Sorting out what's in a word from what's not: Evaluating Clark's Semantic Features Acquisition theory

The Semantic Features Acquisition theory of semantic development which is due to E. Clark (e.g., 1973b) is reviewed and evaluated against the recent experimental literature, with special reference to the acquisition of English antonyms. The review critically examines the three major ontogenetic principles of Clark's theory in light of numerous recent findings, many of which are at variance in some major way with predictions from the theory. In many instances, new data are available which call into question previous findings. A recurrent problem has been that children's comprehension task performance is confounded with their response biases which are specific to the linguistic and nonlinguistic contexts in which the lexical terms are presented. Methodological implications are discussed, with recommendations for employing the logic of converging operations.     

Behavioral treatment of thunder and lightning phobias.

The use of four different behavioral techniques in the treatment of six female clients with thunder and lightning phobia is described. The techniques (Systematic desensitization. Covert reinforcement. Stress inoculation training, and Self administered desensitization with tape recorder) were evaluated in single-case experimental designs, using both self-report, behavioral, and physiological data.The immediate and follow-up results showed that five of the clients were completely recovered and the sixth markedly improved after their respective treatment (10–14 session). These results and the questions concerning continuous assessment in single-case design and external validity of laboratory assessment in phobic conditions are discussed.     

Less is not more: Further observations on nonlinguistic strategies

In an attempt to clarify the role of nonlinguistic preferences in children's responses to the words more and less, children 3–4 years of age were administered three tasks. Two of these required the child to indicate which of two arrays had more or less items, as instructed; the third task required the child to point to any one of two arrays. Children consistently selected the arrays with more items on all three tasks. The present finding of a response bias necessitates a reinterpretation of earlier studies of more and less. The results are discussed in terms of the full and partial semantics hypotheses as articulated by E. Clark.     

Feature selection and classification: A developmental study

Two hundred and thirteen children between the ages of 4 and 16 sorted 30 complex objects freely into groups. These were either schematic faces, schematic imaginary animals, or histoform patterns and were constructed from 9 independently and continuously varying features, each with 10 levels. The three sets were equivalent in terms of underlying numerical structure. A new method of analysis of the groups formed yielded the following direct measures of subjective organization in the sorting of each child: the number of features used in sorting, the accuracy of sorting, and the number of independent dimensions of classification. Both the material and the analysis of sorting were devised on the assumption that only some of the component features of complex objects are used for classification, while others are ignored. Sorting performance differed markedly both with age and with different types of material. The improvement in sorting ability with age, except for the youngest children, could be attributed to an increase in the number of features used rather than an improvement in the accuracy of use. In contrast, the poor sorting of histoform patterns as opposed to faces and animals was due to a low level of sorting accuracy. The basic results on the development of classification confirmed previous studies, and hence suggest that it is valid to consider feature selection as a basic component of classification.     

Repetition in the transcortical aphasias

Transcortical aphasic patients were assessed on a repetition task comprised of both well-formed and deviant sentences. The patients faithfully repeated those sentences that were factually incorrect but grammatically well formed, and those sentences that were ungrammatical because of selection restriction violations. In contrast, presented with sentences featuring only minor syntactic violations (e.g., lack of number agreement), the patients spontaneously, and without awareness, resisted exact repetition; moreover, the resultant changes most often served to correct the syntactic deviations. Repetitions of sentences of this latter type also revealed a difference between the patients as a function of level of comprehension. The transcortical motor aphasic patient was influenced by semantic factors in his alterations of the minor syntactic violations, while the transcortical sensory aphasic was not. These findings are discussed in relation to the notion of autonomous syntactic processing. They are taken to suggest that syntactic facts such as number agreement are represented at a level in the processing chain that is distinct from that of semantic representation.     

Modeling spatial knowledge

A person's cognitive map, or knowledge of large-scale space, is built up from observations gathered as he travels through the environment. It acts as a problem solver to find routes and relative positions, as well as describing the current location. The TOUR model captures the multiple representations that make up the cognitive map, the problem-solving strategies it uses, and the mechanisms for assimilating new information. The representations have rich collections of states of partial knowledge, which support many of the performance characteristics of common-sense knowledge.     

Dichhaptic hand-order effects with verbal and nonverbal tactile stimulation

The palms of normal right-handed subjects were stimulated dichhaptically, i.e., with competing, bimanually presented tactile stimuli consisting of pairs of letters, pairs of digits, or pairs of line orientations. The subjects were required to identify both stimuli in a particular order, and order of report was compared between hands and across stimulus materials. Results indicated right-hand superiority for letters and left-hand superiority for lines; no hand differences occurred for digits. However, observed differences between hands appeared with second reports only, suggesting that measures of tactile storage are more sensitive to laterality differences than measures closer in time to actual stimulation.     

Acquisition of phobias and anxiety response patterns in clinical patients

The ways in which phobic patients (N = 106; animal-, social- and claustrophobics) acquired their phobias were investigated in the present study. The results showed that a large majority (58%) of the patients attributed their phobias to conditioning experiences, while 17% recalled vicarious experiences, 10% instructions/information and 15% could not recall any specific onset circumstances. There was no clearcut relationship between the ways of acquisition and anxiety components (subjective, behavioral, physiological), nor did the conditioning and indirectly acquired phobias differ in severity. However, some interesting trends emerged in the data, showing that animal phobics who recalled conditioning experiences to a larger extent also responded physiologically. For patients with indirect onset experiences (for all three types of phobias) the reverse was true, i.e. they responded to a larger extent in a cognitive-subjective way, rather than with increased physiological arousal.     

Categorization and representation of physics problems by experts and novices

The representation of physics problems in relation to the organization of physics knowledge is investigated in experts and novices. Four experiments examine (a) the existence of problem categories as a basis for representation; (b) differences in the categories used by experts and novices; (c) differences in the knowledge associated with the categories; and (d) features in the problems that contribute to problem categorization and representation. Results from sorting tasks and protocols reveal that experts and novices begin their problem representations with specifiably different problem categories, and completion of the representations depends on the knowledge associated with the categories. For, the experts initially abstract physics principles to approach and solve a problem representation, whereas novices base their representation and approaches on the problem's literal features.