Participation of hippocampal cholinergic system in memory persistence for inhibitory avoidance in rats

Memory persistence needs a new event of consolidation 12h after the acquisition. We investigated the role of the cholinergic activity on the persistence of memory. For this purpose, we performed the treatments 9 or 12h after acquisition and the memory tested 2 or 7 days after inhibitory avoidance (IA) training. Here we report that activity of medial septum, by transitorily inactivating this structure with lidocaine 12h after IA training, is essential for memory persistence at the 7th day, but not for the formation at the 2nd day. We also report that muscarinic and nicotinic cholinergic receptors of CA1 area are engaged on memory persistence. Since scopolamine (mAChRs antagonist) and mecamylamine (nAChRs blocker) infusions, 12h post-training, demonstrated impairment on long term memory (LTM), persistence on the 7th day but no effect on LTM formation was found on the 2nd day in the IA test. The same effects were found with pirenzepine, an M1 antagonist. No effects on the formation and persistence of memory on the 2nd and 7th days were demonstrated after DHβE infusions (nAChRs subtype antagonist α4β2, α3β2). These findings suggest that mAChR and nAChR at the CA1 area, and also MS activation, are required for the persistence of memory.     

The effect of age on decision making according to the Iowa gambling task

Aging has been associated with several brain changes that often affect the cognitive functioning of adults, but changes in executive functions, particularly in the field of decision making, have not been fully investigated. The Iowa Gambling Task (IGT) is a widely used tool to evaluate decision making, but little is known about the effect of age on its results. This study used the IGT and compared healthy young (n = 40) and elderly (n = 40) adults to evaluate their decision making processes. There were significant differences in the learning curve of the two age groups, but no difference in overall IGT performance. The results for the first IGT block were different from those of the rest of the task, and the group of elderly adults had a better performance in this block. Elderly adults also showed a preference for deck A, the one that resulted in greater losses. Findings confirmed the results of other studies, which reported that the IGT block score is the variable with the greatest sensitivity to age in this instrument.     

Adaptation in conflict: are conflict-triggered control adjustments protected in the presence of motivational distractors?

Solving a conflict between two response options in an interference task has been found to increase control in a subsequent conflict situation. The present research examined whether such conflict adaptation persists in the presence of distractors that have motivational relevance and are therefore competing for attentional resources (i.e. they signal opportunities for monetary gains or losses contingent on overall task performance). In an adjusted flanker task, motivational (versus neutral versus no) distractors were presented together with the current trial while the previous trial never included any distractor. Accumulated evidence across three studies showed that motivational distractors reduced the conflict adaptation effect. This was found irrespective of the location at which the distractor occurred (Study 1), and independent of its valence (i.e. reward or loss, Study 2). Study 3 and a merged data analysis ruled out low-level alternative explanations. In line with a dual competition account (Pessoa, L. (2009). How do emotion and motivation direct executive control? Trends in Cognitive Sciences, 13(4), 160–166. doi:10.1016/j.tics.2009.01.006), our results show that conflict adaptation is not fully protected in the presence of motivational distractors. We discuss whether this should be interpreted as a limitation, or as reflecting the flexibility of the control system in dealing with motivationally relevant information.     

Factorial structure of the ‘ToM Storybooks’: A test evaluating multiple components of Theory of Mind

This study examined the factorial structure of the Theory of Mind (ToM) Storybooks, a comprehensive 93‐item instrument tapping the five components in Wellman's model of ToM (emotion recognition, understanding of desire and beliefs, ability to distinguish between physical and mental entities, and awareness of the link between perception and knowledge). A sample of 681 three‐ to eight‐year‐old Italian children was divided into three age groups to assess whether factorial structure varied across different age ranges. Partial credit model analysis was applied to the data, leading to the empirical identification of 23 composite variables aggregating the ToM Storybooks items. Confirmatory factor analysis was then conducted on the composite variables, providing support for the theoretical model. There were partial differences in the specific composite variables making up the dimensions for each of the three age groups. A single test evaluating distinct dimensions of ToM is a valuable resource for clinical practice which may be used to define differential profiles for specific populations.