Developmental changes in the semantic processing of pictures and words

Second- and fifth-graders' semantic decision times for pictures and words were analyzed relative to the predictions derived from unitary- and dual-memory models. At both grade levels, word-word response latencies were greater than picture-word latencies which, in turn, were greater than picture-picture latencies. An interaction between Grade and Condition indicated that verbal access times decreased more than pictorial access times. The data fit the predictions of a memory model postulating category storage in a single memory system as opposed to simultaneous representation in verbal and nonverbal memory systems. It was concluded that with increasing experience verbal access to this single semantic system is more rapid.     

The interpretation of ambiguous trimorphemic words in sentence context

Many trimorphemic words are structurally and semantically ambiguous. For example, unlock-able can either be un-lockable (cannot be locked) or unlock-able (can be unlocked). Which interpretation is preferred and whether the preceding sentence context affects the initial interpretation is not clear from prior research. The present experiment embedded ambiguous trimorphemic words in sentence contexts, manipulated whether or not preceding context disambiguated the meaning, and examined the pattern of fixation durations on the ambiguous word and the remainder of the text. The results indicated that the unlock-able interpretation was preferred; moreover, preceding context did not exert a significant effect until the eyes had initially exited from the target word.     

Hemispheric asymmetries in semantic processing: evidence from false memories for ambiguous words

We used fMRI to investigate competition during language production in two word production tasks: object naming and color naming of achromatic line drawings. Generally, fMRI activation was higher for color naming. The line drawings were followed by a word (the distractor word) that referred to either the object, a related object, or an unrelated object. The effect of the distractor word on the BOLD response was qualitatively different for the two tasks. The activation pattern suggests two different kinds of competition during lexical retrieval: (1) Task-relevant responses (e.g., red in color naming) compete with task-irrelevant responses (i.e., the object’s name). This competition effect was dominant in prefrontal cortex. (2) Multiple task-relevant responses (i.e., target word and distractor word) compete for selection. This competition effect was dominant in ventral temporal cortex. This study provides further evidence for the distinct roles of frontal and temporal cortex in language production, while highlighting the effects of competition, albeit from different sources, in both regions.     

Developmental changes in the internal structure of semantic categories

The present experiment was designed to examine the development of the cognitive representation of semantic categories. Response latencies on a classification task were compared for second, fourth, and sixth graders (8, 10, and 12 years of age, respectively) and college students. On each trial the subjects were presented with two pictures that represented either typical or atypical category exemplars. The two pictures were physically identical, nonidentical pictures from the same category, or pictures from different categories. One half of the trials were primed by presenting a category name in advance of the stimuli. In addition, stimulus degradation was manipulated in order to assess the locus of priming effects. A significant interaction of age × priming × typicality was found for physically identical stimuli. This interaction indicated that the nature of the internal representation of categories changed from the second graders to the adults. It was suggested that the second graders might weigh features inappropriately in generating semantic prototypes. The fact that stimulus degradation and priming did not interact at any age level for any of the match types indicates that priming affected a conceptual encoding stage rather than a perceptual encoding stage.     

Selection mechanisms in reading lexically ambiguous words

Readers' eye movements were monitored as they read sentences containing lexically ambiguous words. The ambiguous words were either biased (one strongly dominant interpretation) or nonbiased. Readers' gaze durations were longer on nonbiased than biased words when the disambiguating information followed the target word. In Experiment 1, reading times on the disambiguating word did not differ whether the disambiguation followed the target word immediately or occurred several words later. In Experiment 2, prior disambiguation eliminated the long gaze durations on nonbiased target words but resulted in long gaze durations on biased target words if the context demanded the subordinate meaning. The results indicate that successful integration of one meaning with prior context terminates the search for alternative meanings of that word. This results in selective (single meaning) access when integration of a dominant meaning is fast (due to a biasing context) and identification of a subordinate meaning is slow (a strongly biased ambiguity with a low-frequency meaning).     

Developmental changes in neural activity to familiar words and gestures

Infants younger than 20 months of age interpret both words and symbolic gestures as object names. Later in development words and gestures take on divergent communicative functions. Here, we examined patterns of brain activity to words and gestures in typically developing infants at 18 and 26 months of age. Event-related potentials (ERPs) were recorded during a match/mismatch task. At 18 months, an N400 mismatch effect was observed for pictures preceded by both words and gestures. At 26 months the N400 effect was limited to words. The results provide the first neurobiological evidence showing developmental changes in semantic processing of gestures.     

Accessing ambiguous words during sentence comprehension

In five experiments visual processing of sentences containing either a more frequent or a less frequent usage of an ambiguous word was examined. When prior or subsequent context was pragmatically related to the relevant sense of the ambiguous word, sentences intending the more frequent sense produced longer ambiguity detection times and shorter immediate comprehension times than sentences intending the less frequent sense. This relative frequency effect was not obtained in comprehension of corresponding unambiguous sentences containing relatively high or low frequency unambiguous synonyms of the senses. These results suggest that access of ambiguous word-senses tends to occur in order of relative frequency, and that multiple access of senses tends only to occur for low frequency usages. When the preceding verb imposed selection constraints on which sense could follow, the frequency effect did not occur consistently; and it was virtually eliminated when biasing context took the form of a previous sentence containing an unambiguous synonym of the relevant sense. Implications for models of access of unambiguous words in sentences, as well as for models of processing ambiguous sentences, are considered.     

Pragmatic inference, not semantic competence, guides 3-year-olds' interpretation of unknown number words

Before children learn the specific meanings of numerals like six, do they know that they represent precise quantities? Previous studies have reported conflicting evidence and have found that children expect numerals to label precise quantities in some tasks but not in others (Condry & Spelke, 2008; Sarnecka & Gelman, 2004). In this article, we present evidence that some of children's apparent successes are best explained not by domain-specific semantic understanding of number but instead by language-general pragmatic abilities. In Experiment 1, we replicated the findings of the previous studies in a within-subject design. When 3-year-olds saw a set labeled with a number (e.g., five) and an item was added, they preferred a new label (six) over the old one, as though they believed that number words have precise meanings. However, when 1 of 2 sets was labeled (e.g., as five) and children were asked to find the same quantity (five) or a new quantity (six), they performed identically whether the original set was changed in quantity or merely rearranged. Thus, when 2 numerals were offered as alternative labels for 1 set, children behaved as though they had precise meanings, whereas when they were asked to determine which of 2 sets a single numeral referred to, they did not. In Experiment 2, children were tested using similar methods but with novel nouns and objects that were transformed, instead of sets. Children showed the identical pattern of results despite lacking meanings for these words, suggesting that their judgments for numerals may not have relied on semantic knowledge that numerals have precise meanings. We propose that children's behavior can be explained by the use of domain-general pragmatic inference and does not require positing domain-specific numerical knowledge. (PsycINFO Database Record (c) 2013 APA, all rights reserved).     

Priming dominant and unusual senses of ambiguous words

The priming technique was used to investigate the conditions under which a homograph’s dominant and/or nondominant semantic sense will be retrieved. Subjects verified whether “A(n) A is a(n) B” when A was an ambiguous word and B was a word corresponding to either a dominant or an unusual semantic sense of word A. When word B most often corresponded to the dominant sense of word A (Experiment I), a Priming by Dominance interaction was obtained in the reaction time (RT) data; viz, the facilitatory effect of priming was greater for the dominant-sense sentences than for the unusual-sense sentences. When the word B equally often corresponded to the dominant and unusual senses of A (Experiment 2), the facilitatory effect of priming was equal for the dominant-sense and unusual-sense sentences. These results were interpreted within the framework of a two-stage model of lexical access (d. Posner & Snyder, 1975; Neely, 1977). An application of this two-stage model to the now rather extensive literature on homographic processing helps clear up the apparent contradictions that have been prevalent in this literature.     

Developmental changes in children's use of semantic information in recall

Third and seventh graders (age 9 and 13 years) were randomly assigned to three instructional groups and engaged in a sort/recall task. The instructions emphasized either (a) recall of the items, (b) meaningful organization of the items, or (c) meaningful organization and recall of the items. Regardless of instruction, seventh graders sorted 20 unrelated items into semantically-based groupings and exhibited elevated levels of recall. Third graders instructed to group items to facilitate recall formed seemingly random groupings and recalled significantly fewer items than third graders instructed to make semantically-based groupings, even when some of these latter subjects were unaware of a subsequent recall trial. The results indicated that young children are capable of adult-like organizational strategies but are unaware of their relevance to recall performance or conditions under which organization might be an appropriate strategy.     

Event-related potentials indicate context effect in reading ambiguous words

The aim of the study was a comparison of lexical and contextual factors in understanding ambiguous words in German. First, a sample of native speakers selected 56 words having maximally strong differences between a dominant and a subordinate meaning. After this, another sample from the same population was visually presented with sentences that activated dominant or subordinate meanings of the words and were accompanied by probes associated with dominant or subordinate meanings. This resulted in a crossed design with two factors: sentence dominant vs. sentence subordinate and probe dominant vs. probe subordinate. An analysis of event-related brain potentials revealed a large, long-lasting and highly-significant N400 wave whenever the meaning of the probe was incongruent with the meaning of the sentence and the lack of this wave whenever the two meanings were congruent. In the typical N400 space and time, the effect was independent of whether the lexical word meaning was dominant or subordinate. At other sites and times, however (e.g., at lateral frontal electrodes F7/F8, and after 700 ms), the congruence effect was significant after dominant sentences only. The data indicate that lexical factors have a rather limited influence on the activation of a particular meaning of ambiguous words. A strong context can virtually override even a very strong difference in the preference for different meanings.     

汉语名词、动词和动名兼类词语义加工的偏侧化现象——来自ERP的研究

将ERP技术和半视野技术相结合,采用词汇判断任务,对汉语名词、动词和动名兼类词在左脑和右脑中的加工机制进行了考察。实验结果显示,名词和动词的N400仅在左视野/右脑存在差异,名词和动词的N400在左视野/右脑和右视野/左脑中都比偏（动）和偏（名）更负。不同词类的LPC在右视野/左脑中没有显著差异;偏（名）和偏（动）的LPC在左视野/右脑中比名词和动词更正。实验结果表明,在没有语境条件下,汉语名词和动词的差异主要在具体性上,动名兼类词体现出不同于名词、动词的加工机制。     

Social anxiety and interpretation of ambiguous smiles

This study investigated whether social anxiety facilitates the discrimination between genuine and ambiguous smiles. Socially anxious (N=20) and nonanxious (N=20) participants categorized as “happy” or “not happy” faces with either (1) a truly happy expression (i.e., happy eyes and a smile), (2) truly nonhappy expressions (e.g., angry eyes and an angry mouth), or (3) blended expressions with a smiling mouth and nonhappy (e.g., angry, sad, etc.) eyes. Results indicated that, relative to nonanxious participants, those high in social anxiety were more likely to judge as “not happy” any blended expression with nonhappy eyes, and they were faster in judging as “not happy” the blended expressions with angry, fearful, or disgusted eyes (but not those with sad, surprised, or neutral eyes). These results suggest, respectively, that social anxiety inhibits a benign interpretation of all the ambiguous expressions with a smile, and speeds up the detection of threatening eyes in such expressions. Importantly, no differences appeared as a function of social anxiety for truly happy or nonhappy faces. This rules out a response-bias explanation, and also reveals that social anxiety does not affect sensitivity in the recognition of prototypical expressions.     

Remindings influence the interpretation of ambiguous stimuli

Remindings—stimulus-guided retrievals of prior events—may help us interpret ambiguous events by linking the current situation to relevant prior experiences. Evidence suggests that remindings play an important role in interpreting complex ambiguous stimuli (Ross & Bradshaw Memory & Cognition, 22, 591–605, 1994); here, we evaluate whether remindings will influence word interpretation and memory in a new paradigm. Learners studied words on distinct visual backgrounds and generated a sentence for each word. Homographs were preceded by a biasing cue on the same background three items earlier, preceded by a biasing cue on a different background three items earlier, or followed by a biasing cue on the same background three items later. When biasing cues preceded the homographs on the same backgrounds as the homographs, the meanings of the homographs in learner-generated sentences were consistent with the biasing cues more often than in the other two conditions. These results show that remindings can influence word interpretation. In addition, later memory for the homographs and cues was greater when the meaning of the homograph in the sentence was consistent with the earlier biasing cue, suggesting that remindings enhanced mnemonic performance. Remindings play an important role in how we interpret ambiguous stimuli and enhance memory for the involved material.     

Frequency of meaning use for ambiguous and unambiguous words

When using verbal stimuli, researchers usually equate words on frequency of use. However, for some ambiguous words (e.g.,ball as a round object or a formal dance), frequency counts fail to distinguish how often a particular meaning is used. This study evaluates the use of ratings to estimate meaning frequency. Analyses show that ratings correlate highly with word frequency counts when orthographic and meaning frequencies should converge, are not unduly influenced by semantic factors, and may provide a better measure of relative meaning dominance than the word association task does. Furthermore, the ratings allow researchers to equate or manipulate frequency of meaning use for ambiguous and unambiguous words. Ratings for 211 words are reported.     

Semantic neighborhood effects on the recognition of ambiguous words

The effect of semantic neighborhood on the processing of ambiguous words was examined in two lexical decision experiments. Semantic neighborhood was defined in terms of semantic set size and network connectivity. In Experiment 1, the variables of semantic set size, network connectivity, and ambiguity were crossed. An ambiguity advantage was observed only within small-set low-connectivity words. In Experiment 2, the effect of network connectivity on the processing of words of high and low meaning relatedness was examined. Participants responded more rapidly to words of high meaning relatedness, relative to words of low meaning relatedness, but only within high-connectivity words. These results are interpreted within a framework in which both semantic feedback processes and meaning-level competition can affect the recognition of semantically ambiguous words.     

Recognition failure of recallable words in semantic memory

In an experiment in which there was no study phase, 54 subjects were tested for recognition of famous surnames and then were tested for cued recall of the same surnames. Subjects failed to recognize 53.4% of names that they subsequently recalled. Recall was significantly higher than recognition. The relationship between overall recognition rate and recognition rate of recallable words closely resembled that reported by Tulving and Wiseman (1975) for episodic memory experiments. The present data therefore extend the generality of this relationship, and of the principle that the probability of retrieval from memory depends critically on the cues provided. It is argued that the similarity between results for episodic memory experiments and the present semantic memory experiment can be more parsimoniously accommodated by tagging theory than by episodic theory.