Facilitating morphosyntactic and semantic prediction among second language speakers of German

Using two visual priming experiments, the present study investigates whether presenting facilitative semantic (i.e. colour) and morphosyntactic (i.e. grammatical gender) information in a prime image prior to reading a target sentence facilitates naming of a sentence-final target image among L1 German and L1 English-L2 German speakers. In Experiment 1, L1 and L2 German speakers used both semantic and gender cues to predict the sentence-final target image. In Experiment 2, a new group of L2 German speakers used gender cues to predict, but this effect was stronger when gender information was provided via a gender-marked indefinite article and adjective in the prime, than when the prime contained only the gender-marked article. These results suggest that if L2 speakers are able to overcome unstable and often inaccurate L2 gender assignment, they can use gender cues in a native-like manner for prediction, but that multiple gender-marked cues may be necessary for such prediction to occur.     

Social Cohesion,Neighborhood Collective Efficacy,and Adolescent Subjective Well‐being in Urban and Rural Taiwan

This study investigates the association between neighborhood social cohesion, collective efficacy, and adolescent subjective well‐being in a nationally representative sample of Taiwanese youth. The study represents a first to adapt and test a developmental ecological model within a Chinese cultural context. Data came from the Taiwan Youth Project, which assessed representative samples of seventh graders (n = 2,690) and ninth graders (n = 2,851) from both urban and rural counties. The analytic sample included 4,988 adolescents (M age = 14.4, SD = 1.14; 50% female) in Taiwan. A path analysis estimated the direct and indirect effects of social cohesion on adolescent well‐being. The results suggest that neighbors can affect young people's well‐being by reinforcing their perception of safety and enhancing their self‐esteem. Comparisons between youth from urban and rural areas demonstrate a general similarity in the developmental processes, though the perception of safety is less of a concern in rural areas. Findings emphasize universal aspects of neighborhood collective efficacy and developmental–ecological models, as well as allude to culturally specific dimensions in a Chinese‐based context.     

Engineering Eden: Does Earthly Pursuit of Eternal Life Threaten the Future of Religion?

The eternal life promised by many religions is mirrored by the drastically longer lifespans proposed by radical life extension (RLE) and transhumanism (H+). RLE and H+ represent extreme contingents of longevity research among the broader scientific initiatives to extend the length and quality of human life. In striving toward literal immortality, these movements offer an “alternative” to the spiritual eternity that functions as a religious solution to fear of death and loss. In this article, we probe the question of whether a radically extended—even eternal—life through advancements in biotechnology could replace religion as a means of managing this terror of death.     

Mechanism of action of methylphenidate: insights from PET imaging studies

Methylphenidate (MPH) is the most commonly prescribed drug for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). We have used Positron Emission Tomography (PET) to investigate the mechanism of action of MPH in the human brain. We have shown (a) that oral MPH reaches peak concentration in the brain 60-90 minutes after its administration, (b) that therapeutic doses of MPH block more than 50% of the dopamine transporters (DAT), and (c) that of the two enantiomers that compose MPH, it is d-threo-methylphenidate (d-MPH) and not l-threo-methylphenidate (l-MPH) that binds to the DAT. We have also shown that therapeutic doses of MPH significantly enhance extracellular dopamine (DA) in the basal ganglia, which is an effect that appears to be modulated by the rate of DA release and that is affected by age (older subjects show less effect). Thus, we postulate (a) that MPH's therapeutic effects are in part due to amplification of DA signals, (b) that variability in responses is in part due to differences in DA tone between subjects, and (c) that MPH's effects are context dependent. Because DA enhances task specific neuronal signaling and decreases noise, we also postulate that MPH-induced increases in DA could improve attention and decrease distractibility; and that since DA modulates motivation, the increases in DA would also enhance the saliency of the task facilitating the 'interest it elicits' and thus improving performance.     

Role of dopamine,the frontal cortex and memory circuits in drug addiction: insight from imaging studies

Drug addiction is characterized by a set of recurring processes (intoxication, withdrawal, craving) that lead to the relapsing nature of the disorder. We have used positron emission tomography to investigate in humans the role of dopamine (DA) and the brain circuits it regulates in these processes. We have shown that increases in DA are associated with the subjective reports of drug reinforcement corroborating the relevance of drug-induced DA increases in the rewarding effects of drugs in humans. During withdrawal we have shown in drug abusers significant reductions in DA D2 receptors and in DA release. We postulate that this hypodopaminergic state would result in a decreased sensitivity to natural reinforcers perpetuating the use of the drug as a means to compensate for this deficit and contributing to the anhedonia and dysphoria seen during withdrawal. Because the D2 reductions are associated with decreased activity in the anterior cingulate gyrus and in the orbitofrontal cortex we postulate that this is one of the mechanisms by which DA disruption leads to compulsive drug administration and the lack of control over drug intake in the drug-addicted individual. This is supported by studies showing that during craving these frontal regions become hyperactive in proportion to the intensity of the craving. Craving is also associated with activation of memory circuits including the amygdala (implicated in conditioned learning), hippocampus (implicated in declarative learning), and dorsal striatum (implicated in habit learning) all of which receive DA innervation. We therefore postulate that dopamine contributes to addiction by disrupting the frontal cortical circuits that regulate motivation, drive, and self-control and by memory circuits that increase the motivational salience of the drug and drug-associated stimuli.     

Perceptual parsing of acoustic consequences of velum lowering from information for vowels

Three experiments were designed to investigate how listeners to coarticulated speech use the acoustic speech signal during a vowel to extract information about a forthcoming oral or nasal consonant. A first experiment showed that listeners use evidence of nasalization in a vowel as information for a forthcoming nasal consonant. A second and third experiment attempted to distinguish two accounts of their ability to do so. According to one account, listeners hear nasalization in the vowel as such and use it to predict that a forthcoming nasal consonant is nasal. According to a second, they perceive speech gestures and hear nasalization in the acoustic domain of a vowel as the onset of a nasal consonant. Therefore, they parse nasal information from a vowel and hear the vowel as oral. In Experiment 2, evidence in favor of the parsing hypothesis was found. Experiment 3 showed, however, that parsing is incomplete.     

National personality characteristics: II. Adaption-innovation in Canadian,American, and British samples

On the Kirton Adaption-Innovation Inventory 1,106 Canadians scored as more adaptive than American and British standardization samples. Means for Canadian females and males were congruent with those in national samples from six other countries.     

Asymmetric interference in implicit memory: effects of study-test awareness and stimulus order

This study examined the extent to which fragment completion performance is susceptible to the effects of two different forms of interference (proactive and retroactive) and whether any of these effects depend on participants' awareness of the relationship between study and test. Unaware participants were found to be susceptible to proactive but not retroactive interference. Aware participants did not show evidence of susceptibility to either form of interference. These results contribute to the debate about whether implicit memory is immune to interference effects by demarcating the limits of such an immunity.