#classic study

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This report is one of a series on the epidemiology of coronary disease. Study of coronary heart-disease suggests that there has been a true increase of it, and that this is not due simply to an increase of coronary atheroma. The atheroma, it seems, is the basic condition of the heart-disease; but other conditions are necessary, and the complex of atheroma, thrombosis, and the capacity of the heart to deal with these in relation the demands med upon it, all need to be studied. Surveys have been made from Social Medicine Research Unit to gain some knowledge of coronary heart-disease as a problem in public health, and in the hope of uncovering social factors which may be favourable or unfavourable to its occurrence. Observations on a group of medical practitioners indicated that such epidemiological study can be carried out with relatively small numbers, and that it may be rewarding. The present report extends this study to other workers and describes the findings among them. Readers are referred to the previous papers where the possibilities and limitations of this type of investigation are considered, and points of theory and method are discussed in some detail.

We wish to suggest a structure for the salt of deoxyribose nucleic acid (D.N.A.). This structure has novel features which are of considerable biological interest.

In a recent note [1] it was shown that the Goldstone theorem [2], that Lorentz-covariant field theories in which spontaneous breakdown of symmetry under an internal Lie group occurs contain zero-mass particles, fails if and only if the conserved currents associated with the internal group are coupled to gauge fields. The purpose of the present note is to report that, as a consequence of this coupling, the spin-one quanta of some of the gauge fields acquire mass; the longitudinal degrees of freedom of these particles (which would be absent if their mass were zero) go over into the Goldstone bosons when the coupling tends to zero. This phenomenon is just the relativistic analog of the plasmon phenomenon to which Anderson [3] has drawn attention: that the scalar zero-mass excitations of a superconducting neutral Fermi gas become longitudinal plasmon modes of finite mass when the gas is charged.

In this longitudinal study, the proportion of time preschoolers directed their attention away from rewarding stimuli during a delay-of-gratification task was positively associated with efficiency (greater speed without reduced accuracy) at responding to targets in a go/no-go task more than 10 years later. The overall findings suggest that preschoolers’ ability to effectively direct their attention away from tempting aspects of the rewards in a delayof-gratification task may be a developmental precursor for the ability to perform inhibitory tasks such as the go/no-go task years later. Because performance on the go/no-go task has previously been characterized as involving activation of fronto-striatal regions, the present findings also suggest that performance in the delay-of-gratification task may serve as an early marker of individual differences in the functional integrity of this circuitry.

Describes 3 experiments with a total of 92 3-5 yr. olds. Exp. I compared the effects of external and cognitive distraction from reward objects on the length of time which Ss waited for a preferred delayed reward before forfeiting it for a less preferred immediate one. In accord with predictions from an extension of frustrative nonreward theory, Ss waited much longer for a preferred reward when they were distracted from the rewards. Exp. II demonstrated that only certain cognitive events (thinking "fun things") served as effective ideational distractors. Thinking "sad thoughts" produced short delay times, as did thinking about the rewards themselves. In Exp. III the delayed rewards were not physically available for direct attention during the delay period, and Ss' cognitive attention was manipulated by prior instructions. While Ss waited, cognitions about the rewards significantly reduced, rather than enhanced, the length of their delay of gratification. Overall, attentional and cognitive mechanisms which enhanced the salience of rewards shortened the length of voluntary delay, while distractions from the rewards, overtly or cognitively, facilitated delay. Results permit a reinterpretation of basic mechanisms in voluntary delay of gratification and self-control.