Some characteristics of concurrent discrimination and retention by monkeys

Before and after learning-set training, 12 rhesus monkeys were tested on the acquisition and retention of tasks consisting of eight concurrent object discrimination problems. Training on the concurrent discrimination was administered unitil a fairly stringent acquisition criterion was met. Under these procedures, retention, unlike acquisition, was little influenced by initial object preferences. Excellent retention was observed both before and after learning-set training. In a second experiment, these same monkeys were tested on a series of concurrent tasks which provided different numbers of objects as the sets of correct and incorrect discriminanda. Task solutions depended largely upon acquiring and retaining a list of correct objects despite designation of the large or small sets as the correct one. The animals seemed not to use “exclusion” strategies even when this might have provided an efficient task solution. It was considered that the monkeys' performances were based on stimulus sampling characteristics like those seen in other discrimination testing situations.     

Effect of positive,negative, and mixed occupational information on cognitive and affective complexity

A series of concentrated research studies over the past 8 years has significantly demonstrated that cognitive complexity in the vocational realm is positively related to congruence or appropriateness of vocational choice. Moreover, research has shown that introducing occupational information significantly reduces, rather than increases, cognitive complexity. The results of the study reported here relate to changes in cognitive complexity as a function of the type of occupational information introduced, namely, information with respect to the advantages of occupations; the disadvantages of occupations, or a combination of positive and negative features of occupations. Our results clearly demonstrated that while positive occupational information alone leads to greater simplicity, negative or mixed information significantly retards the trend toward greater simplicity. Results are discussed from both theoretical and practical perspectives, especially with reference to the typical occupational information provided in routine vocational counseling.     

Effects of varied response modes upon dichotic consonant-vowel identification latency

Reaction times for two right-handed subjects who received 6000 trials of dichotic stop-vowels were obtained under response conditions involving the left hand, right hand, and neck muscles. Results indicated latencies were shorter (150+ msec) when targets were presented to the right rather than the left ear. Large and stable differences in latencies remained invariant with the mode of response. Reaction times did not vary as a function of the target's place or manner of articulation. The relationship between obtained measures of latency and percentage correct ruled out speed-accuracy trade-offs as a source of the obtained differences in latencies.     

The word order problem in agrammatism : I. Comprehension

The results of a picture-pointing comprehension test show that agrammatic aphasics have difficulty understanding sentences in which the underlying semantic roles are marked by the order of noun phrases around a verbal element. Agrammatic patients performed poorly on reversible constructions involving spatial prepositions (e.g., “The square is above the circle”) and verbs (e.g., “The dancer applauds the clown”). These results have significance for the interpretation of the underlying disturbance in agrammatism—whether the deficit is syntactic or purely phonological.     

Decomposing the reaction time distribution: Pure insertion and selective influence revisited

This paper investigates the consequences of extending the assumptions of pure insertion and selective influence (popular in RT theorizing) to the level of the distribution. In the case of pure insertion and under the additional assumption that the additive random variable is exponentially distributed, a solution is obtained which not only allows estimation of the exponential-rate parameter but also provides a test of the assumptions. The result is shown to be applicable not only when processing is serial but also for certain parallel models. In addition, discrimination between self-terminating and exhaustive search strategies is provided, and in the case of either, both parameter estimation and tests of the model are possible. Extensions to nonexponential models are investigated and a general method of moments solution is outlined. In the case of selective influence a general nonparametric alternative to Sternberg's additive factor method is developed. The problem of empirical estimation and application is then considered. Simulations which place bounds on the type I and II error are reported. Finally the first theorem is provided an illustrative application with data from a memory scanning experiment. The results provide some support for the double assumption of pure insertion and that the additive random variable is distributed exponentially.     

Development of speech and language following bilateral frontal lesions

Language and speech were studied in a young child with perinatally acquired bifrontal lesions. Bilateral frontal pathology seriously interfered with the development of intelligible speech and resulted in a persistent expressive aphasia. Analysis of the neuropsychological profile indicated impairments in intelligence and language comprehension. These deficits, however, were considered secondary to the profound speech programming disorder. The findings indicate that, despite the plasticity of the immature central nervous system, bilateral frontal injury sustained at an early age precludes the development of intelligible speech. Furthermore, structurally intact cortical regions outside the territories of the speech zones fail to mediate normal speech and language development.     

Hegel and Sellars on the Unity of Things

ABSTRACT

I have claimed previously that Hegel and Sellars are both, in the end, monistic visionaries, though with radically different visions of the grand unity of things. In this paper I explain and defend that claim. Section one differentiates several kinds of monism; section two discusses Hegel’s vision of the underlying unity of thing, while section three does the same for Sellars. The compare-and-contrast assignment is brought to completion in section four.