The clinician-investigator: unavoidable but manageable tension

The "difference position" holds that clinical research and therapeutic medical practice are sufficiently distinct activities to require different ethical rules and principles. The "similarity position" holds instead that clinical investigators ought to be bound by the same fundamental principles that govern therapeutic medicine--specifically, a duty to provide the optimal therapeutic benefit to each patient or subject. Some defenders of the similarity position defend it because of the overlap between the role of attending physician and the role of investigator in a research trial. This overlap is maximal when the same physician occupies both roles with respect to a particular patient-subject. We address the ethical tensions inherent in that role conflict and argue that the tensions are real but manageable. The difference position provides a sound ethical framework within which to manage those tensions, while the similarity position is unsatisfactory because it seeks to deny the existence of the tensions.     

A Typology of LDS Sociopolitical Worldviews

Members of the Church of Jesus Christ of Latter-Day Saints (Mormons, Latter-Day Saints, or LDS) are sometimes thought of as a monolithic block of economic and social conservatives. This article addresses whether this is caused by strong religious effects, or whether it is an artifact of unrepresentative sampling. Q methodology is used to identify six "types" of political worldviews among a multinational and multiracial sample of active Latter-Day Saints. The six types reveal some interesting ideological variations among Mormons, particularly on economic issues, and even some unique LDS issues. A second-order factor analysis indicates a high level of commonality across types on social issues, but important differences on orientation toward government. I conclude that the failure to include racial and cultural variation in Mormon samples has led us to overestimate the otherwise significant influence of LDS doctrine on members' political views.     

A test of the four-factor model of impulsivity-related traits

In a recent article, Whiteside and Lynam [Person. Indiv. Diff. 30 (2001) 669] proposed a new model for understanding personality pathways to impulsive behavior. Their UPPS model maintains that there are four personality dimensions that are related differentially to impulsive behaviors: urgency, sensation seeking, (lack of) premeditation, and (lack of) perseverance. The purpose of the current study was to provide validation for this model and to test some of the specific hypotheses offered by Whiteside and Lynam. The sample used in this study consisted of 481 individuals who completed mailed surveys at age 20 and an in-depth laboratory protocol at age 21. Zero-order correlations and multiple regression analyses were used to examine the relations between the four personality traits and various forms of externalizing behaviors, several types of internalizing psychopathology, and intelligence. Results revealed that the four traits were differentially related to various behaviors and forms of psychopathology consistent with many of Whiteside and Lynam's predictions. Therefore, the UPPS model does appear to offer a novel and useful way of understanding behaviors and forms of psychopathology considered to be characterized by some form of impulsivity.     

Pavlovian eyeblink conditioning in combat veterans with and without post-traumatic stress disorder

Several recent studies have investigated relationships between post-traumatic stress disorder (PTSD) and learning and memory problems. These reports have found in general that not only does PTSD affect trauma-related memories, but when patients with PTSD are compared with similar trauma patients without PTSD, general memory impairments have been found. The present paper reports a study in which associative learning, using Pavlovian eyeblink conditioning, was investigated in combat veterans with and without chronic PTSD, using interstimulus intervals of 500 and 1000 msec in two separate experiments. Although several recent reports suggest that larger-magnitude autonomic conditioned responses occur in patients with PTSD during Pavlovian conditoning, the present study found evidence of impaired Pavlovian eyeblink conditioning in combat veterans with and without PTSD, compared to non-combat veterans. Although these data suggest that combat leads to an impaired associative learning process regardless of whether PTSD is apparent, a group of community-dwelling combat veterans not under medical treatment showed normal conditioning, suggesting that variables other than prior combat must also be involved.     

Instructions for Authors

Instructions for Authors

Instructions for Authors     

Contrasting Acquisition-Focused and Performance-Focused Models of Acquired Behavior

What is encoded during a learning experience? In a learning situation, a training (acquisition) phase is often followed by a test phase. Acquisition-focused models (most associative models) emphasize information processing that occurs during training and assume that only summary statistics (associative values) are retained to influence behavior during testing. Performance-focused models (a k a "computational" models) emphasize information processing that occurs at test and often assume fairly comprehensive memory of prior experiences. In this article, we contrast these two families of models. We note that neither family can claim unique support from the various learning phenomena commonly cited as favoring one or the other position. Within each family, there are highly diverse models that preclude blanket generalizations. However, the acquisition-focused view that subjects retain only summary statistics suggests unrealistically impoverished memories relative to the fairly veridical memories that clearly are formed. But this oversimplifying assumption of acquisition-focused associative theories is exactly what has made them superior to performance-focused models to date in stimulating research.     

Cues trained apart compete for behavioral control in rats: convergence with the associative interference literature

Contemporary theories of associative learning require cues be trained in compound for cue competition (interference) to occur. That is, Cues A and X should compete for behavioral control only if training consists of AX-outcome (O) trials and not if each cue is separately paired with O (i.e., X-O and A-O). Research with humans challenges this view by showing that A-O trials interpolated between training and testing of a X-O association impair responding to X (i.e., retroactive interference). In six conditioned suppression studies with rats, the authors demonstrate that two cues trained apart can each interfere with the potential of the other to predict the outcome. The authors conclude that this type of interference (a) reflects a failure to retrieve the target association due to priming at test of the interfering association and (b) is attenuated if the outcome is of high biological significance. These findings parallel previous reports in verbal learning research and suggest that a similar associative structure underlies some types of associations in nonverbal subjects.     

Rowed to recovery: the use of phonological and orthographic information in reading Chinese and English

To examine how readers of Chinese and English take advantage of orthographic and phonological features in reading, the authors investigated the effects of spelling errors on reading text in Chinese and English using the error disruption paradigm of M. Daneman and E. Reingold (1993). Skilled readers in China and the United States read passages in their native language that contained occasional spelling errors. Results showed that under some circumstances very early phonological activation can be identified in English, but no evidence for early phonology was found in Chinese. In both languages, homophone errors showed a benefit in measures of later processing, suggesting that phonology helps readers recover from the disruptive effects of errors. These results suggest that skilled readers take advantage of the special features of particular orthographies but that these orthographic effects may be most pronounced in the early stages of lexical access.     

Acquired equivalence of cues by presentation in a common context in rats

It is well established that humans and other animals may treat two perceptually different cues alike, if the cues have been individually paired with a common antecedent or a common consequence. Recently, Molet et al. (Psychon Bull Rev 18:618–623, 2011) reported evidence for a new form of acquired equivalence in human conditional discrimination, namely context-mediated equivalence. In the present research, using a flavor conditioning procedure, we asked whether rats would show similar context-mediated equivalence to demonstrate that this new form of acquired equivalence is a general phenomenon. Rats experienced two flavor cues A and B each presented either in the same context, X, or each in its own distinctive context, X or Y. Subsequently, the rats experienced B with sucrose in a third context, Z, and then the generalization of conditioning to A was assessed. When tested in Context Z, consumption of A was more marked when A and B had both been presented in the same context than when they had been presented in two different contexts. Thus, importantly, in the absence of the training context, cues that shared a common context at different times came to be treated as equivalent. This represents the first evidence of context-mediated equivalence in a nonhuman species.