ERPs studies of cognitive processing during sleep

In the last few decades, several works on cognitive processing during sleep have emerged. The study of cognitive processing with event related potentials (ERPs) during sleep is a topic of great interest, since ERPs allow the study of stimulation with passive paradigms (without conscious response or behavioural response), opening multiple research possibilities during different sleep phases. We review ERPs modulated by cognitive processes during sleep: N1, Mismatch Negativity (MMN), P2, P3, N400-like, N300-N550, among others. The review shows that there are different cognitive discriminations during sleep related to the frequency, intensity, duration, saliency, novelty, proportion of appearance, meaning, and even sentential integration of stimuli. The fascinating results of cognitive processing during sleep imply serious challenges for cognitive models. The studies of ERPs, together with techniques of neuroimaging, have demonstrated the existence of cognitive processing during sleep. A fundamental question to be considered is if these cognitive phenomena are similar to processing that occurs during wakefulness. Based on this question we discussed the existence of possible mechanisms associated with sleep, as well as the specific cognitive and neurophysiologic differences of wakefulness and sleep. Much knowledge is still required to even understand the conjunction of dramatic changes in cerebral dynamics and the occurrence of cognitive processes. We propose some insights based on ERPs research for further construction of theoretical models for integrating both cognitive processing and specific brain sleep dynamics.     

Spanish adaptation of the NDSS (Nicotine Dependence Syndrome Scale) and assessment of nicotine-dependent individuals at primary care health centers in Spain

The availability of adequate instruments for the assessment of nicotine dependence is an important factor that is relevant in the area of tobacco addiction. In this study, we present a Spanish validation of the Nicotine Dependence Syndrome Scale (NDSS) (Shiffman, Waters, & Hickcox, 2004). The sample was composed ofpatients, all daily smokers, who visited their General Practitioner (GP) at five Primary Health Care Centers in different cities of Spain (N = 637). The results indicated adequate reliability for the general factor that assesses nicotine dependence (NDSS-Total) (Cronbach's alpha = .76). Factor analysis confirms the five factors of the original validation: Drive, Continuity, Stereotypy, Priority, and Tolerance. It must be noted that reliability is adequate for the first, and moderate or low for the rest. The NDSS-T and its scales correlate significantly with the Fagerstr?m Test for Nicotine Dependence (FTND), with the nicotine dependence criteria of the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) as assessed through the Structured Clinical Interview for DSM-IV (SCID), with carbon monoxide levels in expired air (CO), and with the number of cigarettes smoked. The ROC curve indicates that the NDSS-T has a score of .79 which is under the curve (.69 for the FTND), thus the prediction of nicotine dependence is adequate. We conclude that this instrument is useful (in terms of its total score NDSS-T) for assessing nicotine dependence for Spanish smokers (in Spain), as has been found in other countries, language groups, and cultures.     

PISA and the assessment triangle

PISA is a well-known and high profile Program for International Student Assessment with 4 editions since 2000. This study aims to examine the validity of PISA proficiency estimates, working with the framework provided by the assessment triangle. We pay explicit attention to how PISA proceeds as far as the three elements of the assessment triangle are concerned: cognition, observation, and interpretation. Results reveal not only the psychometrically sound proficiency estimates of PISA and the high standards reached, but also that there is room for improvement; for instance, cognitive diagnostic models could contribute both to test design and data analysis.     

The Short Nicotine Dependence Syndrome Scale (NDSS-S) in Spanish smokers

We present a brief scale derived from the Nicotine Dependence Syndrome Scale (NDSS). We used a sample of 1.061 daily smokers, which was obtained from five Primary Care Health Centers, a Unit of Alcoholism, and a Smoking Cessation Unit. All smokers were evaluated with the NDSS and the SCID to assess nicotine dependence according to DSM-IV criteria. The results indicate the existence of a general factor of nicotine dependence according to the NDSS. We selected the items with a higher factor loading (>.50), obtaining a short scale of 6 items. With this brief scale, we obtained results similar to those of the total scale in the diverse variables (sociodemographic and smoking) of the study. Scale reliability is satisfactory (a= .79), the correlation between the short and the total scale is very high (r=.95, p<.001) and the short scale discriminates the smokers in terms of cigarette consumption and nicotine dependence, as assessed with the SCID. The operation under the ROC curve is excellent (area under the curve .84). The data indicate the usefulness of this brief scale (NDSS-S) to assess nicotine dependence in smokers.     

Event-related EEG oscillations to semantically unrelated words in normal and learning disabled children

Learning disabilities (LD) are one of the most frequent problems for elementary school-aged children. In this paper, event-related EEG oscillations to semantically related and unrelated pairs of words were studied in a group of 18 children with LD not otherwise specified (LD-NOS) and in 16 children with normal academic achievement. We propose that EEG oscillations may be different in LD NOS children versus normal control children that may explain some of the deficits observed in the LD-NOS group. The EEGs were recorded using the 10/20 system. EEG segments were edited by visual inspection 1000ms before and after the stimulus, and only correct responses were considered in the analysis. Time-frequency (1-50Hz) topographic maps were obtained for the increases and decreases of power after the event with respect to the pre-stimulus average values. Significant differences between groups were observed in the behavioral responses. LD-NOS children show less number of correct responses and more omissions and false alarms than the control group. The event-induced EEG responses showed significant differences between groups. The control group showed greater power increases in the frequencies 1-6Hz than the LD-NOS group from 300 to 700ms. These differences were mainly observed in frontal regions, both to related and non-related words. This was interpreted as a deficit in attention, both to internal and external events, deficits in activation of working memory and deficits in encoding and memory retrieval in the LD-NOS children. Differences between groups were also observed in the suppression of alpha and beta rhythms in the occipital regions to related words in frequencies between 8 and 17Hz from 450 to 750ms. LD-NOS children showed shorter durations of the decreases in power than the control group. These results suggest also deficits in attention and memory retrieval. It may be concluded that LD-NOS children showed physiological differences from normal children that may explain their cognitive deficiencies.     

Sex differences in the patterning of adult roles as a determinant of sex differences in occupational achievement

A sample of 4,035 men and women from the Project TALENT high school class of 1963 cohort was examined to determine the extent to which sex differences in the patterning of adult roles contribute to observed sex differences in occupational achievement. Men and women were found to differ in the comparative timing, ordering, and continuity of educational, occupational, marital, and procreational roles in early adulthood. These differences in role patterns explained only a small portion of the observed sex differences in occupational attainment, as sex appeared to be a strong direct determinant of both role patterns and attainment. However, some aspects of the patterning of these roles appeared to have an independent influence on occupational attainment; in these instances, the patterns associated with lower earnings were more likely to have been followed by women. Further investigation of the impact of variations in the patterning of adult roles on women's (and men's) occupational achievement is recommended.This work was supported by Grant MH29509 from the National Institute of Mental Health.