The critical role of group studies in neuropsychology: comprehension regularities in Broca's aphasia

We reexamine the empirical record of the comprehension abilities of Broca's aphasic patients. We establish clear, commonly accepted, selection criteria and obtain a pool of results. We then subject these results to a detailed statistical analysis and show that these patients comprehend certain canonical sentences (actives, subject relatives, and clefts with agentive predicates) at above-chance levels, whereas comprehension of sentences that contain deviations from canonicity (passives, object-gap relatives, and clefts) is distinct and is at chance. That the latter is the case, and patients indeed guess at such structures, we show by comparing the distribution of individual results in passive comprehension to that of a model for such guessing-an analogous series of tosses of an unbiased coin. The two distributions are virtually identical. We conclude that the group's performance is stable, and well-delineated, despite intersubject variation whose source is now identified. This means that certain comprehension tests may not always be used for the diagnosis of individual patients, but they do characterize the group. It also means that group studies are not just a valid option in neuropsychology; they are a must, since demonstrations like ours indiciate very clearly that single-case studies may be misleading. As we show, the findings from any one patient, without the context of a group, may give a distorted picture of the pathological reality. Our conclusions thus promote studies of groups of brain-damaged patients as a central tool for the investigation of brain/behavior relations.     

Prevalence,Prediction, and Prevention of Psychologist Misconduct

Studies of psychologist misconduct generally focus on unethical sexual behaviours. In contrast, the following study reports on all complaints by the public against psychologists reported to the New South Wales Psychologists Registration Board over a 4‐year period. There were 248 independent notifications of misconduct about 224 registered psychologists, out of a total sample of 9,489 registered psychologists. The most frequent type of misconduct reported was in relation to poor communication standards (35.5%). Other complaints were in relation to professional incompetency (16.5%), poor report writing (14.1%), poor business practices (12.5%), boundary violations (9.7%), poor character (5.6%), registration status (3.2%), impairment (1.6%), and the inappropriate use of specialist titles (1.2%). Males were 2.5 times more likely to have a misconduct complaint made about them than females. Senior highly qualified psychologists attracted a greater number of complaints, but these were generally of a less serious nature. Over a 30‐year career, about 20 out of every 100 psychologists can expect to receive a complaint from the public, and two will receive a serious misconduct complaint that might lead to deregistration. Strategies for preventing malpractice arising from these results include regular peer consultation, developing quality practise standards, and maintaining professional boundaries.     

Language deficits and the theory of syntax

A new structural account of agrammatism is proposed, which analyzes the deficit in terms of one current theory of syntax. First, the motivation for accounts of this kind is given. Then, a variety of experimental findings from sentence comprehension in agrammatism are examined and accounted for in a unified way. It is shown that a minimal change in the syntactic model (achieved by imposing a special condition on a construct called trace), results in a model which accounts for all the data at hand. A number of possible objections to this proposal is then examined, and reasons are given to dismiss these objections. Also, it is shown that this proposal is preferable to other structural accounts which have been recently proposed. Finally, the empirical consequences of this account are discussed, with a special emphasis on the implications for models of language processing.     

The neurology of syntax: language use without Broca's area

A new view of the functional role of the left anterior cortex in language use is proposed. The experimental record indicates that most human linguistic abilities are not localized in this region. In particular, most of syntax (long thought to be there) is not located in Broca's area and its vicinity (operculum, insula, and subjacent white matter). This cerebral region, implicated in Broca's aphasia, does have a role in syntactic processing, but a highly specific one: It is the neural home to receptive mechanisms involved in the computation of the relation between transformationally moved phrasal constituents and their extraction sites (in line with the Trace-Deletion Hypothesis). It is also involved in the construction of higher parts of the syntactic tree in speech production. By contrast, basic combinatorial capacities necessary for language processing--for example, structure-building operations, lexical insertion--are not supported by the neural tissue of this cerebral region, nor is lexical or combinatorial semantics. The dense body of empirical evidence supporting this restrictive view comes mainly from several angles on lesion studies of syntax in agrammatic Broca's aphasia. Five empirical arguments are presented: experiments in sentence comprehension, cross-linguistic considerations (where aphasia findings from several language types are pooled and scrutinized comparatively), grammaticality and plausibility judgments, real-time processing of complex sentences, and rehabilitation. Also discussed are recent results from functional neuroimaging and from structured observations on speech production of Broca's aphasics. Syntactic abilities are nonetheless distinct from other cognitive skills and are represented entirely and exclusively in the left cerebral hemisphere. Although more widespread in the left hemisphere than previously thought, they are clearly distinct from other human combinatorial and intellectual abilities. The neurological record (based on functional imaging, split-brain and right-hemisphere-damaged patients, as well as patients suffering from a breakdown of mathematical skills) indicates that language is a distinct, modularly organized neurological entity. Combinatorial aspects of the language faculty reside in the human left cerebral hemisphere, but only the transformational component (or algorithms that implement it in use) is located in and around Broca's area.     

The neural reality of syntactic transformations: evidence from functional magnetic resonance imaging

The functional anatomy of syntactic transformations, a major computational operation invoked in sentence processing, was identified through a functional magnetic resonance imaging investigation. A grammaticality judgment task was used, presented through a novel hidden-blocks design. Subjects listened to transformational and nontransformational sentences in which a host of other complexity generators (number of words, prepositions, embeddings, etc.) were kept constant. A series of analyses revealed that the neural processing of transformations is localizable, evoking a highly lateralized and localized activation in the left inferior frontal gyrus (Broca's region) and bilateral activation in the posterior superior temporal sulcus. The pattern of activation associated with transformational analysis was distinct from the one observed in neighboring regions, and anatomically separable from the effects of verb complexity, which yielded significant activation in the left posterior superior temporal sulcus. Taken together with neuropsychological evidence, these results uncover the neural reality of syntactic transformations.     

Comprehension regularity in Broca's aphasia? There's more of it than you ever imagined.

We analyze the comprehension data in Broca's aphasia, pooled together by Berndt, Mitchum, and Haendinges (1996). We show that once analyzed properly, these data have statistical structure that is very similar to that revealed by the analysis in Grodzinsky, Pinango, Zurif, and Drai (1999). The suggestion that the latter authors doctored the data to obtain a desired outcome is as false as the claim that the data in Berndt et al. show no regularity. Comprehension scores in Broca's aphasia do have statistical structure, which correlates with syntactic structure. Thus, the role of Broca's area and its vicinity in language processing can be made more precise.     

A Practice-Based Approach to Group Identification in Nonverbal Learning Disorders

Evidence-based practice, the rigorous conduct of clinical analysis and intervention, includes practice-based evidence. Here, practice data were the source of three “clinical portraits” used for exploratory analysis of an array of cognitive and social problems in 30 children whose neurobehavioral profiles fulfilled psychometric criteria for a nonverbal learning disability (NLD). Qualitative analysis of the children's academic and adjustment difficulties revealed patterns of dissociable deficits. These findings argue for at least three groups within the NLD construct. Identifying such subgroups is of practical importance: More precise characterization of neuropsychological competencies leads to improved interventions and better outcomes.