The rapid-smoking technique: Some physiological effects

The effects of rapid smoking on the blood pressure, pulse rate and cardiac functioning of 58 smokers (30 women and 28 men) are reported. All subjects were healthy volunteers, 45 were under 40 yr of age, the remaining 13 between 40 and 50 yr. They received between 6 and 12 rapid smoking sessions. It was found that, in both the under and over 40 age groups, blood pressure levels and pulse rates increased significantly following rapid smoking sessions. There were, however, significant decreases between sessions and no evidence of a cumulative effect of successive rapid smoking sessions. Some qualitative changes in cardiac functioning were observed, namely the appearance of T wave flattening and S-T depression. None of the changes were considered to be of sufficient magnitude to necessitate exclusion from the programme, but confirm the need to monitor closely the physiological functioning of persons undergoing rapid smoking.     

A computational procedure for tau correlation

Thetau coefficient is defined, and a computational procedure for tied ranks is described. The procedure maintains continuous computational checks, saves labor, and particularly facilitates the use oftau with large samples. It is also shown howtau correlation may be applied toQ-sorts with any shape of forced distribution or with unforced distributions.The procedure described was developed in connection with research at the Counseling Center, University of Chicago. The research is supported by a grant (PHS M 903) from the National Institute of Mental Health, of the National Institutes of Health, Public Health Service.     

A rapid non-parametric estimate of multi-judge reliability

A technique is presented for obtaining a rapid estimate of reliability between judges, with special reference to qualitative judgments. It is shown that reliability and discrimination are independent and that estimates of both are needed. A method of obtaining an independent estimate of multi-judge discrimination is developed. It is shown that the size of item-samples is specified by the latter method. Tests of significance for both reliability and discrimination are described.This technique was developed in connection with research at the Counseling Center, University of Chicago. This investigation was supported by a research grant (PHS M 903) from the National Institute of Mental Health, of the National Institutes of Health, Public Health Service. Acknowledgment is made to Dr. Lyle V. Jones, University of Chicago, for valuable discussions relevant to the technique. Responsibility rests, however, entirely with the writer.     

Laterality and pattern persistence in bistable motion perception

Bistable motion perception refers to two competing perceptions that can result when frames consisting of three elements are displaced laterally by one element. At short inter-frame intervals, the dominant percept is that the end elements in the display are moving; at long inter-frame intervals, perception is of all the elements moving coherently to the right or left. This research shows that coherent motion is more likely to be perceived when presentations are parafoveal than foveal and when they are to the right visual field than the left visual field. These results support the idea that visual pattern persistence is shorter in the parafovea than in the fovea, and shorter in the right than in the left visual field.     

Convergent cortical representation of semantic processing in bilinguals

This study examined whether semantic processes in two languages (English and Spanish) are mediated by a common neural system in fluent bilinguals who acquired their second language years after acquiring their first language. Functional magnetic resonance imaging was performed while bilingual participants made semantic and nonsemantic decisions about words in Spanish and English. There was greater activation for semantic relative to nonsemantic decisions in left and right frontal regions, with greater left frontal activation. The locations of activations were similar for both languages, and no differences were found when semantic decisions for English and Spanish words were compared directly. These results demonstrate a shared frontal lobe system for semantic analysis of the languages and are consistent with cognitive research on bilingualism indicating that the two languages of a bilingual person access a common semantic system.     

BDNF Regulates the Intrinsic Excitability of Cortical Neurons

Neocortical pyramidal neurons respond to prolonged activity blockade by modulating their balance of inward and outward currents to become more sensitive to synaptic input, possibly as a means of homeostatically regulating firing rates during periods of intense change in synapse number or strength. Here we show that this activity-dependent regulation of intrinsic excitability depends on the neurotrophin brain-derived neurotrophic factor (BDNF). In experiments on rat visual cortical cultures, we found that exogenous BDNF prevented, and a TrkB–IgG fusion protein reproduced, the change in pyramidal neuron excitability produced by activity blockade. Most of these effects were also observed in bipolar interneurons, indicating a very general role for BDNF in regulating neuronal excitability. Moreover, earlier work has demonstrated that BDNF mediates a different kind of homeostatic plasticity present in these same cultures: scaling of the quantal amplitude of AMPA-mediated synaptic inputs up or down as a function of activity. Taken together, these results suggest that BDNF may be the signal controlling a coordinated regulation of synaptic and intrinsic properties aimed at allowing cortical networks to adapt to long-lasting changes in activity.     

Comparison of three antismoking interventions among pregnant women in an urban setting: a randomized trial

This study examined smoking cessation and cigarette reduction of indigent inner city pregnant women (n = 193) who completed one of three interventions: a special video program based on their perceptions of the effects of smoking during pregnancy, the American Lung Association's "Freedom From Smoking For You and Your Baby" program, or the usual physician's advice. Six percent of the women quit smoking, and 43% reduced the number of cigarettes they smoked. There were no significant differences among the three groups for either the number who quit smoking or who reduced the number of cigarettes smoked.     

Age differences in prefrontal cortical activity in working memory

Working memory (WM) declines with advancing age. Brain imaging studies indicate that ventral prefrontal cortex (PFC) is active when information is retained in WM and that dorsal PFC is further activated for retention of large amounts of information. The authors examined the effect of aging on activation in specific PFC regions during WM performance. Six younger and 6 older adults performed a task in which, on each trial, they (a) encoded a 1- or 6-letter memory set, (b) maintained these letters over 5-s. and (c) determined whether or not a probe letter was part of the memory set. Comparisons of activation between the 1- and 6-letter conditions indicated age-equivalent ventral PFC activation. Younger adults showed greater dorsal PFC activation than older adults. Older adults showed greater rostral PFC activation than younger adults. Aging may affect dorsal PFC brain regions that are important for WM executive components.