The investigation of semantic context effects has served as a valuable tool in investigating mechanisms of language production. Classic semantic interference effects have provided influential support for and interest in a competitive lexical selection mechanism. However, recent interest in semantic facilitation effects has stimulated a discussion on whether context effects reflect competition during lexical selection. In this review we propose a framework of lexical selection by competition that is sensitive to the activation of lexical cohorts. We outline our proposal and then present a selective review of the empirical evidence, much of which has been central to the development of alternative non-competitive models. We suggest that by adopting the assumptions of our proposal we can parsimoniously account for a majority of the discussed semantic facilitation and interference effects.Investigations of semantic context effects, a widely used tool to study the architecture of the speech production system, have considerably shaped our assumptions on the nature of lexical selection. Traditionally the term semantic context has referred primarily to the relationship between a target stimulus and some second stimulus within an experiment. In this paper, we intend semantic context to refer to any meaning-constraining context, i.e., discourse context, experimental context, situational context, within which a target word is uttered.

In this study, we investigated semantic context effects in language production with event-related brain potentials, extracted from the ongoing EEG recorded during overt speech production. We combined the picture-word interference paradigm and the semantic blocking paradigm to investigate the temporal dynamics and functional loci of semantic facilitation and interference effects. Objects were named in the context of semantically homogeneous blocks consisting of related objects and heterogeneous blocks consisting of unrelated objects. In each blocking condition, semantically related and unrelated distractor words were presented. Results show that classic patterns of semantically induced facilitation and interference effects in RTs can be directly related to ERP modulations located at temporal and frontal sites, starting at about 200 msec. Results also suggest that the processes associated with semantic facilitation and interference effects (i.e., conceptual and lexical processing) are highly interactive and coincide in time. Implications for the use of event-related brain potentials in speech production research and implications for current models of speech production are discussed.

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In this article, the authors explore semantic context effects in speaking. In particular, the authors investigate a marked discrepancy between categorically and associatively induced effects; only categorical relationships have been reported to cause interference in object naming. In Experiments 1 and 2, a variant of the semantic blocking paradigm was used to induce two different types of semantic context effects. Pictures were either named in the context of categorically related objects (e.g., animals: bee, cow, fish) or in the context of associatively related objects from different semantic categories (e.g., apiary: bee, honey, bee keeper). Semantic interference effects were observed in both conditions, relative to an unrelated context. Experiment 3 replicated the classic effects of categorical interference and associative facilitation in a picture-word interference paradigm with the material used in Experiment 2. These findings suggest that associates are active lexical competitors and that the microstructure of lexicalization is highly flexible and adjustable to the semantic context in which the utterance takes place.

Extracting meaning from faces to understand other people's mental states and intentions, and to quickly adjust our actions accordingly, is a vital aspect of our social interactions. However, not all emotionally relevant attributes of a person are directly observable from facial features or expressions. In this study event-related brain potentials were used to investigate the effects of affective information about a person's biography that cannot be derived from the visual appearance of the face. Faces of well-known and initially unfamiliar persons with neutral expressions were associated with negative, positive or neutral biographical information. For well-known faces, early event-related brain potential (ERP) modulations induced by emotional knowledge, their scalp topographies and time course strongly resemble the effects frequently reported for emotional facial expressions even though here, access to stored semantic knowledge is required. These results demonstrate that visually opaque affective knowledge is extracted at high speed and modulates sensory processing in the visual cortex.

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According to a widely held view, basic emotions such as happiness or anger are reflected in facial expressions that are invariant and uniquely defined by specific facial muscle movements. Accordingly, expression perception should not be vulnerable to influences outside the face. Here, we test this assumption by manipulating the emotional valence of biographical knowledge associated with individual persons. Faces of well-known and initially unfamiliar persons displaying neutral expressions were associated with socially relevant negative, positive or comparatively neutral biographical information. The expressions of faces associated with negative information were classified as more negative than faces associated with neutral information. Event-related brain potential modulations in the early posterior negativity, a component taken to reflect early sensory processing of affective stimuli such as emotional facial expressions, suggest that negative affective knowledge can bias the perception of faces with neutral expressions toward subjectively displaying negative emotions.

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