Reception of Morse code through motional, vibrotactile, and auditory stimulation

The potential for communication through the kinesthetic aspect of the tactual sense was examined in a series of experiments employing Morse code signals. Experienced and inexperienced Morse code operators were trained to identify Morse code signals that were delivered as sequences of motional stimulation through up-down displacements (roughly 10 mm) of the fingertip. Performance on this task was compared with that obtained for both vibrotactile and acoustic presentation of Morse code using a 200-Hz tone delivered either to the fingertip through a minishaker or diotically to the two ears under headphones. For all three modalities, the ability to receive Morse code was examined as a function of presentation rate for tasks including identification of single letters, random three-letter sequences, common words, and sentences. Equivalent word-rate measures (i.e., product of percent correct scores and stimulus presentation rate) were nearly twice as high for auditory presentation as for vibrotactile stimulation, which in turn was about 1.3 times that for motional stimulation. The experienced subjects outperformed the inexperienced subjects by amounts that increased with task complexity. For example, the former were able to receive sentences at 18 words/min with motional stimulation, whereas the latter, following 75 h of training, were unable to perform this task. The present results and those of other research with tactual communication systems are compared, particularly regarding estimates of information-transfer rates.     

The development of infants' preference for motherese

Generally, infants prefer infant-directed (ID) to adult-directed (AD) speech. Mostly, researchers have used unfamiliar female voices in these studies. We investigated preferences for maternal ID speech in 1- and 4-month-olds. Using a procedure in which infants controlled access to voices by fixating a visual display, infants listened to recordings of natural female ID and AD speech. In Experiment 1, 1-month-olds heard recordings of maternal ID and AD speech, but these infants showed no preference for maternal ID speech. In Experiment 2, 1-month-olds heard the same ID and AD speech tapes but were not familiar with the speakers. Contrary to Experiment 1, these infants preferred ID speech. In Experiment 3, 4-month-olds heard recordings of maternal ID and AD speech and showed a significant preference for ID speech. Collectively, these results suggest that infant attention to ID speech depends on both speaker-general and speaker-specific characteristics, with interesting developmental changes occuring during early infancy.     

Psychotherapy for the treatment of depression: a comprehensive review of controlled outcome research

Previous quantitative reviews of research on the efficacy of psychotherapy for depression have included only a subset of the available research or limited their focus to a single outcome measure. The present review offers a more comprehensive quantitative integration of this literature. Using studies that compared psychotherapy with either no treatment or another form of treatment, this article assesses (a) the overall effectiveness of psychotherapy for depressed clients, (b) its effectiveness relative to pharmacotherapy, and (c) the clinical significance of treatment outcomes. Findings from the review confirm that depressed clients benefit substantially from psychotherapy, and these gains appear comparable to those observed with pharmacotherapy. Initial analysis suggested some differences in the efficacy of various types of treatment; however, once the influence of investigator allegiance was removed, there remained no evidence for the relative superiority of any 1 approach. In view of these results, the focus of future research should be less on differentiating among psychotherapies for depression than on identifying the factors responsible for improvement.     

Effect of preconditioning unconditioned stimulus experience on learned taste aversions.

One taste-aversion study using male Long-Evans rats in which ethanol was the unconditioned stimulus (UCS) and six studies in which lithium chloride (LiCl) was the UCS demonstrate that (a) exposure to the UCS prior to conditioning retards subsequent acquisition of learned taste aversions; (b) a single preconditioning UCS exposure is sufficient to attenuate conditioning; (c) the preconditioning UCS exposure must occur within a limited period prior to conditioning to attenuate learning; (d) repeated conditioning trials will override the effect of prior exposure to the UCS; (e) tolerance to the UCS is not a necessary condition for the attenuation effect to occur; (f) pairing the preconditioning UCS with a novel flavor other than the CS does not remove the preexposure effect, although it may reduce its magnitude; and (g) the degree of disruption is a positive function of preconditioning UCS dosage and an inverse function of conditioning UCS dosage.     

Sex differences in attraction to infants: When do they occur?

Harlow (1971) observed that all-female college audiences responded to a pictured infant rhesus monkey with an “ecstasy response,” while males were “completely unresponsive,” and females in coeducational audiences “inhibited the ecstasy response,” explaining these differences in terms of innate sex differences. The present study compared college students' self-reported attraction to pictures of 15 infant and adult nonhuman primates under several conditions. Infant pictures were of two types: infants which were engaged in typical infant behaviors (Infant Behavior), and those which were not (Infant). Subjects made judgments in same- or mixed-sex groups and reported degree of attraction publicly or privately. Ratio scores were used to represent each subject's attraction to infant or infant-behavior pictures compared with his or her attraction to pictures of adults. There were no significant sex differences in attraction to infant or infant-behavior pictures, and sex did not interact with any other variable. However, situational variables significantly affected the response. Males as well as females reported greater attraction to infant and infant-behavior pictures when they viewed the pictures in same-sex compared with mixed-sex groups. Both sexes reported greater attraction to infant and infant-behavior pictures privately than publicly.     

Gilbert's first night anxiety.

W. S. Gilbert, librettist of the Gilbert and Sullivan operas, suffered from such extreme anxiety at the opening night performance of his plays that he was unable to remain in the theater. This paper explores the dynamics behind Gilbert's first night anxiety, utilizing his literary works as well as biographical and autobiographical sources.     

Improving the validity and reliability of medical-legal certifications of suicide

On a very basic level, those who study suicide are either explicitly or implicitly concerned with the certification of suicide deaths by coroners and medical examiners. Although many authors have questioned the reliability and validity of officially reported rates, these statistics continue to be quoted as fact--a potentially problematic practice for researchers who seek accurate and true causative factors for suicidal behavior. In relation to this topic, this article provides an overview of the existing vital statistics registry system and describes and proposes innovations that could ultimately improve the quality of officially reported suicide statistics.