Understanding the dorsal and ventral systems of the human cerebral cortex: beyond dichotomies

Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more fruitful way to organize human cortical brain functions. However, current characterizations of the functions of the dorsal (top) and ventral (bottom) systems have rested on dichotomies, namely where versus what and how versus what. We propose that characterizing information-processing systems leads to a better macrolevel organization of cortical function; specifically, we hypothesize that the dorsal system is driven by expectations and processes sequences, relations, and movement, whereas the ventral system categorizes stimuli in parallel, focuses on individual events, and processes object properties (such as shape in vision and pitch in audition). To test this hypothesis, we reviewed over 100 relevant studies in the human neuroimaging and neuropsychological literatures and coded them relative to 11 variables, some of which characterized our hypothesis and some of which characterized the previous dichotomies. The results of forward stepwise logistic regressions supported our characterization of the 2 systems and showed that this model predicted the empirical findings better than either the traditional dichotomies or a left-right difference.     

Is it a he or a she? Behavioral and computational approaches to sex categorization

Can people categorize the sex of neonate faces? Our experiment tested the sex categorization of neonate faces by adult participants. We used a set of 120 Caucasian faces (adults and 4-day-old neonates) that were presented just once to a large sample of participants. A computational model of low-level visual processing, based on Gabor filters, was used to explore the relation between spatial-frequency information and sex categorization. The results showed that participants were able to categorize the sex of the faces, but were less accurate with neonate (d' = 0.36, β = –.97) than with adult (d' = 3.02, β = –.93) faces. Moreover, faces were more frequently categorized as boys’ than girls’ faces. The computational model suggests that specific spatial-frequency channels carry most of the useful information for the categorization task. Overall, the findings reveal that subtle differences in neonate facial structure were enough to allow the sex categorization of neonate faces, although accuracy was low in both adults and the computational model of low-level visual processing.     

Multiple-look effects on temporal discrimination within sound sequences

The multiple-look notion holds that the difference limen (DL) decreases with multiple observations. We investigated this notion for temporal discrimination in isochronous sound sequences. In Experiment 1, we established a multiple-look effect when sequences comprised nine standard time intervals (S) followed by an increasing number of comparison time intervals (C), but no multiple-look effect when one trailing C interval was preceded by an increasing number of S intervals. In Experiment 2, we extended the design. There were four sequential conditions: (a) 9 leading S intervals followed by 1, 2, …, or 9 C-intervals; (b) 9 leading C intervals followed by 1, 2, …, or 9 S intervals; (c) 9 trailing C-intervals preceded by 1, 2, …, or 9 S-intervals; and (d) 9 trailing S-intervals preceded by 1, 2, …, or 9 C-intervals. Both the interval accretions before and after the tempo change caused multiple-look effects, irrespective of the time order of S and C. Complete deconfounding of the number of intervals before and after the tempo change was accomplished in Experiment 3. The multiple-look effect of interval accretion before the tempo change was twice as big as that after the tempo change. The diminishing returns relation between the DL and interval accretion could be described well by a reciprocal function.     

Are cyberbullies less empathic? Adolescents' cyberbullying behavior and empathic responsiveness

Meta-analyses confirm a negative relationship between aggressive behavior and empathy, that is, the ability to understand and share the feelings of others. Based on theoretical considerations, it was, therefore, hypothesized that a lack of empathic responsiveness may be characteristic for cyberbullies in particular. In the present study, 2.070 students of Luxembourg secondary schools completed an online survey that included a cyberbullying questionnaire(4) and a novel empathy short scale. According to the main hypothesis, analyses of variances indicated that cyberbullies demonstrated less empathic responsiveness than non-cyberbullies. In addition, cyberbullies were also more afraid of becoming victims of cyberbullying. The findings confirm and substantially extend the research on the relationship between empathy and aggressive behavior. From an educational point of view, the present findings suggest that training of empathy skills might be an important tool to decrease cyberbullying.     

Differences in eye-movement patterns between anorexic and control observers when judging body size and attractiveness

Attentional biases may influence the eye-movements made when judging bodies and so alter the visual information sampled when making a judgment. This may lead to an overestimation of body size. We measured the eye-movements made by 16 anorexic observers and 16 age-matched controls when judging body size and attractiveness. We combined behavioural data with a novel eye-movement analysis technique that allowed us to apply spatial statistical techniques to make fine spatial discriminations in the pattern of eye-movements between our observer groups. Our behavioural results show that anorexic observers overestimate body size relative to controls and find bodies with lower body mass indexes more attractive. For both judgments, the controls' fixations centre on the stomach, but the anorexic observers show a much wider fixation pattern extending to encompass additional features such as the prominence of the hip and collar bones. This additional visual information may serve to alter their behavioural judgments towards an overestimation of body size and shift their ideal body size towards a significantly lower value.     

Developmental change in working memory strategies: from passive maintenance to active refreshing

Change in strategies is often mentioned as a source of memory development. However, though performance in working memory tasks steadily improves during childhood, theories differ in linking this development to strategy changes. Whereas some theories, such as the time-based resource-sharing model, invoke the age-related increase in use and efficiency of a strategy of active maintenance of memory traces, other theories, such as the task-switching model, do not mention strategy change. According to these models, either the cognitive load of the task or the duration of maintenance would account for recall performance. In the present study, we varied orthogonally these 2 factors. The results revealed that a different and unique factor affected recall performance at different ages: the duration of maintenance at age 6 and the cognitive load at age 7. As described by the task-switching model, younger children would not implement any maintenance activities while performing a concurrent task, their memory traces suffering from a time-based decay. This suggests that an increasing capacity of cognitive monitoring allows children to shift from this passive maintenance of memory traces to the active refreshing thereof at around the age of 7, reunifying the 2 current accounts of working memory development as 2 developmental stages.     

Did lifetime rates of alcohol use disorders increase by 67% in 10 years? A comparison of NLAES and NESARC

Two nationally representative epidemiological samples (the National Longitudinal Alcohol Epidemiological Survey and the National Epidemiological Survey of Alcohol and Related Conditions) have been used to track changes in the prevalence of alcohol use disorders (AUDs) between 1992 and 2002 in the United States. Strikingly, estimates from these two data sets suggest that the lifetime prevalence of AUD increased by approximately 67% (from 18.2% to 30.3%) during this time frame. This article explores potential reasons for these discrepant estimates. Analyses indicated that a vast majority of change in lifetime AUD occurred with respect to alcohol abuse and not alcohol dependence. Most of this increase in abuse was attributable to self-reported changes in hazardous use that did not track with other archival measures of outcomes related to hazardous use in the population. Key methodological differences regarding the frequency requirements for prior-to-past-year alcohol abuse appeared to explain most of the discrepancy in lifetime AUD estimates. These findings, in conjunction with the relative lack of differences in the 12-month prevalence of AUDs, suggest that the discrepant lifetime estimates are likely due to methodological differences between the two surveys. These findings have important implications for substance use and other psychiatric surveillance and epidemiology where meaningful cross-temporal comparisons are desired.     

The role of form and meaning in the processing of written morphology: A priming study in French developing readers

Three visual priming experiments using three different prime durations (60 ms in Experiment 1, 250 ms in Experiment 2, and 800 ms in Experiment 3) were conducted to examine which properties of morphemes (form and/or meaning) drive developing readers’ processing of written morphology. French third, fifth, and seventh graders and adults (the latter as a control group) performed lexical decision tasks in which targets were preceded by morphological (e.g., tablette–TABLE, “little table–table”), pseudoderived (e.g., baguette–BAGUE, “little stick–ring”), orthographic control (e.g., abricot–ABRI, “apricot–shelter”), and semantic control (e.g., Tulipe–FLEUR, “tulip–flower”) primes. Across all groups, different patterns of priming were observed in both morphological and orthographic/semantic control conditions, suggesting that they all process morphemes as units when reading. In developing readers, the processing of written morphology is triggered by the form properties of morphemes, and their semantic properties are activated later in the time course of word recognition. In adults, patterns of priming were similar except that the activation of the form properties of morphemes decreased earlier in the time course of word recognition. Taken together, these findings indicate that French developing readers process both the form and meaning properties of morphemes when reading and support a progressive quantitative change in the development of morphological processing over the course of reading development.     

Maternal stress and perceptions of self-efficacy in socioeconomically disadvantaged mothers: an explicative model

Studies have demonstrated that maternal stress and perceptions of self-efficacy influence a mother's performance, affecting her ability to interact with her child and to understand and answer his needs. The purpose of this study was to evaluate maternal stress and the perception of self-efficacy in the mothers of infants who are cared for in child-care centers and belong to the poorest segment of the Chilean population. To this end, these aspects were studied in 121 low-income, high-social-risk mothers with children between the ages of 4 and 9 months. The final goal was to generate an explicative model of self-efficacy and maternal stress that considered characteristics of the family and the child. The results revealed that family characteristics - especially household size, per capita incomes and mother age - are more relevant for explaining maternal self-efficacy and stress. The findings and implications for practice are discussed.     

Ethnic Minority‐Majority Asymmetry in National Attitudes around the World: A Multilevel Analysis

Using data from the International Social Survey Programme, this research investigated asymmetric attitudes of ethnic minorities and majorities towards their country and explored the impact of human development, ethnic diversity, and social inequality as country‐level moderators of national attitudes. In line with the general hypothesis of ethnic asymmetry, we found that ethnic, linguistic, and religious majorities were more identified with the nation and more strongly endorsed nationalist ideology than minorities (H1, 33 countries). Multilevel analyses revealed that this pattern of asymmetry was moderated by country‐level characteristics: the difference between minorities and majorities was greatest in ethnically diverse countries and in egalitarian, low inequality contexts. We also observed a larger positive correlation between ethnic subgroup identification and both national identification and nationalism for majorities than for minorities (H2, 20 countries). A stronger overall relationship between ethnic and national identification was observed in countries with a low level of human development. The greatest minority‐majority differences in the relationship between ethnic identification and national attitudes were found in egalitarian countries with a strong welfare state tradition.