Olfactory fear conditioning induces field potential potentiation in rat olfactory cortex and amygdala

The widely used Pavlovian fear-conditioning paradigms used for studying the neurobiology of learning and memory have mainly used auditory cues as conditioned stimuli (CS). The present work assessed the neural network involved in olfactory fear conditioning, using olfactory bulb stimulation-induced field potential signal (EFP) as a marker of plasticity in the olfactory pathway. Training consisted of a single training session including six pairings of an odor CS with a mild foot-shock unconditioned stimulus (US). Twenty-four hours later, the animals were tested for retention of the CS as assessed by the amount of freezing exhibited in the presence of the learned odor. Behavioral data showed that trained animals exhibited a significantly higher level of freezing in response to the CS than control animals. In the same animals, EFPs were recorded in parallel in the anterior piriform cortex (aPC), posterior piriform cortex (pPC), cortical nucleus of the amygdala (CoA), and basolateral nucleus of the amygdala (BLA) following electrical stimulation of the olfactory bulb. Specifically, EFPs recorded before (baseline) and after (during the retention test) training revealed that trained animals exhibited a lasting increase (present before and during presentation of the CS) in EFP amplitude in CoA, which is the first amygdaloid target of olfactory information. In addition, a transient increase was observed in pPC and BLA during presentation of the CS. These data indicate that the olfactory and auditory fear-conditioning neural networks have both similarities and differences, and suggest that the fear-related behaviors in each sensory system may have at least some distinct characteristics.     

Evidence for two pitch encoding mechanisms using a selective auditory training paradigm

The neural mechanisms underlying the perception of pitch, a sensory attribute of paramount importance in hearing, have been a matter of debate for over a century. A question currently at the heart of the debate is whether the pitch of all harmonic complex tones can be determined by the auditory system's using a single mechanism, or whether two different neural mechanisms are involved, depending on the stimulus conditions. When the harmonics are widely spaced, as is the case at high fundamental frequencies (FOs), and/or when the frequencies of the harmonics are low, the frequency components of the sound fall in different peripheral auditory channels and are then "resolved" by the peripheral auditory system. In contrast, at low F0s, or when the harmonics are high in frequency, several harmonics interact within the passbands of the same auditory filters, being thus "unresolved" by the peripheral auditory system. The idea that more than one mechanism mediates the encoding of pitch depending on the resolvability status of the harmonics was investigated here by testing for transfer of learning in F0 discrimination between different stimulus conditions involving either resolved or unresolved harmonics after specific training in one of these conditions. The results, which show some resolvability-specificity of F0-discrimination learning, support the hypothesis that two different underlying mechanisms mediate the encoding of the F0 of resolved and unresolved harmonics.     

Time perspective,socioeconomic status,and psychological distress in chronic pain patients

Time perspective (TP) is a fundamental dimension of the psychological construction of time. It refers to a subjective experience and can be defined as the relationship that individuals and groups have with the present, past, and future. Studies have shown that it is interesting to take into account TP in the field of health, especially for the study of the psychological distress (PD) of individuals faced with aversive situations. We conducted a research, which aimed to explore the relationship between TP and PD in patients with chronic pain. A total of 264 first-time patients (72.3% women; mean age = 49 years) at CHU Timone (Marseille) pain center answered a questionnaire included TP, socioeconomic status, pain beliefs (PB), pain characteristics, and sociodemographic characteristics. Using hierarchical regression analyses adjusted to the characteristics of pain, sociodemographic characteristics, and PB, we can observe significant relationships between different components of TP, socioeconomic status, and PD. These results emphasize the importance of TP as psychosocial variable in the analysis of PD in patients with chronic pain. These results also lead us to point out the role of the socioeconomic status that predicts levels of PD.     

Analyzing head roll and eye torsion by means of offline image processing

Ocular torsion is a key problem in the understanding of many visual perceptual effects. However, since it is difficult to record, its integration with other sensorimotor signals is still poorly understood. Unfortunately, eyetracker systems are generally not dedicated to the monitoring of eye torsion. In addition, the classical methods used with video-based systems present some limits in the accuracy of torsion calculation. These limits are especially related to the detection of pupil center and the effects of pupil size changes. This article aims at (1) proposing a solution to analyze ocular torsion together with head roll using EyeLink II or similar equipment, (2) reviewing and adapting classical polar cross-correlation methods in order to improve the accuracy of torsion measurement, (3) providing a lower-cost method compared with the existing ones. Video sequences issued from the EyeLink II host computer monitor were recorded by means of a second computer equipped with a video acquisition card and converted into image sequences. Images were analyzed with algorithms of pupil center detection (median-based algorithm), torsion analysis (adapted polar cross-correlation method which takes into account pupil size variations) and marker tracking (head roll analysis). This method was tested on virtual eye images. Results are discussed with respect to other algorithms found in the literature.     

A reproductive threat-based model of evolved sex differences in jealousy

Although heterosexual women and men consistently demonstrate sex differences in jealousy, these differences disappear among lesbians and gay men as well as among heterosexual women and men contemplating same-sex infidelities (infidelities in which the partner and rival are the same sex). Synthesizing these past findings, the present paper offers a reproductive threat-based model of evolved sex differences in jealousy that predicts that the sexes will differ only when the jealous perceivers' reproductive outcomes are differentially at risk. This model is supported by data from a web-based study in which lesbians, gay men, bisexual women and men, and heterosexual women and men responded to a hypothetical infidelity scenario with the sex of the rival randomly determined. After reading the scenario, participants indicated which type of infidelity (sexual versus emotional) would cause greater distress. Consistent with predictions, heterosexual women and men showed a sex difference when contemplating opposite-sex infidelities but not when contemplating same-sex infidelities, whereas lesbians and gay men showed no sex difference regardless of whether the infidelity was opposite-sex or same-sex.     

Factors Affecting Censorship by Canadian Librarians

This study investigated the risk propensity and self-actualization of public librarians with regard to censorship behavior. A sample of 169 librarians from the province of Ontario responded to a 124-item mail questionnaire that incorporated a number of previously validated instruments, including the Adorno F Scale (Adorno, Frenkel-Brunswick, Levinson, & Sanford, 1950), the Short Index of Self-Actualization (Jones & Crandall, 1986), and the Choice Dilemmas Questionnaire (Kogan & Wallach, 1964). Analyses indicated that the librarians were generally liberal in attitude but conservative in behavior with respect to censorship and book selection. Moreover, they appear to have been averse to taking risks and not selfactualized. These results are discussed in terms of cognitive dissonance theory and risk propensity theory.     

Newborns modulate their crawling in response to their native language but not another language

Human newborns can propel themselves to their mother's breast when positioned skin to skin on her abdomen just after birth. For decades, researchers have considered this primitive crawling behavior a spinal reflex, immune to supra spinal control. However, recent research suggests that neonatal crawling is already responsive to visual and olfactory stimuli processed at a supra spinal level. Here we report that a few hours post birth, French newborns can also modulate their crawling in response to their native language – a source of information that is processed supra-spinally. The crawling patterns of 23 French-born newborns were recorded on video and via an infrared motion capture system during two randomly ordered 2-min trials. The newborns were secured on a mini skateboard to facilitate arm and leg movements during their crawling propulsion. They heard a repetitive sequence of the same sentences either in French, their native language, or in English, a rhythmically different and hence discriminable unfamiliar language, on each trial. In French, compared to English, crawling was enhanced, with significantly more arm and leg steps and significantly more and larger trunk rotations in the cephalo-caudal axis. Moreover, newborns rotated their heads and trunk toward the appropriate loud speaker when hearing French but not English. These preliminary findings suggest that newborn crawling is not a simple stereotyped reflex under spinal control, but a complex pattern that can be modulated in response to higher-order, supra-spinally processed stimuli. The findings open fascinating questions about the range of stimuli to which newborn crawling is responsive.     

The global workspace (GW) theory of consciousness and epilepsy

The global workspace (GW) theory proposes that conscious processing results from coherent neuronal activity between widely distributed brain regions, with fronto-parietal associative cortices as key elements. In this model, transition between conscious and non conscious states are predicted to be caused by abrupt non-linear massive changes of the level of coherence within this distributed neural space. Epileptic seizures offer a unique model to explore the validity of this central hypothesis. Seizures are often characterized by the occurrence of brutal alterations of consciousness (AOC) which are largely negatively impacting patients' lives. Recently, we have shown that these sudden AOC are contemporary to non-linear increases of neural synchrony within distant cortico-cortical and cortico-thalamic networks. We interpreted these results in the light of GW theory, and suggested that excessive synchrony could prevent this distributed network to reach the minimal level of differentiation and complexity necessary to the coding of conscious representations. These observations both confirm some predictions of the GW model, and further specify the physiological window of neural coherence (minimum and maximum) associated with conscious processing.