The effect of signal probability on the slope of the receiver operating characteristic given by the rating procedure

Signal detection theory (SDT) requires that the slope of the receiver operating characteristic (ROC) is independent of the probability of signal and noise. But it has been shown that when the rating procedure is applied to detection, the slope of the receiver operating characteristic may increase as a function of the probability of the signal (Schulman & Greenberg, 1970). This presents a serious problem for signal detection theory. This problem is examined in relation to a recent theory of criterion setting (Treisman & Williams, 1984), and an explanation for the effect of signal probability on ROC slope is derived which is compatible with SDT. Further data on the relation between signal probability and ROC slope are reported.     

Ingratiation tactics channeled by target values and threat capability1

Several hypotheses concerning the use of ingratiation tactics were tested in a paradigm where subjects believed that monetary rewards were contingent on a favorable evaluation from a supervisor. Manipulated variables in the 2 × 2 × 2 factorial design were (a) the nature of the supervisor's values (i.e., efficiency vs. sociability), (b) the level of threats issued by the supervisor (no threat vs. high threat), and (c) the extent to which the subjects were dependent on the supervisor's evaluation (low dependency vs. high dependency). The dependent variables were the extent to which the subjects used the ingratiation tactics of other-enhancement (flattery) and selective self-presentation. Findings indicate that the manipulation of the supervisor's values affected the form of other-enhancement used by subjects; more flattery in terms of efficiency occurred in the efficiency values condition, while more flattery in terms of sociability occurred in the sociability values condition. The supervisor's values also affected self-presentation; subjects claimed to hold efficiency ideals when the supervisor held efficiency values, but (in line with earlier findings) they did not claim to hold sociability ideals when the supervisor held sociability values. The manipulation of threats issued by the supervisor had a significant effect on the subjects' use of other-enhancement with respect to the target's sociability, but it had no effect on other ingratiation measures. Finally, the manipulation of dependency had no effect on other-enhancement, but it did produce a surprising “modesty effect” on self-presentation. Subjects presented themselves as both less efficient and less sociable under high dependency than under low. These findings are discussed in the light of previous research on ingratiation tactics.     

The localization over time of exogenous aldosterone and angiotensin II in various organs

Central nervous system effects have been demonstrated for angiotensin II and suggested for aldosterone. In order to determine whether either of these chemicals naturally crosses the blood-brain barrier, radioactive aldosterone and angiotensin II were introduced via intracardiac injections in rats. Samples of blood, liver, kidney, adrenals, cerebral cortex, and hypothalamus were collected at three, 15, and 60 minutes, frozen, dissolved, and counted. Blood levels for aldosterone and angiotensin II remained constant over 60 minutes. Aldosterone accumulated in the liver, kidney, adrenals and hypothalamus three minutes after injection, and levels diminished over time. Angiotensin II levels peaked in the adrenal, kidney, and liver after three minutes, and in the hypothalamus after 15 minutes. Cerebral cortex levels were lower than hypothalamic levels by 30% for aldosterone and 50% for angiotensin II. This suggests that both drugs may enter the central nervous system and selectively accumulate in the hypothalamus.     

Perception of clicks in music

Subjects were asked to judge the position of a click that occurred during a short piece of music. Clicks were, on average, judged to be later than their actual position. The click and the music were presented through headphones to different ears, and the clicks were judged to be significantly later if they arrived at the right ear rather than at the left. There was also a significant tendency for clicks to be attracted to phrase boundaries in the music. These last two results are similar to those from experiments with a click during speech, but the late judgments of a click in music contrast with the early judgments of a click in speech.     

Semantic errors or statistical flukes? a note on allport's “on knowing the meaning of words we are unable to report”

Allport (1977) has claimed that normal subjects who view briefly a multi-word array, which is then pattern-masked, produce semantic errors analogous to those made by subjects with “deep dyslexia”. We claim that the rate at which normal subjects make such errors is consistent with their arising purely by chance.