Children's scales of length and loudness: A developmental application of cross-modal matching

The cross-modal matching techniques that have produced scales of sensory magnitude for a variety of perceptual continua in adults were used to construct similar scales in children. Subjects were adults and children 4, 6, 8, and 12 years old. Their task was, first, to match the loudness of a 1000-Hz tone to various visual lengths, and, second, to match the length of a white tape to various loudnesses of the tone. Almost all subjects were able to perform the matching tasks; the average precision of older subjects (12 and Adult) was somewhat greater, but in each of the younger age groups a majority of subjects performed with a precision that equaled that of older subjects. The exponent of the power function that relates length and loudness does not change with age. The scale factor does change, in a way that suggests either that a given sound intensity seems softer, or, more probable, that a given length seems longer, to younger children. The success of cross-modal matching with subjects as young as 4 years means that it is possible to investigate not only single perceptual scales but also intermodal organization in young children.     

Sensory stores and high-speed scanning

A model of scanning based on separate sensory and short-term stores was suggested and tested. The experiment used a probe recognition method, with set size varied from 1 to 8 and a fast presentation rate. A masking procedure was used to vary the number of items available in a possible sensory store. Although conditions were such as to maximize the chances of detecting an effect, none was found: the possible size of the sensory store had no effect on reaction time whatsoever. Other aspects of the data lent little support to a serial exhaustive scanning model, but a previously proposed parallel processing model fared better. Finally, not only was the function for positive probes steeper than that for negative probes but also there was a crossover effect as well. This crossover is not without precedent and may indicate the need for consideration of both accuracy and latency in high-speed scanning studies.     

Response latencies in short-term memory

This paper deals with the problem of the interpretation of response latencies in short-term memory. A paired-associate study using a probe technique was conducted with the main experimental variation the length of the recall interval (1, 2, or 4 sec.). While shortening the interval had a statistically significant effect on recall probability the interaction between recall interval and probe position was negligible. While traditionally response latency is considered a measure of associative strength, such an interpretation seems inappropriate here. As an alternative, latencies may reflect more criterion values than sensitivity as these measures are interpreted in signal-detection theory.     

Methylphenidate and cognitive therapy: A comparison of treatment approaches with hyperactive boys

This study of hyperactive boys evaluated the effects of three modes of treatment in relation to an untreated group. The treatments were administered over a 3-month period and included cognitive training, stimulant drug therapy (methylphenidate), and the two treatments combined. A follow-up assessment was conducted approximately 3 months after contact between the training staff and the child had ceased. Analyses of attentional deployment and cognitive style measures, tests of academic achievement, and behavioral ratings showed that only those children in the two medication treatment conditions demonstrated improvement in attentional deployment and behavioral ratings. In the cognitive therapy condition, there were changes only on measures of attentional deployment. The data did not provide evidence indicating that the combined medication and cognitive therapy condition was any more effective than that condition involving medication alone. Discussion provides future guidelines for evaluation of the relative effectiveness of stimulant drug therapy and other psychological treatment modalities.     

Contrasting speech patterns in apraxia of speech and phonemic paraphasia

This study was designed to determine if perceptual phonological analysis would reveal distinctions between patients with apraxia of speech and patients with phonemic paraphasic speech. Test findings from 10 Broca's aphasics with apraxia of speech were compared to findings from 10 paraphasic speakers (5 conduction and 5 Wernicke's aphasics). Several marked differences were revealed. Predominant locus of errors and relative difficulty of different classes of phonemic segments were significant discriminators. There was a nonsignificant trend for substituted phonemes to be further from target phonetically in the paraphasic patients. In addition, the two groups showed certain consistent differences in the types of errors they produced. Apraxic patients produced many errors of transitionalization, while sequencing errors were more typical of the patients with phonemic paraphasia. The findings are interpreted in relation to a neuropsychological model of speech. It is suggested that phonemic paraphasia represents a breakdown mainly in the retrieval of phonological word patterns, while apraxia of speech is characterized predominantly by a disturbance in encoding phonological patterns into appropriate speech movements.