The Relationship Between Respiration Phase and Reaction Time

The relationship between phase of normal respiration and reaction time (RT) was studied. Ss were required to respond by pressing a switch each time a simple auditory signal was presented. Averages of response times were calculated for signals occurring during each of three identifiable phases of normal respiration. It was found that mean RT for signals presented during the inhalation phase of respiration was significantly less than for signals presented during either the exhalation phase or the pause between exhalation and inhalation.     

Perceptual distortion of an oblique line in the presence of an abutting vertical line

Two experiments measured line-dot alignment errors to either a long (2 deg 6 min) or short (12.7 min) oblique test line which was presented either in isolation or abutting a vertical inducing line. Alignment PSE's were obtained for a variety of line-dot separations at both the free end and at the intersect end of the test line, using a multiple randomly interleaved staircase technique.A number of aspects of the data were inconsistent with the hypothesis that alignment errors reflect whole-of-line changes in perceived orientation or intercept when the inducing line is present. Rather, the results were consistent with the notion that long lines are processed by integrating the outputs of analysers which respond to short line segments and that alignment errors reflect the differential weighting given to such analysers, depending upon the distance between the dot and the relevant segment of the line. An alternate hypothesis involving “cognitive mistracking” (Tong and Weintraub, 1974) could not be excluded by the results.     

Effects of fibroblast growth factor-4 (k-FGF) on long-term cultures of human bone marrow cells

Fibroblast growth factor-4 (FGF-4), a highly mitogenic protein encoded by the k-fgf/hst oncogene, stimulates the growth of a variety of cells of mesenchymal and neuroectodermal origin. Addition of FGF-4 to human long-term bone marrow cultures increased both the cell density of the stromal layer and the number of hematopoietic colony forming cells in the cultures in a dose-dependent manner. Hematopoiesis in the stromal layer persisted for up to 8 months. Erythropoiesis was maintained for up to 4 weeks, but granulocytes were the predominant nonadherent cell type. Cultures treated with FGF had increased numbers of monocytes compared with control cultures and some CD14+, CD45+ monocytes could still be detected after 8 months of continuous culture. The addition of the growth factor increased the rate of growth of the stromal layer and appeared to delay its senescence. Subcultures made in the presence of FGF-4 had up to 10-fold increases in plating efficiency and grew as relatively uniform monolayers. These subcultures retained the capacity to support hematopoiesis for several months, while untreated subcultures, made without FGF-4, grew erratically and generally lost the capacity to support hematopoiesis within 4 to 6 weeks. The improved growth after subculture greatly enhanced the reliability of limit- dilution assays of multipotential hematopoietic stem cells that use stromal cell monolayers. The primary effect of FGF-4 appeared to be on the stromal cells of the long-term bone marrow cultures, but a direct effect on hematopoietic progenitors could not be ruled out.     

Rape in Hong Kong: an overview of current knowledge

This paper summarises all published and unpublished material available on the topic of rape in Hong Kong. Data including epidemiology, victim profile, assault characteristics, are presented. Most of the data shown are from the 15-year period between 1981 and 1995. Gaps in knowledge are highlighted so as to direct the attention of local researchers and overseas research collaborators.     

Horizontal Direction‐Changing Positional Nystagmus and Vertigo: A Case of Vestibular Migraine Masquerading as Horizontal Canal BPPV

Episodic positional vertigo is typically due to benign paroxysmal positional vertigo (BPPV) but may also be a manifestation of vestibular migraine. Distinguishing vestibular migraine from BPPV is essential since the treatment of each disorder is markedly different. The 31‐month clinical course of a 41‐year‐old woman with vestibular migraine causing recurrent positional vertigo is described. During vestibular migraine attacks, she developed left‐beating nystagmus in the upright position with removal of fixation, and geotropic horizontal nystagmus during the supine roll test. Interictally, her exam demonstrated positional apogeotropic horizontal nystagmus with the supine roll test, more intense in the supine head left position. Her vestibular migraine was successfully controlled with topiramate and eletriptan.