A simple histological technique for localizing electrode tracks and lesions within the brain.

Histological procedures are necessary in brain stimulation or lesion work to determine the neural area which has been stimulated or damaged. Preparation of brain tissue often involves embedding and staining techniques that require specialized training, and the expense of a technician and a large assortment of special apparatus and supplies. In addition, the results of such techniques are unavailable for at least several days. A photographic method, which requires little special skill and a minimal amount of apparatus, is described here. Results can be available within minutes after the subject is sacrificed. This method has been shown to be adequate for the gross determination of lesion boundaries and electrode or cannula tip loci in brains of rats, cats, and squirrel monkeys.     

The effect of prior recall on multiple response recognition

Certain investigators have found that recognition is impaired when a recall test is interpolated during the retention interval. One possible explanation of this finding is that interpolated recall leads subjects to employ a more stringent recognition criterion. In the two experiments reported here, the influence of the recognition criterion was eliminated by using a multiple-response test requiring subjects to rank a recognition list consisting of old and new items. Nevertheless recall impaired subsequent recognition in both experiments, the effect being most marked for lowly ranked items. The recognition test in the first experiment was carried out in two stages. This made possible a direct examination of whether recall has an effect on the recognition criterion. No evidence for such an effect was obtained. Other ways in which recall may affect the recognition criterion are discussed.     

Apparatus accurate delays for auditory feedback experiments

This note describes a way of modifying a tape recorder for producing accurately controllable delays for experiments with delayed auditory feedback. Any value of delay from 80 millisec. to 1.2 sec. can be obtained to the nearest millisec., and the range could be extended by some minor changes. The delay is continuously monitored on a digital electronic timer.     

Women's Interests—Fact or Fiction?

The data used in this study were made available through the Center for Interest Measurement Research and the Student Counseling Bureau, University of Minnesota. Computer analysis was provided by the Numerical Analysis Center, University of Minnesota. While attempting to increase the number of A and B+ scores on the women's SVIB by varying the composition of the criterion group on marital status, it was found that the desired effect was achieved by using a different item selection and weighting system from Strong's original one and not by varying the marital status of the criterion group. The experimental scoring keys developed in the study also acted selectively on original scores of B and B—, raising or lowering them, and generally reducing their number. These findings went beyond the original hypotheses and intent of the study and suggested an explanation for the apparent heterogeneity of women's interests and the resulting difficulty in measuring them.