Divided attention does not affect the acquisition and consolidation of transitional probabilities.

Statistical learning facilitates the efficient processing and prediction of environmental events and contributes to the acquisition of automatic behaviors. Whereas a minimal level of attention seems to be required for learning to occur, it is still unclear how acquisition and consolidation of statistical knowledge are affected when attention is divided during learning. To test the effect of divided attention on statistical learning and consolidation, ninety-six healthy young adults performed the Alternating Serial Reaction Time task in which they incidentally acquired second-order transitional probabilities. Half of the participants completed the task with a concurrent secondary intentional sequence learning task that was applied to the same stimulus stream. The other half of the participants performed the task without any attention manipulation. Performance was retested after a 12-h post-learning offline period. Half of each group slept during the delay, while the other half had normal daily activity, enabling us to test the effect of delay activity (sleep vs. wake) on the consolidation of statistical knowledge. Divided attention had no effect on statistical learning: The acquisition of second-order transitional probabilities was comparable with and without the secondary task. Consolidation was neither affected by divided attention: Statistical knowledge was similarly retained over the 12-h delay, irrespective of the delay activity. Our findings can contribute to a better understanding of the role of attentional processes in and the robustness of visuomotor statistical learning and consolidation.

Deconstructing Procedural Memory: Different Learning Trajectories and Consolidation of Sequence and Statistical Learning.

Procedural learning is a fundamental cognitive function that facilitates efficient processing of and automatic responses to complex environmental stimuli. Here, we examined training-dependent and off-line changes of two sub-processes of procedural learning: namely, sequence learning and statistical learning. Whereas sequence learning requires the acquisition of order-based relationships between the elements of a sequence, statistical learning is based on the acquisition of probabilistic associations between elements. Seventy-eight healthy young adults (58 females and 20 males) completed the modified version of the Alternating Serial Reaction Time task that was designed to measure Sequence and Statistical Learning simultaneously. After training, participants were randomly assigned to one of three conditions: active wakefulness, quiet rest, or daytime sleep. We examined off-line changes in Sequence and Statistical Learning as well as further improvements after extended practice. Performance in Sequence Learning increased during training, while Statistical Learning plateaued relatively rapidly. After the off-line period, both the acquired sequence and statistical knowledge was preserved, irrespective of the vigilance state (awake, quiet rest or sleep). Sequence Learning further improved during extended practice, while Statistical Learning did not. Moreover, within the sleep group, cortical oscillations and sleep spindle parameters showed differential associations with Sequence and Statistical Learning. Our findings can contribute to a deeper understanding of the dynamic changes of multiple parallel learning and consolidation processes that occur during procedural memory formation.

The interrelated effect of sleep and learning in dogs (Canis familiaris); an EEG and behavioural study.

The active role of sleep in memory consolidation is still debated, and due to a large between-species variation, the investigation of a wide range of different animal species (besides humans and laboratory rodents) is necessary. The present study applied a fully non-invasive methodology to study sleep and memory in domestic dogs, a species proven to be a good model of human awake behaviours. Polysomnography recordings performed following a command learning task provide evidence that learning has an effect on dogs' sleep EEG spectrum. Furthermore, spectral features of the EEG were related to post-sleep performance improvement. Testing an additional group of dogs in the command learning task revealed that sleep or awake activity during the retention interval has both short- and long-term effects. This is the first evidence to show that dogs' human-analogue social learning skills might be related to sleep-dependent memory consolidation.

[The psychometric properties of the Hungarian version of the Morningness-Eveningness Questionnaire (MEQ-H): the separate factors of Morning Freshness and Circadian Rhythmicity]. / A MEQ-H (Morningness-Eveningness Questionnaire) hazai adaptáciojának pszichometriai jellemzoi: a Reggeli éberség és a Napszaki ritmus elkülönülo faktorai.

INTRODUCTION: A large body of research has been accumulated concerning the relationship between circadian preferences (chronotype) and certain personality traits and psychopathological symptoms. Given that chronotype is related to clinically relevant personality traits, risk factors as well as diurnal variations in behavioural performance, the reliable measurement of circadian preferences might become an important step in daily psychiatric practice. In the present study, we examined the psychometric properties of the Hungarian adaptation of the Morningness- Eveningness Questionnaire (MEQ-H). METHODS: Based on the (online) questionnaire data of 840 healthy individuals, we examined the factor structure and the internal reliability of the questionnaire. The validity was assessed by different scales (sensory seeking, depressive symptoms and sleep complaints) that were previously shown to be associated with chronotype. Test-retest reliability was calculated from the data of 55 participants who completed the questionnaire twice (eight months apart). RESULTS: We identified two strongly correlated but separate factors, that we called Morning freshness and Circadian rhythm. According to our results, the questionnaire is a reliable instrument in order to measure individual differences in these factors, however, to increase the reliability of the scale as well as in light of practical considerations, the use of a shortened 13-itemed version might be reasonable. The two factors of the MEQ-H showed the expected associations with the examined constructs, however, the independent predictors of Morning freshness were age, gender, depressive symptoms and sleep complaints (insomniac symptoms and morning misalignment), while the independent predictors of Circadian rhythm were age, gender, depressive symptoms, circadian misalignment and sensory seeking. CONCLUSION: The MEQ-H fulfils the methodological requirements of reliability and validity testing, and proved to be an adequate instrument in order to measure circadian preferences: an important factor that could be included in experimental or clinical investigations.

The influence of sleep complaints on the association between chronotype and negative emotionality in young adults.

A great body of research indicates that eveningness is associated with negative psychological outcomes, including depressive and anxiety symptoms, behavioral dyscontrol and different health impairing behaviors. Impaired subjective sleep quality, increased circadian misalignment and daytime sleepiness were also reported in evening-type individuals in comparison with morning-types. Although sleep problems were consistently reported to be associated with poor psychological functioning, the effects of sleep disruption on the relationship between eveningness preference and negative emotionality have scarcely been investigated. Here, based on questionnaire data of 756 individuals (25.5% males, age range = 18-43 years, mean = 25.3 ± 5.8 years), as well as of the evening-type (N = 211) and morning-type (N = 189) subgroups, we examined the relationship among sleep problems, eveningness and negative emotionality. Subjects completed the Hungarian Version of the Horne and Östberg Morningness-Eveningness Questionnaire (MEQ-14), The Athen Insomnia Scale (AIS) and the Epworth Sleepiness Scale (ESS). Moreover, a composite score of Negative Emotionality (NE) was computed based on the scores of the Short Beck Depression Inventory (BDI-9), the Perceived Stress Scale (PSS-4) and the General Health Questionnaire (GHQ-12). Morning and evening circadian misalignment was calculated based on the difference between preferred and real wake- and bedtimes. Two possible models were tested, hypothesizing that sleep problems (circadian misalignment, insomniac symptoms and daytime sleepiness) moderate or mediate the association between eveningness and negative emotionality. Eveningness preference was correlated with increased NE and increased AIS, ESS and circadian misalignment scores. Our results indicate that eveningness-preference is an independent risk factor for higher negative emotionality regardless of the effects of age, gender, circadian misalignment and sleep complaints. Nevertheless, while chronotype explained ∼6%, sleep problems (AIS and ESS) accounted for a much larger proportion (∼28%) of the variance of NE. We did not find a significant effect of interaction (moderation) between chronotype and sleep problems. In contrast, insomniac symptoms (AIS) emerged as a partial mediator between chronotype and NE. These findings argue against the assumption that indicators of mental health problems in evening-type individuals can be explained exclusively on the basis of disturbed sleep. Nevertheless, negative psychological outcomes seem to be partially attributable to increased severity of insomniac complaints in evening-types.