The modulation of stimulus structure on visual field asymmetry effects: The case of Chinese character recognition

Recent research suggests that visual field (VF) asymmetry effects in visual recognition may be influenced by information distribution within the stimuli for the recognition task in addition to hemispheric processing differences: Stimuli with more information on the left have a right VF (RVF) advantage because the left part is closer to the centre, where the highest visual acuity is obtained. It remains unclear whether visual complexity distribution of the stimuli also has similar modulation effects. Here we used Chinese characters with contrasting structures—left-heavy, symmetric, and right-heavy, in terms of either visual complexity of components or information distribution defined by location of the phonetic component—and examined participants' naming performance. We found that left-heavy characters had the largest RVF advantage, followed by symmetric and right-heavy characters; this effect was only observed in characters that contrasted in information distribution, in which information for pronunciation was skewed to the phonetic component, but not in those that contrasted only in visual complexity distribution and had no phonetic component. This result provides strong evidence for the influence of information distribution within the stimuli on VF asymmetry effects; in contrast, visual complexity distribution within the stimuli does not have similar modulation effects.     

Automatic semantic encoding in verbal short-term memory: Evidence from the concreteness effect

The concreteness effect in verbal short-term memory (STM) tasks is assumed to be a consequence of semantic encoding in STM, with immediate recall of concrete words benefiting from richer semantic representations. We used the concreteness effect to test the hypothesis that semantic encoding in standard verbal STM tasks is a consequence of controlled, attention-demanding mechanisms of strategic semantic retrieval and encoding. Experiment 1 analysed the effect of presentation rate, with slow presentations being assumed to benefit strategic, time-dependent semantic encoding. Experiments 2 and 3 provided a more direct test of the strategic hypothesis by introducing three different concurrent attention-demanding tasks. Although Experiment 1 showed a larger concreteness effect with slow presentations, the following two experiments yielded strong evidence against the strategic hypothesis. Limiting available attention resources by concurrent tasks reduced global memory performance, but the concreteness effect was equivalent to that found in control conditions. We conclude that semantic effects in STM result from automatic semantic encoding and provide tentative explanations for the interaction between the concreteness effect and the presentation rate.     

Deterioration of the phonological processing skills in adults with an acquired severe hearing loss

Phonological processing was examined in a group of individuals with an acquired severe hearing loss and compared to a group of matched normal hearing individuals. The hearing-impaired group was significantly slower and less accurate when performing a visual rhyme-judgement task, and produced fewer rhyming word pairs on a rhyme-generation task than the normal hearing group. In contrast, the hearing-impaired group performed on a par with the normal hearing group on verbal working memory tasks. It is concluded that specific aspects of the phonological system deteriorate in this population as a function of auditory deprivation. In particular, the phonological representations are impaired and this impairment also affects the ability to rapidly perform phonological operations (i.e., analyse and compare). In contrast, phonological processing involved in verbal working memory is preserved in this population.     

Executive control is shared between sentence processing and digit maintenance: Evidence from a strictly timed dual-task paradigm

We investigated whether the comprehension of syntactically difficult sentences taxes the executive control component of working memory more than the comprehension of their easier counterparts. To that end, we tested the effect of sharing executive control between sentence comprehension and the maintenance of a digit load in two dual-task experiments with strictly controlled timing (Barrouillet, Bernardin, & Camos, 2004). Recall was worse after participants had processed one (Experiment 2) or two (Experiment 1) difficult sentences than after they had processed one or two easy sentences, respectively. This finding suggests that sentence processing and the maintenance of a digit load share executive control. Processing syntactically difficult sentences seems to occupy executive control for a longer time than processing their easy counterparts, thereby blocking refreshments of the memory traces of the digits so that these traces decay more and recall is worse. There was no effect of the size of the digit load on sentence-processing performance (Experiment 2), suggesting that sentence processing completely occupied executive control until processing was complete.     

False memories in patients suffering from obstructive sleep apnoea syndrome (OSAS)

We assessed the propensity for false memories among patients with obstructive sleep apnoea syndrome (OSAS). Twenty-one patients with OSAS and 21 controls matched for sex, age and education were recruited. At encoding, an adaptation of the Deese-Roediger-McDermott paradigm was used to induce false memories. At retrieval, participants completed a forced-choice recognition task to distinguish memories based on verbatim traces from those based on gist traces. When the task encouraged retrieval based on either gist or verbatim traces, the groups performed similarly. However, when the task required retrieval based solely on verbatim traces, OSAS patients exhibited poor discrimination and produced more false memories. Our finding that OSAS leads to an increased propensity to produce false memories is discussed within the framework of both fuzzy-trace theory and activation-monitoring theory.     

Foreign accents reduce false recognition rates in the DRM paradigm

ABSTRACT

More cognitive resources are required to comprehend foreign-accented than native speech. Focusing these cognitive resources on resolving the acoustic mismatch between the foreign-accented input and listeners’ stored representations of spoken words can affect other cognitive processes. Across two studies, we explored whether processing foreign-accented speech reduces the activation of semantic information. This was achieved using the DRM paradigm, in which participants study word lists and typically falsely remember non-studied words (i.e. critical lures) semantically associated with the studied words. In two experiments, participants were presented with word lists spoken both by a native and a foreign-accented speaker. In both experiments we observed lower false recognition rates for the critical lures associated with word lists presented in a foreign accent, compared to native speech. In addition, participants freely recalled more studied words when they had been presented in a native, compared to a foreign, accent, although this difference only emerged in Experiment 2, where the foreign speaker had a very strong accent. These observations suggest that processing foreign-accented speech modulates the activation of semantic information.

Highlights

• The DRM paradigm was used to explore whether semantic activation is reduced when processing foreign-accented speech.

• Across two experiments, false recognition of non-studied semantic associates was lower when word lists were presented in a foreign accent, compared to native speech.

• The above results suggest semantic activation may be reduced when processing foreign-accented speech.

• Additionally, it was found that when the foreign speaker had a mild accent, correct recall of studied words was uninfluenced. If the foreign speaker had a strong accent, however, correct recall of studied words was reduced.

     

Susceptibility of spatial and verbal working memory to demands of the central executive

We used a dual-task paradigm to examine the degree to which domain-specific spatial and verbal subsystems depend on the domain-general central executive. Forty participants were asked to retain spatial or verbal information while performing a concurrent secondary task related to simple arithmetic. The secondary tasks consisted of three cognitive processes: single-digit addition, a digit-carrying operation, and digit reading. The single-digit addition and carry operation include central executive functioning, while digit reading relies solely on the phonological loop. The single-digit addition caused a performance decrement on the spatial working memory task, while the digit reading impaired performance on the verbal working memory task. The carry operation interfered with recall accuracy on both working memory tasks. The spatial working memory task was significantly correlated with the verbal working memory task only when the secondary task was more demanding on the central executive. Our results suggest that spatial working memory rather than verbal working memory is susceptible to failure of central executive functioning and that the central executive plays an important role in regulating the cognitive demands of different domains.     

移植免疫学的新突破与器官移植

现代器官移植是建立在移植免疫学基础上,移植免疫学基础研究的每一个进展都推动了器官移植的发展。９０年代以来,Ｓｔａｒｚｌ提出了移植排斥的“双向移植排斥理论”,反映了在临床应用免疫抑制药物的情况下,移植排斥的特点,是移植免疫学发展史上的一个重要理论地临床器官移植耐受的诱导具有重要的指导作用。     

合体汉字字形识别过程探索

该研究用微观发生范式探索了合体汉字和假字的字形识别过程 ,结果发现 :(1 )部件字、真字和假字的正确提取率随呈现时间增长而提高 ,字形刺激的特征加工是一个有序的发展过程 ,对字形的识别加工过程受字形熟悉性和字形结构方式的影响 ;(2 )在左右型字刺激和上下型字刺激中 ,经常首先从右部件或下部件中提取笔画或笔画组合 (称首特征 ) ,而且首特征的提取不受字形熟悉性影响。根据以上结果可以推测 ,字形结构属性在字形识别加工的最初阶段先于特征获加工 ,字形熟悉性则对首特征提取后的特征或部件加工过程产生影响。     

Nonlinearity in the Epidemiology of Complex Health and Disease Processes

Theoretical Medicine and Bioethics - The challenges posed by chronic illness have pointed out to epidemiologists the multifactorial complex nature of disease causality. This notion has been...