Retrieval processes that produce interference in modified forced-choice recognition tests

Recognition can suffer if the retrieval cues activate more than one trace (e.g., for Flower A and Flower A′). We found evidence for two retrieval processes by examining interference effects in forcedchoice tests (e.g., Did you see Flower A or Flower A″?). Experiment 1 provided evidence of a problem in discriminating between temporally and contextually similar traces that were formed in the study phase. A competitor (Flower A′) interfered more if it was shown in the study phase rather than in the test phase. Experiments 2 and 3 found evidence for a blocking process in recognizing pairs of words (child—apple). A competitor interfered more if it was recent, shown at test rather than at study. This pattern occurred regardless of whether the competitor was similar to the target (child—orange) or dissimilar to it (child—truck). The importance of a particular retrieval process may depend on an item’s representation as well as on the retrieval cues.     

A Representation Theorem for a Decision Theory With Conditionals

This paper investigates the role of conditionals in hypothetical reasoning and rational decision making. Its main result is a proof of a representation theorem for preferences defined on sets of sentences (and, in particular, conditional sentences), where an agent’s preference for one sentence over another is understood to be a preference for receiving the news conveyed by the former. The theorem shows that a rational preference ordering of conditional sentences determines probability and desirability representations of the agent’s degrees of belief and desire that satisfy, in the case of non-conditional sentences, the axioms of Jeffrey’s decision theory and, in the case of conditional sentences, Adams’ expression for the probabilities of conditionals. Furthermore, the probability representation is shown to be unique and the desirability representation unique up to positive linear transformation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Brain Oxidative Damage Following Acute Immobilization and Mild Emotional Stress

We studied the role of free radicals on brain oxidative damage in rats after acute immobilization stress (restraint) and mild emotional stress (handling). To investigate brain oxidative damage, CuZn and Mn dependent superoxide dismutase (CuZn SOD, Mn SOD) activities, lipid peroxidation (TBARs), Na ⁺ K ⁺ ATPase activity, protein carbonyl (PrC), and reduced and oxidized glutathione (GSH, GSSG) levels were measured in the cerebral cortex (CTX), hippocampus (HIP), and striatum (ST) of the animals after the two different stress stimuli. Because stress produces abnormalities in the hypothalamic-pituitary-adrenal axis, the intensity of the two stress conditions were measured by plasmatic corticosteroid (COR) levels: particularly, COR levels doubled in handled rats and increased 15-fold in restrained animals. The SOD activities increased in CTX and decreased in HIP of the handled rats, while in ST a significant decrease in handled animals but an increase in restrained animals occurred. TBARs, GSH, and GSSG levels remained unchanged, while an index of glutathione redox decreased significantly in ST of handled animals and in CTX of restrained ones. Na ⁺ K ⁺ ATPase activity increased significantly in the HIP and ST of both groups of stressed rats. The stress induced a remarkable increase in PrC levels in all studied cerebral areas. These findings provide evidence to support the idea that stress produces oxidants but that the oxidative damage in stress differs in cerebral areas and could contribute to the degenerative mechanism of aging.     

Some cautions regarding statistical power in split-plot designs

We show that if overall sample size and effect size are held constant, the power of theF test for a one-way analysis of variance decreases dramatically as the number of groups increases. This reduction in power is even greater when the groups added to the design do not produce treatment effects. If a second independent variable is added to the design, either a split-plot or a completely randomized design may be employed. For the split-plot design, we show that the power of theF test on the betweengroups factor decreases as the correlation across the levels of the within-groups factor increases. The attenuation in between-groups power becomes more pronounced as the number of levels of the withingroups factor increases. Sample size and total cost calculations are required to determine whether the split-plot or completely randomized design is more efficient in a particular application. The outcome hinges on the cost of obtaining (or recruiting) a single subject relative to the cost of obtaining a single observation: We call this thesubject-to-observation cost (SOC) ratio. Split-plot designs are less costly than completely randomized designs only when the SOC ratio is high, the correlation across the levels of the within-groups factor is low, and the number of such levels is small.     

The accuracy of four approximations to noncentralF

The accuracy of the two-moment, three-moment, square root, and cube root approximations to the noncentralF distribution was assessed using 7,920 entries from Tiku’s (1967) power tables. Tiku’s tables list exact values of β for α= .005?.05, ν₁ = 1?12, ν₂ = 2?120, and ?= 0.5?3.0. Analysis of the errors showed generally satisfactory performance for all four approximations. The three-moment approximation was most accurate, registering a maximum error of only .009. The other three approximations had maximum errors of ±.02, except for the square root approximation at ν₂ = 2, where maximum errors of .05 occur. Approximation error increased with decreases in ν₁ and, less consistently, with increases in ν2. Error was nonmonotonically related to ?. A second investigation explored the accuracy of the approximations at values of αranging from .10 to .90. All four approximations degraded substantially in this situation, with maximum errors ranging from ?.09 to .05. If the analysis is restricted to cases where ν₁ τ; 1 and ν₂ τ; 2, maximum errors drop to roughly ±.03. We conclude that the approximations perform reasonably well for small αand moderately well for larger values, if certain restrictions are imposed. From a computational standpoint, however, there is little advantage to using approximate as opposed to exact methods unless exact values ofF _α are known in advance.     

Women in male-dominated professions: Contrasts in their personal and vocational histories

Women in four high-status, male-dominated professions—architecture, law, medicine, and psychology—are described in terms of a variety of historical, social, and career variables. The women share common antecedents of their vocational choices and similar perceptions of their work, but the occupational groups are dissimilar on a number of dimensions. Psychologists stand in particular contrast to the other three groups of professionals, describing experiences and career patterns less in conflict with stereotypic female roles. These contrasts may reflect differences in the sex-typed characterizations of the professions even though all are male-dominated.     

Establishing discriminative stimulus control within generalized oddity performance,without reinforcement

In two oddity learning studies with children, subjects were reinforced for oddity (or nonoddity) responding on line-tilt or dot numerosity problems. Interposed form and color problems were not reinforced. No instructions to make oddity choices were given. In Experiment I it was found that reinforcement for oddity or nonoddity responding on tilt and numerosity problems produced the corresponding tendency toward oddity or nonoddity performance on these problems and also on the nonreinforced form and color problems. These results show a generalized oddity phenomenon similar to generalized imitation. In Experiment II a third type of nonreinforced problem was presented in this same format: compound stimuli permitting either a color or a form solution. It was found that immediate prior training with nonreinforced form problems, interpolated among the reinforced tilt and numerosity problems, led to form-oddity choices in the compound problems. Similarily, color pretraining produced color-oddity choices. These results show that selective discriminative stimulus control can be obtained in oddity learning, without reinforcement for choices on either of the two dimensions involved.     

A common factor in the MMPI scales of married couples.

Using canonical analysis, a common factor in the MMPI scales of husbands and wives was found. The Sc, Pd, and Hs scales for both the husbands and the wives contributed heavily to the relationship. Other scales contributing to the correlation between the personality components of the pairs were F, Hy Pt, and Si for the husbands and Pa for the wives. The results were interpreted as indicating areas of homogeneity and heterogeneity in the personalities of married couples.     

The “Paradox of Self‐Constitution” and Korsgaard's Two Conceptions of Maxims for Action

This article argues that Christine Korsgaard gives two accounts of maxims, the identity‐priority account and the form‐priority account. There is a tension between the accounts because (1) Korsgaard's form‐priority maxims account cannot function apart from the identity of a well‐formed agent that precedes and tests maxims to determine if they should count as reasons or laws, and (2) Korsgaard's identity‐priority maxims account needs the form of the maxim to precede, bind, and constitute the well‐formed agent. This tension mirrors the two sides of what Korsgaard has called the “paradox of self‐constitution.” The article concludes that Korsgaard's paradox of self‐constitution leads to an arbitrariness that undermines the formation of moral laws.