Influence of dorsal hippocampal lesions and MMP inhibitors on spontaneous recovery following a habituation/classical conditioning head–shake task

The present investigation combined a classical conditioning paradigm with a head–shake response (HSR) habituation task in order to evaluate the importance of dorsal hippocampal neural plasticity to spontaneous recovery. In the first experiment animals exhibited rapid HSR habituation (air stimulus to the ear) and an 85% level of spontaneous recovery following a 24 h inter-session interval. The addition of a brief tone prior to the air stimulus produced a similar pattern of habituation during the first session, but the level of spontaneous recovery was reduced (44%) during Session II. In a second experiment dorsal hippocampal lesioned rats placed on this tone/HSR paradigm responded with an 87% level of spontaneous recovery during Session II; while neocortex lesioned control rats indicated significantly reduced levels of spontaneous recovery (55%). In a third experiment bilateral injections of a general MMP inhibitor, FN-439, into the dorsal hippocampus resulted in high levels of spontaneous recovery (81%); while control rats injected with artificial cerebrospinal fluid displayed a significant attenuation of spontaneous recovery (45%). Finally, animals bilaterally injected with a specific MMP-3 inhibitor into the dorsal hippocampus indicated very similar results to those obtained following FN-439 injection. These findings indicate that animals prepared with dorsal hippocampal lesions, or injections with an MMP inhibitor, revealed an impaired association between the tone and air stimulus thus maximum spontaneous recovery was present 24 h later. Thus, it appears that the dorsal hippocampus influences habituation by conserving responses and reducing spontaneous recovery when a temporally contingent signaling cue is present.     

making the case: demonstrating the impact of career and employment services

Career development practitioners understand that the value of career and employment services extends beyond attachment to the labor market. However, “soft” outcomes such as increased self‐efficacy and improved ability to manage transitions are difficult to measure. Convincing funders and policy makers of the significance of such outcomes may be challenging; consequently, important interventions may not be mandated or funded. In this article, the importance of effective program evaluation is highlighted, limitations of current evaluation models are identified, and a draft evaluation framework that facilitates tracking long‐term impacts of career and employment services is applied to critique a government‐commissioned summative evaluation report.     

Smoking in movies, implicit associations of smoking with the self, and intentions to smoke

We examined whether identifying with a film character who smokes increases implicit associations of the self with smoking. Undergraduate men were randomly assigned to view film clips in which the male protagonist either smoked or did not smoke. We measured subsequent levels of self-smoking associations using a reaction time task, as well as self-reported beliefs about smoking and smokers. Greater identification with the smoking protagonist predicted stronger implicit associations between the self and smoking (for both smokers and nonsmokers) and increased intention to smoke (among the smokers). Stronger implicit self-smoking associations uniquely predicted increases in smokers' intentions to smoke, over and above the effects of explicit beliefs about smoking. The results provide evidence that exposure to smoking in movies is causally related to changes in smoking-related thoughts, that identification with protagonists is an important feature of narrative influence, and that implicit measures may be useful in predicting deliberative behavior.     

Family-level impact of the CHAMP Family Program: a community collaborative effort to support urban families and reduce youth HIV risk exposure

This article presents family-level results from an ongoing study examining the impact of the CHAMP (Chicago HIV prevention and Adolescent Mental health Project) Family Program, a family-based HIV preventative intervention meant to reduce the amount of time spent in situations of sexual possibility and delay initiation of sexual activity for urban youth in the 4th and 5th grades living in neighborhoods with high rates of HIV infection. The CHAMP Family Program has been developed, delivered, and overseen by a collaborative partnership, consisting of community parents, school staff, community-based agency representatives, and university-based researchers. Design of the program was informed by input from this collaborative partnership, child developmental theory of sexual risk, and empirical data gathered from the targeted community. This article presents findings that suggest CHAMP Family Program impact on family communication, family decision-making, and family-level influences hypothesized to be related to later adolescent HIV risk. Implications for future family-based HIV prevention research are discussed here.     

Neuropsychological Performance in Gulf War Era Veterans: Motivational Factors and Effort

Assuming that the underlying etiology of unexplained health-related symptoms in returning Gulf War (GW) veterans is multifactorial, the possible role of feigning or exaggeration of symptoms is worth consideration as a contributing factor. The present study assessed the relationship between motivation to perform well during neuropsychological assessment and objective neuropsychological test performance. Motivation was measured as the score on a visual memory task (Test of Memory Malingering, TOMM) of low difficulty. Participants included 77 veterans from the cohorts of GW- (n = 58) and Germany-deployed (n = 19) GW-era veterans described in two other papers in this issue who were administered the TOMM. Most veterans earned perfect or near-perfect scores on the TOMM (48–50/50). Scores 47 were associated with lower scores on neuropsychological tasks assessing attention, executive functions, and memory. Variability in test performance within and between tasks measuring similar functions was also found in participants with lower TOMM scores.     

Anandamide and memory in CD1 mice: effects of immobilization stress and of prior experience

Five sets of experiments were carried out with CD1 mice tested in a one-trial inhibitory avoidance task. In a first set, immediately posttraining administrations of the endogenous ligand for the cannabinoid CB1 receptor anandamide (arachidonylethanolamide) (3 or 6 mg/kg) dose-dependently impaired memory consolidation in mice. A lower dose (1.5 mg/kg) was ineffective. In a second set of experiments, which was carried out at the same time of the first set, preexposure of the animals to the testing apparatus decreased the effect of the drug, as compared with non-preexposed mice. In a third set of experiments, administration of anandamide (3 or 6 mg/kg) prior to the retention test did not affect the retention performance of mice given posttraining injections of either saline or anandamide. These findings indicate that the memory-impairing effects of posttraining administration of anandamide are not state-dependent. In the fourth and fifth series of experiments, carried out with non-preexposed mice, an otherwise ineffective immobilization stress (15 min) enhanced the memory-impairing effect of anandamide, and an otherwise ineffective dose of naltrexone (0.1 mg/kg) completely antagonized the effect. The results are discussed in terms of attenuation of emotionality, resulting in impaired retention, following anandamide administration, and of involvement of opioid system in the effect of this drug.     

Watching a cursor distorts haptically guided reproduction of mouse movement

Participants moved a mouse along a force-feedback-defined linear path, either without vision or while watching a cursor set to 1 of 3 levels of visual:haptic gain (all >1:1). They attempted to haptically reproduce the movement without visual feedback. Errors increased with gain, reaching 70% overestimation at the highest gain. Forewarning participants about gain variability did not eliminate this effect. The gain level was potentially cued during the movement by the mismatch between visual feedback and kinesthetic feedback. Moreover, because participants did not achieve cursor-speed constancy across gain levels, visual speed was another cue to gain. Collectively, these cues failed to prevent visual distortion of movement reproduction.     

Mommy and me: familiar names help launch babies into speech-stream segmentation

How do infants find the words in the tangle of speech that confronts them? The present study shows that by as early as 6 months of age, infants can already exploit highly familiar words-including, but not limited to, their own names-to segment and recognize adjoining, previously unfamiliar words from fluent speech. The head-turn preference procedure was used to familiarize babies with short passages in which a novel word was preceded by a familiar or a novel name. At test, babies recognized the word that followed the familiar name, but not the word that followed the novel name. This is the youngest age at which infants have been shown capable of segmenting fluent speech. Young infants have a powerful aid available to them for cracking the speech code. Their emerging familiarity with particular words, such as their own and other people's names, can provide initial anchors in the speech stream.     

Validity and Necessity

In this paper I argue against the commonly received view that Kripke’s formal Possible World Semantics (PWS) reflects the adoption of a metaphysical interpretation of the modal operators. I consider in detail Kripke’s three main innovations vis-à-vis Carnap’s PWS: a new view of the worlds, variable domains of quantification, and the adoption of a notion of universal validity. I argue that all these changes are driven by the natural technical development of the model theory and its related notion of validity: they are dictated by merely formal considerations, not interpretive concerns. I conclude that Kripke’s model theoretic semantics does not induce a metaphysical reading of necessity, and is formally adequate independently of the specific interpretation of the modal operators.