The NK3 receptor agonist senktide ameliorates scopolamine-induced deficits in memory for object, place and temporal order

Senktide, a potent neurokinin-3 receptor (NK₃-R) agonist, increases acetylcholine (ACh) release in the striatum, the prefrontal cortex (Schäble et al., 2011), the amygdala and hippocampus, presumably via postsynaptic mechanisms. A promnestic action of NK₃-R agonists has been described in a variety of learning/memory tasks. The memory-enhancing effects of NK₃-R agonists and their activating influence on ACh suggest a possible role of the NK₃-R in learning and memory via cholinergic modulation. Deterioration of the cholinergic system in the basal forebrain has been associated with learning and memory deficits and cholinergic agents have promnestic effects in a variety of learning paradigms. The anticholinergic drug, scopolamine, a muscarinic ACh receptor antagonist, incurs deficits in a variety of learning tasks and provides a useful tool to investigate the role of the cholinergic systems in mechanisms underlying learning and memory. The aim of this study was to ascertain the effect of the NK₃-R agonist, senktide, in the scopolamine-induced deficit model. We hypothesized that senktide treatment would attenuate scopolamine-induced (subcutaneous – s.c. 0.75 mg/kg) memory impairment in three novelty preference paradigms based on spontaneous object exploration: namely object recognition, object–place recognition and object recognition for temporal order. Administration of senktide reversed the scopolamine-induced memory deficits by re-establishing object recognition (s.c. 0.2 mg/kg), object–place recognition (0.2 and 0.4 mg/kg), as well as object recognition for temporal order (0.4 mg/kg) in adult Wistar rats. These results indicate memory enhancing effects of senktide in animals subjected to scopolamine-induced memory impairments and indicate that the promnestic action of NK₃-R agonists is mediated by muscarinic cholinergic mechanisms.     

The relationship between early lexical and grammatical development in Spanish: evidence in children with different linguistic levels

This study analyzes the relationship between lexical and grammatical development in Spanish children. The (European) Spanish version of the MacArthur-Bates CDI was used and administered to 593 Spanish-speaking children between the ages of 16 and 30-months-old. Regression analysis was applied to evaluate the relationship between age, vocabulary (total vocabulary, nouns, and verbs) and grammatical scores on two subsections of the Grammar Part. Total vocabulary explained a significantly greater proportion of variance in grammatical outcomes than age did. However, noun and verb vocabularies did not explain a greater proportion of variance in their respective morphologies than total vocabulary did. Additionally, the predictive relationship between vocabulary and grammar was found to be weaker for children whose scores were below the 10th percentile, although this could be due to the minor variability in this group and to extreme cases. We discuss the implications of these results in relation to the question of continuity between early vocabulary and grammar development in children.     

Forced treadmill exercise prevents oxidative stress and memory deficits following chronic cerebral hypoperfusion in the rat

Physical activity impacts functional recovery following stroke in humans, however its effects in experimental animals submitted to chronic cerebral hypoperfusion have not been investigated. The aim of this study was to evaluate the therapeutic potential of exercise, as assessed by cognitive activity in the Morris water maze and the brain oxidative status, through measurement of macromolecules damage, TBARS levels and total cellular thiols, as well as antioxidant enzymes in hippocampus, striatum and cerebral cortex. Adult male Wistar rats were submitted to the modified permanent bilateral occlusion of the common carotid arteries (2VO) method, with right common carotid artery being first occluded, and tested 3 months after the ischemic event. The effects of three different exercise protocols were examined: pre-ischemia, post-ischemia and pre+post-ischemia. Physical exercise consisted of sessions of 20-min, 3 times per week during 12 weeks (moderate intensity). Rats were submitted to cognitive assessment, in both reference and working spatial memory and after the last testing session were sacrificed to have oxidative stress parameters determined. Hypoperfusion caused a significant cognitive deficit in both spatial water maze tasks and this effect was reversed in rats receiving exercise protocol post and pre+post the ischemic event. Moreover, forced regular treadmill exercise regulated oxidative damage and antioxidant enzyme activity in the hippocampus. These results suggest that physical exercise protects against cognitive and biochemical impairments caused by chronic cerebral hypoperfusion.     

Emotional nouns affect attachment decisions in sentence completion tasks

We report three sentence completion experiments in which we manipulate the emotional dimension of the nouns in a complex noun phrase (NP) that precedes a relative clause (RC), as in the classic ambiguity in Someone shot the servant of the actress who was on the balcony. The aim was to see whether nouns such as orgy or genocide affect the well-established preference of Spanish to adjoin the relative clause high in the tree (to servant instead of actress in the example above). We manipulated the valence and arousal of the lexical entities residing in the NP. Our results indicate that (a) the inclusion of either pleasant or unpleasant words induces changes in the usual NP1 preference found in Spanish; (b) the effects of high-arousal words are especially clear, in that they pull RC adjunction towards the NP where they are located, be it the NP1 or the NP2; and (c) in the context of sentence production, these kinds of words seem intense enough to promote changes in (and even reverse) a solid syntactic bias. We discuss these findings in the light of existing theories of syntactic ambiguity resolution.     

La comunicación y la manipulación de objetos en crías de gorilla

Resumen

En este artículo se presentan datos sobre las capacidades manipulativas y comunicativas del gorila en edad infantil. En un estudio anterior (Perinat y Dalmáu, 1988), se negaba la existencia en esta especie de manipulaciones de objetos intrínsecamente motivadas y de la capacidad de comunicarse sobre objetos. Nuestros datos demuestran, en primer lugar, que el gorila sí es capaz de manipular objetos con motivación intrínseca, tanto en acciones sencillas como en acciones constructivas complejas en las que se combinan varios objetos. En segundo lugar, se demuestra que el gorila es capaz de comunicarse gestualmente con adultos humanos a propósito de los objetos y las manipulaciones que pueden efectuarse sobre ellos. Finalmente, se discute cuál debe ser el enfoque de la investigación comparada del desarrollo cognitivo en primates humanos y no humanos.     

An antidote to illusory inferences

The mental model theory predicts that reasoners normally represent what is true, but not what is false. One consequence is that reasoners should make “illusory” inferences, which are compelling but invalid. Three experiments confirmed the existence of such illusions based on disjunctions of disjunctions. They also established a successful antidote to them: Reasoners are much less likely to succumb to illusions if the inferences concern disjunctions of physical objects (alternative newspaper advertisements) rather disjunctions of the truth values of assertions. The results shed light both on the cause of the illusions and on the current controversy among different theories of reasoning.     

Vividness and Control of Mental Imagery and the Components of In-Depth Drawing

The aim of this study was to examine the associations of control and vividness of mental imagery on performance in several components of in-depth drawing in a sample of fine arts undergraduates. The sample consisted of 56 second-year undergraduates (44 women and 12 men, mean age = 21.18 years) from the Fine Arts Faculty of Vigo University, Pontevedra, Spain. Participants were required to undertake a plastic art assignment focusing on the pictorial representation of space. Participants scoring high on the image control test obtained higher scores on the spatial analysis and in the formal construction of a work than participants with poor image control. Further research involving spatial image performance tests and mental image rotation tests is proposed.     

Reports of My Death Anxiety Have Been Greatly Exaggerated: A Critique of Terror Management Theory from an Evolutionary Perspective

Although terror management theory's proponents claim that it is an evolutionary theory of human behavior, its major tenets are implausible when examined carefully from a modern evolutionary perspective. We explain why it is unlikely that natural selection would have designed a “survival instinct” or innate “fear of death,” nor an anxiety-reduction system in general, or worldview-defense system in particular, to ameliorate such fears. We argue that results of mortality-salience experiments are better explained as by-products of a psychological system of coalitional computation that evolved for a variety of functions, including defense against other humans, that is activated by certain kinds of death-related thoughts.