Neuroimaging and neuropsychological studies have implicated left inferior prefrontal cortex (LIPC) in both semantic and phonological processing. In this study, functional magnetic resonance imaging was used to examine whether separate LIPC regions participate in each of these types of processing. Performance of a semantic decision task resulted in extensive LIPC activation compared to a perceptual control task. Phonological processing of words and pseudowords in a syllable-counting task resulted in activation of the dorsal aspect of the left inferior frontal gyrus near the inferior frontal sulcus (BA44/45) compared to a perceptual control task, with greater activation for nonwords compared to words. In a direct comparison of semantic and phonological tasks, semantic processing preferentially

Written Chinese as logographic script differs notably from alphabets such as English in visual form, orthography, phonology, and semantics. Thus, research on the Chinese language is important to advance our understanding of the universality and particularity of the organization of language systems in the brain. In this study, we examine the neural systems associated with logographic reading using functional magnetic resonance imaging. Two experimental tasks were devised, one based on semantic decision and the other on homophone decision. Compared to the fixation baseline, peak activations resulting from semantic as well as homophony decisions were localized in the left middle frontal gyrus (BA 9). Left inferior frontal cortex also mediated Chinese processing. In addition, more right hemisphere cortical regions (i.e., BAs 47/45, 7, 40/39, and the right visual system) were involved in reading Chinese relative to reading English. This is attributed to the square shape of the logograph which requires an elaborated analysis of the spatial information and locations of various strokes comprising the logographic character. We suggest that the left middle frontal area (BA 9) coordinates and integrates the intensive visuospatial analysis demanded by logographs ’ square configuration and the semantic (or phonological) analysis required by the present experimental tasks. Our study has implicated brain regions common to both logographic and alphabetic languages as well as brain regions specialized in processing logographs. © 2001 Academic Press

n Localized, task-induced decreases in cerebral blood �ow are a frequent �nding in functional brain imaging research but remain poorly understood. One account of these phenomena postulates processes ongoing during conscious, resting states that are interrupted or inhibited by task performance. Psychological evidence suggests that conscious humans are engaged almost continuously in adaptive processes involving semantic knowledge retrieval, representation in awareness, and directed manipulation of represented knowledge for organization, problem-solving, and planning. If interruption of such “conceptual” processes accounts for task-induced deactivation, tasks that also engage these conceptual processes should not cause deactivation. Furthermore, comparisons between conceptual and nonconceptual tasks should show activation during conceptual tasks of the same brain areas that are “deactivated ” relative to rest.

The current study addresses the controversial issue of how different grammatical categories are neurally processed. Several lesion-deficit studies suggest that distinct neural substrates underlie the representation of nouns and verbs, with verb deficits associated with damage to left inferior frontal gyrus (LIFG) and noun deficits with damage to left temporal cortex. However, this view is not universally shared by neuropsychological and neuroimaging studies. We have suggested that these inconsistencies may reflect interactions between the morphological structure of nouns and verbs and the processing implications of this, rather than differences in their neural representations (Tyler et al. 2004). We tested this hypothesis using eventrelated functional magnetic resonance imaging, to scan subjects performing a valence judgment on unambiguous nouns and verbs, presented as stems (‘snail, hear’) and inflected forms (‘snails, hears’). We predicted that activations for noun and verb stems would not differ, whereas inflected verbs would generate more activation in left frontotemporal areas than inflected nouns. Our findings supported this hypothesis, with greater activation of this network for inflected verbs compared with inflected nouns. These results support the claim that form class is not a first-order organizing principle underlying the representation of words but rather interacts with the processes that operate over lexical representations.

: A basic but neglected question regarding cognitive control is how control processes might detect situations calling for their mobilization. One interesting possibility is that this might be accomplished in part through monitoring for conflicts in information processing. An initial motivation for this hypothesis is provided by theories portraying the prevention of conflict as a basic function of cognitive control. More importantly, the actual occurrence of conflict monitoring is supported by data from cognitive neuroscience, concerning the responsivity of the anterior cingulate cortex. In addition to a wide range of evidence indicating the relevance of this cortical area to cognitive control, recent brain activation studies suggest that the area may respond selectively to the occurrence of conflict. In the present report, we discuss two computational modeling studies that together serve to articulate the conflict monitoring hypothesis and examine its implications. The first of these ...

The current experiment was designed to investigate the nature of cognitive control in within- and between-language switching in bilingual participants. To examine the neural substrate of language switching we used functional magnetic resonance imaging (fMRI) as subjects named pictures in one language only or switched between languages. Participants were also asked to name (only in English) a separate set of pictures as either the actions or the objects depicted or to switch between these two types of responses on each subsequent picture. Picture naming compared to rest revealed activation in the dorsolateral prefrontal cortex, which extended down into Broca’s area in the left hemisphere. There were no differences in the activation pattern for

& Here we address the contentious issue of how nouns and verbs are represented in the brain. The co-occurrence of noun and verb deficits with damage to different neural regions has led to the view that they are differentially represented in the brain. Recent neuroimaging evidence and inconsistent lesion– behavior associations challenge this view. We have suggested that nouns and verbs are not differentially represented in the brain, but that different patterns of neural activity are triggered by the different linguistic functions carried by nouns and verbs. We test these claims in a functional magnetic resonance imaging study using homophones—words which function grammatically as nouns or verbs but have the same form and meaning—ensuring that any neural differences reflect differences in grammatical function. Words were presented as single stems and in phrases in which each homophone was preceded by an article to create a noun phrase (NP) or a pronoun to create a verb phrase (VP), thus establishing the word’s functional linguistic role. Activity for single-word homophones was not modulated by their frequency of usage as a noun or verb. In contrast, homophones marked as verbs by appearing in VPs elicited greater activity in the left posterior middle temporal gyrus (LpMTG) compared to homophones marked as nouns by occurring in NPs. Neuropsychological patients with grammatical deficits had lesions which overlapped with the greater LpMTG activity found for VPs. These results suggest that nouns and verbs do not invariably activate different neural regions; rather, differential cortical activity depends on the extent to which their different grammatical functions are engaged. &

This paper is meant to be an introduction to connectionism for linguists. It covers fundamentals of connectionism and applications of connectionism to human language processing. Because the first (and the last for some) question that linguists want to ask is "why bother with connectionism?" it would be appropriate to try to answer this question first. A quick and rather naive answer is that both linguistics and connectionism are branches of cognitive science, the science of human mind. However, there seem to be two main sources of skepticism against connectionism. (1) Connectionism is an offspring of behaviorism, which is refuted as a method for investigating language by Chomsky decades ago. (2) Connectionism could be used to implement linguistic theory, but it does not provide a new perspective. This section tries to refute these skepticisms and tries to indicate how connectionism may contribute to the understanding of language. 1.1 Behaviorism and connectionism

and episodic memory of music are subserved

Introduction One of the premises of contemporary cognitive science is that an organism's response to a stimulus requires sensory, perceptual, and memory processes on an order of complexity unexpected from observations of simple reactions to physical stimulation. It was a touchstone of the cognitive revolution in the late 1950s and early 1960s that these interpretative processes are a proper subject for psychology, setting the goal of explaining how a stimulus is processed through successive mental transformations. In contrast, within behaviorist conceptions that regarded the relationships between stimuli and responses as little more than learned reflexes (Skinner, 1953; Watson, 1913), the role that mental transformations played was on a par with the hyphen in the term stimulusresponse (S-R) psychology. Put into the terms of the theoretical framework that cognitive psychology supplanted, the thrust of the cognitive revolution was therefore directed toward elaborating the S of S