Selective attention to a specific talker does not change the effect of surrounding acoustic context

Spoken sentences contain considerable prosodic variation, for instance in their speech rate [1]. One mechanism by which the listener can overcome such variation is by interpreting the durations of speech sounds relative to the surrounding speech rate. Indeed, in a fast context, a durationally ambiguous sound is perceived as longer than in a slow context [2]. In abstractionist models of spoken word comprehension, this process – known as rate normalization – affects pre-lexical representations before abstract phonological representations are accessed [3]. A recent study [4] provided support for such an early perceptual locus of rate normalization. In that study, participants performed a visual search task that induced high (large grid) vs. low (small grid) cognitive load, while listening to fast and slow context sentences. Context sentences were followed by durationally ambiguous targets. Fast sentences were shown to bias target perception towards more ‘long’ target segments than slow contexts. Critically, changes in cognitive load did not modulate this rate effect. These findings support a model in which normalization processes arise early during perceptual processing; too early to be affected by attentional modulation. The present study further evaluated the cognitive locus of normalization processes by testing the influence of another form of attention: auditory stream segregation. Specifically, if listeners are presented with a fast and a slow talker at the same time but in different ears, does explicitly attending to one or the other stream influence target perception? The aforementioned model [4] predicts that selective attention should not influence target perception, since normalization processes should be robust against changes in attention allocation. Alternatively, if attention does modulate normalization processes, two participants, one attending to fast, the other to slow speech, should show different perception. Dutch participants (Expt 1: N=32; Expt 2: N=16; Expt 3: N=16) were presented with 200 fast and slow context sentences of various lengths, followed by a target duration continuum ambiguous between, e.g., short target “geven” /ˈxevə/ give vs. long target “gegeven” /xəˈxevə/ given (i.e., 20 target pairs differing presence/absence of unstressed syllable /xə-/). Critically, in Experiment 1, participants heard two talkers simultaneously (talker and location counter-balanced across participants), one (relatively long) sentence at a fast rate, and one (half as long) sentence at a slow rate (rate varied within participants). Context sentences were followed by ambiguous targets from yet another talker (Fig. 1). Half of the participants was instructed to attend to talker A, while the other half attended to talker B. Thus, participants heard identical auditory stimuli, but varied in which talker they attended to. Debriefing questionnaires and transcriptions of attended talkers in filler trials confirmed that participants successfully attended to one talker, and ignored the other. Nevertheless, no effect of attended rate was found (Fig. 2; p>.9), indicating that modulation of attention did not influence participants’ rate normalization. Control experiments showed that it was possible to obtain rate effects with single talker contexts that were either talker-incongruent (Expt 2) or talker-congruent (Expt 3) with the following target (Fig. 1). In both of these experiments, there was a higher proportion of long target responses following a fast context (Fig. 2). This shows that contextual rate affected the perception of syllabic duration and that talker-congruency with the target did not change the effect. Therefore, in line with [4], the current experiments suggest that normalization processes arise early in perception, and are robust against changes in attention

Modelling human factors in perceptual multimedia quality: On the role of personality and culture

Perception of multimedia quality is shaped by a rich interplay between system, context, and human factors. While system and context factors are widely researched, few studies in this area consider human factors as sources of systematic variance. This paper presents an analysis on the influence of personality (Five-Factor Model) and cultural traits (Hofstede Model) on the perception of multimedia quality. A set of 144 video sequences (from 12 short movie excerpts) were rated by 114 participants from a cross-cultural population, producing 1232 ratings. On this data, three models are compared: a baseline model that only considers system factors; an extended model that includes personality and culture as human factors; and an optimistic model in which each participant is modeled as a random effect. An analysis shows that personality and cultural traits represent 9.3% of the variance attributable to human factors while human factors overall predict an equal or higher proportion of variance compared to system factors. In addition, the quality-enjoyment correlation varied across the movie excerpts. This suggests that human factors play an important role in perceptual multimedia quality, but further research to explore moderation effects and a broader range of human factors is warranted

Ice(berg) transport costs

Iceberg transport costs are a key ingredient of modern trade and economic geography models. Using detailed information on Boston’s nineteenth-century global ice trade, we show that the cost of shipping the only good that truly melts in transit is not well-proxied by this assumption. Additive cost components account for the largest part of per unit ice(berg) transport costs in practice. Moreover, the physics of the melt process and the practice of insulating the ice in transit meant that shipping ice is subject to economies of scale. This finding supports, from an unexpected historical angle, recent efforts to incorporate more realistic features of the transportation sector in trade and economic geography models

The predictive power of track recommendations in Dutch secondary education

In the transition from Dutch primary to secondary education, two indicators are used to place students in the right track: primary school teachers' track recommendations (TTR) and standardized achievement tests (SATs) at the end of primary school. Which indicator is better for placing students is a long-standing issue among educational researchers and professionals. Since 2015, the SAT is administered after the TTR has been given; previously, SAT was administered first. In the current study, it was investigated to what extent TTR and a commonly used SAT predict students' educational attainment after three years of secondary education for multiple cohorts before and after 2015. The results were compared for educational tracks and for different socio-economic status (SES) groups, using multiple samples approaching population data. For all educational tracks and SES groups the results show that TTR is a better predictor of educational attainment than SAT. Furthermore, large differential effects for SES were found. The change of administrative sequence in 2015 had no effect on the overall predictive accuracy: TTR remained the better predictor. The results give new insights into the predictive value of both TTR and SAT before and after the change in administration sequence

Discourse markers activate their, <i>like</i>, cohort competitors

Speech in everyday conversations is riddled with discourse markers (DMs), such as well, you know, and like. However, in many lab-based studies of speech comprehension, such DMs are typically absent from the carefully articulated and highly controlled speech stimuli. As such, little is known about how these DMs influence online word recognition. The present study specifically investigated the online processing of DM like and how it influences the activation of words in the mental lexicon. We specifically targeted the cohort competitor (CC) effect in the Visual World Paradigm: Upon hearing spoken instructions to “pick up the beaker,” human listeners also typically fixate—next to the target object—referents that overlap phonologically with the target word (cohort competitors such as beetle; CCs). However, several studies have argued that CC effects are constrained by syntactic, semantic, pragmatic, and discourse constraints. Therefore, the present study investigated whether DM like influences online word recognition by activating its cohort competitors (e.g., lightbulb). In an eye-tracking experiment using the Visual World Paradigm, we demonstrate that when participants heard spoken instructions such as “Now press the button for the, like … unicycle,” they showed anticipatory looks to the CC referent (lightbulb)well before hearing the target. This CC effect was sustained for a relatively long period of time, even despite hearing disambiguating information (i.e., the /k/ in like). Analysis of the reaction times also showed that participants were significantly faster to select CC targets (lightbulb) when preceded by DM like. These findings suggest that seemingly trivial DMs, such as like, activate their CCs, impacting online word recognition. Thus, we advocate a more holistic perspective on spoken language comprehension in naturalistic communication, including the processing of DMs

Electroconvulsive seizures (ECS) do not prevent LPS-induced behavioral alterations and microglial activation

Background: Long-term neuroimmune activation is a common finding in major depressive disorder (MDD). Literature suggests a dual effect of electroconvulsive therapy (ECT), a highly effective treatment strategy for MDD, on neuroimmune parameters: while ECT acutely increases inflammatory parameters, such as serum levels of pro-inflammatory cytokines, there is evidence to suggest that repeated ECT sessions eventually result in downregulation of the inflammatory response. We hypothesized that this might be due to ECT-induced attenuation of microglial activity upon inflammatory stimuli in the brain. Methods: Adult male C57Bl/6J mice received a series of ten electroconvulsive seizures (ECS) or sham shocks, followed by an intracerebroventricular (i.c.v.) lipopolysaccharide (LPS) or phosphate-buffered saline (PBS) injection. Brains were extracted and immunohistochemically stained for the microglial marker ionized calcium-binding adaptor molecule 1 (Iba1). In addition, a sucrose preference test and an open-field test were performed to quantify behavioral alterations. Results: LPS induced a short-term reduction in sucrose preference, which normalized within 3 days. In addition, LPS reduced the distance walked in the open field and induced alterations in grooming and rearing behavior. ECS did not affect any of these parameters. Phenotypical analysis of microglia demonstrated an LPS-induced increase in microglial activity ranging from 84 to 213 % in different hippocampal regions (CA3 213 %; CA1 84 %; dentate gyrus 131 %; and hilus 123 %). ECS-induced alterations in microglial activity were insignificant, ranging from -2.6 to 14.3 % in PBS-injected mice and from -20.2 to 6.6 % in LPS-injected mice. Conclusions: We were unable to demonstrate an effect of ECS on LPS-induced microglial activity or behavioral alterations