at a confidence interval less or equal to 95%. Acrylamide adversely affected the tested physiologic responses in all ages during the phase of exposure. The distance covered and escape attempts were significantly reduced in all ages during acrylamide exposure phase with significant recovery in 45 and 60 days old animals. Group 45 and 60 days old animals had a wider field area during recovery phase but no observed improvement in exploratory behavior in ages 75 and 90 days. Olfactory and neuromuscular function was significantly improved in all age groups during recovery, however, the response of ages 45, 60 and 75 were similar during recovery. In this study, Acrylamide caused manifestations typical of a neurotoxic agent. The neurologic effect of acrylamide may be reversed if exposure period with the studied dose is within 7 days. Recovery in cognitive, exploratory, emotional, olfactory and neuromuscular function may be dependent on age during exposure.

Rhythmic Recursion? Human Sensitivity to a Lindenmayer Grammar with Self-similar Structure in a Musical Task

Processing of recursion has been proposed as the foundation of human linguistic ability. Yet this ability may be shared with other domains, such as the musical or rhythmic domain. Lindenmayer grammars (L-systems) have been proposed as a recursive grammar for use in artificial grammar experiments to test recursive processing abilities, and previous work had shown that participants are able to learn such a grammar using linguistic stimuli (syllables). In the present work, we used two experimental paradigms (a yes/no task and a two-alternative forced choice) to test whether adult participants are able to learn a recursive Lindenmayer grammar composed of drum sounds. After a brief exposure phase, we found that participants at the group level were sensitive to the exposure grammar and capable of distinguishing the grammatical and ungrammatical test strings above chance level in both tasks. While we found evidence of participants’ sensitivity to a very complex L-system grammar in a non-linguistic, potentially musical domain, the results were not robust. We discuss the discrepancy within our results and with the previous literature using L-systems in the linguistic domain. Furthermore, we propose directions for future music cognition research using L-system grammars.

Fire performance of concrete-encased CFST columns and beam-column joints

Concrete-encased CFST (concrete filled steel tube) structure is a type of composite structure featuring an inner CFST component and an outer reinforced concrete (RC) component. They are gaining popularity in high-rise buildings and large-span buildings in China nowadays. To date, the behaviour of concrete-encased CFST structures at ambient temperature has been investigated, but their fire performance has seldom been addressed, including the performance in fire and after exposure to fire. This paper summarizes the fire test results of concrete-encased CFST columns and beam-column joints. The cruciform beam-column joint was composed of one continuous concrete-encased CFST column and two cantilevered reinforced concrete (RC) beams. These specimens were subjected to a combined effect of load and full-range fire. The test procedure included four phases, i.e. a loading phase at ambient temperature, a standard fire exposure phase with constant load applied, a sequential cooling phase and a postfire loading phase. The main findings are presented and analysed. Two types of failure were identified, i.e. the failure during fire exposure and the failure during postfire loading. Global buckling failure was observed for all the column specimens. The column specimens with common load ratios achieved high fire ratings without additional fire protection. The concrete-encased CFST columns also retained high postfire residual strength. As for the joint members, beam failure was observed in all cases. The measured temperature-time history and deformation-time history are also presented and discussed. For both the column and joint specimens, the deformation over the cooling phase was significantly greater than that in the standard fire exposure phase.