Effects of glucose-saccharin preloads on schedule- and deprivation-induced drinking in rats

The present series of experiments found that high volumes of a glucose-saccharin solution consumed by rats prior to testing (i.e., a preload) produced a small, but significant suppression of established schedule-induced drinking (Experiment 2). This reduction in polydipsic drinking did not appear to be due to the caloric value of the preload (Experiment 1) or to any changes in food motivation, since Experiment 2 showed that there were no changes in lever pressing on a fixed-interval 1-min food schedule. In Experiment 3, the glucose-saccharin preloads produced a complete suppression of water deprivation-induced drinking. While schedule-induced drinking does appear to be a nonhomeostatic form of drinking, under certain testing conditions, it is sensitive to manipulations which affect homeostatic thirst mechanisms.     

Illusory expectations can affect retrieval-monitoring accuracy

The present study investigated how expectations, even when illusory, can affect the accuracy of memory decisions. Participants studied words presented in large or small font for subsequent memory tests. Replicating prior work, judgments of learning indicated that participants expected to remember large words better than small words, even though memory for these words was equivalent on a standard test of recognition memory and subjective judgments. Critically, we also included tests that instructed participants to selectively search memory for either large or small words, thereby allowing different memorial expectations to contribute to performance. On these tests we found reduced false recognition when searching memory for large words relative to small words, such that the size illusion paradoxically affected accuracy measures (d' scores) in the absence of actual memory differences. Additional evidence for the role of illusory expectations was that (a) the accuracy effect was obtained only when participants searched memory for the aspect of the stimuli corresponding to illusory expectations (size instead of color) and (b) the accuracy effect was eliminated on a forced-choice test that prevented the influence of memorial expectations. These findings demonstrate the critical role of memorial expectations in the retrieval-monitoring process.     

How accurate are women's estimates of date of onset of next menses?

Abstract

Because of individual differences in Occurrence of ovulation and patterns of hormonal secretions, one would usually prefer to measure locus in the menstrual cycle using physiological assessment procedures. But such methods are time consuming and costly. When exploring a new domain for possible relations to the menstrual cycle, it would be cost effective to use the simpler procedure of having each women verbally estimate date of onset of next menses. The accuracy of such estimates was studied in two college age samples. Estimated number of days until next onset correlated highly with actual number of days, as verified by follow-up (r = 0.90). As a group, women neither under- nor overestimated number of days. The precision with which these judgments were made was reasonably high. In sum, when a group of women are followed for one cycle, the average accuracy is very high, certainly high enough to support use of such verbal reports for certain scientific purposes.     

Depressive Symptomatology Mediates Associations With Community Reintegration in Veterans With TBI

Community reintegration (CR) is a challenge for military veterans with traumatic brain injury (TBI). Posttraumatic stress disorder (PTSD), depression, bodily pain, and limitations in physical functioning—common comorbidities with TBI in veterans—have all been associated with problems in CR, but their interrelationships are unclear. The role of depression as a possible mediator of effects on CR has not been examined. We tested depressive symptoms as a possible mediator of CR’s associations with physical limitations, PTSD, and bodily pain. This cross-sectional study used baseline data from a larger randomized controlled trial that evaluated the impact of an in-home intervention for veterans with TBI and their families. Eighty-three military veterans with TBI recruited from a medical rehabilitation service at an urban U.S. Department of Veterans Affairs medical center participated in the study. Interview instruments measured CR, depressive symptoms, physical limitations (limitations in physical functioning), bodily pain, quality of the relationship with key family members, and sociodemographic characteristics. PTSD was determined through review of the electronic medical record. Interview data were collected in veterans’ homes. Depressive symptoms totally mediated the association between physical limitations and CR and the association between PTSD and CR. The bodily pain–CR association was not significant after quality of relationship had been entered into the regression models. Findings suggest that interventions to increase CR of veterans with TBI should address depression, a treatable condition. Replication of our mediation findings in larger veteran and civilian samples with TBI is needed.     

Autobiographical elaboration reduces memory distortion: cognitive operations and the distinctiveness heuristic

Retrieval monitoring enhances episodic memory accuracy. For instance, false recognition is reduced when participants base their decisions on more distinctive recollections, a retrieval monitoring process called the distinctiveness heuristic. The experiments reported here tested the hypothesis that autobiographical elaboration during study (i.e., generating autobiographical memories in response to cue words) would lead to more distinctive recollections than other item-specific encoding tasks, enhancing retrieval monitoring accuracy at test. Consistent with this hypothesis, false recognition was less likely when participants had to search their memory for previous autobiographical elaborations, compared to previous semantic judgments. These false recognition effects were dissociated from true recognition effects across four experiments, implicating a recollection-based monitoring process that was independent from familiarity-based processes. Separately obtained subjective measures provided converging evidence for this conclusion. The cognitive operations engaged during autobiographical elaboration can lead to distinctive recollections, making them less prone to memory distortion than other types of deep or semantic encoding.     

A Rosa multiflora by Any Other Name: Taxonomic Incommensurability and Scientific Kinds

The following paper attempts to explore, criticizeand develop Thomas Kuhn's mostmature – and surprisingly neglected – view ofincommensurability. More specifically, itfocuses on (1) undermining an influential picture ofscientific kinds that lies at the heartof Kuhn's understanding of taxonomic incommensurability;(2) sketching an alternativepicture of scientific kinds that takes advantage ofKuhn's partially developed theory ofdisciplinary matrices; and (3) using these two resultsto motivate revisions to Kuhn'stheory of taxonomic incompatibility, as well as, tothe purported bridge betweentaxonomic incompatibility and some of the traditionalproblems associated withincommensurability.     

Understanding spatial relations: flexible infants,lexical adults

Concepts of containment, support, and degree of fit were investigated using nonverbal, preferential-looking tasks with 9- to 14-month-old infants and adults who were fluent in either English or Korean. Two contrasts were tested: tight containment vs. loose support (grammaticized as 'in' and 'on' in English by spatial prepositions and 'kkita' and 'nohta' in Korean by spatial verbs) and tight containment vs. loose containment (both grammaticized as 'in' in English but separately as 'kkita' and 'nehta' in Korean). Infants categorized both contrasts, suggesting conceptual readiness for learning such spatial semantics in either language. English-speaking adults categorized tight containment vs. loose support, but not tight vs. loose containment. However, Korean-speaking adults were successful at this latter contrast, which is lexicalized in their language. The adult data suggest that some spatial relations that are salient during the preverbal stage become less salient if language does not systematically encode them.     

Progressing from programmatic to discovery research: a case example with the overjustification effect

Scientific research progresses along planned (programmatic research) and unplanned (discovery research) paths. In the current investigation, we attempted to conduct a single-case evaluation of the overjustification effect (i.e., programmatic research). Results of the initial analysis were contrary to the overjustification hypothesis in that removal of the reward contingency produced an increase in responding. Based on this unexpected finding, we conducted subsequent analyses to further evaluate the mechanisms underlying these results (i.e., discovery research). Results of the additional analyses suggested that the reward contingency functioned as punishment (because the participant preferred the task to the rewards) and that withdrawal of the contingency produced punishment contrast.