Visual-auditory interactions on explicit and implicit information processing.

Interactions among sensory information are important for generating a coherent percept of the external world. Facilitation and inhibition effects in cross-modal perception have been widely studied for decades. The present study tried to confirm the interaction effects between sensory information in a bimodal context and explore these influences when part of the sensory information was presented without participants' subjective awareness. A total of 40 undergraduate participants were recruited in this mixed design study. Participants were required to count the flashing of the black circle (visual task) or the presentation frequency of the beep sound (auditory task) with the presence of either congruent or incongruent sensory signals in the background. Participants in the explicit group generally performed more accurately and also faster with the congruent stimuli than with the incongruent stimuli. Performance accuracy in the visual task in the implicit group was affected by the non-target sound signals which were presented beneath participants' subjective awareness. The better performance yielded in the auditory task than in the visual task was explained by the appropriateness of the auditory stimulation to the task nature. In addition, the supportive findings regarding processing without awareness should be interpreted with caution.

Running in fear: an investigation into the dimensional account of emotion in discriminating emotional expressions.

Emotion can be conceptualized by the dimensional account of emotion with the dimensions of valence and arousal. There is little discussion of the difference in discriminability across the dimensions. The present study hypothesized that any pair of emotional expressions differing in the polarity of both valence and arousal dimensions would be easier to distinguish than a pair differing in only one dimension. The results indicate that the difference in the dimensions did not affect participants' reaction time. Most pairs of emotional expressions, except those involving fear, were similarly discriminative. Reaction times to pairs with a fearful expression were faster than to those without. The fast reaction time to fearful facial expressions underscores the survival value of emotions.

A quick eye to anger: An investigation of a differential effect of facial features in detecting angry and happy expressions.

Detection of angry and happy faces is generally found to be easier and faster than that of faces expressing emotions other than anger or happiness. This can be explained by the threatening account and the feature account. Few empirical studies have explored the interaction between these two accounts which are seemingly, but not necessarily, mutually exclusive. The present studies hypothesised that prominent facial features are important in facilitating the detection process of both angry and happy expressions; yet the detection of happy faces was more facilitated by the prominent features than angry faces. Results confirmed the hypotheses and indicated that participants reacted faster to the emotional expressions with prominent features (in Study 1) and the detection of happy faces was more facilitated by the prominent feature than angry faces (in Study 2). The findings are compatible with evolutionary speculation which suggests that the angry expression is an alarming signal of potential threats to survival. Compared to the angry faces, the happy faces need more salient physical features to obtain a similar level of processing efficiency.

Angry Versus Furious: A Comparison Between Valence and Arousal in Dimensional Models of Emotions.

The present study compared the roles of valence and arousal, proposed by the dimensional models of emotions, in recognizing emotional expressions. It was hypothesized that the dimension of valence, due to its functional significance, would be more salient in the recognition of emotional expressions than the dimension of arousal would be. The results of the current study supported this hypothesis. The participants in all age groups were more accurate and quicker in recognizing an emotion when the expression was paired up with another emotional expression that was different in the polarity of the valence dimension than with this similar polarity difference in the arousal dimension. The insignificant difference in recognizing the positive and negative emotional expressions in the group of elders also rejected the Socio-Emotional Selectivity Theory.

Changes of surface texture of enamel in vivo.

There are various methods of measuring tooth wear, including that which could be considered to be associated with acid erosion. However, the present systems are limited in that they require an extended period of study to detect wear and also they do not give any insight as to the underlying mechanism of the tooth tissue loss. The aim of this study was to use a profilometric measuring system analysing novel surface texture parameters normally associated with the automobile industry to describe the wear and run-in behaviour of machined sliding engine parts. The texture parameters selected were the traditional Ra parameter and also parameters derived from the bearing ratio. Analyses of the surface texture of the labial surface of upper central incisors at an interval of three months indicated that the enamel surface was smoother but there were subtle changes occurring to the enamel. There was a statistically significant increase in the depth of pits/pores of the enamel surface, which could be identified as sites of retention of exogenous acid or chelating agent. The effects of acid erosion are not uniform but are dependent upon several factors; the configuration of the enamel surface may play an important part in the mediation of acid erosion type lesions.

Asymptomatic bruit, carotid and vertebrobasilar transient ischemic attacks--a clinical and ultrasonic correlation.

One hundred patients with asymptomatic carotid bruit or transient ischemic attack (TIA) underwent continuous-wave Doppler (CWD) and real time ultrasound (RTU) testing of their cervical carotid arteries. After ultrasonic studies, 51 patients also underwent bilateral carotid angiography. There was 95% agreement between CWD and angiography for the diagnosis of a significant (greater than 50%) stenosis. The RTU diagnosis of a normal or occluded vessel was correct in 100% of cases. Seven plaques appreciated on RTU may not have been large enough for detection by angiography. In this small series, ulceration confirmed pathologically was more reliably predicted by RTU than by cerebral angiography. Significant ipsilateral carotid plaques occurred more often in patients with amaurosis fugax than in patients with hemispheric TIAs. Ipsilateral plaque ulceration occurred in 50% of symptomatic carotid bruits, but in only 10% of asymptomatic carotid bruits. Plasma concentrations of total cholesterol were significantly higher in TIA patients with carotid stenosis than in controls.