Observation learning of tool use by captive Guinea baboons (Papio papio)

A subadult male from a captive group of Guinea baboons learned, by trial-and-error, to use a tool to rake in food. He then used the tool 104 times over 26 days, thereby providing the group with most of its food. No other group member used the tool during this period. The tool user was removed, and the remainder of the group was given access to the display. None imitated his tool use. It took longer for another finally to learn to use the tool than it had for the initial solution. However, compared with the period before initial solution, group members manipulated the tool more frequently and touched the food pan with the tool nearly twice as many times after the tool user's separation. This type of tool use appears to be too complex for baboons to imitate directly. However, as a result of observing successful tool use, they attend more to the problem and manipulate the tool more frequently and more accurately. This increase in frequency and accuracy may, in turn, accelerate acquisition of the response by observers through instrumental trial-and-error learning.     

The endocannabinoid system and prospects her stimulation in clinical medicine

The history of use by the man of plants of a sort Cannabis totals more than 4000 years. The people have begun to use Cannabis in stone century. On Taiwan archaeologist the rests of utensils made with application of stalks Cannabis more of 10000 years back were found. Cannabis (Cannabis sativa, Cannabis sowing, named also "Indian") - cultural plant, which has set of applications. From it received fibres for hemp of ropes and make a fabric similar on linen. Its stalks went on manufacture glossy of a paper and building of plates. Her sabadilla were used for graziery a bird; oil from sabadilla Cannabis offered as fuel instead of diesel. The greatest popularity Cannabis has received as raw material for reception of products (marijuana, hashish etc.), causing at the man psychotropic--first of all psychomymetic--effects, that at their regular application can result in formation of dependence. Besides the attempts were undertaken to use preparations Cannabis in the medical purposes: at migraine, spasmes, vomiting, pains of a different origin etc.     

Incidental Acquisition of Foreign Language Vocabulary through Brief Multi-Modal Exposure

First language acquisition requires relatively little effort compared to foreign language acquisition and happens more naturally through informal learning. Informal exposure can also benefit foreign language learning, although evidence for this has been limited to speech perception and production. An important question is whether informal exposure to spoken foreign language also leads to vocabulary learning through the creation of form-meaning links. Here we tested the impact of exposure to foreign language words presented with pictures in an incidental learning phase on subsequent explicit foreign language learning. In the explicit learning phase, we asked adults to learn translation equivalents of foreign language words, some of which had appeared in the incidental learning phase. Results revealed rapid learning of the foreign language words in the incidental learning phase showing that informal exposure to multi-modal foreign language leads to foreign language vocabulary acquisition. The creation of form-meaning links during the incidental learning phase is discussed.     

Photomyoclonic seizures in the baboon, Papio papio.

The inborn seizure response of Papio papio to intermittent light stimulation has been reviewed as a model of human epilepsy. The electrographic and clinical features have been described and useful methodology has been outlined. A diurnal cyclicity in seizure responsiveness has been described with greatest seizure severity at 8 AM in parallel with a rise in urinary output of cortisol. Hormonal influences on the seizure response have been described for ethinyl estradiol, thyroxin, and triiodothyronine. Evidence regarding neurotransmitter involvement has been reviewed. Data regarding use of the animal for anticonvulsant testing in single and chronic doses has been discussed. Particular advantages of the model for study of age-related drug effects and the assessment of the effects of chronically administered anticonvulsant agents on learning and memory have been described.     

Flower power: floral reversion as a viable alternative to nodal micropropagation in Cannabis sativa.

In Vitro Cellular & Developmental Biology - Plant - The legalization of recreational and medicinal Cannabis sativa L. has been gaining global momentum, therefore increasing interest in Cannabis...     

Natural selection of the critical period for language acquisition

The language acquisition period in humans lasts about 13 years. After puberty it becomes increasingly difficult to learn a language. We explain this phenomenon by using an evolutionary framework. We present a dynamical system describing competition between language acquisition devices, which differ in the length of the learning period. There are two selective forces that play a role in determining the critical learning period: (i) having a longer learning period increases the accuracy of language acquisition; (ii) learning is associated with certain costs that affect fitness. As a result, there exists a limited learning period which is evolutionarily stable. This result is obtained analytically by means of a Nash equilibrium analysis of language acquisition devices. Interestingly, the evolutionarily stable learning period does not maximize the average fitness of the population.     

Effects of age and sex on intra-group spacing behaviour in juvenile savannah baboons,Papio cynocephalus cynocephalus

Twenty juvenile members of known genealogies in two baboon groups were studied over a 16-month period to evaluate a number of predictions about juvenile spacing behaviour based on the natural history of savannah baboons. Young juveniles (1–2·5 years old) approached more frequently and spent more time in proximity to other group members than did old juveniles (3–5·5 years old). In particular, young juveniles associated more closely with their mothers, particular adult males (possible fathers) and age-peers than did old juveniles. Approaches of young juveniles towards unrelated, high-ranking adults were more likely to occur during feeding than were those of old juveniles. Also, following such an approach, young juveniles were more likely than old juveniles to begin feeding immediately. The overall rates of feeding of old juveniles were depressed when they were in proximity to unrelated, high-ranking adults, whereas the feeding rates of young juveniles were not. Juvenile males approached adult males more often than did juvenile females. Juvenile females approached unrelated adult females more often than did juvenile males. Sex differences also existed in juveniles' choices of unrelated adult female neighbours. Juvenile females associated most often with lactating females, whereas juvenile males associated primarily with cycling females. During group resting, juvenile females approached adult females from higher-ranking matrilines more often than they approached adult females from lower-ranking matrilines. Juvenile males did not exhibit this attraction. Also, among old juveniles, females associated closely with their mothers, whereas males did not. Taken together, the results support the hypotheses that juvenile baboons associate with group members in ways that (1) enhance the probability of surviving an early period of high mortality, (2) create opportunities for social learning of sex-typical behaviours/skills, and, for females, (3) facilitate acquisition of familial dominance status.     

不同储存条件对大麻化学稳定性的影响

为探讨光照和温度对大麻植物中大麻酚类稳定性的影响,该研究将大麻植物检材以固体粉末和甲醇提取溶液的形式分别在室温(22±2)℃见光、室温(22±2)℃避光、4℃避光、-20℃避光条件下储存20 d后,采用超高效液相(UPLC-PDA)检测分析样本中Δ9-四氢大麻酚(Δ9-THC)、大麻二酚(CBD)和大麻酚(CBN)的含量变化情况。结果表明:3种大麻酚类在不同化学表型大麻中的含量变化趋势相同,固体粉末样本的Δ9-THC、CBD含量在室温光照条件下显著下降,CBN含量基本不变;甲醇提取样本中Δ9-THC、CBN和CBD含量在室温光照条件下均显著下降。避光条件下的室温(22±2)℃及低温(4℃、-20℃)可稳定保存两种形式的大麻样本。大麻中的精神活性成分Δ9-THC的降解满足一级反应动力学规律,光照是影响Δ9-THC降解的重要因素,如果在室温避光条件下储存,大麻或其甲醇提取物可稳定保存,可以更好地指导司法实践活动中短期内大麻检材的取证、运送、保存及鉴定。     

Learning set formation in a group of Guinea baboons (Papio papio): Importance of the behavioral variable measured

A recent report of one-trial learning in a group of saddle-back tamarins (Saguinus fuscicollis) conflicted with views of learning set formation based on traditional techniques employing isolated subjects. An experiment is reported in which a group of Guinea baboons (Papio papio) was given a series of discrimination and habit reversal tasks. Both one-trial learning and learning set formation occurred. Analysis of spatial behavior revealed that the group learned in a single trial to discriminate stocked from unstocked zones. Improvement in successes (reinforced “digging”) was progressive but not rapid, indicating learning set formation. It appears that outcomes depend on the behavioral variables chosen.     

Stress Modulates Instrumental Learning Performances in Horses (Equus caballus) in Interaction with Temperament

The present study investigates how the temperament of the animal affects the influence of acute stress on the acquisition and reacquisition processes of a learning task. After temperament was assessed, horses were subjected to a stressor before or after the acquisition session of an instrumental task. Eight days later, horses were subjected to a reacquisition session without any stressor. Stress before acquisition tended to enhance the number of successes at the beginning of the acquisition session. Eight days later, during the reacquisition session, contrary to non-stressed animals, horses stressed after acquisition, and, to a lesser extent, horses stressed before acquisition, did not improve their performance between acquisition and reacquisition sessions. Temperament influenced learning performances in stressed horses only. Particularly, locomotor activity improved performances whereas fearfulness impaired them under stressful conditions. Results suggest that direct exposure to a stressor tended to increase acquisition performances, whereas a state of stress induced by the memory of a stressor, because it has been previously associated with the learning context, impaired reacquisition performances. The negative effect of a state of stress on reacquisition performances appeared to be stronger when exposure to the stressor occurred after rather than before the acquisition session. Temperament had an impact on both acquisition and reacquisition processes, but under stressful conditions only. These results suggest that stress is necessary to reveal the influence of temperament on cognitive performances.     

Kin recognition by paternal half-siblings in captive Papio cynocephalus

Our objective in this study was to evaluate whether a group of paternally related, subadult baboons (Papio cynocephalus) would preferentially interact with kin or nonkin when they had been raised apart from kin other than their mothers. Subjects and their mothers were removed from the breeding group and placed in alternate housing within 24 h after birth to ensure that the subjects would not have a social history with either their sire or their half-siblings. At 90 days of age, the 23 subjects were separated from their mothers and assigned to a peer–peer social group. Behavioral performance was measured using focal animal sampling techniques and 12 molecular behavioral criteria. Analyses of the data indicate that in dyadic interactions kin did not interact more frequently than nonkin in performance of affiliative, sociosexual, and agonistic behaviors. The hypothesis that baboons recognize kin in the absence of maternal associations was not supported by the data; moreover, we suggest that social learning and social history are the most likely mechanisms for kin recognition. Am. J. Primatol. 43:147–157, 1997. © 1997 Wiley-Liss, Inc.     

Second Language Acquisition: A Framework for Studying the Importance of Input and Interaction in Exceptional Song Acquisition

Recent studies demonstrate that specific types of live input and social interaction facilitate “exceptional” song acquisition. The term “exceptional” denotes time-independent song acquisition and learning of nonspecies-specific song (or parts of song) and second dialects by birds generally thought to have restrictions on their learning capabilities. Recent research in human second language acquisition (SLA) also emphasizes the roles of input and interaction. The purpose of this paper is to focus on these parallels and suggest that SLA studies can provide further insights into exceptional song acquisition, particularly with respect to new directions for ornithological research.     

Effect of selective muscarinic receptor agonists and antagonists on active-avoidance learning acquisition in rats

Effect of some selective muscarinic receptor agonists and antagonists was investigated on learning acquisition in an active-avoidance paradigm in rats which records an anticipatory conditioned avoidance apart from the classical conditioned avoidance response. The muscarinic M1 agonists, arecholine, pilocarpine and McN-A-343, facilitated learning acquisition, which was attenuated by the selective M1 antagonist, pirenzepine. On the other hand, M2 receptor agonist, carbachol, and physostigmine, induced a dose-related dual response, with lower doses retarding and higher doses facilitating the learning acquisition. The former effect was attenuated by gallamine, a muscarinic M2 antagonist, while the latter response was inhibited by pirenzepine, indicating that these putative M2 receptor agonist lose their receptor specificity on dose increment. The selective M2 receptor antagonists, gallamine and AF-DX 116, facilitated learning acquisition, which was inhibited by pirenzepine and the acetylcholine synthesis inhibitor hemicholinium. The results support the cholinergic hypothesis of learning and memory and indicate that M1 receptor agonists and M2 receptor antagonists are likely to prove beneficial in memory deficits. The data also indicates that the clinical dose of some drugs, like physostigmine, needs to be carefully established for optimum therapeutic benefit.     

Cranial ontogeny of Papio baboons (Papio hamadryas)

Cranial form in subspecies of Papio baboons (Papio hamadryas) varies in relation to size, geography, and sex. However, knowledge about this variation is based mainly on adults, precluding direct assessments of the evolutionary factors that are ultimately responsible for adult shape variation. Consequently, this study tests hypotheses about the development of size and shape differences among subspecies of Papio baboons, anticipating limited evolutionary divergences in the ontogenetic pathways leading to adult endpoints. Geometric morphometric and bivariate allometric analyses are used to explore developmental size and shape variation. Allometric scaling in adult Papio baboons occurs because both sexes and all subspecies follow similar developmental pathways to a variety of adult forms. However, complex allometry contributes to form differences, producing potentially important shape differences that emerge during development. Modest shape differences that are statistically independent of size distinguish chacma baboons (P. h. ursinus) from other forms. A small-headed subspecies, the Kinda baboon (P. h. kindae), also presents a distinctive ontogeny, and may provide insights into the evolution of size change in this species. Variation among subspecies that is statistically independent of size involves the rostrum, zygomatic breadths, and cranial flexion. These features may be related to diet, but the precise biomechanical correlates of baboon form variation remain unclear.     

Glucocorticoids are necessary for enhancing the acquisition of associative memories after acute stressful experience

Exposure to acute stressful experience can enhance the later ability to acquire new memories about associations between stimuli. This enhanced learning is observed during classical eyeblink conditioning of both hippocampal-dependent and -independent learning. It can be induced within minutes of the stressful event and persists for days. Here we examined the role of the major stress hormones glucocorticoids in the enhancement of learning after stress. In the first two experiments, it was determined that adrenalectomy (ADX), with and without replacement of basal levels of corticosterone, prevented the stress-induced enhancement of trace conditioning, a task that is dependent on the hippocampus for acquisition. In a third experiment, demedullation, which removes the adrenal medulla but leaves the adrenal cortex and corticosterone levels intact, did not affect the enhancement of learning after stress. In a fourth experiment, ADX prevented the stress-induced enhancement of delay conditioning, a hippocampal-independent task. In a final experiment, it was determined that one injection of stress levels of corticosterone enhanced new learning within minutes but not new learning 24 h later. Together these results suggest that endogenous glucocorticoids are necessary and sufficient for transiently enhancing acquisition of new associative memories and necessary but insufficient for persistently enhancing their acquisition after exposure to an acute stressful experience.     

Tactile learning and the individual evaluation of the reward in honey bees (Apis mellifera L.)

Using the proboscis extension response we conditioned pollen and nectar foragers of the honey bee (Apis mellifera L.) to tactile patterns under laboratory conditions. Pollen foragers demonstrated better acquisition, extinction, and reversal learning than nectar foragers. We tested whether the known differences in response thresholds to sucrose between pollen and nectar foragers could explain the observed differences in learning and found that nectar foragers with low response thresholds performed better during acquisition and extinction than ones with higher thresholds. Conditioning pollen and nectar foragers with similar response thresholds did not yield differences in their learning performance. These results suggest that differences in the learning performance of pollen and nectar foragers are a consequence of differences in their perception of sucrose. Furthermore, we analysed the effect which the perception of sucrose reward has on associative learning. Nectar foragers with uniform low response thresholds were conditioned using varying concentrations of sucrose. We found significant positive correlations between the concentrations of the sucrose rewards and the performance during acquisition and extinction. The results are summarised in a model which describes the relationships between learning performance, response threshold to sucrose, concentration of sucrose and the number of rewards. Accepted: 14 April 1999     

Le nouveau paysage du cannabis II. Données récentes sur la psychotoxicité du cannabis

After delta-9-tetrahydrocannabinol (Δ9-THC) has supported the anandamidergic tone, thereby increasing its anxiolytic and antidepressant effects, it loses its efficacy in this respect. Anxious and/or depressive troubles which could have prompted the abuse of cannabis then reappear more intensely. They peak when consumption is completely stopped. Cannabis consumption may contribute to polydrug abuse. Its association with tobacco makes it more difficult to give up both substances of abuse. Cannabis use encourages the consumption of alcohol and this association is especially deleterious as regards car accidents. Δ9-THC sensitises cannabis abusers to perceive the appetitive effects of heroin in a more acute manner. Cannabis consumption also makes withdrawal symptoms associated with heroin abuse more severe. Cannabis appears to be able to reveal schizophrenia in patients bearing a neurobiological vulnerability substratum to this disease. It seems especially appreciated by people suffering of negative symptoms of schizophrenia, which could prompt them to abuse cannabis, and then triggering the positive symptoms of the disease. These positive symptoms are particularly resistant to treatment with antipsychotic medication when cannabis abuse is continued. All this recent data necessitates extreme care with this drug of abuse, whose dangerous effects are becoming more and more known.     

Inhibiting DNA methylation alters olfactory extinction but not acquisition learning in Apis cerana and Apis mellifera

DNA methylation plays a key role in invertebrate acquisition and extinction memory. Honey bees have excellent olfactory learning, but the role of DNA methylation in memory formation has, to date, only been studied in Apis mellifera. We inhibited DNA methylation by inhibiting DNA methyltransferase (DNMT) with zebularine (zeb) and studied the resulting effects upon olfactory acquisition and extinction memory in two honey bee species, Apis cerana and A. mellifera. We used the proboscis extension reflex (PER) assay to measure memory. We provide the first demonstration that DNA methylation is also important in the olfactory extinction learning of A. cerana. DNMT did not reduce acquisition learning in either species. However, zeb bidirectionally and differentially altered extinction learning in both species. In particular, zeb provided 1 h before acquisition learning improved extinction memory retention in A. mellifera, but reduced extinction memory retention in A. cerana. The reasons for these differences are unclear, but provide a basis for future studies to explore species-specific differences in the effects of methylation on memory formation.     

Influence of Action-Effect Associations Acquired by Ideomotor Learning on Imitation

According to the ideomotor theory, actions are represented in terms of their perceptual effects, offering a solution for the correspondence problem of imitation (how to translate the observed action into a corresponding motor output). This effect-based coding of action is assumed to be acquired through action-effect learning. Accordingly, performing an action leads to the integration of the perceptual codes of the action effects with the motor commands that brought them about. While ideomotor theory is invoked to account for imitation, the influence of action-effect learning on imitative behavior remains unexplored. In two experiments, imitative performance was measured in a reaction time task following a phase of action-effect acquisition. During action-effect acquisition, participants freely executed a finger movement (index or little finger lifting), and then observed a similar (compatible learning) or a different (incompatible learning) movement. In Experiment 1, finger movements of left and right hands were presented as action-effects during acquisition. In Experiment 2, only right-hand finger movements were presented during action-effect acquisition and in the imitation task the observed hands were oriented orthogonally to participants’ hands in order to avoid spatial congruency effects. Experiments 1 and 2 showed that imitative performance was improved after compatible learning, compared to incompatible learning. In Experiment 2, although action-effect learning involved perception of finger movements of right hand only, imitative capabilities of right- and left-hand finger movements were equally affected. These results indicate that an observed movement stimulus processed as the effect of an action can later prime execution of that action, confirming the ideomotor approach to imitation. We further discuss these findings in relation to previous studies of action-effect learning and in the framework of current ideomotor approaches to imitation.     

A partial agonist at strychnine-insensitive glycine sites facilitates spatial learning in aged rats.

1-Aminocyclopropanecarboxylic acid (ACPC) is a high affinity ligand at strychnine-insensitive glycine sites of the N-methyl-D-aspartate (NMDA) channels and exhibits partial agonist properties in both biochemical and electrophysiological measures. While ACPC was reported active in animal models used to evaluate potential antidepressants and anxiolytics, its effects on learning and memory are unknown. In the present study we investigated the effects of ACPC on spatial learning in the Morris water maze. On a schedule of 12 learning trials, one trial per day, mature male Wistar rats (3 months of age) rapidly acquired the task. Electroconvulsive shocks applied after each of the learning trials markedly inhibited the consolidation of spatial memory. Administration of either a muscarinic agonist, arecoline (1 mg/kg) or ACPC (250 or 400 mg/kg) 20 min before each of the learning trials did not affect the acquisition of spatial learning. Aged (16 months old) male Wistar rats demonstrated difficulties in the acquisition of spatial learning task. In these subjects, ACPC administered 20 min before each of the learning trials at a dose of 400, but not 250 mg/kg, facilitated the acquisition of spatial memory as indicated on trials 3-5. ACPC did not affect the strength of spatial memory as assessed at the end of conditioning, by measuring swimming behavior of rats in the pool with platform removed. It is suggested that ACPC may alleviate learning deficits observed in the elderly.