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Learning Task (learning + task)
Kinds of Learning Task Selected AbstractsMaternal and littermate deprivation disrupts maternal behavior and social-learning of food preference in adulthood: Tactile stimulation, nest odor, and social rearing prevent these effectsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2006Angel I. Melo Abstract Maternal and littermate (social) separation, through artificial rearing (AR), disrupts the development of subsequent maternal behavior and social learning in rats. The addition of maternal-licking-like stimulation during AR, partially reverses some of these effects. However, little is know about the role of social stimuli from littermates and nest odors during the preweaning period, in the development of the adult maternal behavior and social learning. The purpose of this study was to examine the effects of peer- and peer-and-odor rearing on the development of maternal behavior and social learning in rats. Female pups were reared with mothers (mother reared,MR) or without mothers (AR) from postnatal day (PND) 3. AR rats received three different treatments: (1) AR-CONTROL group received minimal tactile stimulation, (2) AR-ODOR females received exposure to maternal nest material inside the AR-isolation-cup environment, (3) AR-SOCIAL group was reared in the cup with maternal nest material and a conspecific of the same-age and same-sex and received additional tactile stimulation. MR females were reared by their mothers in the nest and with conspecifics. In adulthood, rats were tested for maternal behavior towards their own pups and in a social learning task. Results confirm our previous report that AR impairs performance of maternal behavior and the development of a social food preference. Furthermore, social cues from a littermate, in combination with tactile stimulation and the nest odor, reversed the negative effects of complete isolation (AR-CONTROL) on some of the above behaviors. Exposure to the odor alone also had effects on some of these olfactory-mediated behaviors. These studies indicate that social stimulation from littermates during the preweaning period, in combination with odor from the nest and tactile stimulation, contributes to the development of affiliative behaviors. © 2006 Wiley Periodicals, Inc. Dev Psyshobiol 48: 209,219, 2006. [source] The first steps in word learning are easier when the shoes fit: comparing monolingual and bilingual infantsDEVELOPMENTAL SCIENCE, Issue 1 2010Karen Mattock English, French, and bilingual English-French 17-month-old infants were compared for their performance on a word learning task using the Switch task. Object names presented a /b/ vs. /g/ contrast that is phonemic in both English and French, and auditory strings comprised English and French pronunciations by an adult bilingual. Infants were habituated to two novel objects labeled ,bowce' or ,gowce' and were then presented with a switch trial where a familiar word and familiar object were paired in a novel combination, and a same trial with a familiar word,object pairing. Bilingual infants looked significantly longer to switch vs. same trials, but English and French monolinguals did not, suggesting that bilingual infants can learn word,object associations when the phonetic conditions favor their input. Monolingual infants likely failed because the bilingual mode of presentation increased phonetic variability and did not match their real-world input. Experiment 2 tested this hypothesis by presenting monolingual infants with nonce word tokens restricted to native language pronunciations. Monolinguals succeeded in this case. Experiment 3 revealed that the presence of unfamiliar pronunciations in Experiment 2, rather than a reduction in overall phonetic variability was the key factor to success, as French infants failed when tested with English pronunciations of the nonce words. Thus phonetic variability impacts how infants perform in the switch task in ways that contribute to differences in monolingual and bilingual performance. Moreover, both monolinguals and bilinguals are developing adaptive speech processing skills that are specific to the language(s) they are learning. [source] Do children with developmental dyslexia have impairments in implicit learning?DYSLEXIA, Issue 2 2010Elpis V. Pavlidou Abstract We explored implicit learning in a group of typically developing and developmental dyslexic primary school children (9,12,y) using a modified artificial grammar learning task. Performance was calculated using two measures of performance: a perfect free recall (PFR) score and a grammaticality judgment score. Both groups of children required the same amount of exposure to memorize the items (i.e. PFR performance) (t(30)=1.620, p>0.05; p -value reported two-tailed). However, repeated measures ANOVA (Participant type × Grammaticality × Chunk strength) revealed a Participant type effect for grammaticality judgment scores (F(1,30)=4.521, p<0.05; p -value reported two-tailed). Typically developing children showed above chance performance in terms of both grammaticality and chunk strength of the stimuli. Children with developmental dyslexia on the other hand, failed to show implicit learning irrespective of the substring characteristics (i.e. grammaticality or chunk strength). We propose that children with developmental dyslexia may be impaired in their implicit rule abstraction mechanism, which can partially explain their persistent reading problems. Copyright © 2010 John Wiley & Sons, Ltd. [source] Investigating learning deficits associated with dyslexiaDYSLEXIA, Issue 1 2004Emmanuel M. Pothos Abstract An artificial grammar learning task was used to define two learning tasks of identical complexity at the symbolic level, but which differed in terms of stimulus format. The stimuli in one learning task were created so as to encourage participants to perceive each stimulus as a whole, with less emphasis on the stimulus constituent elements (the ,embedded' stimuli), while in the second task the constituent elements of each stimulus were emphasized by presenting them serially (the ,sequences' stimuli). Using a between participants design, dyslexic participants performed equally well in the two versions of the learning task. By contrast, non-dyslexic participants performed as well as dyslexic ones with the embedded stimuli but were impaired in the sequences stimuli. This finding was interpreted as showing that dyslexic participants were less able, compared to controls, to process individual stimulus elements of both the sequences and the embedded stimuli, consistently with recent work associating dyslexia with problems in attention focusing and shifting. Copyright © 2004 John Wiley & Sons, Ltd. [source] Protein degradation, as with protein synthesis, is required during not only long-term spatial memory consolidation but also reconsolidationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2008Julien Artinian Abstract The formation of long-term memory requires protein synthesis, particularly during initial memory consolidation. This process also seems to be dependant upon protein degradation, particularly degradation by the ubiquitin-proteasome system. The aim of this study was to investigate the temporal requirement of protein synthesis and degradation during the initial consolidation of allocentric spatial learning. As memory returns to a labile state during reactivation, we also focus on the role of protein synthesis and degradation during memory reconsolidation of this spatial learning. Male CD1 mice were submitted to massed training in the spatial version of the Morris water maze. At various time intervals after initial acquisition or after a reactivation trial taking place 24 h after acquisition, mice received an injection of either the protein synthesis inhibitor anisomycin or the protein degradation inhibitor lactacystin. This injection was performed into the hippocampal CA3 region, which is specifically implicated in the processing of spatial information. Results show that, in the CA3 hippocampal region, consolidation of an allocentric spatial learning task requires two waves of protein synthesis taking place immediately and 4 h after acquisition, whereas reconsolidation requires only the first wave. However, for protein degradation, both consolidation and reconsolidation require only one wave, taking place immediately after acquisition or reactivation, respectively. These findings suggest that protein degradation is a key step for memory reconsolidation, as for consolidation. Moreover, as protein synthesis-dependent reconsolidation occurred faster than consolidation, reconsolidation did not consist of a simple repetition of the initial consolidation. [source] Dopamine gene predicts the brain's response to dopaminergic drugEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2007Michael X Cohen Abstract Dopamine is critical for reward-based decision making, yet dopaminergic drugs can have opposite effects in different individuals. This apparent discrepancy can be accounted for by hypothesizing an ,inverted-U' relationship, whereby the effect of dopamine agents depends on baseline dopamine system functioning. Here, we used functional MRI to test the hypothesis that genetic variation in the expression of dopamine D2 receptors in the human brain predicts opposing dopaminergic drug effects during reversal learning. We scanned 22 subjects while they engaged in a feedback-based reversal learning task. Ten subjects had an allele on the Taq1A DRD2 gene, which is associated with reduced dopamine receptor concentration and decreased neural responses to rewards (A1+ subjects). Subjects were scanned twice, once on placebo and once on cabergoline, a D2 receptor agonist. Consistent with an inverted-U relationship between the DRD2 polymorphism and drug effects, cabergoline increased neural reward responses in the medial orbitofrontal cortex, cingulate cortex and striatum for A1+ subjects but decreased reward responses in these regions for A1, subjects. In contrast, cabergoline decreased task performance and fronto-striatal connectivity in A1+ subjects but had the opposite effect in A1, subjects. Further, the drug effect on functional connectivity predicted the drug effect on feedback-guided learning. Thus, individual variability in how dopaminergic drugs affect the brain reflects genetic disposition. These findings may help to explain the link between genetic disposition and risk for addictive disorders. [source] Serotonin transporter deficiency in rats improves inhibitory control but not behavioural flexibilityEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2007Judith R. Homberg Abstract Impulsivity and aggression have been suggested to inversely correlate with central serotonin (5-HT) levels in a trait-like manner. However, this relationship is far from straightforward. In the present study we addressed the effect of lifelong reduced or absent serotonin transporter (SERT) function, which is associated with constitutively increased extracellular 5-HT levels, on impulsivity and aggression. We used unique SERT knockout rats in a resident,intruder test, five-choice serial reaction time task and serial reversal learning task to assay aggression, inhibitory control and behavioural flexibility, respectively. Homozygous SERT knockout rats (SERT,,/,) displayed reduced aggression and improved inhibitory control, but unchanged behavioural flexibility. The behavioural phenotype of heterozygous SERT knockout rats (SERT,+/,) was not different from that of wild-type controls in any of the behavioural paradigms. We determined monoamine (metabolite) tissue levels in the medial prefrontal cortex, orbitofrontal cortex, lateral hypothalamus, raphe nuclei and cerebrospinal fluid, and found that the 5-HT levels, but not other monoamine tissue levels, were reduced in SERT,,/, rats. In addition, the 5-hydroxyindoleacetic acid (5-HIAA)/5-HT ratio in cerebrospinal fluid was increased in these rats. In conclusion, our data show that the absence of the SERT affects aggression and inhibitory control, but not behavioural flexibility, characteristics that may reflect the trait-like consequences of constitutive changes in central 5-HT levels. [source] Elements of a neurobiological theory of hippocampal function: the role of synaptic plasticity, synaptic tagging and schemasEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2006R. G. M. MorrisArticle first published online: 8 JUN 200 Abstract The 2004 EJN Lecture was an attempt to lay out further aspects of a developing neurobiological theory of hippocampal function [Morris, R.G.M., Moser, E.I., Riedel, G., Martin, S.J., Sandin, J., Day, M. & O'Carroll, C. (2003) Phil. Trans. R. Soc. Lond. B Biol. Sci., 358, 773,786.] These are that (i) activity-dependent synaptic plasticity plays a key role in the automatic encoding and initial storage of attended experience; (ii) the persistence of hippocampal synaptic potentiation over time can be influenced by other independent neural events happening closely in time, an idea with behavioural implications for memory; and (iii) that systems-level consolidation of memory traces within neocortex is guided both by hippocampal traces that have been subject to cellular consolidation and by the presence of organized schema in neocortex into which relevant newly encoded information might be stored. Hippocampal memory is associative and, to study it more effectively than with previous paradigms, a new learning task is described which is unusual in requiring the incidental encoding of flavour,place paired associates, with the readout of successful storage being successful recall of a place given the flavour with which it was paired. NMDA receptor-dependent synaptic plasticity is shown to be critical for the encoding and intermediate storage of memory traces in this task, while AMPA receptor-mediated fast synaptic transmission is necessary for memory retrieval. Typically, these rapidly encoded traces decay quite rapidly over time. Synaptic potentiation also decays rapidly, but can be rendered more persistent by a process of cellular consolidation in which synaptic tagging and capture play a key part in determining whether or not it will be persistent. Synaptic tags set at the time of an event, even many trivial events, can capture the products of the synthesis of plasticity proteins set in train by events before, during or even after an event to be remembered. Tag,protein interactions stabilize synaptic potentiation and, by implication, memory. The behavioural implications of tagging are explored. Finally, using a different protocol for flavour,place paired associate learning, it is shown that rats can develop a spatial schema which represents the relative locations of several different flavours of food hidden at places within a familiar space. This schema is learned gradually but, once acquired, enables new paired associates to be encoded and stored in one trial. Their incorporation into the schema prevents rapid forgetting and suggests that schema play a key and hitherto unappreciated role in systems-level memory consolidation. The elements of what may eventually mature into a more formal neurobiological theory of hippocampal memory are laid out as specific propositions with detailed conceptual discussion and reference to recent data. [source] Distinct kinds of novelty processing differentially increase extracellular dopamine in different brain regionsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2006Elvira De Leonibus Abstract Behaviourally relevant novel stimuli are known to activate the mesocorticolimbic dopaminergic (DAergic) system. In this study we tested the reactivity of this system in response to distinct kinds of novelty processing. Using the in vivo microdialysis technique, we measured extracellular amounts of dopamine (DA) in different DAergic terminal regions during a social learning task in rats. In the first session (40 min) rats were exposed to two never previously encountered juveniles (i.e. unconditional novelty). Afterwards, the animals were divided into three groups: Control group was not exposed to any other stimulus; Discrimination group was exposed to one familiar and one new juvenile (i.e. novel stimulus discrimination); and Recognition group was re-exposed to the two familiar juveniles (i.e. familiarity recognition). In both the medial prefrontal cortex and the nucleus accumbens shell DA increased in response to the first presentation of the juveniles, showing that both structures are involved in processing unconditional social novelty. During the novel stimulus discrimination, we found no change in the prefrontal cortex, although DA increased in the accumbal shell in comparison with the group exposed to two familiar juveniles, showing that the shell is also involved in processing novel social stimulus discrimination. None of the stimuli presented affected DA in the accumbal core. This study provided the original evidence that DA in the various terminal regions is differentially coupled to distinct aspects of novelty processing. [source] Different behavioral effects of neurotoxic dorsal hippocampal lesions placed under either isoflurane or propofol anesthesiaHIPPOCAMPUS, Issue 3 2008Mark G. Baxter Abstract Anesthetic protocols for behavioral neuroscience experiments are evolving as new anesthetics are developed and surgical procedures are refined to improve animal welfare. We tested whether neurotoxic dorsal hippocampal lesions produced under two different anesthetic protocols would have different behavioral and/or histo-pathological effects. Rats were anesthetized with either propofol, an intravenous anesthetic, or isoflurane, a gaseous anesthetic, and multiple injections of an excitotoxin (N -methyl- D -aspartate) were stereotaxically placed in the dorsal hippocampus bilaterally. Intraoperative physiological parameters were similar in the two surgical groups, as were the volumes of the lesions, although the profile of postoperative impairment in a spatial learning task differed between the lesion groups depending on the anesthetic regimen used. These results show that the choice of anesthetic protocol is a critical variable in designing behavioral neuroscience experiments using neurosurgical procedures. This factor should be considered carefully in experimental design and in cross-study comparisons of lesion effects on behavior. © 2007 Wiley-Liss, Inc. [source] Differential involvement of the dorsal hippocampus in passive avoidance in C57bl/6J and DBA/2J miceHIPPOCAMPUS, Issue 1 2008Petra J.J. Baarendse Abstract The inferior performance of DBA/2 mice when compared to C57BL/6 mice in hippocampus-dependent behavioral tasks including contextual fear conditioning has been attributed to impaired hippocampal function. However, DBA/2J mice have been reported to perform similarly or even better than C57BL/6J mice in the passive avoidance (PA) task that most likely also depends on hippocampal function. The apparent discrepancy in PA versus fear conditioning performance in these two strains of mice was investigated using an automated PA system. The aim was to determine whether these two mouse strains utilize different strategies involving a different contribution of hippocampal mechanisms to encode PA. C57BL/6J mice exhibited significantly longer retention latencies than DBA/2J mice when tested 24 h after training irrespective of the circadian cycle. Dorsohippocampal NMDA receptor inhibition by local injection of the selective antagonist DL -2-amino-5-phosphonovaleric acid (AP5, 3.2 ,g/mouse) before training resulted in impaired PA retention in C57BL/6J but not in DBA/2J mice. Furthermore, nonreinforced pre-exposure to the PA system before training caused a latent inhibition-like reduction of retention latencies in C57BL/6J, whereas it improved PA retention in DBA/2J mice. These pre-exposure experiments facilitated the discrimination of hippocampal involvement without local pharmacological intervention. The results indicate differences in PA learning between these two strains based on a different NMDA receptor involvement in the dorsal hippocampus in this emotional learning task. We hypothesize that mouse strains can differ in their PA learning performance based on their relative ability to form associations on the basis of unisensory versus multisensory contextual/spatial cues that involve hippocampal processing. © 2007 Wiley-Liss, Inc. [source] Environment-spatial conditional learning in rats with selective lesions of medial septal cholinergic neuronsHIPPOCAMPUS, Issue 2 2004Agnieszka M. Janisiewicz Abstract Cholinergic medial septal neurons may regulate several aspects of hippocampal function, including place field stability and spatial working memory. Monkeys with damage to septal cholinergic neurons are impaired in visual-spatial conditional learning tasks; however, this candidate function of septal cholinergic neurons has not been studied extensively in the rat. In the present study, rats with selective lesions of cholinergic neurons in the medial septum and vertical limb of the diagonal band of Broca (MS/VDB), made with 192 IgG-saporin, were tested on a conditional associative learning task. In this task, which we term "environment-spatial" conditional learning, the correct location of a spatial response depended on the array of local environmental cues. MS/VDB-lesioned rats were impaired when the two parts of the conditional problem were presented concurrently, but not when one environment had been learned before the full conditional problem was presented. Our findings suggest that cholinergic MS/VDB neurons participate in some aspects of conditional associative learning in rats. They may also shed light on the involvement of cholinergic projections to the hippocampus in modulating and remodeling hippocampal spatial representations. © 2004 Wiley-Liss, Inc. [source] BDNF,triggered events in the rat hippocampus are required for both short- and long-term memory formationHIPPOCAMPUS, Issue 4 2002Mariana Alonso Abstract Information storage in the brain is a temporally graded process involving different memory types or phases. It has been assumed for over a century that one or more short-term memory (STM) processes are involved in processing new information while long-term memory (LTM) is being formed. Because brain-derived neutrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in the adult hippocampus, we examined the role of BDNF in STM and LTM formation of a hippocampal-dependent one-trial fear-motivated learning task in rats. Using a competitive RT-PCR quantitation method, we found that inhibitory avoidance training is associated with a rapid and transient increase in BDNF mRNA expression in the hippocampus. Bilateral infusions of function-blocking anti-BDNF antibody into the CA1 region of the dorsal hippocampus decreased extracellular signal,regulated kinase 2 (ERK2) activation and impaired STM retention scores. Inhibition of ERK1/2 activation by PD098059 produced similar effects. In contrast, intrahippocampal administration of recombinant human BDNF increased ERK1/2 activation and facilitated STM. The infusion of anti-BDNF antibody impaired LTM when given 15 min before or 1 and 4 hr after training, but not at 0 or 6 hr posttraining, indicating that two hippocampal BDNF-sensitive time windows are critical for LTM formation. At the same time points, PD098059 produced no LTM deficits. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of an inhibitory avoidance learning. Additionally, they suggest that this requirement involves ERK1/2-dependent and -independent mechanisms. Hippocampus 2002;12:551,560. © 2002 Wiley-Liss, Inc. [source] Frontal operculum temporal difference signals and social motor response learningHUMAN BRAIN MAPPING, Issue 5 2009Poornima Kumar Abstract Substantial experimental evidence supports the theory that the dopaminergic system codes a phasic (short duration) signal predicting the delivery of primary reinforcers, such as water when thirsty, during Pavlovian learning. This signal is described by the temporal difference (TD) model. Recently, it has been suggested that the human dopaminergic system also codes more complex cognitive goal states, including those required for human social interaction. Using functional magnetic resonance imaging (fMRI) with 18 healthy subjects, we tested the hypothesis that TD signals would be present during a Pavlovian learning task, and during a social motor response learning task. Using an identical model, TD signals were present in both tasks, although in different brain regions. Specifically, signals were present in the dorsal anterior cingulate, ventral striatum, amygdala, and thalamus with Pavlovian learning, and the dorsal anterior cingulate and bilateral frontal operculum with social motor response learning. The frontal operculum is believed to be the human homologue of the monkey mirror neuron system, and there is evidence which links the region with inference about other peoples' intentions and goals. The results support the contention that the human dopaminergic system predicts both primary reinforcers, and more complex cognitive goal states, such as motor responses required for human social group interaction. Dysfunction of such a mechanism might be associated with abnormal affective responses and incorrect social predictions, as occur in psychiatric disorders. Hum Brain Mapp 2009. © 2008 Wiley-Liss, Inc. [source] Better Processing of Consonantal Over Vocalic Information in Word Learning at 16 Months of AgeINFANCY, Issue 4 2009Mélanie Havy Previous research using the name-based categorization task has shown that 20-month-old infants can simultaneously learn 2 words that only differ by 1 consonantal feature but fail to do so when the words only differ by 1 vocalic feature. This asymmetry was taken as evidence for the proposal that consonants are more important than vowels at the lexical level. This study explores this consonant-vowel asymmetry in 16-month-old infants, using an interactive word learning task. It shows that the pattern of the 16-month-olds is the same as that of the 20-month-olds. Infants succeeded with 1-feature consonantal contrasts (either place or voicing) but were at chance level with 1-feature vocalic contrasts (either place or height). These results thus contribute to a growing body of evidence establishing, from early infancy to adulthood, that consonants and vowels have different roles in lexical acquisition and processing. [source] Learning cooperative linguistic fuzzy rules using the best,worst ant system algorithmINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 4 2005Jorge Casillas Within the field of linguistic fuzzy modeling with fuzzy rule-based systems, the automatic derivation of the linguistic fuzzy rules from numerical data is an important task. In the last few years, a large number of contributions based on techniques such as neural networks and genetic algorithms have been proposed to face this problem. In this article, we introduce a novel approach to the fuzzy rule learning problem with ant colony optimization (ACO) algorithms. To do so, this learning task is formulated as a combinatorial optimization problem. Our learning process is based on the COR methodology proposed in previous works, which provides a search space that allows us to obtain fuzzy models with a good interpretability,accuracy trade-off. A specific ACO-based algorithm, the Best,Worst Ant System, is used for this purpose due to the good performance shown when solving other optimization problems. We analyze the behavior of the proposed method and compare it to other learning methods and search techniques when solving two real-world applications. The obtained results lead us to remark the good performance of our proposal in terms of interpretability, accuracy, and efficiency. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 433,452, 2005. [source] Dietary restriction affects lifespan but not cognitive aging in Drosophila melanogasterAGING CELL, Issue 3 2010Joep M.S. Burger Summary Dietary restriction extends lifespan in a wide variety of animals, including Drosophila, but its relationship to functional and cognitive aging is unclear. Here, we study the effects of dietary yeast content on fly performance in an aversive learning task (association between odor and mechanical shock). Learning performance declined at old age, but 50-day-old dietary-restricted flies learned as poorly as equal-aged flies maintained on yeast-rich diet, even though the former lived on average 9 days (14%) longer. Furthermore, at the middle age of 21 days, flies on low-yeast diets showed poorer short-term (5 min) memory than flies on rich diet. In contrast, dietary restriction enhanced 60-min memory of young (5 days old) flies. Thus, while dietary restriction had complex effects on learning performance in young to middle-aged flies, it did not attenuate aging-related decline of aversive learning performance. These results are consistent with the hypothesis that, in Drosophila, dietary restriction reduces mortality and thus leads to lifespan extension, but does not affect the rate with which somatic damage relevant for cognitive performance accumulates with age. [source] Neurogenesis in a rat model of age-related cognitive declineAGING CELL, Issue 4 2004J. L. Bizon Summary Age-related decrements in hippocampal neurogenesis have been suggested as a basis for learning impairment during aging. In the current study, a rodent model of age-related cognitive decline was used to evaluate neurogenesis in relation to hippocampal function. New hippocampal cell survival was assessed approximately 1 month after a series of intraperitoneal injections of 5-bromo-2,-deoxyuridine (BrdU). Correlational analyses between individual measures of BrdU-positive cells and performance on the Morris water maze task provided no indication that this measure of neurogenesis was more preserved in aged rats with intact cognitive abilities. On the contrary, among aged rats, higher numbers of BrdU-positive cells in the granule cell layer were associated with a greater degree of impairment on the learning task. Double-labelling studies confirmed that the majority of the BrdU+ cells were of the neuronal phenotype; the proportion of differentiated neurons was not different across a broad range of cognitive abilities. These data demonstrate that aged rats that maintain cognitive function do so despite pronounced reductions in hippocampal neurogenesis. In addition, these findings suggest the interesting possibility that impaired hippocampal function is associated with greater survival of newly generated hippocampal neurons at advanced ages. [source] Features of sequential learning in hemicerebellectomized ratsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2010L. Mandolesi Abstract Because the sequencing property is one of the functions in which cerebellar circuits are involved, it is important to analyze the features of sequential learning in the presence of cerebellar damage. Hemicerebellectomized and control rats were tested in a four-choice visuomotor learning task that required both the detection of a specific sequence of correct choices and the acquisition of procedural rules about how to perform the task. The findings indicate that the presence of the hemicerebellectomy did not affect the first phases of detection and acquisition of the sequential visuomotor task, delayed but did not prevent the learning of the sequential task, slowed down speed-up and proceduralization phases, and loosened the reward-response associative structure. The performances of hemicerebellectomized animals in the serial learning task as well as in the open field task demonstrated that the delayed sequential learning task could not be ascribed to impairment of motor functions or discriminative abilities or to low levels of motivation. The delay in sequential learning observed in the presence of a cerebellar lesion appeared to be related mainly to a delay of the automatization of the response. In conclusion, it may be advanced that, through cortical and subcortical connections, the cerebellum provides the acquisition of rapid and accurate sensory-guided sequence of responses. © 2009 Wiley-Liss, Inc. [source] Learning To Be Saints or Sinners: The Indirect Pathway From Sensation Seeking to Behavior Through Mastery OrientationJOURNAL OF PERSONALITY, Issue 4 2008Peter J. O'Connor ABSTRACT Recently, a model of learning has been proposed that argues that Sensation Seeking indirectly predicts functional and dysfunctional behaviors through Mastery Orientation. Central components of the model were tested across two studies. Study 1 tested the proposed indirect effect in the prediction of functional behavior using an objective learning task. Study 2 tested the proposed indirect effects in the prediction of functional and dysfunctional self-report behavior across two very different samples. Regression analyses in both studies generally supported the proposed model. [source] Instructional Efficiency of Performance Analysis Training for Learners at Different Levels of Competency in Using a Web-Based EPSSPERFORMANCE IMPROVEMENT QUARTERLY, Issue 4 2004A. Aubteen Darabi ABSTRACT The measure of performance improvement potential (Gilbert, 1978) in human performance technology uses an exemplary performance as a criterion against which to measure the potential improvement in the performance of a workforce. The measure is calculated based on the performance efficiency which compares expended resources to productivity. The same notion is used to measure the efficiency of instructional conditions, based on learners' mental effort invested in a learning task compared to their performance. This article compares the efficiency of an instructional condition for three groups of students differentiated by their use of an electronic performance support system (EPSS) to conduct a performance analysis project. The results indicated that the instruction was most efficient for those learners who showed greater competency in using the EPSS. Implications for using this technique as a means of formative evaluation of a course are discussed. [source] Enhanced conditioned inhibitory avoidance by a combined extract of Zingiber officinale and Ginkgo bilobaPHYTOTHERAPY RESEARCH, Issue 4 2002B. Topic Abstract Previous work has shown that intragastric administration of Zingicomb®, a preparation consisting of Zingiber officinale and Ginkgo biloba extracts, has anxiolytic-like properties. The aim of the present study was to assess the effects of acute treatment with this preparation on inhibitory avoidance learning. The influence of pre-trial administered Zingicomb (ZC) on inhibitory avoidance conditioning was investigated in adult male Wistar rats, with a one-trial step-through avoidance task. The animals were treated intragastrically with either vehicle, 0.5, 1, 10 or 100,mg/kg ZC 60,min prior to the acquisition trial. When tested 24,h after training, rats which had received 10,mg/kg ZC exhibited significantly longer step-through latencies than vehicle treated animals. This result, thus, demonstrates the beneficial effects of Zingicomb on conditioned inhibitory avoidance. Unlike conventional anxiolytic drugs, such as the benzodiazepines, which tend to have amnesic properties, this phytopharmacon is a potent anxiolytic agent which, additionally, can facilitate performance on a learning task, indicating promising clinical applications. Copyright © 2002 John Wiley & Sons, Ltd. [source] The effect of interpersonal competition on monitoring internal and external error feedbackPSYCHOPHYSIOLOGY, Issue 2 2010Catharina S. Van Meel Abstract The present study examined the effect of the social context on early emotional appraisal of performance errors and negative feedback reflected by the error-related negativity (ERN), feedback-related negativity (FRN), and P300. Participants performed a probabilistic learning task in which they received valid and invalid performance feedback. During one half of the task they were led to believe that they were competing online against another participant. As expected, the ERN following response errors was enhanced in the competition compared to the neutral condition. The FRN was more negative following negative compared to positive feedback and valid compared to invalid feedback, but only during competition. The P300 was larger to false positive than false negative feedback, which was independent of the social context. In conclusion, ERN and FRN, but not P300, may be sensitive to affective distress elicited by expectation violations during social interaction. [source] Dopamine-dependent motor learning: Insight into levodopa's long-duration responseANNALS OF NEUROLOGY, Issue 5 2010Jeff A. Beeler PhD Objective Dopamine (DA) is critical for motor performance, motor learning, and corticostriatal plasticity. The relationship between motor performance and learning, and the role of DA in the mediation of them, however, remain unclear. Methods To examine this question, we took advantage of PITx3-deficient mice (aphakia mice), in which DA in the dorsal striatum is reduced by 90%. PITx3-deficient mice do not display obvious motor deficits in their home cage, but are impaired in motor tasks that require new motor skills. We used the accelerating rotarod as a motor learning task. Results We show that the deficiency in motor skill learning in PITx3(,/,) is dramatic and can be rescued with levodopa treatment. In addition, cessation of levodopa treatment after acquisition of the motor skill does not result in an immediate drop in performance. Instead, there is a gradual decline of performance that lasts for a few days, which is not related to levodopa pharmacokinetics. We show that this gradual decline is dependent on the retesting experience. Interpretation This observation resembles the long-duration response to levodopa therapy in its slow buildup of improvement after the initiation of therapy and gradual degradation. We hypothesize that motor learning may play a significant, underappreciated role in the symptomatology of Parkinson disease as well as in the therapeutic effects of levodopa. We suggest that the important, yet enigmatic long-duration response to chronic levodopa treatment is a manifestation of rescued motor learning. ANN NEUROL 2010;67:639,647 [source] Visuo-spatial working memory in navigationAPPLIED COGNITIVE PSYCHOLOGY, Issue 1 2002Sharin Garden Two experiments employed dual task techniques to explore the role of working memory in route learning and subsequent route retrieval. Experiment 1 involved contrasting performance of two groups of volunteers respectively learning a route from a series of map segments or a series of visually presented nonsense words. Both groups performed learning and recognition under articulatory suppression or concurrent spatial tapping. Both concurrent tasks had an overall disruptive effect on each learning task. However, spatial tapping disrupted route recognition rather more than did articulatory suppression, while the nonsense word recognition was impaired more by articulatory suppression than by concurrent spatial tapping. Experiment 2 again used dual task methodology, but explored route learning by asking volunteers to follow the experimenter through the winding streets of a medieval European town centre. Retrieval involved following the same route while the experimenter followed and noted errors in navigation. Overall the results partially replicated those of Experiment 1 in that both concurrent tasks interfered with route learning. However, volunteers with high spatial ability appeared more affected by the concurrent spatial tapping task, whereas low spatial subjects appeared more affected by the concurrent articulatory suppression task. Results are interpreted to suggest that different aspects of working memory are involved in learning a route from a map with a greater emphasis on visuo-spatial resources, but in tasks set in real environments where many cues of a varied nature are available, only high spatial ability subjects appear to rely heavily upon the visuospatial component of working memory. Copyright © 2002 John Wiley & Sons, Ltd. [source] Reward processing in autismAUTISM RESEARCH, Issue 2 2010Ashley A. Scott-Van Zeeland Abstract The social motivation hypothesis of autism posits that infants with autism do not experience social stimuli as rewarding, thereby leading to a cascade of potentially negative consequences for later development. While possible downstream effects of this hypothesis such as altered face and voice processing have been examined, there has not been a direct investigation of social reward processing in autism. Here we use functional magnetic resonance imaging to examine social and monetary rewarded implicit learning in children with and without autism spectrum disorders (ASD). Sixteen males with ASD and sixteen age- and IQ-matched typically developing (TD) males were scanned while performing two versions of a rewarded implicit learning task. In addition to examining responses to reward, we investigated the neural circuitry supporting rewarded learning and the relationship between these factors and social development. We found diminished neural responses to both social and monetary rewards in ASD, with a pronounced reduction in response to social rewards (SR). Children with ASD also demonstrated a further deficit in frontostriatal response during social, but not monetary, rewarded learning. Moreover, we show a relationship between ventral striatum activity and social reciprocity in TD children. Together, these data support the hypothesis that children with ASD have diminished neural responses to SR, and that this deficit relates to social learning impairments. [source] Complete maternal deprivation affects social, but not spatial, learning in adult ratsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2003F. Lévy Abstract The effects of maternal deprivation on learning of social and spatial tasks were investigated in female adult rats. Pups were reared artificially and received "lickinglike" tactile stimulation (AR animals) or were reared with their mothers (MR animals). In adulthood, subjects were tested on paradigms of spatial learning and on paradigms involving learning of social cues. Results showed that maternal deprivation did not affect performance on spatial learning, but it did impair performance on the three social learning tasks. The AR animals made no distinction between a new and a previously presented juvenile conspecific. AR animals also responded less rapidly than MR animals at test for maternal behavior 2 weeks after a postpartum experience with pups. Finally, AR animals did not develop a preference for a food previously eaten by a familiar conspecific whereas MR animals did. This study indicates that animals reared without mother and siblings show no deficits in spatial tasks while showing consistent deficits in learning involving social interactions. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 177,191, 2003. [source] Investigating learning deficits associated with dyslexiaDYSLEXIA, Issue 1 2004Emmanuel M. Pothos Abstract An artificial grammar learning task was used to define two learning tasks of identical complexity at the symbolic level, but which differed in terms of stimulus format. The stimuli in one learning task were created so as to encourage participants to perceive each stimulus as a whole, with less emphasis on the stimulus constituent elements (the ,embedded' stimuli), while in the second task the constituent elements of each stimulus were emphasized by presenting them serially (the ,sequences' stimuli). Using a between participants design, dyslexic participants performed equally well in the two versions of the learning task. By contrast, non-dyslexic participants performed as well as dyslexic ones with the embedded stimuli but were impaired in the sequences stimuli. This finding was interpreted as showing that dyslexic participants were less able, compared to controls, to process individual stimulus elements of both the sequences and the embedded stimuli, consistently with recent work associating dyslexia with problems in attention focusing and shifting. Copyright © 2004 John Wiley & Sons, Ltd. [source] Memory of Social Partners in Hermit Crab DominanceETHOLOGY, Issue 3 2005Francesca Gherardi We investigated the possibility that invertebrates recognize conspecific individuals by studying dominance relationships in the long-clawed hermit crab, Pagurus longicarpus. We conducted three sets of laboratory experiments to define the time limits for acquiring and maintaining memory of an individual opponent. The results reveal two characteristics that make individual recognition in this species different from standard associative learning tasks. Firstly, crabs do not require training over many repeated trials; rather, they show evidence of recognition after a single 30-min exposure to a stimulus animal. Secondly, memory lasts for up to 4 d of isolation without reinforcement. A third interesting feature of individual recognition in this species is that familiar opponents are recognized even before the formation of a stable hierarchical rank. That is, recognition seems to be relatively independent of repeated wins (rewards) or losses (punishments) in a dominance hierarchy. The experimental protocol allowed us to show that this species is able to classify conspecifics into two ,heterogeneous subgroups', i.e. familiar vs. unfamiliar individuals, but not to discriminate one individual of a group from every other conspecific from ,a unique set of cues defining that individual'. In other words, we demonstrated a ,binary', and not a ,true', individual recognition. However, 1 d of interactions with different crabs did not erase the memory of a former rival, suggesting that P. longicarpus uses a system of social partner discrimination more refined than previously shown. [source] Sexually dimorphic effects of hippocampal cholinergic deafferentation in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2004Zachariah Jonasson Abstract To determine whether the basal forebrain-hippocampal cholinergic system supports sexually dimorphic functionality, male and female Long-Evans rats were given either selective medial septum/vertical limb of the diagonal band (MS/VDB) cholinergic lesions using the neurotoxin 192 IgG-saporin or a control surgery and then postoperatively tested in a set of standard spatial learning tasks in the Morris water maze. Lesions were highly specific and effective as confirmed by both choline acetyltransferase/parvalbumin immunostaining and acetylcholinesterase histochemistry. Female controls performed worse than male controls in place learning and MS/VDB lesions failed to impair spatial learning in male rats, both consistent with previous findings. In female rats, MS/VDB cholinergic lesions facilitated spatial reference learning. A subsequent test of learning strategy in the water maze revealed a female bias for a response, relative to a spatial, strategy; MS/VDB cholinergic lesions enhanced the use of a spatial strategy in both sexes, but only significantly so in males. Together, these results indicate a sexually dimorphic function associated with MS/VDB-hippocampal cholinergic inputs. In female rats, these neurons appear to support sex-specific spatial learning processes. [source] | ||||||||||||||||||||||