Intact recognition of facial emotion in Parkinson's disease.

Although the basal ganglia have been shown to be critical for the expression of emotion in prosody and facial expressions, it is unclear whether they are also critical for recognition of emotions. Selective pathology of parts of the basal ganglia is a hallmark of individuals with Parkinson's disease, and such patients have been examined in several studies of emotion. We examined 18 patients with Parkinson's disease (11 men, 7 women) and 13 age-, education-, gender ratio-, and IQ-matched normal controls on their ability to recognize emotions signaled by facial expressions. Parkinson's patients performed entirely normally on a quantitative task of recognizing emotional facial expressions. The findings do not support the notion that the sectors of basal ganglia that are dysfunctional in Parkinson's disease are essential for recognizing emotion in facial expressions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion recognition from faces and prosody following temporal lobectomy.

The anteromedial temporal lobe has been found to participate in processing emotion, but there are unresolved discrepancies in the literature. To address this issue, the authors investigated recognition of emotion from faces and from prosody in 26 participants with unilateral temporal lobectomy (15 left, 11 right) and in 50 brain-damaged controls. Participants with right, but not left, temporal lobectomy did significantly worse in recognizing fear from facial expressions. There were no group differences in recognizing emotional prosody. Neither IQ nor basic perceptual function accounted for task performance; however, there was a moderate negative correlation between extent of amygdala damage and overall performance. Consistent with some prior studies, these findings support a role for the right anteromedial temporal lobe (including amygdala) in recognizing emotion from faces but caution in drawing conclusions from small group samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective effects of triazolam on memory for emotional, relative to neutral, stimuli: Differential effects on gist versus detail.

Benzodiazepines are known to reduce learning and memory performance, presumably through their facilitation of GABAergic neurotransmission, but the effects of these drugs specifically on memory for emotional material has not been addressed in humans. The effects of a benzodiazepine (triazolam, 0.25 mg) on nonincidental memory for emotional stimuli were assessed in 20 healthy volunteers (10 female). Triazolam reduced the normally facilitative effect of emotion on memory. The drug specifically affected memory for the gist of stimuli while leaving detail memory relatively unaffected. This pattern of performance is similar to that seen in patients with amygdala damage. Results suggest an effect of GABAergic neurotransmission at the level of the amygdala on memory modulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The amygdala's role in long-term declarative memory for gist and detail.

In humans, the emotional nature of stimuli appears to have a complex influence on long-term declarative memory for those stimuli: Whereas emotion enhances memory for gist, it may suppress memory for detail. On the basis of prior studies, the authors hypothesized that the amygdala helps mediate the above 2 effects. Long-term memory for gist and for visual detail of aversive and neutral scenes was assessed in 20 subjects with unilateral amygdala damage and 1 rare subject with bilateral amygdala damage. Comparisons with 2 control groups (15 brain-damaged and 47 healthy) provided evidence that bilateral, but not unilateral, damage to the amygdala results in poorer memory for gist but superior memory for visual details. The pattern of findings provides preliminary support for the idea that the amygdala may help filter the encoding of relevant information from stimuli that signal threat or danger. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Surface energies of hardenned cement paste depending on relative humidity

In the lower region of relative humidity, one assumption of the Munich Model regarding the volumetric changes in hardened cement paste (hep) is that adsorbed water molecules decrease surface energy. Recent work with inverse gas chromatography (IGC) on hep provides the first experimental evidence to support this assumption. Under conditions of varying relative humidity, the equipment used (iGC SMS— POROTEC) allowed a series of pulse experiments with non-polar (alkenes) and polar probe molecules at temperatures in the region of 30°C. From the retention times, specific interaction energies and a dispersive surface energy of the solid can be derived. The results are in agreement with the findings of many other experiments conducted under different relative humidities. Furthermore they may help to understand strongly nonliner moisture related phenomena like shrinkage, swelling, change in the pore size, strength, and diffusion in hardened cement paste.

---

Résumé à faible humidité relative, l'une des hypothèses du modèle de Munich concernant les changements volumétriques des pates de ciment durcies (hcp), est que les molécules d'eau adsorbées diminuent les énergies de surface. De récents travaux de Chromatographie en Phase Gazeuse Inverse (CIG) sur les hcp ont fourni les premières preuves de vérification de cette hypothèse. L'appareil utilisé (CIG SMS— POROTEC) a permis, à différentes humidités relatives, des séries de mesures avec des sondes moléculaires non polaires (alcènes) et polaires, à des températures voisines de 30°C. à partir des temps de rétention, les énergies d'interaction spécifiques et l'énergie de surface dispersive du solide ont pu être dérivées. Les résultats sont en accord avec ceux obtenus par d'autres expériences réalisées dans des conditions d'humidité relative variables. Ils permettent en outre d'aider à comprendre les phénomènes fortement non-linéaires induits par l'humidité tels que le retrait, le gonflement, le changement de taille des pores, la résistance et la diffusion dans les pates durcies.

     

Hemispheric perception of emotional valence from facial expressions.

The authors previously reported that normal subjects are better at discriminating happy from neutral faces when the happy face is located to the viewer's right of the neutral face; conversely, discrimination of sad from neutral faces is better when the sad face is shown to the left, supporting a role for the left hemisphere in processing positive valence and for the right hemisphere in processing negative valence. Here, the authors extend this same task to subjects with unilateral cerebral damage (31 right, 28 left). Subjects with right damage performed worse when discriminating sad faces shown on the left, consistent with the prior findings. However, subjects with either left or right damage actually performed superior to normal controls when discriminating happy faces shown on the left. The authors suggest that perception of negative valence relies preferentially on the right hemisphere, whereas perception of positive valence relies on both left and right hemispheres. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired recognition of emotion in facial expressions following bilateral damage to the human amygdala

Studies in animals have shown that the amygdala receives highly processed visual input, contains neurons that respond selectively to faces, and that it participates in emotion and social behaviour. Although studies in epileptic patients support its role in emotion, determination of the amygdala's function in humans has been hampered by the rarity of patients with selective amygdala lesions. Here, with the help of one such rare patient, we report findings that suggest the human amygdala may be indispensable to: (1) recognize fear in facial expressions; (2) recognize multiple emotions in a single facial expression; but (3) is not required to recognize personal identity from faces. These results suggest that damage restricted to the amygdala causes very specific recognition impairments, and thus constrains the broad notion that the amygdala is involved in emotion.     

Changes in pore structure and mercury contact angle of hardened cement paste depending on relative humidity

Hardened cement paste (hcp) is a porous heterogeneous material consisting of dispersed particles like Calcium Silicate Hydrates (C-S-H). These are of micron to nanometer size forming pores on a nanometer scale. Thus, hcp can be regarded as a colloidal system. Surface forces play a dominant role. Adsorbed water molecules interact with the surface. Capillary condensation occurs in the pores below bulk conditions acting in form of capillary and disjoning forces. All these forces are able to alter the structure and properties of the hardened cement paste depending on the moisture content. Pore size distributions were measured with mercury intrusion porosimetry on hcp specimens, which had been prestored over the entire range of relative humidity. Swelling and shrinkage of hcp tubes were also determined. The pore size distribution is corrected for each humidity step regarding the particular porosity, contact angle and volume change. The pore size distribution as a function of relative humidity is nonlinear and characterized by an extreme value in the medium range of humidity.