Anticipatory Processing in a Verb-Initial Mayan Language: Eye-Tracking Evidence During Sentence Comprehension in Tseltal

We present a visual world eye-tracking study on Tseltal (a Mayan language) and investigate whether verbal information can be used to anticipate an upcoming referent. Basic word order in transitive sentences in Tseltal is Verb-Object-Subject (VOS). The verb is usually encountered first, making argument structure and syntactic information available at the outset, which should facilitate anticipation of the post-verbal arguments. Tseltal speakers listened to verb-initial sentences with either an object-predictive verb (e.g., "eat") or a general verb (e.g., "look for") (e.g., "Ya slo'/sle ta stukel on te kereme," Is eating/is looking (for) by himself the avocado the boy/ "The boy is eating/is looking (for) an avocado by himself") while seeing a visual display showing one potential referent (e.g., avocado) and three distractors (e.g., bag, toy car, coffee grinder). We manipulated verb type (predictive vs. general) and recorded participants' eye movements while they listened and inspected the visual scene. Participants' fixations to the target referent were analyzed using multilevel logistic regression models. Shortly after hearing the predictive verb, participants fixated the target object before it was mentioned. In contrast, when the verb was general, fixations to the target only started to increase once the object was heard. Our results suggest that Tseltal hearers pre-activate semantic features of the grammatical object prior to its linguistic expression. This provides evidence from a verb-initial language for online incremental semantic interpretation and anticipatory processing during language comprehension. These processes are comparable to the ones identified in subject-initial languages, which is consistent with the notion that different languages follow similar universal processing principles.

Developmental effects in the online use of morphosyntactic cues in sentence processing: Evidence from Tagalog

Children must necessarily process their input in order to learn it, yet the architecture of the developing parsing system and how it interfaces with acquisition is unclear. In the current paper we report experimental and corpus data investigating adult and children's use of morphosyntactic cues for making incremental online predictions of thematic roles in Tagalog, a verb-initial symmetrical voice language of the Philippines. In Study 1, Tagalog-speaking adults completed a visual world eye-tracking experiment in which they viewed pictures of causative actions that were described by transitive sentences manipulated for voice and word order. The pattern of results showed that adults process agent and patient voice differently, predicting the upcoming noun in the patient voice but not in the agent voice, consistent with the observation of a patient voice preference in adult sentence production. In Study 2, our analysis of a corpus of child-directed speech showed that children heard more patient voice- than agent voice-marked verbs. In Study 3, 5-, 7-, and 9-year-old children completed a similar eye-tracking task as used in Study 1. The overall pattern of results suggested that, like the adults in Study 1, children process agent and patient voice differently in a manner that reflects the input distributions, with children developing towards the adult state across early childhood. The results are most consistent with theoretical accounts that identify a key role for input distributions in acquisition and language processing.

Human sickness detection is not dependent on cultural experience

Animals across phyla can detect early cues of infection in conspecifics, thereby reducing the risk of contamination. It is unknown, however, if humans can detect cues of sickness in people belonging to communities with whom they have limited or no experience. To test this, we presented Western faces photographed 2 h after the experimental induction of an acute immune response to one Western and five non-Western communities, including small-scale hunter-gatherer and large urban-dwelling communities. All communities could detect sick individuals. There were group differences in performance but Western participants, who observed faces from their own community, were not systematically better than all non-Western participants. At odds with the common belief that sickness detection of an out-group member should be biased to err on the side of caution, the majority of non-Western communities were unbiased. Our results show that subtle cues of a general immune response are recognized across cultures and may aid in detecting infectious threats.

Attentional inhibition in bilingual naming performance: evidence from delta-plot analyses

It has been argued that inhibition is a mechanism of attentional control in bilingual language performance. Evidence suggests that effects of inhibition are largest in the tail of a response time (RT) distribution in non-linguistic and monolingual performance domains. We examined this for bilingual performance by conducting delta-plot analyses of naming RTs. Dutch-English bilingual speakers named pictures using English while trying to ignore superimposed neutral Xs or Dutch distractor words that were semantically related, unrelated, or translations. The mean RTs revealed semantic, translation, and lexicality effects. The delta plots leveled off with increasing RT, more so when the mean distractor effect was smaller as compared with larger. This suggests that the influence of inhibition is largest toward the distribution tail, corresponding to what is observed in other performance domains. Moreover, the delta plots suggested that more inhibition was applied by high- than low-proficiency individuals in the unrelated than the other distractor conditions. These results support the view that inhibition is a domain-general mechanism that may be optionally engaged depending on the prevailing circumstances.

Use of a fluorescent redox probe for direct visualization of actively respiring bacteria

The redox dye 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) was employed for direct epifluorescent microscopic enumeration of respiring bacteria in environmental samples. Oxidized CTC is nearly colorless and is nonfluorescent; however, the compound is readily reduced via electron transport activity to fluorescent, insoluble CTC-formazan, which accumulates intracellularly. Bacteria containing CTC-formazan were visualized by epifluorescence microscopy in wet-mount preparations, on polycarbonate membrane filter surfaces, or in biofilms associated with optically opaque surfaces. Counterstaining of CTC-treated samples with the DNA-specific fluorochrome 4',6-diamidino-2-phenylindole allowed enumeration of active and total bacterial subpopulations within the same preparation. Municipal wastewater, groundwater, and seawater samples supplied with exogenous nutrients yielded CTC counts that were generally lower than total 4',6-diamidino-2-phenylindole counts but typically equal to or greater than standard heterotrophic (aerobic) plate counts. In unsupplemented water samples, CTC counts were typically lower than those obtained with the heterotrophic plate count method. Reduction of CTC by planktonic or biofilm-associated bacteria was suppressed by formaldehyde, presumably because of inhibition of electron transport activity and other metabolic processes. Because of their bright red fluorescence (emission maximum, 602 nm), actively respiring bacteria were readily distinguishable from abiotic particles and other background substances, which typically fluoresced at shorter wavelengths. The use of CTC greatly facilitated microscopic detection and enumeration of metabolically active (i.e., respiring) bacteria in environmental samples.

Oral ciprofloxacin compared with parenteral antibiotics in the treatment of osteomyelitis

We undertook a prospective, randomized comparison of oral ciprofloxacin with standard parenteral therapies for the treatment of biopsy-proven osteomyelitis caused by susceptible organisms. Following surgical debridement, the ciprofloxacin patients received 750 mg twice a day, and the other patients received a broad-spectrum cephalosporin or a nafcillin-aminoglycoside combination intravenously (i.v.). There were 31 evaluable patients in the ciprofloxacin group, treated an average of 56 days, and 28 in the i.v. group, treated an average of 47 days. Clinical success rates were 24 of 31 (77%) for the ciprofloxacin group and 22 of 28 (79%) for the i.v. group. Of the seven failures in the ciprofloxacin group, one was due to a persistent Klebsiella pneumoniae infection and six were due to relapse of the infection within 1 year of therapy. Of the six failures in the i.v. group, one was due to an Enterobacter aerogenes strain which emerged resistant and five were due to relapse. The most troublesome etiology was polymicrobial osteomyelitis involving Pseudomonas aeruginosa, in which five of six (83%) regimens failed. Adverse reactions occurred infrequently, i.e., in 1 of 31 (3%) of the ciprofloxacin patients and in 4 of 28 (14%) of the i.v. patients, yet all reactions responded to therapy and none required protocol deviation. Our data indicate that oral ciprofloxacin monotherapy is as safe and effective as conventional parenteral therapy in cases of osteomyelitis caused by susceptible organisms.