Brain responses to filled gaps

An unresolved issue in the study of sentence comprehension is whether the process of gap-filling is mediated by the construction of empty categories (traces), or whether the parser relates fillers directly to the associated verb's argument structure. We conducted an event-related potentials (ERP) study that used the violation paradigm to examine the time course and spatial distribution of brain responses to ungrammatically filled gaps. The results indicate that the earliest brain response to the violation is an early left anterior negativity (eLAN). This ERP indexes an early phase of pure syntactic structure building, temporally preceding ERPs that reflect semantic integration and argument structure satisfaction. The finding is interpreted as evidence that gap-filling is mediated by structurally predicted empty categories, rather than directly by argument structure operations.     

What's so funny about not having money? The effects of power on laughter

Two studies tested the hypothesis that occupying a position of low power increases the likelihood of laughter, presumably as a means of gaining friends and supporters. In Study 1, participants laughed more at an interviewer's jokes when the interviewer controlled their cash rewards than in the absence of monetary contingencies. Study 2 found that low-power participants (manipulated again by expecting that someone else would decide their cash rewards) laughed more than high-power participants even when they were alone. Low power also increased laughing at a fellow low-power coworker. These findings suggest that low power motivates interest in making friends and hence increases behaviors that promote social bonding.     

Examining neurochemical determinants of inspection time: Development of a biological model

Inspection time (IT), an information-processing correlate of psychometric intelligence, has been extensively studied. Previous research has shown that IT is a reliable correlate of psychometric intelligence across different developmental periods, mirroring developmental trends of fluid intelligence. Despite this extensive previous literature, very little is known about the biological basis of IT. In the present review, we discuss recent results from our laboratories examining the neurochemical determinants of IT. In this review, we outline the significance of several studies in which performance on the IT task is measured before and after modulating key human central nervous system (CNS) neurotransmitters and receptor systems (e.g., cholinergic, serotonergic, noradrenergic, and dopaminergic systems). The results of these studies indicate a primarily cholinergic basis for IT, although other aspects of psychometric intelligence may have serotonergic and dopaminergic determinants in addition to a cholinergic basis. The results are consistent with data reporting cholinergic depletion and impaired IT performance in dementia of the Alzheimer's type (DAT). Speculatively, we propose that compounds that enhance the release of the neurotransmitter acetylcholine (Ach) will improve IT and the variance that IT shares with IQ test performance.     

Effects of early institutionalization on the development of emotion processing: a case for relative sparing?

We tested the capacity to perceive visual expressions of emotion, and to use those expressions as guides to social decisions, in three groups of 8‐ to 10‐year‐old Romanian children: children abandoned to institutions then randomly assigned to remain in ‘care as usual’ (institutional care); children abandoned to institutions then randomly assigned to a foster care intervention; and community children who had never been institutionalized. Experiment 1 examined children's recognition of happy, sad, fearful, and angry facial expressions that varied in intensity. Children assigned to institutional care had higher thresholds for identifying happy expressions than foster care or community children, but did not differ in their thresholds for identifying the other facial expressions. Moreover, the error rates of the three groups of children were the same for all of the facial expressions. Experiment 2 examined children's ability to use facial expressions of emotion to guide social decisions about whom to befriend and whom to help. Children assigned to institutional care were less accurate than foster care or community children at deciding whom to befriend; however, the groups did not differ in their ability to decide whom to help. Overall, although there were group differences in some abilities, all three groups of children performed well across tasks. The results are discussed in the context of theoretical accounts of the development of emotion processing.