Initial experience using propranolol as an adjunctive treatment in children with aggressive recurrent respiratory papillomatosis

We performed a retrospective chart review with a 6-month follow-up to examine the initial use of propranolol as an adjunctive treatment in children with severe recurrent respiratory papillomatosis. This is the first such report. Two of 3 children with severe recurrent respiratory papillomatosis demonstrated a response to oral propranolol therapy, as evidenced by an improved voice and by an increased time between surgical interventions. One child demonstrated no response to propranolol, and medication was halted. Both children who demonstrated a response had undergone more than 10 surgical interventions in the previous year, along with prior treatment including surgical excision and adjuvant therapy. Both children more than doubled the interval between treatments after propranolol administration, and the parents of both children noted marked improvement of the child's voice as measured by their Pediatric Voice-Related Quality of Life score (from 40 to 67.5 in one child and from 27 to 60 in the other child). No child experienced hypoglycemia or blood pressure abnormalities. We conclude that initial use of propranolol as an adjunctive measure in severe recurrent respiratory papillomatosis shows it to have some efficacy in delaying surgical intervention and improving voice. Previous reports have demonstrated relatively safe use of propranolol in children with hemangiomas. Further studies are needed to determine the long-term effectiveness, dosing strategies, and side-effect profile of propranolol for treatment of recurrent respiratory papillomatosis.     

Maternal fear associated with pregnancy and childbirth in Hong Kong Chinese women

BACKGROUND: Women's fear toward pregnancy and childbirth is a common and important health concern. This study examined the objects, causes, and manifestations of maternal fears and their associated demographic factors in a sample of Hong Kong Chinese pregnant women. METHODS: Three hundred Chinese pregnant women were recruited in an obstetric unit in Hong Kong in 2003. Data were collected using a 73-item questionnaire. Principal components factor analysis was applied to identify the objects, causes, and manifestations of fear toward pregnancy and childbirth. RESULTS: The mean maternal age was 30 (SD 5.6) years. All participants reported some degree of fear. The main objects of fear were "fear of childbirth" and "child's and mother's wellbeing." The first factor identified for causes of fear was "negative stories," followed by "negative attitude or mood." Regarding the various manifestations of fear, "stress symptoms" and "wish to avoid pregnancy and childbirth" ranked highest. Twenty-two percent of participants had considered requesting an elective cesarean section due to fear of childbirth. CONCLUSIONS: Even in a group of low-risk pregnant women, fear toward pregnancy and childbirth was frequently experienced. Better strategies to address women's psychological needs during pregnancy are warranted.     

Microsaccade directions do not predict directionality of illusory brightness changes of overlapping transparent surfaces

Tse (2005) recently introduced a new class of illusory brightness changes where shifts of attention lead to shifts in perceived brightness across overlapping, transparent figures, under conditions of visual fixation. In the absence of endogenous attentional shifts, illusory brightness changes appear to shift from figure to figure spontaneously, much as occurs in other multistable phenomena. The goal of the present research is to determine whether fixational microsaccades are correlated with perceived brightness changes. It has recently been demonstrated that microsaccades can reveal the direction of covert attentional shifts either toward (Engbert, R. & Kliegl, R. (2003). Microsaccades uncover the orientation of covert attention. Vision Research, 43, 1035-1045; Hafed, Z. M. & Clark, J. J. (2002). Microsaccades as an overt measure of covert attention shifts. Vision Research, 42(22), 2533-2545) or away from (Rolfs, M., Engbert, R., & Kliegl, R. (2004). Microsaccade orientation supports attentional enhancement opposite a peripheral cue: commentary on Tse, Sheinberg, and Logothetis (2003). Psychological Science, 15(10), 705-707) a peripheral cue under certain circumstances. Others (Horwitz, G. D. & Albright, T. D. (2003). Short-latency fixational saccades induced by luminance increments. Journal of Neurophysiology, 90(2), 1333-1339; Tse, P. U., Sheinberg, D. L., & Logothetis, N. K. (2002). Fixational eye movements are not affected by abrupt onsets that capture attention. Vision Research, 42, 1663-1669; Tse, P. U., Sheinberg, D. L., & Logothetis, N. K. (2004). The distribution of microsaccade directions need not reveal the location of attention. Psychological Science, 15(10), 708-710) found no change in the distribution of microsaccade directions as a function of where attention is allocated, although changes in the rate of microsaccades were observed in all of these studies in response to the onset of attentional reallocation. It is therefore possible that the distribution of microsaccade directions will change as a function of which figure is perceived to darken, or that changes in this distribution predict which figure will subsequently darken. We find no correlation between this distribution and which figure undergoes the effect, and therefore conclude that microsaccade directionality is not influenced by and does not influence which figure undergoes the effect. Moreover, the directions of microsaccades that occur immediately prior to a perceptual switch are not correlated with the perceived position of the figure that undergoes the effect. However, we do find that the rate of microsaccades decreases upon a perceptual switch, signifying an attentional shift coincident with the perceptual shift. We conclude that microsaccade directionality does not determine, predict, or cause which figure will subsequently be perceived to undergo an illusory brightness change.     

The infinite regress illusion reveals faulty integration of local and global motion signals

We report a new visual illusion, where a global shape appears to continually move away from fixation, even though it remains a fixed distance from fixation. The illusion occurs because local motion signals within the object indicate motion away from fixation, and are incorrectly attributed by the visual system to the motion trajectory of the global object. A simple weighted vector summation of global and local motion signals, while a reasonable first approximation, cannot fully account for our data. We show that the faster the local motion signal, the more it biases judgments of global motion direction. We propose that local and global motion signals are summed non-linearly for this stimulus because as local motion speed increases, moving luminance blobs are visible for less time, affording less time to inhibit inappropriate component motion signals. This effect reveals the degree to which the visual system can incorrectly combine local and global motion signals belonging to a single object.     

Preattentive timing of empty intervals is from marker offset to onset

The internal marker hypothesis explains the superior timing performance for empty intervals over filled intervals by assuming that timing an empty interval starts from the offset of the first marker stimulus and stops at the onset of the second marker stimulus. Other models suggest that timing an empty interval is from first marker onset to second marker onset. We used an electrophysiological measure of preattentive change detection, the mismatch negativity (MMN), to examine processing of empty intervals. Participants watched a silent movie while a stream of auditory stimuli demarcating empty intervals was presented in the background. Most intervals were of the same duration (standards), but shorter intervals (deviants) were presented occasionally also. The pattern of MMN amplitudes obtained across five deviant conditions indicated that preattentive timing of empty intervals occurred from marker offset to onset.