The cortical organization of lexical knowledge: a dual lexicon model of spoken language processing

Current accounts of spoken language assume the existence of a lexicon where wordforms are stored and interact during spoken language perception, understanding and production. Despite the theoretical importance of the wordform lexicon, the exact localization and function of the lexicon in the broader context of language use is not well understood. This review draws on evidence from aphasia, functional imaging, neuroanatomy, laboratory phonology and behavioral results to argue for the existence of parallel lexica that facilitate different processes in the dorsal and ventral speech pathways. The dorsal lexicon, localized in the inferior parietal region including the supramarginal gyrus, serves as an interface between phonetic and articulatory representations. The ventral lexicon, localized in the posterior superior temporal sulcus and middle temporal gyrus, serves as an interface between phonetic and semantic representations. In addition to their interface roles, the two lexica contribute to the robustness of speech processing.     

Human values: Genetic and environmental effects on five lexically derived domains and their facets

Whereas a substantial genetic component of Conservatism and Religiosity is well documented, there is little evidence with respect to the behavior genetics of other aspects of human values. A sample of 157 monozygotic and 74 dizygotic twins reared together received the Austrian Value Questionnaire (AVQ), which measures a broad variety of value domains and their facets, found by the lexical approach in the German language. Family resemblance of Intellectualism, Harmony, Materialism, and Conservatism was best explained by additive or dominance genetic and non-shared environmental effects, whereas the influence of the environment shared by twins was negligible. In contrast, Religiosity was transmitted by additive genetic, shared and non-shared environmental influences. At the level of facets, the Intellectualism and Harmony showed a homogenous etiology while Religiosity, Materialism, and Conservatism were etiologically heterogeneous.     

The brain's hemispheres and controlled search of the lexicon: evidence from fixated words and pseudowords

Difference between the brain's hemispheres in efficiency of intentional search of the mental lexicon with phonological, orthographic, and semantic strategies was investigated. Letter strings for lexical decision were presented at fixation, with a lateralized distractor to the LVF or RVF. Word results revealed that both hemispheres were capable of using each of the three strategies, but the right hemisphere had better baseline processing of orthography and was better at processing semantics. Pseudoword results supported the right hemisphere advantage for orthography and showed a left hemisphere advantage for phonology and assessment of possible semantic relationships. Taken together, the data support the idea that the right hemisphere uses orthography to make efficient decisions about novelty of an item, while the left engages in grapheme-to-phoneme conversion to test hypotheses about unfamiliar items. The convergence of data with previous research reveals that the procedure, as well as analyses of pseudowords, inform laterality research.     

Is the go/no-go lexical decision task preferable to the yes/no task with developing readers?

The lexical decision task is probably the most common laboratory visual word identification task together with the naming task. In the usual setup, participants need to press the “yes” button when the stimulus is a word and the “no” button when the stimulus is not a word. A number of studies have employed this task with developing readers; however, error rates and/or response times tend to be quite high. One way to make the task easier for young readers is by employing a go/no-go procedure: “If word, press ‘yes’; if not, refrain from responding.” Here we conducted a lexical decision experiment that systematically compared the yes/no and go/no-go variants of the lexical decision task with developing readers (second- and fourth-grade children). Results showed that (a) error rates for words and nonwords were much lower in the go/no-go task than in the yes/no task, (b) lexical decision times were substantially faster in the go/no-go task, and (c) there was less variability in the latency data of the go/no-go task for high-frequency words. Thus, the go/no-go lexical decision task is preferable to the “standard” yes/no task when conducting experiments with developing readers.     

LIFG-based attentional control and the resolution of lexical ambiguities in sentence context

The role of attentional control in lexical ambiguity resolution was examined in two patients with damage to the left inferior frontal gyrus (LIFG) and one control patient with non-LIFG damage. Experiment 1 confirmed that the LIFG patients had attentional control deficits compared to normal controls while the non-LIFG patient was relatively unimpaired. Experiment 2 showed that all three patients did as well as normal controls in using biasing sentence context to resolve lexical ambiguities involving balanced ambiguous words, but only the LIFG patients took an abnormally long time on lexical ambiguities that resolved toward a subordinate meaning of biased ambiguous words. Taken together, the results suggest that attentional control plays an important role in the resolution of certain lexical ambiguities - those that induce strong interference from context-inappropriate meanings (i.e., dominant meanings of biased ambiguous words).     

“Does degree of asymmetry relate to performance?” A critical review

In a recent paper, Chiarello, Welcome, Halderman, and Leonard (2009) reported positive correlations between word-related visual field asymmetries and reading performance. They argued that strong word processing lateralization represents a more optimal brain organization for reading acquisition. Their empirical results contrasted sharply with those of another such large-scale study, by Boles, Barth, and Merrill (2008). We reported negative correlations between asymmetry and performance when both were measured using the same visual lexical tasks. Most recently, within-task negative correlations were also reported by Hirnstein, Leask, Rose, and Hausmann (2010). Here two major differences between studies are explored. Task purity refers to the influence of the same mental processes on both the asymmetry and performance measures, and is arguably maximal in studies measuring both within the same task. The other difference concerns the measurement of asymmetry. Linear corrections for ceiling and floor effects were used by Chiarello et al. and Hirnstein et al., while we used a more appropriate nonlinear one. Their results are difficult to interpret for those reasons. The operation of a third variable to which both asymmetry and performance are positively correlated could also be a factor in the Chiarello et al. findings. The Boles et al. findings reflect a negative correlation between an asymmetric visual lexical process and performance measured within the same task.     

What Does Children's Spatial Language Reveal About Spatial Concepts? Evidence From the Use of Containment Expressions

Children's overextensions of spatial language are often taken to reveal spatial biases. However, it is unclear whether extension patterns should be attributed to children's overly general spatial concepts or to a narrower notion of conceptual similarity allowing metaphor‐like extensions. We describe a previously unnoticed extension of spatial expressions and use a novel method to determine its origins. English‐ and Greek‐speaking 4‐ and 5‐year‐olds used containment expressions (e.g., English into, Greek mesa) for events where an object moved into another object but extended such expressions to events where the object moved behind or under another object. The pattern emerged in adult speakers of both languages and also in speakers of 10 additional languages. We conclude that learners do not have an overly general concept of Containment. Nevertheless, children (and adults) perceive similarities across Containment and other types of spatial scenes, even when these similarities are obscured by the conventional forms of the language.     

Is it better to be happy or to be proud at school before doing a text comprehension task? First evidence with 10-year-old children

Introduction and objective

An experiment was conducted in a school context to examine whether joy and pride, two positive emotions, can promote children's acquisition of knowledge in a reading comprehension situation.