Category size effects revisited: frequency and masked priming effects in semantic categorization

Previous work indicates that semantic categorization decisions for nonexemplars (e.g., deciding that TURBAN is not an animal name) are faster for high-frequency words than low-frequency words. However, there is evidence that this result might depend on category size. When narrow categories are used (e.g., Months, Numbers), there is no frequency effect for nonexemplars. This result is confirmed, and is explained in terms of a category search model, which allows a "No" decision to be generated without access to the lexical entry for the target word. This explains the absence of a frequency effect, but not the presence of a strong masked repetition priming effect, which is assumed to have a lexical source. It is shown that this effect may not be lexical, since nonwords also show similar priming. Both of these priming effects disappear when a larger category is used. This pattern of results is explained on the assumption that category search is only possible with small categories, and that tentative category decisions are generated for the unconsciously perceived prime, which leads to a marked response congruence effect.     

Silent letters and phonological priming

Many written English words contain silent letters. Omitting them produces nonwords pronounced identically to the original words, for example, SALM for PSALM and COLUM for COLUMN. We report two naming and two lexical decision experiments in which targets of 4–11 letters followed primes exposed for 100 ms in mask-prime-mask-target sequences. Priming in SALM-psalm and COLUM-column pairs exceeded priming in orthographic control pairs such as ASTA-pasta and COUSI-cousin, pairs in which pronounced letters are omitted to form the primes. SALM and COLUM, however, were less effective primes than PSALM and COLUMN. Results were discussed in terms of the phonological coherence hypothesis, the role of orthographic codes in filtering phonologically activated representations, and graphemes as reading units.     

Physical and conceptual priming effects on picture and word identification

In the study phase of these experiments, subjects were asked to think of an item suggested by the omission in an incomplete sentence, and then look at a picture or word describing an item and say whether it was the same as theirs. In the test phase, they were asked to identify studied and nonstudied items presented briefly in either picture or word form. Subjects were then required to recall the words or pictures shown in the study phase. Experiment 1, with a within-subjects design, revealed that the studied pictures were identified more readily than studied words and nonstudied pictures. This indicates a physical priming effect. In word identification, studied words were identified more readily than nonstudied words; however, there was no difference between studied words and studied pictures, and the performance for studied pictures and nonstudied items were largely the same. The physical priming effect on picture identification was also shown in Experiment 2, with a between-subjects design. Different processing mechanisms in picture and word identification are discussed.     

The Development of Infant Memory

Over the first year and a half of life, the duration of memory becomes progressively longer, the specificity of the cues required for recognition progressively decreases after short test delays, and the latency of priming progressively decreases to the adult level. The memory dissociations of very young infants on recognition and priming tasks, which presumably tap different memory systems, are also identical to those of adults. These parallels suggest that both memory systems are present very early in development instead of emerging hierarchically over the 1st year, as previously thought. Finally, even young infants can remember an event over the entire "infantile amnesia" period if they are periodically exposed to appropriate nonverbal reminders. In short, the same fundamental mechanisms appear to underlie memory processing in infants and adults.     

遗忘症患者外显与内隐记忆实验研究:语义性启动效应任务

采用ＷＭＳ—ＣＲ和ＭＭＳＥ对临床脑损伤患者进行了认知功能与记忆功能两方面的筛选,获得９名遗忘症患者。然后采用偏好和自由联想两项语义性启动效应任务进行测验,发现遗忘症患者在外显记忆受损情况下,的确存在语义性启动效应,且与正常对照相近。推论语义性启动效应任务与遗忘患者损伤的颞叶或间脑结构无关。同时还讨论了启动效应任务,认为偏好任务采用言语性材料不是理想的方法。     

右侧基底节损伤遗忘症患者的知觉性启动效应与语义性启动效应的分离与定位

采用偏好、自由联想、字根补笔和字辨认等４项任务观察一例单纯性右侧基底节损伤遗忘症患者和两组正常对照的启动效应。结果发现：（１）该患者知觉性启动效应障碍、而语义性启动效应正常。认为知觉性启动效应的神经学基础可能在基底节。（２）该患者知觉性启动效应与语义性启动效应分离。认为神经组织的损伤可导致不同形式启动效应的分解,提出内隐记忆或启动效应的不同形式可能存在不同的神经学基础。     

连绵词语音类似的启动效应

研究采用快速启动范型考察了视觉连绵词加工中语音的自动激活.两个实验发现,无论是首字同音还是尾字同音启动都可以促进对连绵词的命名反应,且基本不受目标词熟悉性(词频高低)及真假词的影响.可以推断,至少在连绵词--这种单词素词的词汇通达中存在语音的自动激活,这种语音的激活可以说是前词的装配与词水平上的改变.     

提取干扰对不同类型内隐记忆的影响

以往研究关于提取阶段的干扰是否会影响内隐记忆存在着异义, 其中一个重要因素可能源于所采用的内隐记忆测验类型的差异。本研究采用学习-测验范式, 通过4个实验, 分别考察了提取干扰对识别式知觉内隐测验、识别式概念内隐测验、产生式知觉内隐测验和产生式概念内隐测验的影响, 以期对提取干扰和内隐记忆之间的关系有着更全面的了解。结果表明: (1)词汇判断任务(识别式知觉)和语义分类任务(识别式概念)的启动效应在提取干扰下消失了, (2)而产生式词汇判断任务(产生式知觉)和产生式语义分类任务(产生式概念)在提取干扰下仍发现了明显的启动效应, 但与无干扰条件相比, 启动效应量也有着明显的减少。由此可见, 不同类型的内隐记忆都会受到提取干扰的影响, 相比于产生式启动, 识别式启动更容易受到提取干扰的破坏。     

Priming autobiographical memories: How recalling the past may affect everyday forms of autobiographical remembering

This study investigated the idea that when one recalls past episodes, that the content of those memories will activate additional episodic memories with like content, and such memories will then have the potential of surfacing in subsequent acts of involuntary and voluntary recall. We tested the episodic content priming hypothesis in two experiments. In Experiment 1, priming group participants first recalled memories about specific activities or events and then they were subsequently engaged in a word-cue voluntary autobiographical memory task. The results showed that priming group participants produced more episodic memories involving the primed content on this task than control participants occupied in the same task. In Experiment 2, episodic content priming was further tested on a measure of involuntary autobiographical memory (i.e., the vigilance task). The results on this task also revealed support for the episodic content priming hypothesis, including after a delay of 24 h.     

Meaning Selection and the Subcortex: Evidence of Reduced Lexical Ambiguity Repetition Effects Following Subcortical Lesions

Recent research indicates that individuals with nonthalamic subcortical (NS) lesions can experience difficulties processing lexical ambiguities in a variety of contexts. This study examined how prior processing of a lexical ambiguity influences subsequent meaning activation in 10 individuals with NS lesions and 10 matched healthy controls. Subjects made speeded lexical decisions on related or unrelated targets following homophone primes. Homophones were repeated with different targets biasing the same or different meanings on the second presentation. The effects of prime-target relatedness, interstimulus interval (200 or 1250 ms), and same vs. different meaning repetition were examined. Both the patient and control groups showed priming when the same homophone meaning was biased on repetition. When a different meaning was biased on the second presentation, no priming was evident in the controls, while facilitation remained present for the NS group, consistent with aberrant meaning selection and deactivation processes. These findings are discussed in terms of age and task-related repetition effects and current conceptions of frontal–subcortical involvement in cognition.David Copland is supported by the Australian Research Council