Sparse but not 'grandmother-cell' coding in the medial temporal lobe

Although a large number of neuropsychological and imaging studies have demonstrated that the medial temporal lobe (MTL) plays an important role in human memory, there are few data regarding the activity of neurons involved in this process. The MTL receives massive inputs from visual cortical areas, and evidence over the last decade has consistently shown that MTL neurons respond selectively to complex visual stimuli. Here, we focus on how the activity patterns of these cells might reflect the transformation of visual percepts into long-term memories. Given the very sparse and abstract representation of visual information by these neurons, they could in principle be considered as 'grandmother cells'. However, we give several arguments that make such an extreme interpretation unlikely.     

The Relationships Among Parental Anxiety, Parenting, and Children’s Anxiety: The Mediating Effects of Children’s Cognitive Vulnerabilities

Theoretical models have emphasized the roles played by parental anxiety and behavior in the development of childhood anxiety problems. Little is known regarding the differential impacts of mothers and fathers or regarding the processes that mediate these influences. The present study examines the relationships between maternal and paternal trait anxiety, overprotection, and emotional support on the one hand and anxiety symptoms in children on the other hand. This study also explores the mediating role of children’s cognitive vulnerabilities to anxiety disorders in the relationship between parental variables and children’s anxiety. A sample of 80 children and their parents (fathers and mothers), selected from an initial screening of 905 school-aged children, participated in this study. The results indicate that both parents had unique influences on children’s anxiety symptoms: maternal trait anxiety and paternal overprotection and concern were found to independently and positively contribute to children’s anxiety. Furthermore, children’s interpretative biases mediated the relation between maternal trait anxiety and children’s anxiety symptoms. The results of this study underline the importance of considering both paternal and maternal factors in the development of children’s anxiety problems. These findings also have implications for theoretical models of the etiology of anxiety and for the treatment of these problems in children.     

ESCOLEX: A grade-level lexical database from European Portuguese elementary to middle school textbooks

In this article, we introduce ESCOLEX, the first European Portuguese children’s lexical database with grade-level-adjusted word frequency statistics. Computed from a 3.2-million-word corpus, ESCOLEX provides 48,381 word forms extracted from 171 elementary and middle school textbooks for 6- to 11-year-old children attending the first six grades in the Portuguese educational system. Like other children’s grade-level databases (e.g., Carroll, Davies, & Richman, 1971; Corral, Ferrero, & Goikoetxea, Behavior Research Methods, 41, 1009–1017, 2009; Lété, Sprenger-Charolles, & Colé, Behavior Research Methods, Instruments, & Computers, 36, 156–166, 2004; Zeno, Ivens, Millard, Duvvuri, 1995), ESCOLEX provides four frequency indices for each grade: overall word frequency (F), index of dispersion across the selected textbooks (D), estimated frequency per million words (U), and standard frequency index (SFI). It also provides a new measure, contextual diversity (CD). In addition, the number of letters in the word and its part(s) of speech, number of syllables, syllable structure, and adult frequencies taken from P-PAL (a European Portuguese corpus-based lexical database; Soares, Comesaña, Iriarte, Almeida, Simões, Costa, …, Machado, 2010; Soares, Iriarte, Almeida, Simões, Costa, França, …, Comesaña, in press) are provided. ESCOLEX will be a useful tool both for researchers interested in language processing and development and for professionals in need of verbal materials adjusted to children’s developmental stages. ESCOLEX can be downloaded along with this article or from http://p-pal.di.uminho.pt/about/databases.     

Trauma and Religiousness

Victims of traumatic events who experience re-traumatization often develop a highly ambivalent relationship to God and all religiosity as extremely conflictual. On the one hand, they may choose to blame God for not having protected them, for having left them to feel so alone, for having been indifferent to them or they may even turn their wrath upon God, as the source of cruelty. Often though, the traumas experienced by individuals prompt them to turn to God and religion in search of help. This gives reason for the need of new and up-to-date research that can help elucidate why some people choose to seek help in religion and others turn away from it.     

Dissociable yet tied inhibitory processes: The structure of inhibitory control

Cognitive and neural models have proposed the existence of a single inhibitory process that regulates behavior and depends on the right frontal operculum (rFO). The aim of this study was to make a contribution to the ongoing debate as to whether inhibition is a single process or is composed of multiple, independent processes. Here, within a single paradigm, we assessed the links between two inhibitory phenomena—namely, resistance to involuntary visual capture by abrupt onsets and resolving of spatial stimulus–response conflict. We did so by conducting three experiments, two involving healthy volunteers (Exps. 1 and 3), and one with the help of a well-documented patient, R.J., with selectively weakened inhibition following a lesion of the rFO. The results suggest that resistance to capture and stimulus–response conflict are independent, because (a) additive effects were found (Exps. 1 and 3), (b) capture did not correlate with compatibility effects (Exp. 1), (c) dual tasking affected the two phenomena differently (Exp. 3), and (d) a dissociation was found between the two in patient R.J. (Exp. 2). However, the results also show that these two phenomena may share some processing components, given that (a) both were affected in patient R.J., but to different degrees (Exp. 2), and (b) increasing the difficulty of dual tasking produced an increasingly negative correlation between capture and compatibility (Exp. 3), which suggests that when resources are withdrawn from the control of the former, they are used to control the latter.     

Effects of negative content on the processing of gender information: An event-related potential study

Previous research on emotion in language has mainly concerned the impact of emotional information on several aspects of lexico-semantic analyses of single words. However, affective influences on morphosyntactic processing are less understood. In the present study, we focused on the impact of negative valence in the processing of gender agreement relations. Event-related potentials (ERPs) were recorded while participants read three-word phrases and performed a syntactic judgment task. Negative and neutral adjectives could agree or disagree in gender with the preceding noun. At an electrophysiological level, the amplitude of a left anterior negativity (LAN) to gender agreement mismatches decreased in negative words, relative to neutral words. The behavioral data suggested that LAN amplitudes might be indexing the processing costs associated with the detection of gender agreement errors, since the detection of gender mismatches resulted in faster and more accurate responses than did the detection of correct gender agreement relations. According to this view, it seems that negative content facilitated the processes implicated in the early detection of gender agreement mismatches. However, gender agreement violations in negative words triggered processes involved in the reanalysis and repair of the syntactic structure, as reflected in larger P600 amplitudes to incorrect than to correct phrases, irrespective of their emotional valence.     

Differential effects of muscarinic receptor blockade in prelimbic cortex on acquisition and memory formation of an odor-reward task

The present experiments determined the consequences of blocking muscarinic cholinergic receptors of the prelimbic (PL) cortex in the acquisition and retention of an odor-reward associative task. Rats underwent a training test (five trials) and a 24-h retention test (two retention trials and two relearning trials). In the first experiment, rats were bilaterally infused with scopolamine (20 or 5 microg/site) prior to training. Although scopolamine rats showed acquisition equivalent to PBS-injected controls, they exhibited weakened performance in the 24-h retention test measured by number of errors. In the second experiment, rats were injected with scopolamine (20 microg/site) immediately or 1 h after training and tested 24 h later. Scopolamine rats injected immediately showed severe amnesia detected in two performance measures (errors and latencies), demonstrating deficits in retention and relearning, whereas those injected 1 h later showed good 24-h test performance, similar to controls. These results suggest that muscarinic transmission in the PL cortex is essential for early memory formation, but not for acquisition, of a rapidly learned odor discrimination task. Findings corroborate the role of acetylcholine in consolidation processes and the participation of muscarinic receptors in olfactory associative tasks.     

Relationship between burnout, job strain, and sleep characteristics

The purpose of the present study is to analyse the relationship between sleep, burnout, and job strain in a sample of 316 healthy workers from various professional sectors. Multiple significant correlations between the principal sleep parameters, the dimensions of burnout, and job strain were found. The regression analyses show that sleep quality and various dimensions of job strain are significant predictors of several aspects of burnout. Sleep quality explains an even higher percentage of the variance in emotional exhaustion than the variance explained by more well-known variables such as job demands. Moreover, sleep quality interacts with aspects of job strain in its influence on the dimensions of burnout, although the exact relationship between these variables needs to be investigated in future longitudinal studies. Our results suggest that interventions to optimise sleep habits could prevent or alleviate burnout and could be a part of organisational work.     

Seven psychosocial principles to explain terrorism

Research approaches leading to the understanding of the terrorist phenomenon are suggested. Seven principles explaining terrorism are analysed from a psychosocial approach: They could complete the explanations of terrorism focused in socio-structural and psychological variables, the latter being insufficient and often erroneous. Thus, terrorism is presented as a strategy of political influence, and the psychological attributes of terrorists are explained as the result of several influential social processes. We considered that terrorist attacks and campaigns correspond to strategic reasons, but we also assume that the rationality of the terrorists perspective is limited. As far as the organisational parameters are concerned, we propose an analogy with ordinary social movements, especially relating to their ideological frameworks of legitimisation and resource mobilization processes.     

IQ heritability estimation: analyzing genetically-informative data with structural equation models

When analyzing genetic data, Structural Equations Modeling (SEM) provides a straightforward methodology to decompose phenotypic variance using a model-based approach. Furthermore, several models can be easily implemented, tested, and compared using SEM, allowing the researcher to obtain valuable information about the sources of variability. This methodology is briefly described and applied to re-analyze a Spanish set of IQ data using the biometric ACE model. In summary, we report heritability estimates that are consistent with those of previous studies and support substantial genetic contribution to phenotypic IQ; around 40% of the variance can be attributable to it. With regard to the environmental contribution, shared environment accounts for 50% of the variance, and non-shared environment accounts for the remaining 10%. These results are discussed in the text.