Individual Differences in Spatial Memory and Striatal ChAT Activity among Young and Aged Rats

Individual differences in spatial memory among young and aged rats were assessed using memory tasks related to integrity of the hippocampus and the neostriatum. Relationships were then examined between measures of spatial memory and regional choline acetyltransferase (ChAT) activity, a marker for cholinergic integrity. Twenty-four-month-old Long-Evans rats were impaired in comparisons with 6-month-old rats on measures of place learning, working memory, reference memory, and perseveration in water-maze tasks. Aged rats that were impaired on one measure of memory, however, were not necessarily impaired on other measures. ChAT activity in the ventromedial and dorsolateral neostriatum of aged rats was significantly reduced in comparisons with young rats whereas no difference was found in the hippocampus. Aged rats with the most ChAT activity in the anterior ventromedial neostriatum performed best on the place-learning and reference memory tasks but also made the most perseverative errors on the working memory task. In addition, young and aged rats with the most ChAT activity in the anterior dorsolateral neostriatum were those with the least accurate working memory. No relationships were found between ChAT activity in the hippocampus and spatial memory. Thus age-related memory impairment has components that can be segregated by measuring relationships between cholinergic integrity in subregions of the anterior neostriatum and memory tasks with different strategic requirements.     

Emotions associated with counterfactual comparisons drive decision-making in Footbridge-type moral dilemmas

Based on the dual-process theory of moral judgment, it has been suggested that in Footbridge-type dilemmas the anticipation of the emotional consequences of causing intentional harm might contribute to the decision of rejecting utilitarian resolutions. However, no empirical data have been reported on the emotions felt by participants after their decisions, and the role played by emotions in Trolley-type dilemmas remains to be determined. The present study investigated the specific emotions engaged both after decision choices and after the generation of the counterfactual scenario in Trolley- and Footbridge-type dilemmas. The results support the idea that in Footbridge-type dilemmas decision-making is driven by the attempt to minimize the aversive emotional state evoked by the decision outcome. A greater increase in emotional intensity was found overall for Footbridge-type than Trolley-type dilemmas after the counterfactual generation following typical (non-utilitarian) choices, with guilt, regret, and shame being the emotions that increased most. Critically, in Footbridge-type dilemmas only, typical choices were predicted by the increase in regret intensity experienced after counterfactual generation.     

Interference with reelin signaling in the lateral entorhinal cortex impairs spatial memory

Entorhinal neurons receive extensive intracortical projections, and form the primary input to the hippocampus via the perforant pathway. The glutamatergic cells of origin for the perforant pathway are distinguished by their expression of reelin, a glycoprotein involved in learning and synaptic plasticity. The functional significance of reelin signaling within the entorhinal cortex, however, remains unexplored. To determine whether interrupting entorhinal reelin signaling might have consequences for learning and memory, we administered recombinant receptor-associated protein (RAP) into the lateral entorhinal cortex (LEC) of young Long-Evans rats. RAP prevents reelin from binding to its receptors, and we verified the knockdown of reelin signaling by quantifying the phosphorylation state of reelin’s intracellular signaling target, disabled-1 (DAB1). Effective knockdown of reelin signaling was associated with impaired performance in the hippocampus-dependent version of the water maze. Moreover, inhibition of reelin signaling induced a localized loss of synaptic marker expression in the LEC. These observations support a role for entorhinal reelin signaling in spatial learning, and suggest that an intact reelin signaling pathway is essential for synaptic integrity in the adult entorhinal cortex.     

Reducing Measurement Error in Student Achievement Estimation

The achievement level is a variable measured with error, that can be estimated by means of the Rasch model. Teacher grades also measure the achievement level but they are expressed on a different scale. This paper proposes a method for combining these two scores to obtain a synthetic measure of the achievement level based on the theory developed for regression with covariate measurement error. In particular, the focus is on ordinal scaled grades, using the SIMEX method for measurement error correction. The result is a measure comparable across subjects with smaller measurement error variance. An empirical application illustrates the method.     

Psychometric characteristics of the Italian Clinical Depression Questionnaire using a 5-point rating scale with undergraduates

The aim was to investigate the psychometric properties of a proposed experimental version of the 1979 Italian adaptation of the Clinical Depression Questionnaire (Krug & Laughlin, 1976). This version is composed of an increased number of choice alternatives (5 instead of 3), tested with 240 Italian undergraduates. An exploratory item-factor analysis yielded one factor, which accounted for 28.2% of the variance. Analysis of the relationship between this version and an experimental one in 2002 of the 1979 Italian edition of the Anxiety Scale Questionnaire showed the corrective factor was not effective in increasing the discriminative power of the questionnaire for anxiety.     

ASTEF: A simple tool for examining fixations

In human factors and ergonomics research, the analysis of eye movements has gained popularity as a method for obtaining information concerning the operator's cognitive strategies and for drawing inferences about the cognitive state of an individual. For example, recent studies have shown that the distribution of eye fixations is sensitive to variations in mental workload---dispersed when workload is high, and clustered when workload is low. Spatial statistics algorithms can be used to obtain information about the type of distribution and can be applied over fixations recorded during small epochs of time to assess online changes in the level of mental load experienced by the individuals. In order to ease the computation of the statistical index and to encourage research on the spatial properties of visual scanning, A Simple Tool for Examining Fixations has been developed. The software application implements functions for fixation visualization, management, and analysis, and includes a tool for fixation identification from raw gaze point data. Updated information can be obtained online at www.astef.info, where the installation package is freely downloadable.     

Observing Behavior Topography in Delayed Matching to Multiple Samples

The Psychological Record - This study examined relations between eye movements and accuracy scores in a delayed matching-to-sample procedure with multiple sample stimuli. Four adult humans...     

Short-Term Inpatient DBT Combined with Metacognitive Interventions for Personality Disorders: A Pilot Acceptability and Effectiveness Study

This study aims at evaluating the effectiveness of an intensive 1-month residential treatment course in an Italian psychiatric unit for patients meeting criteria for personality disorders (PD). This study involved 189 patients consecutively admitted to the unit and assessed at admission and discharge. The inpatient program was based on Dialectical Behavior Therapy (DBT) combined with Metacognitive interventions. Primary outcome was a reduction of general symptom severity (as measured by SCL-90-R). Secondary outcomes were reduction in depression (BDI), interpersonal problems (IIP-47). Other outcomes were impulsivity (BIS-11), aggressiveness (AQ), and dissociation (DES). We found a significant reduction in symptom severity, as well as in depression, interpersonal problems, dissociation, impulsivity and aggressiveness. The size of this benefit was predicted mostly by number of criteria met at SCID-II and intake scores mostly for impulsiveness and dissociation. In conclusion, intensive 1-month residential DBT combined with metacognitive interventions can be effective in treating patients with any PD presenting with severe global suffering, prominent self-harm and suicidal risk.

     

Emotion recognition and expression in young obese participants: preliminary study

This study of the presence of alexithymic characteristics in obese adolescents and preadolescents tested the hypothesis of whether they showed impaired recognition and expression of emotion. The sample included 30 obese young participants and a control group of 30 participants of normal weight for their ages. Stimuli, 42 faces representing seven emotional expressions, were shown to participants who identified the emotion expressed in the face. The Level of Emotional Awareness Scale was adapted for children to evaluate their ability to describe their emotions. Young obese participants had significantly lower scores than control participants, but no differences were found in recognition of emotion. The lack of words to describe emotions might suggest a greater prevalence of alexithymic characteristics in the obese participants, but the hypothesis of a general deficit in the processing of emotional experiences was not supported.     

Genetic background differences and nonassociative effects in mouse trace fear conditioning

Fear conditioning, including variants such as delay and trace conditioning that depend on different neural systems, is widely used to behaviorally characterize genetically altered mice. We present data from three strains of mice, C57/BL6 (C57), 129/SvlmJ (129), and a hybrid strain of the two (F(1) hybrids), trained on various versions of a trace fear-conditioning protocol. The initial version was taken from the literature but included unpaired control groups to assess nonassociative effects on test performance. We observed high levels of nonassociative freezing in both contextual and cued test conditions. In particular, nonassociative freezing in unpaired control groups was equivalent to freezing shown by paired groups in the tests for trace conditioning. A number of pilot studies resulted in a new protocol that yielded strong context conditioning and low levels of nonassociative freezing in all mouse strains. During the trace-CS test in this protocol, freezing in unpaired controls remained low in all strains, and both the C57s and F(1) hybrids showed reliable associative trace fear conditioning. Trace conditioning, however, was not obtained in the 129 mice. Our findings indicate that caution is warranted in interpreting mouse fear-conditioning studies that lack control conditions to address nonassociative effects. They also reveal a final set of parameters that are important for minimizing such nonassociative effects and demonstrate strain differences across performance in mouse contextual and trace fear conditioning.