Consciousness and emotion: ERP modulation and attentive vs. pre-attentive elaboration of emotional facial expressions by backward masking

Facial stimulus processing is an important topic to explain how people comprehend affective disposition in others. The effect of attentive and pre-attentive elaboration of emotional facial expression was explored in the present research by using backward masking procedure. Specifically, unconscious mental process of emotion comprehension was analyzed: pictures presenting a happy, sad, angry, fearful, disgusted, surprised expressions were submitted to 21 subjects in both attentive and pre-attentive conditions and event-related potentials (ERPs) were registered in the two conditions. The two processes, attentive and pre-attentive, seem to be similar in their nature, since they are marked by analogous ERP deflections. In fact, two ERP effects were found, a positive (P300) deflection, maximally distributed on the parietal regions, and a negative (N200) deflection, more localized on the frontal sites. Nevertheless, some differences between the two conditions were found in terms of quantitative modulations of the two peaks. The N200 effect, ampler in attentive condition, may be considered such as an index of conscious processing of emotional faces, whereas the P3 (P3a) effect, higher in pre-attentive condition, was considered a specific marker of the automatic, unconscious process during the emotional face comprehension.     

An ERP study on facial expression of emotion: comparison of linguistic and visual semantic decoding

The present research compared the semantic information processing of linguistic stimuli with semantic elaboration of nonlinguistic facial stimuli. To explore brain potentials (ERPs, event-related potentials) related to decoding facial expressions and the effect of semantic valence of the stimulus, we analyzed data for 20 normal subjects (M age = 23.6 yr., SD = 0.2). Faces with three basic emotional expressions (fear, happiness, and sadness from the 1976 Ekman and Friesen database), with three semantically anomalous expressions (with respect to their emotional content), and the neutral stimuli (face without an emotional content) were presented in a random order. Differences in peak amplitude of ERP were observed later for anomalous expressions compared with congruous expressions. In fact, the results demonstrated that the emotional anomalous faces elicited a higher negative peak at about 360 msec., distributed mainly over the posterior sites. The observed electrophysiological activity may represent specific cognitive processing underlying the comprehension of facial expressions in detection of semantic anomaly. The evidence is in favour of comparability of this negative deflection with the N400 ERP effect elicited by linguistic anomalies.     

Topological Aspects of Branching-Time Semantics

The aim of this paper is to present a new perspective under which branching-time semantics can be viewed. The set of histories (maximal linearly ordered sets) in a tree structure can be endowed in a natural way with a topological structure. Properties of trees and of bundled trees can be expressed in topological terms. In particular, we can consider the new notion of topological validity for Ockhamist temporal formulae. It will be proved that this notion of validity is equivalent to validity with respect to bundled trees.     

Exploring consciousness in emotional face decoding: an event-related potential analysis

The author analyzed the role of consciousness in emotional face comprehension. The author recorded psychophysiological measures of event-related potentials (ERPs), elicited by supraliminal and subliminal stimuli when participants viewed emotional facial expressions of 4 emotions or neutral stimuli. The author analyzed an ERP emotion-specific effect (N200 peak variation; temporal interval was 180-300 ms poststimulus) in terms of peak amplitude and latency variables. The results indicated 4 important findings. First, there was an emotional-specific ERP deflection only for emotional stimuli, not for neutral stimuli. Second, the unaware information processing was quite similar to that of aware in terms of peak morphology, but not in terms of latency. In fact, unconscious stimulation produced a more delayed peak variation than did conscious stimulation. Third, valence of facial stimulus (positive or negative) was supraliminally and subliminally decoded because it was showed by differences of peak deflection between negative high arousing (fear and anger) and low arousing (happiness, sadness, and neutral) stimuli. Finally, the author found a more posterior distribution of ERP as a function of emotional content of the stimulus. Cortical lateralization (right or left) was not correlated to conscious or unconscious stimulation. The author discussed the functional significance of her results in terms of supraliminal and subliminal conditions.     

Savoring versus dampening: self-esteem differences in regulating positive affect

Five studies examined the hypotheses that when people experience positive affect, those low in self-esteem are especially likely to dampen that affect, whereas those high in self-esteem are especially likely to savor it. Undergraduate participants' memories for a positive event (Study 1) and their reported reactions to a success (Study 2) supported the dampening prediction. Results also suggest that dampening was associated with worse mood the day after a success (Study 2), that positive and negative affect regulation are distinct, that self-esteem is associated with affect regulation even when Neuroticism and Extraversion are controlled (Studies 3 and 4), and that self-esteem may be especially important for certain types of positive events and positive affect regulation (Study 5).     

Differences in cortical activity related to motor planning between experienced guitarists and non-musicians during guitar playing

The influence of motor skill learning on movement-related brain activity was investigated using electroencephalography. Previous research has indicated that experienced performers display movement-related cortical potentials (MRCPs) of smaller amplitude and later onset compared to novices. Unfortunately, previous studies have lacked ecological validity with experimenters recording the MRCP prior to simple motor tasks and applying the results to more complex motor skills. This study replicated previous research using an ecologically valid motor skill; recording the MRCP from a group of experienced guitarists and a control group of non-musicians while they played a simple scale on the guitar. Results indicated no difference between groups in early motor planning. In contrast, the later, negative slope and motor potential components were of smaller amplitude and the negative slope began later in the experienced guitarists. The data may indicate that, for experienced guitarists, a reduced level of effort is required during the motor preparation phase of the task. These findings have implications for musical instrument learning as well as motor skill acquisition in general.     

Eye movements and bisection behavior in spatial neglect syndrome: representational biases induced by the segment length and spatial dislocation of the stimulus

The present study explored behavioral and eye-movement measures in unilateral neglect patients in response to online bisection task (unfilled gap line). Two different tasks supported the bisection performance, a pointing and a grasping strategy. It was explored whether these different strategies may influence subjects’ behavioral and eye-movement measures in response to different segment features: segment length (from shorter to longer) and segment spatial dislocation (from right to left spatial location). Consistent spatial biases were found for both bisection responses, fixation count, and duration, as well as for the first fixation count in case of pointing task. An “extreme-left” gradient effect was suggested and discussed, with patients’ behavioral and eye measures more impaired. On the contrary, the patients’ performance overlaps with the controls’ one in case a grasping task. The direct link of visual pointing and grasping strategy, respectively, with the two cortical ventral and dorsal pathways was adduced to explain our results.     

IRT Test Equating in Complex Linkage Plans

Linkage plans can be rather complex, including many forms, several links, and the connection of forms through different paths. This article studies item response theory equating methods for complex linkage plans when the common-item nonequivalent group design is used. An efficient way to average equating coefficients that link the same two forms through different paths will be presented and the asymptotic standard errors of indirect and average equating coefficients are derived. The methodology is illustrated using simulations studies and a real data example.