Spectral restoration of speech: Intelligibility is increased by inserting noise in spectral gaps

In order to function effectively as a means of communication, speech must be intelligible under the noisy conditions encountered in everyday life. Two types of perceptual synthesis have been reported that can reduce or cancel the effects of masking by extraneous sounds: Phonemic restoration can enhance intelligibility when segments are replaced or masked by noise, and contralateral induction can prevent mislateralization by effectively restoring speech masked at one ear when it is heard in the other. The present study reports a third type of perceptual synthesis induced by noise: enhancement of intelligibility produced by adding noise to spectral gaps. In most of the experiments, the speech stimuli consisted of two widely separated narrow bands of speech (center frequencies of 370 and 6000 Hz, each band having high-pass and low-pass slopes of 115 dB/octave meeting at the center frequency). These very narrow bands effectively reduced the available information to frequency-limited patterns of amplitude fluctuation lacking information concerning formant structure and frequency transitions. When stochastic noise was introduced into the gap separating the two speech bands, intelligibility increased for “everyday” sentences, for sentences that varied in the transitional probability of keywords, and for monosyllabic word lists. Effects produced by systematically varying noise amplitude and noise bandwidth are reported, and the implications of some of the novel effects observed are discussed.     

An examination of the relationship between visual capture and prism adaptation

The phenomena of prismatically induced “visual capture” and adaptation of the hand were compared. In Experiment 1, it was demonstrated that when the subject’s hand was transported for him by the experimenter (passive movement) immediately preceding the measure of visual capture, the magnitude of the immediate shift in felt limb position (visual capture) was enhanced relative to when the subject moved the hand himself (active movement). In Experiment 2, where the dependent measure was adaptation of the prism-exposed hand, the opposite effect was produced by the active/passive manipulation. It appears, then, that different processes operate to produce visual capture and adaptation. It was speculated that visual capture represents an immediate weighting of visual over proprioceptive input as a result of the greater precision of vision and/or the subject’s tendency to direct his attention more heavily to this modality. In contrast, prism adaptation is probably a recalibration of felt limb position in the direction of vision, induced by the presence of a registered discordance between visual and proprioceptive inputs.     

A non-parametric test of correlation using rank orders within subgroups

Kendall's rank order test for association between two variables is generalized to the case where the total sample is made up of several subgroups and the data on one or both variables consist of the rank order within each subgroup. The test involves no assumptions concerning scales of measurement, shapes of distributions, or relative level of excellence or amount of variability of the different subgroups. Two empirical examples indicate that the normal approximation to the exact test of significance can be considered adequate for most practical situations. Special consideration is given to the case of tied ranks. If ties occur in but one variable within any given subgroup, only a slight modification in procedure is needed. Extensive ties in both variables within subgroups lead to difficulties in determining the appropriate correction for continuity.     

Predicting toddler anxiety/depressive symptoms: Effects of caregiver sensitivity on temperamentally vulnerable children

This research examines whether maternal sensitivity in early childhood reduces later anxiety/depressive symptoms for children with more temperamental vulnerability, and whether these effects are different for boys and girls. Data from the National Institute of Child Health and Human Development Early Child Care study with 1,226 subjects (631 boys, 595 girls) were analyzed. Mothers and other caregivers rated children's difficult temperament at 1 and 6 months. Trained observers scored maternal sensitivity when children were 6 and 15 months. Child anxiety/depressive symptoms were rated by mothers and other caregivers when children were 2 and 3 years of age. Maternal sensitivity in early childhood significantly predicted decreased 2‐ and 3‐year‐old anxiety/depressive symptoms. Children with more difficult temperament were significantly more likely to show decreased anxiety/depressive symptoms at 2 years of age if their mothers had been more sensitive. Maternal sensitivity also was a significant predictor of decreased anxiety/depressive symptoms for more temperamentally difficult boys, and temperamentally difficult boys with more sensitive mothers were found to be significantly more likely than girls to show decreased anxiety/depressive symptoms at 3 years of age. The findings of this pilot research suggest that facilitating and supporting increased sensitivity for mothers with more temperamentally difficult children could be beneficial. ©2005 Michigan Association for Infant Mental Health.     

Future Colleague or Convenient Friend: The Ethics of Mentorship

Student mentoring is a common and often encouraged practice within graduate psychology and counseling programs. Although both mentors and protégés typically report multiple benefits from the practice, the mentoring relationship is also subject to a variety of ethical issues. The author presents a brief overview of professional literature regarding mentoring relationships, including key features and stages of development of these relationships, and then addresses potential ethical concerns. Guidelines and implications for ethical mentoring practice are also presented to encourage more specific attention to this vital component of counselor training.     

Patterns of maternal responding in postpartum mothers with schizophrenia

Little is known about how schizophrenia might affect how a mother responds to her infant, such as whether responding is reduced or impaired. The aim was to identify, from brief videotaped interactions, whether the responses of mothers with schizophrenia were fewer, less positive, more negative, and more ‘abnormal’ than mothers with affective disorder, and whether their infants (mean age: 15 weeks) lacked activity or initiation to which mothers could respond. Mothers with schizophrenia (N = 14) were as responsive as mothers with affective disorder (N = 31), but they showed markedly low positive responsiveness. Only the schizophrenia group exhibited non-responses as a result of being psychologically withdrawn from the interaction, and abnormal behaviors. Inconsistent to our hypothesis, infants in both groups showed similar levels of activity, initiative and negativity. The findings highlight the need for further research to examine the contribution of maternal response impairments to the developmental vulnerability of this genetically high-risk group.