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A Caramazza

Publications and source records attributed to A Caramazza.

At least 55 records · Page 3Linked to original sources
PubMed1995

Selective deficit in processing double letters.

This paper reports a patient with a selective difficulty in spelling words and pseudowords with geminate (double) consonants. In all writing tasks, deletions of a geminate consonant occurred ten times more often than deletions of a consonant in a non-geminate cluster. In addition, the probability of substituting both geminate consonants was indistinguishable from the probability of substituting one consonant in a non-geminate cluster; and, the probability of substituting only one geminate consonant was close to zero, and significantly lower than the probability of substituting one consonant in a non-geminate cluster. This pattern of performance is consistent with the hypothesis that grapheme quantity and identity are separately represented in orthographic representations. The fact that these errors occurred in the absence of a significant number of geminate transpositions is interpreted as support for the hypothesis that letter gemination is specified by a "doubling feature."

Adult↗
PubMed1995

Repetition blindness under minimum memory load: effects of spatial and temporal proximity and the encoding effectiveness of the first item.

Repetition blindness (RB) refers to the reduced performance in reporting a repeated as opposed to a nonrepeated item in rapid serial visual presentation. In Experiment 1, we found RB for two-item stimuli in uncertain locations. The magnitude of RB decreased significantly with increases in interstimulus interval, but not with increases in spatial separation, indicating that RB is determined primarily by temporal factors. In Experiment 2, we found RB when subjects were required to report only the second of two successively presented items. The magnitude of RB increased with the duration of the first item, indicating that RB is determined by the encoding effectiveness of the first item. The results of this study collectively indicate that RB is not a memory or a sensory phenomenon, but rather a perceptual phenomenon occurring at the stage of identity encoding. The findings also undermine the arguments (Kanwisher, 1987) that have been offered in favor of the type-token binding failure hypothesis and indicate instead that type-node refractoriness may be the cause of RB.

Humans↗
PubMed1994

Parallels and divergences in the acquisition and dissolution of language.

Analyses of the relation between the acquisition and dissolution of language have typically focused on whether or not the forms of language dysfunction that result from brain damage correspond to specific stages of language acquisition: the Regression Hypothesis. These analyses have not met with great success: although there are a number of superficial similarities between aphasic disorders and different stages of the immature linguistic system, there are also important differences. I will suggest that a focus on the behavioral similarities between language acquisition and dissolution is unlikely to be productive. A more productive course would be to focus, instead, on the general principles that constrain the acquisition and dissolution of language.

Anomia↗
PubMed1994

The interaction of lexical and sublexical processes in reading, writing and repetition.

It has recently been proposed that in the course of repetition, reading aloud and writing to dictation, lexical representations are activated and selected for output by the joint operation of the semantic system and of sublexical conversion mechanisms--the Summation Hypothesis [Hillis and Caramazza, Brain Lang. 40, 106-144, 1991]. The hypothesis predicts that semantic errors in oral reading and in writing to dictation should only occur when both the semantic system and the sublexical component involved in that task (orthography to phonology and phonology to orthography conversion, respectively) are damaged. The performance of Italian patient E.C.A. indicates damage to the semantic system, and to sublexical phonology to phonology and phonology to orthography conversion mechanisms, but with substantial sparing of sublexical orthography to phonology conversion processes. In agreement with expectations derived from the Summation Hypothesis, E.C.A. produced semantic errors in repetition and in writing to dictation, but not in reading aloud. The paucity of semantic errors in speakers of languages with relatively transparent orthographies is discussed in the context of the Summation Hypothesis.

Aged↗
PubMed1991

Lexical organization of nouns and verbs in the brain.

The analysis of neuropsychological disorders of lexical processing has provided important clues about the general organization of the lexical system and the internal structure of the processing components. Reports of patients with selective dysfunction of specific semantic categories such as abstract versus concrete words, living things versus inanimate objects, animals, fruits and vegetables, proper names and so forth, support the hypothesis that the neural organization of the semantic processing component is organized in these categories. There are reports of selective dysfunction of the grammatical categories noun and verb, suggesting that a dimension of lexical organization is the grammatical class of words. But the results reported in these studies have not provided unambiguous evidence concerning two fundamental questions about the nature and the locus of this organization within the lexical system. Is the noun-verb distinction represented in the semantic or in the phonological and orthographic lexicons? Is grammatical-class knowledge represented independently of lexical forms or is it represented separately and redundantly within each modality-specific lexicon? Here we report the performance of two brain-damaged subjects with modality-specific deficits restricted principally (H.W.) or virtually only (S.J.D) to verbs in oral and written production, respectively. The contrasting performance suggests that grammatical-class distinctions are redundantly represented in the phonological and orthographic output lexical components.

Aphasia↗
PubMed1991

Deficit to stimulus-centered, letter shape representations in a case of "unilateral neglect".

A brain-damaged subject is described whose pattern of performance in various reading tasks can be explained by proposing damage at a level of the word recognition process in which a representation with stimulus-centered, rather than retinal- or word-centered, coordinates is processed. Analysis of her reading performance as a function of topographical arrangement of letters, position of errors in the letter string, and the effects of letter spacing and of adding a prefix or suffix provide evidence not only for the existence of this level of representation (the letter-shape map in a model proposed by Caramazza and Hillis [3]), but also for specific assumptions about its functioning and structure.

Attention↗
PubMed1991

Mechanisms for accessing lexical representations for output: evidence from a category-specific semantic deficit.

We report the performance of a neurologically impaired patient, JJ, whose oral reading of words exceeded his naming and comprehension performance for the same words--a pattern of performance that has been previously presented as evidence for "direct, nonsemantic, lexical" routes to output in reading. However, detailed analyses of JJ's reading and comprehension revealed two results that do not follow directly from the "direct route" hypothesis: (1) He accurately read aloud all orthophonologically regular words and just those irregular words for which he demonstrated some comprehension (as indicated by correct responses or within-category semantic errors in naming and comprehension tasks); and (2) his reading errors on words that were not comprehended at all (but were recognized as words) were phonologically plausible (e.g., soot read as "suit"). We account for these results by proposing that preserved sublexical mechanisms for converting print to sound, together with partially preserved semantic information, serve to mediate the activation of representations in the phonological output lexicon in the task of reading aloud. We present similar arguments for postulating an interaction between sublexical mechanisms and lexical output components of the spelling process.

Aged↗
PubMed1991

Selective impairment of thematic role assignment in sentence processing.

We report the performance of a brain-damaged subject showing a particularly pure dissociation between impairment in processing thematic roles and spared ability to process the morphological structure of sentences. The thematic role processing impairment was observed in both comprehension and production of active and passive reversible sentences, although it was more severe for the latter sentence type. This pattern of performance poses interesting challenges for current conceptions of the nature of language breakdown in aphasia and for models of normal sentence processing.

Aphasia, Wernicke↗
PubMed1991

Clinical syndromes are not God's gift to cognitive neuropsychology: a reply to a rebuttal to an answer to a response to the case against syndrome-based research.

In this paper we consider several issues about single-patient versus syndrome-based research in response to E. Zurif, D. Swinney, and J. A. Fodor's (1991, Brain and Cognition, 16, 198-210) criticism of A. Caramazza and W. Badecker (1989, Brain and Cognition, 10, 256-295). We argue that these authors have failed to provide convincing arguments in favor of syndrome-based research. In particular, we show that the specific example--a study by D. Swinney, E. Zurif, and J. Nicol (1989, Journal of Cognitive Neurosciences, 1, 25-37)--given by these authors as a demonstration of the usefulness of syndrome-based research to inform theories of normal language processing does not in fact serve this purpose.

Aphasia, Broca↗
PubMed1991

Varieties of sentence comprehension deficits: a case study.

In recent publications, Grodzinsky (1984, 1986, 1990) has offered a new theory of the disruption of sentence comprehension in so-called agrammatic aphasics. In these works Grodzinsky contends that his account, which is based in various ways on the formal apparatus of current syntactic theory (Chomsky, 1981), is an accurate and explanatory characterization of the preserved language of all those who present with both agrammatic sentence production and asyntactic sentence comprehension. We argue that this claim is not in accord with the facts. We present a detailed case study of the sentence comprehension performance of a patient who is clinically categorized as agrammatic. This patient's performance on full and truncated passives, and on subject- and object-cleft sentences fails each of Grodzinsky's predictions for these sentence types. We argue that whether there exists any patient who does exhibit the predicted performance pattern is also in serious doubt.

Aphasia, Broca↗
PubMed1991

The interaction of lexical and non-lexical processing mechanisms: evidence from anomia.

Patient SF presented with a selective deficit in naming, in the presence of normal auditory, visual and pictorial input processing, and of normal comprehension. The naming disorder was independent of input modality, and resulted in the inability to respond to low-frequency items. The analysis of the patient's performance in the repeated administration of the same set of pictures for oral naming and for written naming demonstrated that both tasks were disrupted to a similar extent--high consistency values were observed both across and within modality. Thus, the profile of the naming disorder observed in this patient was consistent with damage to phonological and orthographic output lexicons. SF's performance in reading and writing was apparently at odds with this account, as he was able to read aloud words with lexically-assigned stress, and to write to dictation words whose spelling is also determined lexically. The co-occurrence of the inability to activate output lexical representations in both oral and written picture naming, in the context of normal ability to activate the same representations in reading and in writing is consistent with the notion that phonological and orthographic output lexicons are distinct, but interact with nonlexical conversion mechanisms.

Anomia↗
PubMed1991

Category-specific naming and comprehension impairment: a double dissociation.

We describe 2 neurologically impaired patients with lesions involving primarily the left temporal lobe, whose production and comprehension of words in the semantic category of animals were disproportionately spared in 1 case and disproportionately impaired in the other, in comparison to performance with other common categories. This double dissociation provides neurally based evidence for the view that lexical-semantic information is organized categorically.

Aged↗
PubMed1990

Spatial representation of words in the brain implied by studies of a unilateral neglect patient.

Reading and writing require access to stored knowledge about the spelling of words. Presumably, we recognize chair but not chare or chiar as a word of English, and similarly would write 'chair' but not 'chare' or 'chiar', because we access orthographic representations that specify the identity and the order of the graphemes (abstract letter representations) that comprise the spelling of words. Thus, a fundamental problem concerns the content and structure of the hypothesized orthographic representations, and how information about grapheme order is represented and processed. We present evidence from a brain-damaged patient (N.G.) with unilateral neglect that this information is coded spatially. Unilateral neglect is a disorder clinically characterized by the inability to perceive or respond to stimuli presented to the side contralateral to the site of lesion, despite the absence of significant sensory or motor deficits. The patient made reading and spelling errors only on the right half of words, regardless of length. Furthermore, she produced the same pattern of errors in reading and spelling, irrespective of the topographic arrangement of stimuli in reading (horizontal, vertical or mirror-reversed words) and of the type of response in spelling (written, oral or backward oral spelling). This pattern of performance suggests that order information in orthographic representations is coded spatially in a word-centred coordinate system; that is, in a spatially defined coordinate frame whose centre corresponds to the midpoint of a canonical, orientation-invariant representation of the word and not the midpoint of the word stimulus.

Aged↗
PubMed1990

Lexical morphology and its role in the writing process: evidence from a case of acquired dysgraphia.

A case of acquired dysgraphia is presented in which the deficit is attributed to an impairment at the level of the Graphemic Output Buffer. It is argued that this patient's performance can be used to identify the representational character of the processing units that are stored in the Orthographic Output Lexicon. In particular, it is argued that the distribution of spelling errors and the types of lexical items which affect error rates indicate that the lexical representations passed from the lexical output system to the Graphemic Output Buffer correspond to the productive morphemes of the language.

Agraphia↗
PubMed1990

The structure of graphemic representations.

The analysis of the spelling performance of a brain-damaged dysgraphic subject is reported. The subject's spelling performance was affected by various graphotactic factors, such as the distinction between consonant and vowel and graphosyllabic structure. For example, while the subject produced many consonant and vowel deletion errors when these were part of consonant and vowel clusters, respectively (e.g., sfondo----sondo; giunta----gunta), deletions were virtually never produced for single consonants flanked by two vowels (e.g., onesto----oesto) or for single vowels flanked by two consonants (e.g., tirare----trare). The demonstration that graphosyllabic factors affect spelling performance disconfirms the hypothesis that graphemic representations consist simply of linearly ordered sets of graphemes. It is concluded that graphemic representations are multidimensional structures: one dimension specifies the grapheme identities that comprise the spelling of a word; a second dimension specifies the consonant/vowel status of the graphemes; a third dimension represents the graphosyllabic structure of the grapheme string; and, a fourth dimension provides information about geminate features.

Agraphia↗
PubMed1990

Where do semantic errors come from?

We report the performance of two brain-damaged subjects (RGB and HW) whose frequent errors in spoken production are nearly always semantically related to the target word. Both subjects show similar, high rates of these "semantic" errors in oral naming and oral reading; yet neither subject makes semantic errors in comparable written tasks. Further, results of a variety of lexical tasks with the same stimuli demonstrate unimpaired comprehension of printed or spoken words, including those that are orally produced as semantic errors. These patterns of performance are interpreted as resulting from damage to the phonological output lexicon. The postulated deficit is contrasted to the hypothesis of impairment to the lexical-semantic component, required to explain performance by brain-damaged subjects described elsewhere who make seemingly identical types of oral production errors to those of RGB and HW, but, in addition, make comparable errors in writing and comprehension tasks.

Brain Damage, Chronic↗