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.     

Perceptions of fear in other Children and adolescents: The role of gender and friendship status

Gender differences in fear were examined in 693 Chinese children and adolescents. Subjects were asked to rate their own fears, the fears of their best friends, and the fears of other classmates using the Fear Survey Schedule for Children — Revised (Ollendick, 1983). Consistent with previous investigations in Western and Eastern countries, girls rated themselves as more fearful than boys. In addition, both girls and boys rated their best friends as similar in number, content, and intensity of fears. However, girls rated their classmates as less fearful than themselves or their best friends, while boys rated their classmates as more fearful than themselves or their best friends. Findings are discussed in terms of gender role expectations and similarity-attraction hypotheses.     

The three-stratum theory of cognitive abilities: Test of the structure of intelligence across the life span

Recently a three-stratum theory of intelligence that combines the major aspects of Spearman's (1927) theory of general intelligence (g) and Horn and Cattell's (1966) theory of crystallized and fluid intelligence (G_f-G_c) has been proposed (Carroll, 1993a). The purpose of this study was to test the three-stratum theory using hierarchical confirmatory factor analysis with the LISREL computer program. Developmental changes in the structure of intelligence were also investigated. Results provided support for the three-stratum theory and suggested the possibility of intermediate factors between the second and third strata but did not support developmental changes in the organization of cognitive abilities over the life span.     

Suicidal behavior among youth with severe emotional disturbance

The purpose of this study was to replicate an investigation of risk behaviors associated with suicidal behavior in public high school students, in a population of high school age youth with severe emotional disturbance (SED). Subjects for the study were clients of the South Carolina Continuum of Care (COC) (N=83). Information on suicidal thoughts and acts, aggressive behaviors, substance use and physical recklessness was gathered using a modified version of the self-report National Youth Risk Behavior Survey. Four percent of the youth reported seriously considering suicide, 8% reported planning how they would attempt suicide, 10% reported actually attempting suicide at least once, and 6% reported attempts requiring medical treatment Of the 13 youth who reported attempting suicide, four (31%) did not report planning an attempt. All suicidal behaviors except thoughts occurred more in girls than boys with SED. Alcohol and illicit drug use were associated with suicidal behavior, with larger odds ratios for attempts than for thoughts/plans. Youth with SED who use alcohol and illicit substances are particularly at risk of suicidal behavior. A high index of suspicion is appropriate when evaluating suicidal risk in girls with SED, especially in the presence of known alcohol or substance use.Continuum of Care for Emotionally Disturbed Children Division, S. C. Office of the Governor.     

Book reviews

International Journal for Philosophy of Religion -     

Optimism and Revolt of the Oppressed: A Comparison of Two Polish Jewish Ghettos of World War II

One World War II Jewish ghetto that revolted, the Warsaw Ghetto, is compared to one that did not, the Lodz Ghetto, in order to examine the causes of violent resistance. This structured focused comparative method (George, 1979) illuminates problems with previous explanations for revolt and nonrevolt in Jewish ghettos and suggest psychological variables that might have led to or precluded organized violence. Specifically, it appears that these two ghettos differed in their perceptions about their future. The residents of the Warsaw Ghetto believed they had no hope of survival while residents of the Lodz Ghetto remained optimistic. These differing perceptions seem to have led to the different outcomes. Possible causes of these percetpions are also discussed.     

Short- and long-term behavioral effects of neonatal exposure to bombesin.

Subcutaneous (sc) administration of the tetradecapeptide bombesin (BN) (1-10 mg/kg) elicited grooming in rat pups of 1-10 days of age and the magnitude of this response decreased as a function of age. The form of grooming induced was qualitatively different from that seen following central injection of BN to adult rats. Subchronic neonatal exposure to BN (5 or 10 mg/kg; sc, twice daily for the first 8 postnatal days) had no effect on subsequent adult behavior displayed under mildly stressful or novel conditions, in the open field or in an elevated plus maze. However, both saline and the high dose of BN (10 mg/kg) pretreatments increased adult sensitivity to central BN (0.1 micrograms; icv) as compared to noninjected but neonatally handled controls or those rats neonatally pretreated with the lower dose of BN (5 mg/kg). This was best demonstrated by increases in scratching activity at the 0.1-micrograms dose of icv BN. Neonatal pretreatments had no effect on later adult sensitivity to BN injected intraperitoneally (ip). These data indicate that BN receptors in the rat central nervous system are pharmacologically functional from an early stage in ontogeny. Systems utilizing BN-like peptides are, to a degree, plastic early in ontogeny and altered adult sensitivity to BN icv can be achieved via subchronic exposure to BN during infancy. Endogenous BN-based mechanisms did not appear to play a role in the development and/or expression of behavior(s) elicited under mildly stressful or novel conditions.