Cerebellar-induced apraxic agraphia: a review and three new cases

Apraxic agraphia is a writing disorder due to a loss or lack of access to motor engrams that program the movements necessary to produce letters. Clinical and functional neuroimaging studies have demonstrated that the neural network responsible for writing includes the superior parietal region and the dorsolateral and medial premotor cortex. Recent studies of two cases with atypical lesion localisations in the left thalamus and the right cerebellum support the hypothesis that the written language network is larger than previously assumed. The aim of this study is twofold: (1) to provide a survey of cases of apraxic agraphia published between 1973 and June 2010, and (2) to provide further evidence for a role of the cerebellum in writing via three additional cases who presented with apraxic agraphia after ischemic damage in the cerebellum. Functional neuroimaging studies by means of brain perfusion SPECT showed perfusional deficits in the anatomoclinically suspected supratentorial areas, subserving language dynamics, syntax, naming, writing and executive functioning.     

Clinical validation of the trait and state versions of the Food Craving Questionnaire

This is the first study to evaluate the psychometric properties of the Food Craving Questionnaire-Trait (FCQ-T), and Food Craving Questionnaire-State (FCQ-S) measures using a clinically heterogeneous sample of eating disorder patients (N = 177) recruited from seven different outpatient eating disorder treatment centers in Spain. Confirmatory factor analyses (CFAs) corroborated the factor structures of the FCQ-T and FCQ-S. The measures' scores and their factor-derived scale-scores yielded internal consistency reliability indexes that ranged from adequate to excellent. The measures were predictive of eating disorder symptoms. As expected, the FCQ-T was more strongly associated with eating disorder psychopathology than the FCQ-S. The results replicated the psychometric properties of the FCQ-T and FCQ-S in eating disorder populations and could become useful tools in clinical and research settings.     

Adolescent problem behavior: The effect of peers and the moderating role of father absence and the mother-child relationship

Examined the effect of peer problem behavior, the absence of a father or equivalent in the home, and the mother-adolescent relationship as predictors of adolescent problem behavior in a sample of 112 African American adolescents. Statistical analyses compared a moderator model to a mediational model and a cumulative risk model. As predicted, the moderator model was superior to the alternative models. Specifically, whereas the mediational model predicted that the effect of father absence and the mother-child relationship upon adolescent problem behavior would be mediated by peer problem behavior, neither effected peer problem behavior or adolescent problem behavior. Similarly, a cumulative risk index did not predict either child or parent reports of problem behavior and was not sensitive to specific contingencies that existed between the predictor variables. In contrast, an interactive, moderator model described the data quite well. This model suggested that father or equivalent absence magnifies the negative impact of peer problem behavior, while a positive mother-adolescent relationship attenuates this risk. A strong mother-adolescent relationship also served to protect adolescents in father-absent homes from the risk of peer problem behavior. This research was supported by a grant (NICHHD: HD24056) awarded to A. M. Cauce. The authors thank Nydia Ordonez, Tanya Aguilar, and Laurie Deppman for their assistance on the project, and Cliff Lunneberg for suggestions regarding resampling procedures. Portions of this paper were presented at the meetings of the Western Psychological Association, April 1992.     

Sensitivity to event timing in regular and irregular sequences: Influences of musical skill

In two experiments, the performance of listeners with different amounts of musical training (high skill, low skill) was examined in a two-alternative forced choice time-detection task involving simple five-cycle acoustic sequences. In each of a series of trials, all listeners determined which of two pattern cycles contained a small time change. Sequence context was also varied (regular vs. irregular timing). In Experiment 1, in which context was manipulated as a between-subjects variable, high-skill listeners performed significantly better than low-skill listeners only with regular patterns. In Experiment 2, in which context was manipulated as a within-subjects variable, the only significant source of variance was pattern context: All listeners were better at detecting time changes in regular than in irregular patterns. The results are considered in light of several hypotheses, including the expectancy/contrast model (Jones & Boltz, 1989).     

A tutorial on some issues and methods in serial pattern research

In a review of major trends in serial pattern research, the issue of structural ambiguity and its relationship to representations of hierarchical and nonhierarchical patterns is considered. Also discussed is the role of various kinds of serial rules that can relate events within a sequence (e.g., nominal, ordinal, interval rules), as well as new developments in representing time relationships. Some practical problems that arise in the study of perception of serial structure are shown to involve its formal specification and the enlistment of appropriate controls. Major pitfalls are illustrated using recent research with music-like patterns (e.g., Deutsch, 1980).     

Rate and structure in memory for auditory patterns

Musically knowledgeable listeners heard auditory patterns based on sets of six (Study 1) or eight tones (Study 2). In the first study, listeners ordered events from patterns generated by hierarchical rule trees and which possessed different pitch space and time structures: one type (nondistance nested) was more likely to produce auditory streaming than the other (distance nested). In the second study, different listeners reconstructed pitch intervals contained in one of eight patterns. Patterns differed according to (1) levels of pitch distance occur), (2) levels of pattern contour (two), and (3) rate (two). In both studies, fast patterns with many large pitch distances were more difficult to recollect. Listeners in the second study telided to “telescope” pitch distances. Most difficult were those rapid sequences with large patch intervals combined into a changing contour (nondistance nested); these patterns streamed. A third study replicated effects due to differences in pitch distances observed in Study 2. Results were interpreted in terms of a rhythmic theory of memory.     

Impairment of syntax and lexical semantics in a patient with bilateral paramedian thalamic infarction

Bilateral vascular thalamic lesions are rare. Although a variety of neurobehavioral manifestations have been described, the literature is less documented with regard to accompanying linguistic disturbances. This article presents an in-depth neurolinguistic analysis of the language symptoms of a patient who incurred bilateral paramedian ischemic damage of the thalamus. In the post-acute phase of the stroke, a unique combination of transcortical sensory aphasia with syntactic impairment was found. Because of this atypical semiological association, additional analyses of spontaneous speech were performed. In spite of the typological affinity with the grammatic characteristic of marked simplification of syntax observed in Broca's aphasia, only a wordclass specific, lexical-semantic deficit for verbs was objectified. The hypothesis that lexical-semantic disturbances in our patient might result from a functional deafferentiation of both thalami with the frontal lobe is supported by: (1) associated neuropsychological deficits of frontal origin and (2) frontal-like behavioral disturbances.     

Higher order pattern structure influences auditory representational momentum

Representational momentum refers to the phenomenon that observers tend to incorrectly remember an event undergoing real or implied motion as shifted beyond its actual final position. This has been demonstrated in both visual and auditory domains. In 5 pitch discrimination experiments, listeners heard tone sequences that implied either linear, periodic, or null motions in pitch space. Their task was to judge whether the pitch of a probe tone following each sequence was the same or different from the final sequence tone. Results suggested that listeners made errors consistent with extrapolation of coherent pitch patterns (linear, periodic) but not with incoherent (null) ones. Hypotheses associated with internalized physical principles and pattern-based expectations are discussed.     

Fragment difficulty in priming on word-completion tests

Word-fragment completion is a frequently used test in implicit memory research. In this test priming is the relevant variable. Priming is obtained by subtracting the proportion of nonstudied word fragments correctly completed (called "completion difficulty baseline") from the studied word fragments correctly completed. Since completion difficulty can spuriously vary greatly between experimental conditions, its effect on magnitude of priming is studied. Normative frequency of occurrence of target words was considered because their influence over performance is known. In an experiment using a word-fragment completion test, participants' completion of fragments at three levels of completion difficulty and two levels of frequency was tested. Analysis showed that completion difficulty had a significant effect on global priming. The priming magnitude was higher for Difficult and Moderately Difficult fragments than for Easy ones. An interaction between fragment difficulty and normative word frequency was observed. When the fragments were easy to complete, the expected effect of higher priming for low-frequency words than for high-frequency words was not observed.