Categorizations which humans make of the concrete world are not arbitrary but highly determined. In taxonomies of concrete objects, there is one level of abstraction at which the most basic category cuts are made. Basic categories are those which carry the most information, possess the highest category cue validity, and are, thus, the most differentiated from one another. The four experiments of Part I define basic objects by demonstrating that in taxonomies of common concrete nouns in English based on class inclusion, basic objects are the most inclusive categories whose members: (a) possess significant numbers of attributes in common, (b) have motor programs which are similar to one another, (c) have similar shapes, and (d) can be identified from averaged shapes of members of the class. The eight experiments of Part II explore implications of the structure of categories. Basic objects are shown to be the most inclusive categories for which a concrete image of the category as a whole can be formed, to be the first categorizations made during perception of the environment, to be the earliest categories sorted and earliest named by children, and to be the categories

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Four experiments demonstrated that more time is required to scan further distances across visual images, even when the same amount of material falls between the initial focus point and the target. Not only did times systematically increase with distance but subjectively larger images required more time to scan than did subjectively smaller ones. Finally, when subjects were not asked to base all judgments on examination of their images, the distance between an initial focus point and a target did not affect reaction times. Introspections about visual imagery very often include references to "scanning " across images. Kosslyn (1973) attempted to demonstrate that scanning of images is a functional cognitive process, and his experiment indicated that more time was required to traverse greater distances across mental images. However, in the course of scanning longer distances, 1 people in Kosslyn's experiment also passed over more parts of the imaged object. For example, in scanning from the motor to the porthole of an imaged speedboat, a person passed over the rear deck and part of the cabin; in scanning from the motor to the more distant anchor, one scanned over all of these parts plus the front deck and bow. Given this confounding, then, we have no way of knowing whether Kosslyn's results were a consequence of people actually scanning over a quasi-pictorial, spatial image. One could argue that the image itself was epiphenomenal in this situation and that the apparent effects of distance actually were a consequence of how

Analogy is often viewed as a partial similarity match between domains. But not all partial similarities qualify as analogy: There must be some selection of which commonalities count. Three experiments tested o particular selection constraint in anological mapping, namely, systemoticity. That is, we tested whether a given predicate is more likely to figure in the interpretation of and prediction from on analogy if the predicate participates in a common system of relations. In Experiment 1, subjects judged two matches to be included in on analogy: an isolated match, and a match embedded in. a larger matching system. Subjects preferred the embedded match. In Experiments 2 and 3, subjects mode analogical predictions about a target domain. Subjects predicted information that followed from a causal system that matched the base domain, rather than information that was equally plausible, but that created an isolated match with the base. Results support Gentner's (1983, 1989) structure. mopping theory in that anological mopping concerns systems and not individual predicates, and that attention to shored systematic structure constrains the selection of information to include in an analogy.

Accounts of visually directed actions usually assume that their planning begins with an intention to act. This article describes three experiments that challenged this view through the use of a stimulus-response compatibility paradigm with photographs of common graspable objects as stimuli. Participants had to decide as fast as possible whether each object was upright or inverted. Experiments 1 and 2 examined the effect of the irrelevant dimension of left-fight object orientation on bimanual and tmimanual keypress responses. Experiment 3 examined wrist rotation responses to objects requiring either clockwise or anticlockwise wrist rotations when grasped. The results (a) are consistent with the view that seen objects automatically potentiate components of the actions they afford, (b) show that compatibility effects of an irrelevant stimulus dimension can be obtained across a wide variety of naturally occurring stimuli, and (c) support the view that intentions to act operate on already existing motor representations of the possible actions in a visual scene. The use of vision to control actions has typically been framed as a problem that begins with the intention to act. How we use visual information depends, after all, on the goal of

In 7 experiments the authors investigated the locus of word frequency effects in speech production. Experiment 1 demonstrated a frequency effect in picture naming that was robust over repetitions. Experiments 2, 3, and 7 excluded contributions from object identification and initiation of articulation. Experiments 4 and 5 investigated whether the effect arises in accessing the syntactic word (lemma) by using a grammatical gender decision task. Although a frequency effect was found, it dissipated under repeated access to a word's gender. Experiment 6 tested whether the robust frequency effect arises in accessing the phonological form (lexeme) by having Ss translate words that produced homophones. Low-frequent homophones behaved like high-frequent controls, inheriting the accessing speed of their high-frequent homophone twins. Because homophones share the lexeme, not the lemma, this suggests a lexeme-level origin of the robust effect. The word frequency effect in speech production was discovered by Oldfield and Wingfield (1965). In a picture-naming task, they found that pictures with low-frequency (LF) names (such as syringe) took longer to name than pictures with high-frequency (HF) names (such as basket). Wingfield (1968)

similarity effects in masked associative priming One issue that all models of visual word recognition in alphabetic orthographies must ultimately take a position on is how the human processing system encodes letter positions when creating internal orthographic representations. Furthermore, although the choice of a coding scheme might seem to be a secondary aspect of these models, it can have a large impact on a model’s predictions (Andrews, 1996). For example, virtually all of the current models assume that the derived orthographic representation activates the lexical representations of formally similar words

Speakers often repeat the first word of major constituents, as in, ‘‘I uh I wouldn’t be surprised at that.’ ’ Repeats like this divide into four stages: an initial commitment to the constituent (with ‘‘I’’); the suspension of speech; a hiatus in speaking (filled with ‘‘uh’’); and a restart of the constituent (‘‘I wouldn’t...’’). An analysis of all repeated articles and pronouns in two large corpora of spontaneous speech shows that the four stages reflect different principles. Speakers are more likely to make a premature commitment, immediately suspending their speech, as both the local constituent and the constituent containing it become more complex. They plan some of these suspensions from the start as preliminary commitments to what they are about to say. And they are more likely to restart a constituent the more their stopping has disrupted its delivery. We argue that the principles governing these stages are general and not specific to repeats.

The influence of semantic ambiguity on word identification processes was explored in a series of word naming and lexical-decision experiments. There was no reliable ambiguity effect in 2 naming experiments, although an ambiguity advantage in lexical decision was obtained when orthographi-cally legal nonwords were used. No ambiguity effect was found in iexical decision when orthographically illegal nonwords were used, implying a semantic locus for the ambiguity advantage. These results were simulated by using a distributed memory model that also produces the ambiguity disadvantage in gaze duration that has been obtained with a reading comprehension task. Ambiguity effects in the model arise from the model's attempt to activate multiple meanings of an ambiguous word in response to presentation of that word's orthographic pattern. Reasons for discrepancies in empirical results and implications for distributed memory models are considered. Any comprehensive theory of mental representation and process must accommodate the complex means by which concepts are communicated through language. Through the course of history, humans have developed tools of communica-tion that facilitate the relaying of ideas and concepts, such as a writing system or orthography. This mapping of concepts to orthography is not entirely one to one, however, resulting in some words that correspond to multiple concepts, which are known as semantically ambiguous words. When reading text, the context provided by preceding words and sentences pro-vides a means of disambiguating such words. As a result, we may not even notice the ambiguity in words that we are reading in context. If, on the other hand, semantically ambiguous words are presented in isolation, their alternative meanings are readily accessible, and thus their ambiguous nature is noticed. In the research reported in this article, we compare performance on semantically ambiguous words with that of semantically unambiguous words in isolated word identifica-tion tasks and describe simulations of the empirical effects within the framework of a distributed memory architecture

There is an active debate within the field of phonology concerning the cognitive status of substantive phonetic factors such as ease of articulation and perceptual distinctiveness. A new framework is proposed in which substance acts as a bias, or prior, on phonological learning. Two experiments tested this framework with a method in which participants are first provided highly impoverished evidence of a new phonological pattern, and then tested on how they extend this pattern to novel contexts and novel sounds. Participants were found to generalize velar palatalization (e.g., the change from [k]asinkeep to [t�ʃ]asincheap) in a way that accords with linguistic typology, and that is predicted by a cognitive bias in favor of changes that relate perceptually similar sounds. Velar palatalization was extended from the mid front vowel context (i.e., before [e]asincape) to the high front vowel context (i.e., before [i]asin keep), but not vice versa. The key explanatory notion of perceptual similarity is quantified with a psychological model of categorization, and the substantively biased framework is formalized as a conditional random field. Implications of these results for the debate on substance, theories of phonological generalization, and the formalization of similarity are discussed.