Adult age differences in visual word identification: functional neuroanatomy by positron emission tomography

Adult age differences in the neural systems mediating semantic (context-independent) memory were investigated using positron emission tomography (PET). Younger (20-29 years) and older (62-70 years) participants performed lexical decision (word/nonword discrimination) and nonsemantic (simple visual search) baseline tasks during PET scanning. Within the lexical decision task, display duration and presentation rate were varied across scans. The behavioral data suggested that although an age-related slowing was evident in visual feature and response processing, the retrieval of semantic/lexical information was similar for younger and older adults. For both age groups, lexical-related activation occurred in inferior prefrontal and occipitotemporal regions of the left hemisphere. Differential activation, as a function of age group, was observed in the left occipitotemporal pathway as a result of older adults' maintaining higher levels of neural activity in striate cortex (during visual search) and in inferior temporal cortex (during lexical decision). The prefrontal activation was similar for the two age groups. Thus, although this form of semantic memory retrieval does not undergo significant age-related decline, an age-related change in the associated pattern of neural activation is evident. These findings differ from previous neuroimaging studies of episodic (context-dependent) memory retrieval, which have suggested that age-related compensatory mechanisms are expressed primarily by greater activation of prefrontal regions for older adults than for younger adults.     

Iconic Prosody in Story Reading

Recent experiments have shown that people iconically modulate their prosody corresponding with the meaning of their utterance (e.g., Shintel et al., 2006). This article reports findings from a story reading task that expands the investigation of iconic prosody to abstract meanings in addition to concrete ones. Participants read stories that contrasted along concrete and abstract semantic dimensions of speed (e.g., a fast drive, slow career progress) and size (e.g., a small grasshopper, an important contract). Participants read fast stories at a faster rate than slow stories, and big stories with a lower pitch than small stories. The effect of speed was distributed across the stories, including portions that were identical across stories, whereas the size effect was localized to size‐related words. Overall, these findings enrich the documentation of iconicity in spoken language and bear on our understanding of the relationship between gesture and speech.     

Happier,faster: Developmental changes in the effects of mood and novelty on responses

Positive mood ameliorates several cognitive processes: It can enhance cognitive control, increase flexibility, and promote variety seeking in decision making. These effects of positive mood have been suggested to depend on frontostriatal dopamine, which is also associated with the detection of novelty. This suggests that positive mood could also affect novelty detection. In the present study, children and adults saw either a happy or a neutral movie to induce a positive or neutral mood. After that, they were shown novel and familiar images. On some trials a beep was presented over headphones either at the same time as the image or at a 200-ms stimulus onset asynchrony (SOA), and the task of the participant was to detect these auditory targets. Children were slower in responding than adults. Positive mood, however, speeded responses, especially in children, and induced facilitatory effects of novelty. These effects were consistent with increased arousal. Although effects of novelty were more consistent with an attentional response, in children who had watched a happy movie the novel images evoked a more liberal response criterion, suggestive of increased arousal. This suggests that mood and novelty may affect response behaviour stronger in children than in adults.     

Clinical applications of Matte Blanco's thinking

Ignacio Matte Blanco (1908–1995) left very few specific indications about the applications of his theoretical notions to his interpretative style. The author shows how he uses Matte Blanco to formulate some of his own interpretations. The first part of the paper uses clinical vignettes to illustrate some of Matte‐Blanco's concepts. Their theoretical vocabulary is thus made explicit. Then two psychoanalytic sessions are discussed at greater length, together with one from a therapy, so that the use of Matte‐Blanco's notions can be seen clearly, allowing for a fresh perspective on areas of psychoanalytic theory, particularly dreams, psychopathology viewed according to the proportions of asymmetrical and symmetrical functioning in the patient's bi‐logical mental system, the multidimensionality of the unconscious, the structural unconscious, the emotion‐thought relationship, projective identification, resistance, and negative therapeutic reaction. The practical consequences of all this are elaborated, particularly the ensuing possibility of ‘thinking with the patient' in the session. This enables the patient to introject a form of mental functioning in which the asymmetrical mode is not invaded by the symmetric mode (a parallel can be seen here with the Bionian concept of dialogue between the psychotic and non‐psychotic parts of the mind).     

Presentism: Foreigner-Friendly or Xenophobic?

I argue that, for all we know, there are perfectly ordinary actual entities that are temporal in the usual sense and yet never present, past, or future. This epistemic fact requires us to modify the theses of presentism and eternalism. More importantly, it generates three new and quite serious objections to presentism, which I formulate and partially evaluate in this paper.     

Measurement and comparative analysis of driver’s perception–reaction time to green phase at the intersections with and without a countdown timer

This paper proposes a method based on digital image processing for measuring drivers’ perception–reaction time (PRT) to the green phase. The detection of the onset of a green signal was based on the RGB color model. The detection of the start of the vehicle was based on the frame difference. The driver’s perception–reaction time was equal to the difference between the frame of the onset of the green signal and the frame of the start of the vehicle divided by the video frame rate. Drivers’ PRT with and without a countdown timer were comparatively analyzed. First, the means and variances of drivers’ PRT with a timer and without a timer were compared. Second, Normal, Lognormal, Gamma and Weibull distributions were used to fit the PRT data. Third, the fuzzy c-means clustering was utilized for PRT classification and comparison. The results show that the method for measuring drivers’ PRT based on digital image processing was effective. The drivers’ PRT was decreased from 2.12 s to 1.48 s with countdown signals. Weibull distribution appeared to best fit the PRT with No-Timer and Lognormal distribution appeared to best fit the PRT with Timer. The PRT data were classified into three groups: “Fast”, “Moderate” and “Slow”. Clustering centers without Timer were 1.16 s, 2.47 s and 3.98 s respectively. Clustering centers with Timer were 0.95 s, 1.64 s and 2.70 s respectively. The clustering centers can be regarded as reference values of drivers’ starting response for microscopic traffic simulation software.     

Evaluation of motorized two-wheeler rider responses towards jaywalking pedestrians through mockup control studies for urban streets

This study aims to model the motorized two-wheeler (MTW) riders’ evasive-action behavior towards jaywalking pedestrians using a mockup study. The brake reaction times (BRTs), approach speeds, decelerations, headings, and yaw rates were analyzed for two surprise scenarios (scenarios 1 and 3), one stationary scenario (scenario-2), and one expected scenario (scenario-4). In total, 50 riders participated in the mockup study. The results revealed that the 90th percentile BRT for the expected and surprise scenarios were 3.6 and 1.6 s, respectively. Further, repeated-measures ANOVA was performed followed by mixed effect modeling to ascertain the effect of conflict severity (two groups: group-1 with Time to Collision (TTC) < 1.5 s and group-2 with TTC > 1.5 s) and scenario type (three groups: scenarios 1, 3 and 4) on BRT. The results indicated that the main effects were significant while the interaction effect was not significant. The positive and significant coefficient (0.32) of TTC group-2 indicated higher BRTs than TTC group-1. Considering scenario-1 as the base scenario, the coefficient of scenario 3 (-0.02) indicated that scenario-1 and scenario-3 had a similar effect on BRT, while the coefficient of scenario-4 (1.47) indicated higher BRTs compared to scenario-1. The analysis of evasive action behavior revealed that 32% of riders performed hard braking in surprise scenarios. Further, yaw rate values at the crossing point indicated a loss of control of MTW in 90% of surprise events. The observations from this study provide a basis for developing countermeasures to improve pedestrian and MTW rider safety.     

糖皮质激素在SARS治疗中利与弊的分析

糖皮质激素在重症SARS治疗过程中发挥了非常重要的作用,绝大部分SARS患者都不同程度地使用了糖皮质激素制剂.但也带来了许多不良后果,尤其是不合理应用更易产生,使病情加重,甚至导致治疗失败.因此,对该类药物的使用应权衡利弊,合理地使用.     

Finishing on time: When do predictions influence completion times?

People typically predict they will finish projects earlier than they do. Whereas previous research has examined the determinants of this prediction bias, the present research explored potential consequences for behavior. In particular, we examined whether and when task completion predictions influence actual completion times. In four experiments we used anchoring manipulations to induce participants to make relatively early or late task completion predictions, and then examined when they started and/or finished the target tasks. As hypothesized, the prediction manipulation influenced completion times under certain conditions defined by the nature of the target task. Manipulated predictions affected completion times of closed tasks, defined as tasks carried out within a single, continuous session but not of open tasks, defined as tasks requiring multiple work sessions. This implies that task completion predictions help to initiate action, but their impact diminishes over the course of extensive, multi-stage projects.     

庄子安顿生命的策略

为了在无道乱世中增加生存机会,庄子提出了"无用之用"与"与物委蛇"这两种生存策略。前者主张世人将自身的世俗之用掩盖起来,以免于祸害,最终实现自身的根本大用;后者主张世人尽量避免与他者发生正面冲突,在矛盾的空隙中求得最大的生存空间。庄子吁请世人尽其所能保全生命,是为实现生命意义做必要准备。庄子对生命的态度可概括为:不伤生,乐然生,不贪生,安然死。