Mental calculation in an autistic savant: a case study.

We present a detailed investigation of mental calculation in RH, an autistic savant. In Experiment 1 RH performed faster and more accurately than control subjects in mentally solving multi-digit multiplication problems. However, we found no evidence that RH employed short-cut strategies to solve these problems. His response times were consistent with application of a left-to-right computational procedure employed by expert calculators. He also responded extremely quickly to 2-digit squares, suggesting that he may have memorized the answers. In Experiment 2 we taught RH a new computational algorithm for converting temperatures from Celsius to Fahrenheit. RH was able to learn the new algorithm, but required much assistance and made only slight gains with practice. RH did not recognize an easy solution strategy based on inverting steps in the conversion algorithm. We suggest that the inflexible nature of RH's performance may reflect his autistic tendencies coupled with limited intelligence.

Facts, rules, and procedures in normal calculation: evidence from multiple single-patient studies of impaired arithmetic fact retrieval.

This article presents results from multiple single-case studies of brain-damaged patients with impairments in retrieval of arithmetic facts (i.e., "table" facts such as 8 x 7 = 56). The results provide a basis for exploring the types of knowledge implicated in simple arithmetic performance, the internal representations for the various knowledge types, the processes operating upon these representations, and the ways in which the representations or processes may be disrupted by brain damage.

Number impairments following hypokalemia: a case study.

A case study is reported of a 55 year old female (B.B.) who complained of significant difficulty manipulating and remembering numbers. Twenty-four years prior to the present complaint, B.B. had been hospitalized for idiopathic hypokalemia and secondary hyperaldosteronism. The present study examined the nature and extent of B.B.'s cognitive impairments. On standardized and experimental tests of intelligence and general cognitive ability, she scored quite well. However, she demonstrated significant impairments in digit span, number processing and calculation, memory for biographical details involving numbers and general number knowledge. The implications of such a constellation of impairments are discussed from both cognitive and neurological perspectives.

Cambio de actitud a través de la [quot ]odontología afectiva[quot ]. La entrevista inicial / [Change in attitude toward the [quot ]affective dentist[quot ]. The initial interview]

The role of initial patient assessment as part of a total program designed to change negative attitudes towards the dental visit is discussed. The strategy endorsed is one which takes into account the affective component of a patient’s attitude and allows for its expression trough an empathic client-centered itake. Two case studies area presented as illustrations of this approach.

Models of arithmetic fact retrieval: an evaluation in light of findings from normal and brain-damaged subjects.

Retrieval of basic arithmetic facts is a central aspect of almost any arithmetic performance. Furthermore, the arithmetic facts provide an opportunity to study memory processes in the context of a naturally occurring but circumscribed set of facts. This article examines current models of arithmetic fact retrieval in light of previously reported data from normal subjects, as well as the results from brain-damaged patients reported by Sokol, McCloskey, Cohen, and Aliminosa (1991) in the preceding article. The discussion serves to delineate the strengths and limitations of the models and, more generally, to identify important theoretical and empirical issues in the study of arithmetic fact retrieval.

Cognitive representations and processes in arithmetic: inferences from the performance of brain-damaged subjects.

In this article, we present data from two brain-damaged patients with calculation impairments in support of claims about the cognitive mechanisms underlying simple arithmetic performance. We first present a model of the functional architecture of the cognitive calculation system based on previous research. We then elaborate this architecture through detailed examination of the patterns of spared and impaired performance of the two patients. From the patients' performance we make the following theoretical claims: that some arithmetic facts are stored in the form of individual fact representations (e.g., 9 x 4 = 36), whereas other facts are stored in the form of a general rule (e.g., 0 x N = 0); that arithmetic fact retrieval is mediated by abstract internal representations that are independent of the form in which problems are presented or responses are given; that arithmetic facts and calculation procedures are functionally independent; and that calculation algorithms may include special-case procedures that function to increase the speed or efficiency of problem solving. We conclude with a discussion of several more general issues relevant to the reported research.

[Change in attitude toward the "affective dentist". The initial interview]. / Cambio de actitud a través de la "odontología afectiva". La entrevista inicial.

The role of initial patient assessment as part of a total program designed to change negative attitudes towards the dental visit is discussed. The strategy endorsed is one which takes into account the affective component of a patient's attitude and allows for its expression trough an empathic client-centered itake. Two case studies area presented as illustrations of this approach.

In defense of a modular architecture for the number-processing system: reply to Campbell and Clark.

In several recent articles we have developed a model of the cognitive number-processing and calculation systems. Campbell and Clark (1988), commenting on one of these articles (McCloskey, Sokol, & Goodman, 1986), called into question our model's assumption of a modular functional architecture and a single form of internal numerical representation. Campbell and Clark proposed as an alternative a nonmodular encoding-complex view. In this reply we discuss the results offered by Campbell and Clark as evidence against our model, arguing that several of these results are in fact consistent with the model and that the remaining results, while raising significant issues, by no means justify abandonment of the modular framework and the constraints it imposes. We also point out that whereas our model provides specific, well-motivated interpretations for a substantial body of empirical findings, the encoding-complex view is so underspecified and unconstrained as to be vacuous.

A biopsychosocial approach to the management of anxious and phobic patients.

In this article, it is suggested that anxious and phobic dental patients represent an important and typically underserved population. A number of practical techniques for their management is offered, taking into account marketplace considerations as well as possible etiologic factors of their avoidance behavior. It is concluded that these patients are indeed tractable and that their incorporation into a dental practice can be highly rewarding for both patient and clinician.

Cognitive processes in verbal-number production: inferences from the performance of brain-damaged subjects.

This article presents a model of the cognitive processes involved in the spoken production of verbal numbers (e.g., thirteen thousand four hundred two). On the basis of single-case studies of two brain-damaged subjects with number production deficits, we argue that verbal-number production involves the generation of a syntactic frame that constitutes a plan for the production of the appropriate sequence of words. The syntactic frame specifies each to-be-retrieved word in terms of a number-lexical class (i.e., ones, teens, or tens) and a position within that class. These class/position-within-class specifications guide the retrieval of lexical representations from a production lexicon that is partitioned into functionally distinct ones, teens, and tens classes. We conclude with a brief discussion of the rationale for, and advantages of, using patterns of impaired performance as a basis for drawing inferences about normal cognition.