Regulation of low-threshold afferent activity may contribute to short-term habituation in Aplysia californica

The goal of this study was to characterize the contribution of a population of low-threshold mechanoreceptors to short-term habituation of siphon-elicited reflex responses in Aplysia californica. Since the location of their somata is unknown, we refer to them as the Unidentified Low-Threshold mechanoreceptors (ULTs). The ULTs operate in parallel to the higher-threshold and well-characterized LE sensory neurons, yet little is known regarding their contribution to behavioral plasticity. Using extracellular recordings from the siphon nerve, we found that habituation training that favors ULT activation resulted in a significant decrease in afferent activity at training intervals up to 1 min per stimulus (1 min ISI). To determine how this reduction impacts responses at other sites of the reflex network, we used intracellular recordings to measure training-induced changes in either L29 excitatory interneurons or LFS siphon motor neurons. With a 30s ISI, changes at both locations were training site-specific and matched the rate of change of afferent activity, implicating regulated sensory activity as a primary mechanism. With a shorter training interval (1s ISI), site-specificity of training was not observed in the L29s, but was still preserved in the motor neurons. For both, the rate of change during training was faster than the rate of change of afferent activity. Taken together, we conclude that regulation of low-threshold sensory neuron activity can play a significant role in short-term habituation, but other network processes may be recruited at more rapid training intervals.     

Climate Change,Nuclear Economics,and Conflicts of Interest

Merck suppressed data on harmful effects of its drug Vioxx, and Guidant suppressed data on electrical flaws in one of its heart-defibrillator models. Both cases reveal how financial conflicts of interest can skew biomedical research. Such conflicts also occur in electric-utility-related research. Attempting to show that increased atomic energy can help address climate change, some industry advocates claim nuclear power is an inexpensive way to generate low-carbon electricity. Surveying 30 recent nuclear analyses, this paper shows that industry-funded studies appear to fall into conflicts of interest and to illegitimately trim cost data in several main ways. They exclude costs of full-liability insurance, underestimate interest rates and construction times by using “overnight” costs, and overestimate load factors and reactor lifetimes. If these trimmed costs are included, nuclear-generated electricity can be shown roughly 6 times more expensive than most studies claim. After answering four objections, the paper concludes that, although there may be reasons to use reactors to address climate change, economics does not appear to be one of them.     

Toddlers' context-varying emotions, maternal responses to emotions, and internalizing behaviors

Relations of toddlers' observed negative affect in high- and low-threat contexts to maternal perceptions of their toddlers' internalizing problems and to mothers' responses to emotions (RTE) for fear and sadness were examined. Child-driven, parent-driven, and reciprocal transactional models across 1 year were directly compared. Two-year-old toddlers (N = 106) participated in lab-based activities to elicit distress, and their negative affect was coded. Mothers completed measures of their child's internalizing behaviors and their responses to their toddler's fear and sadness at ages 2 and 3. At age 2, only negative affect in low-threat contexts was associated with greater internalizing problems. Mothers' punishing and minimizing RTE at age 2 predicted an increase in internalizing problems across 1 year. Age 2 internalizing problems predicted an increase in mother's use of supportive RTE over time. Results highlight the importance of considering the context of toddlers' negative affective displays and supported a reciprocal conceptualization of toddlers' internalizing behaviors and mothers' RTE.     

Spiritual well-being and spiritual practices in elderly depressed psychiatric inpatients

This study's aims were to describe the spirituality of depressed elderly psychiatric inpatients and to examine associations among spirituality, depression, and quality of life (QOL). Forty-five persons participated. Most reported frequent, stable spiritual practices and experiencing spiritual comfort and guidance. Some reported spiritual distress and changes in spirituality. During hospitalization, participants demonstrated increased spiritual well-being (SWB) and peacefulness, and reduced hopelessness, worthlessness, and guilt. Positive associations were found between SWB and QOL and negative associations between SWB and depression.     

The differential effects of thalamus and basal ganglia on facial emotion recognition

This study examined if subcortical stroke was associated with impaired facial emotion recognition. Furthermore, the lateralization of the impairment and the differential profiles of facial emotion recognition deficits with localized thalamic or basal ganglia damage were also studied. Thirty-eight patients with subcortical strokes and 19 matched normal controls volunteered to participate. The participants were individually presented with morphed photographs of facial emotion expressions over multiple trials. They were requested to classify each of these morphed photographs according to Ekman's six basic emotion categories. The findings indicated that the clinical participants had impaired facial emotion recognition, though no clear lateralization pattern of impairment was observed. The patients with localized thalamic damage performed significantly worse in recognizing sadness than the controls. Longitudinal studies on patients with subcortical brain damage should be conducted to examine how cognitive reorganization post-stroke would affect emotion recognition.     

The processing of free and bound gender-marked morphemes in speech production: evidence from Dutch

In many languages, the production of noun phrases requires the selection of gender-marked elements like determiners or inflectional suffixes. There is a recent debate as to whether the selection of freestanding gender-marked elements, such as determiners, follows the same processing mechanisms as the selection of bound gender-marked morphemes, such as adjective suffixes. Most of the evidence on which this debate is based relates to the gender-congruency effect in picture-word interference experiments. In the present article, the authors address this issue with a pure picture-naming task, extending previous work in German (H. Schriefers, J. D. Jescheniak, & A. Hantsch, 2005). The results of the present study on noun phrase production in Dutch show that both types of gender-marked morphemes are selected via the same basic processing mechanisms.     

The Action-Sentence Compatibility Effect: It's All in the Timing

When participants are asked to make sensibility judgments on sentences that describe action toward the body (i.e., "Mark dealt the cards to you") or away from the body (i.e., "You dealt the cards to Mark"), they are faster to respond when the response requires an arm movement in the same direction as the action described by the sentence. This congruence effect is known as the Action–Sentence Compatibility Effect (ACE). This study reports 4 experiments that extend our understanding of the ACE by exploring how the time at which one prepares the motor response required for the sensibility judgment affects the magnitude of the ACE. Results show that the ACE arises only when participants have the opportunity to plan their motor response while they are processing the sentence.     

Panic disorder and suicide attempt in the National Comorbidity Survey

Clinical and some epidemiological data conflict concerning the likelihood of suicide attempt in individuals with panic disorder (PD). The purpose of this study was to illuminate the panic disorder-suicide attempt association in the National Comorbidity Survey (NCS; R. C. Kessler et al., 1994). Specifically, suicide attempt histories of those 5,872 respondents answering "yes" or "no" to the suicide attempt question were regressed against lifetime diagnostic histories. Lifetime PD history, in the presence of other disorders, was unrelated to elevated risk of suicide attempt and did not account for additional variance. PD respondents who had made a suicide attempt were characterized by Comorbidity. Epidemiological respondents with lifetime histories of PD alone are not at heightened risk for self-reported suicide attempt.     

Evaluation of behavioral skills training to prevent gun play in children

This study evaluated behavioral skills training (BST), in a multiple baseline across subjects design, for teaching firearm safety skills to 6 6- and 7-year-old children. Similar to previous research with 4- and 5-year-olds, half of the children acquired the safety skills following BST and half acquired the skills following BST plus in situ training.     

Evaluation of behavioral skills training for teaching abduction-prevention skills to young children

This study examined the effectiveness of individual behavioral skills training in conjunction with in situ training in teaching 13 preschool children abduction prevention skills. Children's performance was measured during baseline, training, and at 2-week, 1-month, and 3-month follow-ups using in situ assessments in which abduction prevention skills were measured in naturalistic settings. Results revealed that all the children learned the skills and all the children available at the 2-week and 1-month follow-ups maintained the skills at criterion level. All but 3 children's criterion-level performances were maintained at the 3-month follow-up as well.