Mechanisms and the current state of transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) is unique among the current brain stimulation techniques because it is relatively non-invasive. TMS markedly differs from vagus nerve stimulation, deep brain stimulation and magnetic seizure therapy, all of which require either an implanted prosthesis or general anesthesia, or both. Since its rebirth in its modern form in 1985, TMS has already shown potential usefulness in at least three important domains-as a basic neuroscience research instrument, as a potential clinical diagnostic tool, and as a therapy for several different neuropsychiatric conditions. The TMS scientific literature has now expanded beyond what a single summary article can adequately cover. This review highlights several new developments in combining TMS with functional brain imaging, using TMS as a psychiatric therapy, potentially using TMS to enhance performance, and finally recent advances in the core technology of TMS. TMS' ability to non-invasively and focally stimulate the brain of an awake human is proving to be a most important development for neuroscience in general, and neuropsychiatry in particular.     

Do pigeons (Columba livia) perceive object unity?

Human infants perceive two rods moving in concert behind an occluder as one unitary rod. In four experiments we tested whether pigeons also perceive unity of objects. Pigeons were trained on a matching-to-sample task to discriminate between one unitary rod moving at a constant speed and two aligned rods moving together at the same speed. The latter stimulus was identical to the former except for a gap in the center. In experiment 1, we tested pigeons in probe trials in which a rectangle occluded the center of the sample rods, to see which comparison stimulus, the unitary rod or the aligned two rods, the subjects would match to the sample. Two of the three subjects pecked at the two rods significantly more often than at the unitary rod. In experiment 2, we trained the same pigeons to match the sample rods moving "in front of" the occluder. Pigeons persisted in matching two separate rods to the unitary rod moving in front of the occluder. In experiments 3 and 4, we used a parallelogram and an undulating shape as the occluder to alter the shape and the size of the portions above and below the occluder by the motion of the sample rods. Both subjects chose the two rods significantly more often than chance in experiment 3 and one of them did so in experiment 4. The results suggest that pigeons do not complete occluded portions even though the two elements move in concert. These negative results suggest that some alternative way of identifying objects may have evolved in pigeons. Accepted after revision: 2 May 2001 Electronic Publication     

Personality and Reaction Time after Sleep Deprivation

The relationship between reaction time and both state and trait personality variables was investigated in 37 participants after 30 h of sleep deprivation. Regression analyses suggested that endorsement of greater Novelty Seeking, anger/hostility, and depression/dejection, and less confusion, was associated with greater reaction time declines on one Multi-Attribute Task Battery index after sleep deprivation. Further, greater Novelty Seeking and depression/dejection, and less vigor/activity, was associated with greater reaction time declines after sleep deprivation on another Multi-Attribute Task Battery index. Additional correlational analyses indicated that better reaction times were associated with greater Novelty Seeking and lower anger/hostility prior to sleep deprivation, and less confusion/bewilderment following sleep deprivation. Findings suggest that both state and trait personality variables are associated with reaction time performance following sleep deprivation.     

A normative set of 98 pairs of nonsensical pictures (droodles)

Our purpose in the present study is to provide a normative set of nonsensical pictures known as droodles and to demonstrate the role of semantic comprehension in facilitating recall of pictorial stimuli. The set consists of 98 pairs of droodles. Experiment 1 standardized these pictorial stimuli with respect to several variables, such as appropriateness of verbal labels, relationship between two droodles, and correct recall. Appropriateness of verbal labels was rated higher for pictures presented in pairs than for pictures presented singly. Experiment 2 used the standardized set of droodles in a recall experiment similar to those of Bower, Karlin, and Dueck (1975) and others. As we expected, semantic interpretation can strongly facilitate recall. Multiple regression analysis showed that several measures had significant power of explanation for recall performance. The full set of norms and pictures from this article may be downloaded from http://brm.psychonomic-journals.org/content/supplemental.     

Culture and social support: who seeks it and why?

Are Asians and Asian Americans more or less likely to seek social support for dealing with stress than European Americans? On the one hand, the collectivist orientation of Asian countries might favor the sharing of stressful problems; on the other hand, efforts to maintain group harmony might discourage such efforts. In 2 studies, Koreans (Study 1) and Asians and Asian Americans in the United States (Study 2) reported using social support less for coping with stress than European Americans. Study 3 examined potential explanations for these effects and revealed that relationship concerns accounted for the cultural differences in use of support seeking. Discussion centers on the potential benefits and liabilities of seeking social support.     

Neuropsychological,Cognitive, and Theoretical Considerations for Evaluation of Bilingual Individuals

As the number of bilinguals in the USA grows rapidly, it is increasingly important for neuropsychologists to be equipped and trained to address the unique challenges inherent in conducting ethical and competent neuropsychological evaluations with this population. Research on bilingualism has focused on two key cognitive mechanisms that introduce differences between bilinguals and monolinguals: (a) reduced frequency of language-specific use (weaker links), and (b) competition for selection within the language system in bilinguals (interference). Both mechanisms are needed to explain how bilingualism affects neuropsychological test performance, including the robust bilingual disadvantages found on verbal tasks, and more subtle bilingual advantages on some measures of cognitive control. These empirical results and theoretical claims can be used to derive a theoretically informed method for assessing cognitive status in bilinguals. We present specific considerations for measuring degree of bilingualism for both clients and examiners to aid in determinations of approaches to testing bilinguals, with practical guidelines for incorporating models of bilingualism and recent experimental data into neuropsychological evaluations. This integrated approach promises to provide improved clinical services for bilingual clients, and will also contribute to a program of research that will ultimately reveal the mechanisms underlying language processing and executive functioning in bilinguals and monolinguals alike.     

Identification as an organizational anchor: how identification and job satisfaction combine to predict turnover intention

The article examines the role of organizational identification and job satisfaction in relation to turnover intentions in seven organizations. Two models are proposed in which either job satisfaction or organizational identification was treated as a mediator of the other's relationship with turnover intention. The organizations varied in terms of culture (Japan vs. UK), and institutional domain (academic, business, health, mail, legal). Within each organization, and meta‐analytically combined across the seven samples (N = 1392), organizational identification mediated the relationship between job satisfaction and turnover intention more than job satisfaction mediated the relationship between organizational identification, and turnover intention. Organizational identification also had the larger overall relationship with turnover intention. This pattern remained true when gender, age, type of organization, culture, and length of tenure were accounted for, although the direct relationship between job satisfaction and turnover intention was stronger in private than public organizations and when the ratio of men was higher. The findings are consistent with a social identity theory (SIT) perspective and with the idea that identification is a more proximal predictor of turnover intention. Over and above job satisfaction, organizational identification offers a strong psychological anchor that discourages turnover intention in a range of organizational contexts. Copyright © 2008 John Wiley & Sons, Ltd.     

Motion impressions enhanced by converging motion lines

We investigated how motion lines drawn in the background of a running human silhouette affect motion impressions of a runner in a static image. Observers evaluated the strength and direction of motion impression. The results show that parallel lines do not enhance frontoparallel motion impressions, while converging lines do so in an in-depth direction. This is a counter-example to the hypothesis that motion lines in the background represent motion streaks of the background when one visually tracks a moving object.