No abstract

We propose a multisensory framework based on Glaser and Glaser's (1989) general reading-naming interference model to account for the semantic priming effect by naturalistic sounds and spoken words on visual picture sensitivity. Four experiments were designed to investigate two key issues: First, can auditory stimuli enhance visual sensitivity when the sound leads the picture as well as when they are presented simultaneously? And, second, do naturalistic sounds (e.g., a dog's "woofing") and spoken words (e.g., /dɔg/) elicit similar semantic priming effects? Here, we estimated participants' sensitivity and response criterion using signal detection theory in a picture detection task. The results demonstrate that naturalistic sounds enhanced visual sensitivity when the onset of the sounds led that of the picture by 346 ms (but not when the sounds led the pictures by 173 ms, nor when they were presented simultaneously, Experiments 1-3A). At the same SOA, however, spoken words did not induce semantic priming effects on visual detection sensitivity (Experiments 3B and 4A). When using a dual picture detection/identification task, both kinds of auditory stimulus induced a similar semantic priming effect (Experiment 4B). Therefore, we suggest that there needs to be sufficient processing time for the auditory stimulus to access its associated meaning to modulate visual perception. Besides, the interactions between pictures and the two types of sounds depend not only on their processing route to access semantic representations, but also on the response to be made to fulfill the requirements of the task.

There has been longstanding interest from both experimental psychologists and cognitive neuroscientists in the potential modulatory role of various top–down factors on multisensory integration/perception in humans. One such top–down influence, often referred to in the literature as the ‘unity assumption,’ is thought to occur in those situations in which an observer considers that various of the unisensory stimuli that they have been presented with belong to one and the same object or event (Welch and Warren, 1980). Here, we review the possible factors that may lead to the emergence of the unity assumption. We then critically evaluate the evidence concerning the consequences of the unity assumption from studies of the spatial and temporal ventriloquism effects, from the McGurk effect, and from the Colavita visual dominance paradigm. The research that has been published to date using these tasks provides support for the claim that the unity assumption influences multisensory perception under at least a subset of experimental conditions. We then consider whether the notion has been superseded in recent years by the introduction of priors in Bayesian causal inference models of human multisensory perception. We suggest that the prior of common cause (that is, the prior concerning whether multisensory signals originate from the same source or not) offers the most useful way to quantify the unity assumption as a continuous cognitive variable.

Cortico-basal ganglia circuits are critical for speech and language and are implicated in autism spectrum disorder (ASD), in which language function can be severely affected. We demonstrate that in the striatum, the gene, Foxp2, negatively interacts with the synapse suppressor, Mef2C. We present causal evidence that Mef2C inhibition by Foxp2 in neonatal mouse striatum controls synaptogenesis of corticostriatal inputs and vocalization in neonates. Mef2C suppresses corticostriatal synapse formation and striatal spinogenesis, but can, itself, be repressed by Foxp2 through direct DNA binding. Foxp2 deletion de-represses Mef2C, and both intrastriatal and global decrease of Mef2C rescue vocalization and striatal spinogenesis defects of Foxp2-deletion mutants. These findings suggest that Foxp2-Mef2C signaling is critical to corticostriatal circuit formation. If found in humans, such signaling defects could contribute to a range of neurologic and neuropsychiatric disorders.

In healthcare settings, nurses’ workload, burnout, and job satisfaction are associated to the patient–nurse ratio. Whether this ratio also affects their intention to leave the nursing profession, along with the underlying stress pathway, remains unclear. This study aimed to investigate the effects of the patient–nurse ratio on nurses’ intention to leave and considering the mediating roles of burnout and job dissatisfaction. The study analyzed the data of two pooled cross-sectional surveys collected in 2013 and 2014. Measures were obtained by a structure questionnaire, which queried the average daily patient–nurse ratio (ADPNR), nurses’ personal burnout, client-related burnout, job dissatisfaction, intention to leave, and other demographics. ADPNRs were standardized according to hospital levels. Multiple regression models examined mediation hypotheses, and a percentile bootstrap confidence interval was applied to determine the significance of indirect effects. A total of 1409 full-time registered nurses in medical and surgical wards of 24 secondary or tertiary hospitals in Taiwan completed self-administered questionnaires. Most of the participants were female (97.2%), and the mean age was 29.9 years. The association between the standardized ADPNR and intention to leave their job was significantly mediated by personal burnout, client-related burnout, and job dissatisfaction. Higher standardized ADPNRs predicted higher levels of personal burnout, client-related burnout, and job dissatisfaction, each of which resulted in higher levels of intention to leave the current job. The results highlight that appropriate patient–nurse ratio standards may be further discussed by selecting personal burnout, client-related burnout, and job dissatisfaction as indicators.