The effects of ordinal load on incidental temporal learning

How can we grasp the temporal structure of events? A few studies have indicated that representations of temporal structure are acquired when there is an intention to learn, but not when learning is incidental. Response-to-stimulus intervals, uncorrelated temporal structures, unpredictable ordinal information, and lack of metrical organization have been pointed out as key obstacles to incidental temporal learning, but the literature includes piecemeal demonstrations of learning under all these circumstances. We suggest that the unacknowledged effects of ordinal load may help reconcile these conflicting findings, ordinal load referring to the cost of identifying the sequence of events (e.g., tones, locations) where a temporal pattern is embedded. In a first experiment, we manipulated ordinal load into simple and complex levels. Participants learned ordinal-simple sequences, despite their uncorrelated temporal structure and lack of metrical organization. They did not learn ordinal-complex sequences, even though there were no response-to-stimulus intervals nor unpredictable ordinal information. In a second experiment, we probed learning of ordinal-complex sequences with strong metrical organization, and again there was no learning. We conclude that ordinal load is a key obstacle to incidental temporal learning. Further analyses showed that the effect of ordinal load is to mask the expression of temporal knowledge, rather than to prevent learning.     

The P600 in Implicit Artificial Grammar Learning

The suitability of the artificial grammar learning (AGL) paradigm to capture relevant aspects of the acquisition of linguistic structures has been empirically tested in a number of EEG studies. Some have shown a syntax‐related P600 component, but it has not been ruled out that the AGL P600 effect is a response to surface features (e.g., subsequence familiarity) rather than the underlying syntax structure. Therefore, in this study, we controlled for the surface characteristics of the test sequences (associative chunk strength) and recorded the EEG before (baseline preference classification) and after (preference and grammaticality classification) exposure to a grammar. After exposure, a typical, centroparietal P600 effect was elicited by grammatical violations and not by unfamiliar subsequences, suggesting that the AGL P600 effect signals a response to structural irregularities. Moreover, preference and grammaticality classification showed a qualitatively similar ERP profile, strengthening the idea that the implicit structural mere‐exposure paradigm in combination with preference classification is a suitable alternative to the traditional grammaticality classification test.     

BIOLOGY TEACHERS’ CONCEPTIONS ABOUT THE ORIGIN OF LIFE IN BRAZIL,ARGENTINA, AND URUGUAY: A COMPARATIVE STUDY

Teachers’ conceptions about the origin of life in three Latin American countries with contrasting levels of secularism were analyzed: Argentina (Catholic constitution), Brazil (formally secular but not in practice), and Uruguay (consolidated secularism). A European survey questionnaire was used and the interpretation of the results drew on Barbour's four categories concerning the relationships of science and religion. A large majority of Argentinian and Uruguayan teachers were clearly evolutionist, even when believing in God (Independence or Dialogue category), with no difference between Argentina and Uruguay. The majority of Brazilian teachers assumed a religious position about the origin of life, being creationist (Conflict or Independence categories) or evolutionary creationist (Dialogue or Integration categories). Differences of Brazilian teachers’ conceptions may result from the higher percentage of evangelicals and lower proportion of agnostics/atheists. Brazilian Catholic teachers were more creationist than their Catholic colleagues in Argentina and Uruguay. Distinct patterns were found, but further research is needed to understand possible classroom impacts.     

Identity matching to sample and exclusion performance in elderly with and without neurocognitive disorders

Neurocognitive disorders (NCDs) affect complex processes of stimulus control, such as relational performance. The aims of this study were (a) to compare the performance of older adults with NCD with that of control older adults in generalized identity matching (GI) tests and in responding by exclusion probes and (b) to verify the effect of identity matching training on subsequent GI and exclusion tests, in older adults with NCD. Participants were 24 older adults (aged 60 to 92 years), eight without NCD (control group I [CG I]), and 16 with NCD: CG II, with accurate performance in the GI tests and the experimental group (EG), with low performance in these tests. After exclusion and GI tests with all participants, the EG underwent identity matching training with 3 pairs of visual stimuli, and exclusion and identity matching posttests. All participants of the CG I and CG II presented accurate performance in the tests. Seven of the 8 older adults of the EG achieved the learning criterion in the training and showed some improvement in the GI posttest; however, positive effects of the training were not observed in the exclusion posttests. Teaching procedures for identity matching in older adult patients with NCD can produce positive results; however, it is necessary to understand the relationship between cognitive decline and other relational performances.     

The impact of object size and rigidity on infant reaching

Although the changes in kinematics of infant reaching have been studied, few researchers have investigated the improvement of reaching regarding objects of distinct physical properties. The aim of this longitudinal study was to verify the impact of object size and rigidity on the development of reaching in 4-6-month-old infants. Four infants were observed with a motion capture system during trials with four objects of distinct sizes and rigidity. A total of 188 reaches were analyzed by using the 3D movement reconstruction. Our results showed that reaching frequency, mean velocity, and straightness index increased with age. The number of movement units decreased with age and increased for small objects. Rigidity was not shown to affect reaching trajectories. These findings suggest that infants are capable of perceiving the more relevant object properties, thus using their available motor capabilities to modify the essential variables so that they can reach the target more accurately.     

Trace eyeblink conditioning requires the hippocampus but not autophosphorylation of alphaCaMKII in mice

Little is known about signaling mechanisms underlying temporal associative learning. Here, we show that mice with a targeted point mutation that prevents autophosphorylation of alphaCaMKII (alphaCaMKII(T286A)) learn trace eyeblink conditioning normally. This forms a sharp contrast to the severely impaired spatial learning in the water maze and contextual fear conditioning observed in alphaCaMKII(T286A) mutants. Importantly, hippocampal lesions impaired trace eyeblink conditioning in alphaCaMKII(T286A) mice, suggesting a potential role of hippocampal alphaCaMKII-independent mechanisms. These results indicate that hippocampal signaling mechanisms that underlie temporal associative learning as assessed by trace eyeblink conditioning may differ from those of spatial and contextual learning.     

Activation of MAPK is necessary for long-term memory consolidation following food-reward conditioning

Although an important role for the mitogen-activated protein kinase (MAPK) has been established for memory consolidation in a variety of learning paradigms, it is not known if this pathway is also involved in appetitive classical conditioning. We address this question by using a single-trial food-reward conditioning paradigm in the freshwater snail Lymnaea stagnalis. This learning paradigm induces protein synthesis-dependent long-term memory formation. Inhibition of MAPK phosphorylation blocked long-term memory consolidation without affecting the sensory and motor abilities of the snails. Thirty minutes after conditioning, levels of MAPK phosphorylation were increased in extracts from the buccal and cerebral ganglia. These ganglia are involved in the generation, modulation, and plasticity of the feeding behavior. We also detected an increase in levels of MAPK phosphorylation in the peripheral tissue around the mouth of the snails where chemoreceptors are located. Although an increase in MAPK phosphorylation was shown to be essential for food-reward conditioning, it was also detected in snails that were exposed to the conditioned stimulus (CS) or the unconditioned stimulus (US) alone, suggesting that phosphorylation of MAPK is necessary but not sufficient for learning to occur.     

Failure to overcome 'innate' fear: a developmental test of the non-associative model of fear acquisition

The non-associative, Darwinian theory of fear acquisition proposes that some individuals fail to overcome biologically-relevant fears (e.g. height) because they (1) do not have sufficient safe exposure to the relevant stimuli early in life or (2) are poor habituators who have difficulty 'learning not to fear'. These two hypotheses were tested in a longitudinal birth cohort study. Study 1 found evidence for reduced exposure to height stimuli in childhood for individuals with a fear of heights compared to study members without fear. Study 2 found evidence for higher levels of stress reactivity (a proxy for habituation) in childhood and adolescence among 18-year-old height phobics compared to study members with dental phobia and those with no fear. The results were discussed in relation to recent findings suggesting that some evolutionary-relevant fears may appear in the absence of traumatic 'learning' experiences. The merits of adding a fourth, non-associative pathway to Rachman's [Rachman, S. (1977)]. The conditioning theory of fear acquisition: a critical examination. Behaviour Research and Therapy, 15, 375-387) three pathways model of fear acquisition were briefly considered.