Speech perception in rats: use of duration and rise time cues in labeling of affricate/fricative sounds

The voiceless affricate/fricative contrast has played an important role in developing auditory theories of speech perception. This type of theory draws some of its support from experimental data on animals. However, nothing is known about differential responding of affricate/fricative continua by animals. In the current study, the ability of hooded rats to "label" an affricate/fricative continuum was tested. Transfer (without retraining) to analogous nonspeech continua was also tested. The nonspeech continua were chosen so that if transfer occurred, it would indicate whether the animals had learned to use rise time or duration cues to differentiate affricates from fricatives. The data from 9 of 10 rats indicated that rats can discriminate between these cues and do so in a similar manner to human subjects. The data from 9 of 10 rats also demonstrated that the rise time of the stimulus was the basis of the discrimination; the remaining rat appeared to use duration.     

Cognitive correlates of depressive symptoms in 11-year-old children

Self-reports of depressive symptoms were obtained for 792 11-year-old New Zealand children using a structured interview. The aim of the present study was to test the hypothesis that depressive symptomatology in children is associated with impairment on cognitive tasks. The results did not support this hypothesis. Depression was unrelated to performance on various subscales of the WISCR, whereas self-reported inattention was associated with poor performance. Depressive symptoms, however, were significantly related to lower self-esteem and a poorer self-perception of scholastic ability.The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council of New Zealand and the Departments of Education and Health, and involves several departments of the University of Otago. Much of the data are gathered by voluntary workers from the Dunedin community. The authors are indebted to the many people whose contributions make this ongoing study possible.     

Signaled Delay of Reinforcement: Effects of Postconditioning Manipulation of Context Associative Strength on Instrumental Performance

Two experiments examined the influence of postconditioning treatments of contextual cues on instrumental responding acquired with a signaled delay of reinforcement schedule. In Experiment 1, mere exposure to the conditioning context after instrumental training resulted in an attenuated response rate during an extinction test. In the second experiment, responding was decreased by exposure to the contextual cues or sessions in which signaled noncontingent reinforcements occurred. The greatest response decrement, however, occurred following unsignaled noncontingent food presentations. The results are discussed with respect to the different roles of contextual cues on operant responding.     

Sex and birth order differences in filial behavior

Personal interviews were conducted with 499 children of elderly white widows. Results showed no birth order differences in the provision of assistance to the elderly; however, there were significant sex differences. Daughters performed more caretaking activities and social services and provided more emotional support for their mothers than did sons. Sons had a tendency, though insignificant, to provide more advisory assistance to their mothers. After adjusting for situational differences between daughters and sons a sex difference remained only for the provision of emotional support.     

Phonetic disintegration in aphasia: Acoustic analysis of spectral characteristics for place of articulation

In this study, we attempted to determine whether phonetic disintegration of speech in Broca's aphasia affects the spectral characteristics of speech sounds as has been shown for the temporal characteristics of speech. To this end, we investigated the production of place of articulation in Broca's aphasics. Acoustic analysis of the spectral characteristics for stop consonants were conducted. Results indicated that the static aspects of speech production were preserved, as Broca's aphasics seemed to be able to reach the articulatory configuration for the appropriate place of articulation. However, the dynamic aspects of speech production seemed to be impaired, as their productions reflected problems with the source characteristics of speech sounds and with the integration of articulatory movements in the vocal tract. Listener perceptions of the aphasics' productions were compared with acoustic analyses for these same productions. The two measures were related; that is, the spectral characteristics of the utterances provided salient cues for place of articulation perception. An analysis of the occurrences of errors along the dimensions of voicing and place showed that aphasics rarely produce utterances containing both voice and place substitutions.     

Analysis of potentiation and overshadowing effects in the instrumental performance of pigeons

In each of two experiments, pigeons were trained on a multiple VI (variable interval) schedule with a 3-s delay of reinforcement. Different components were associated with different key colors. Experiment 1 (stage 2) confirmed a previous finding that the response rate is higher in a component having a signal (illumination of the houselight) filling the delay interval than in a component lacking the signal. This potentiation effect was replaced by an overshadowing effect (i.e., the rate was low in the signaled component) when in stage 1 of Experiment 1 the birds received concurrent experience of a component containing houselight presentations not correlated with reinforcement. In Experiment 2 it was found that this overshadowing effect was abolished when the signal used was the presentation of a pattern on the response key rather than illumination of the houselight. These results are interpreted in terms of an interaction between the rate-enhancing properties of the signal (perhaps a consequence of its conditioned reinforcing power) and the tendency of the signal in some conditions to evoke behavior that competes with the response being recorded.     

A Framework and Themes for Social Network Intervention

This paper is concerned with the development and application of social network concepts in clinical practice. A framework of network levels and sets for ordering data and observations is proposed; the phenomenon of truncated networks is considered and two emphases in network intervention (gathering and connecting forms) are proposed to conceptualize network characteristics and practice that follows from such characteristics. A number of current examples of network practice are placed within the framework, and several advantages of utilizing a network perspective as a complement to existing models of family therapy are noted.