Effects of Posttraining Administration of Glucose on Retention of a Habituation Response in Mice: Participation of a Central Cholinergic Mechanism

Male Swiss mice were allowed to explore a novel environment, provided by an open-field activity chamber, for 10 min. The procedure was repeated twice with a 24-h interval. The difference in the exploratory activity between the first (training) and the second (testing) exposures to the chamber was taken as an index of retention of this habituation task. Posttraining intraperitoneal administration of glucose (10–300 mg/kg) enhanced retention in a dose-related manner, although only the dose of 30 mg/kg of glucose produced significant effects. Thus, the dose–response curve adopted an inverted U-shaped form. Glucose (30 mg/kg) given to untrained mice did not modify their exploratory performance when recorded 24 h later. The effects of glucose on retention were time-dependent, suggesting an action on memory storage. The memory-improving actions of glucose were prevented by the simultaneous administration of both the central acting muscarinic cholinergic antagonist atropine (0.5 mg/kg) and by the central acting nicotinic cholinergic antagonist mecamylamine (5 mg/kg). In contrast, neither methylatropine (0.5 mg/kg), a peripherally acting muscarinic receptor blocker, nor hexamethonium (5 mg/kg), a peripherally acting nicotinic receptor blocker, prevented the effects of glucose on retention. Low subeffective doses of glucose (10 mg/kg) and the central anticholinesterase physostigmine (35 μg/kg), but not neostigmine (35 μg/kg), given together, act synergistically and facilitated retention. We suggest that glucose modulates memory storage of one form of learning elicited by stimuli repeatedly presented without reinforcement, probably through an enhancement of brain acetylcholine synthesis and/or its release.     

Effort deficits and depression: The influence of anhedonic depressive symptoms on cardiac autonomic activity during a mental challenge

Motivational approaches to depression emphasize the role of dysfunctional motivational dynamics, particularly diminished reward and incentive processes associated with anhedonia. A study examined how anhedonic depressive symptoms, measured continuously across a wide range of severity, influenced the physiological mobilization of effort during a cognitive task. Using motivational intensity theory as a guide, we expected that the diminished incentive value associated with anhedonic depressive symptoms would reduce effort during a “do your best” challenge (also known as an unfixed or self-paced challenge), in which effort is a function of the value of achieving the task’s goal. Using impedance cardiography, two cardiac autonomic responses were assessed: pre-ejection period (PEP), a measure of sympathetic activity and our primary measure of interest, and respiratory sinus arrhythmia (RSA), a measure of parasympathetic activity. As expected, PEP slowed from baseline to task as anhedonic depressive symptoms increased (as measured with the Depression Anxiety Stress Scale), indicating diminished effort-related sympathetic activity. No significant effects appeared for RSA. The findings support motivational intensity theory as a translational model of effort processes in depression and clarify some inconsistent effects of depressive symptoms on effort-related physiology found in past work.     

LEXIN: A lexical database from Spanish kindergarten and first-grade readers

The LEXIN database offers psycholinguistic indexes of the 13,184 different words (types) computed from 178,839 occurrences of these words (tokens) contained in a corpus of 134 beginning readers widely used in Spain. This database provides four statistical indicators: F (overall word frequency), D (index of dispersion across selected readers), U (estimated frequency per million words), and SFI (standard frequency index). It also gives information about the number of letters, syntactic category, and syllabic structure of the words included. To facilitate comparisons, LEXIN provides data from LEXESP’s (Sebastián-Gallés, Martí, Cuetos, & Carreiras, 2000), Alameda and Cuetos’s (1995), and Martínez and García’s (2004) Spanish adult psycholinguistic frequency databases. Access to the LEXIN database is facilitated by a computer program. The LEXIN program allows for the creation of word lists by letting the user specify searching criteria. LEXIN can be useful for researchers in cognitive psychology, particularly in the areas of psycholinguistics and education.     

Family Functioning and Coping Behaviors in Parents of Children with Autism

We analyzed family dynamics and coping behaviors of parents with a child with an autistic spectrum disorder. Previous research suggests that moderate levels of cohesion and adaptability are associated with higher levels of positive coping, and that the more coping strategies a family implements, the greater their satisfaction with family functioning. Using a family systems approach, the relationships among the familial variables of cohesion, adaptability, and social support were evaluated for their contributions to coping in the family unit. We also compared the responses of mothers and fathers. Surprisingly, for these parents of children with autism, those who rated their family as enmeshed implemented more positive coping strategies than did those from other cohesion styles. This finding suggests that the enmeshed style may be more adaptive for a family that encounters extreme challenges. Notably, mothers and fathers agreed on all variables except for perception of social support from family and friends. Mothers perceived more social support from family and friends. The results lead to several interesting suggestions for future research.     

‘We are the good guys but they are not bad’. In‐group positivity and cognitive performance in preschoolers

The general purpose of this study was to analyse the developmental relations between the early forms of ethnic attitudes, and the classification abilities of the young child. We designed new cognitive tasks within a detection paradigm adapted to preschoolers and attitudinal tasks that were presented as games in a computer screen. Participants were 75 majority‐group children of 3, 4, and 5 years of age. Children's preferences and positive/negative attitudes towards the in‐group (Spaniards) and three out‐groups (Latin‐Americans, Africans, and Asians) were measured. The results showed a remarkable preference and positivity for the in‐group, but not out‐group derogation. Children's cognitive performance, to a greater extent than their age, was positively associated with in‐group favouritism and positivity. On the other hand, we found some interesting differences and developmental changes in children's positive orientation to the out‐groups that are discussed in the last section.     

Pure left neglect for Arabic numerals

Arabic numerals are diffused and language-free representations of number magnitude. To be effectively processed, the digits composing Arabic numerals must be spatially arranged along a left-to-right axis. We studied one patient (AK) to show that left neglect, after right hemisphere damage, can selectively impair the computation of the spatial frames underpinning recognition and understanding of Arabic numerals, without impairing the spatial frames for coding alphabetic strings or for coding environmental spatial information. The presence in our brain of these specific and precise spatial frames must be rooted in the paramount importance of Arabic numerals processing in our everyday activities.     

Truth holds as such only if we do not torment it

Abstract

Christopher Bollas: Being a Character: Psycho-analysis and Self Experience. London: Routledge, 1993.

“Unconscious Logic. An Introduction to Matte Blanco's Bi-Logic and its Uses” by Eric Rayner. London: Routledge 1995.     

Characterization of Children's Decision Making: Sensitivity to Punishment Frequency,Not Task Complexity

On a gambling task that models real-life decision making, children between ages 7 and 12 perform like patients with bilateral lesions of the ventromedial prefrontal cortex (VMPFC), opting for choices that yield high immediate gains in spite of higher future losses (Crone &; Van der Molen, 2004 Crone, E. A. and Van der Molen, M. W. 2004. Developmental changes in decision-making: Performance on a gambling task previously shown to rely on ventromedial prefrontal cortex. Developmental Neuropsychology, 25(3): 251–279. [PUBMED][INFOTRIEVE][CROSSREF][Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). The current study set out to characterize developmental changes in decision making by varying task complexity and punishment frequency. Three age groups (7–9 years, 10–12 years, 13–15 years) performed two versions of a computerized variant of the original Iowa gambling task. Task complexity was manipulated by varying the number of choices participants could make. Punishment frequency was manipulated by varying the frequency of delayed punishment. Results showed a developmental increase in the sensitivity to future consequences, which was present only when the punishment was presented infrequently. These results could not be explained by differential sensitivity to task complexity, hypersensitivity to reward, or failure to switch response set after receiving punishment. There was a general pattern of boys outperforming girls by making more advantageous choices over the course of the task. In conclusion, 7–12-year-old children—like VMPFC patients—appear myopic about the future except when the potential for future punishment is high.     

Two measures of affect and emotion in Italian children aged 6 to 11 years

The authors investigated the relation between affective and cognitive processes in fantasy play and emotional understanding of 50 Italian children (25 boys and 25 girls) enrolled in regular elementary school in Northern Italy. Children were administered a standardized play task, the Affect in Play Scale, and answered questions about their understanding of emotions. Consistent, yet modest, relationships were found between dimensions of fantasy play and emotional understanding.