Effects of illusory stripes on the Helmholtz illusion

This study examined the Helmholtz illusion by using "illusory stripes." A square patch is perceived as wider when vertical lines are drawn on it and is perceived as taller when horizontal lines are drawn on it, i.e., Helmholtz illusion. With vertical lines curved sinusoidally, horizontal "illusory stripes" are perceived; and with horizontal lines curved sinusoidally, vertical "illusory stripes" are perceived. The purpose of the present study was to test whether the "illusory stripes" produce the Helmholtz illusion. We measured the apparent size of a square patch filled with sinusoidal lines. Our subjects (N=27) judged the patch with horizontal "illusory stripes" taller than the square patch filled with vertical straight lines. The subjects also judged the square patch with vertical "illusory stripes" wider than the square patch filled with horizontal straight lines. These results demonstrate that "illusory stripes" can produce the Helmholtz illusion.     

A qualitative understanding of reflective-teams II: Therapists' perspectives

A research team developed and asked questions to a reflective-team about their clinical practice. The purpose of the questions was to better understand reflective-team members' experiences, beliefs, and aspirations. A participant/observation methodology was used in formulating the questions to the therapists. Therapists stated that reflective-teams were valuable in resolving impasses, developing multiple perspectives on clients' problems, and encouraging interaction among team members, but were problematic if clients were unaccustomed to team practice or if there were physically too many people in the interviewing room. Therapists believed that reflective-teams as a team practice was not practical in typical practice settings.     

A new method for determining the personal constants in the Luneburg theory of binocular visual space

Based on the Luneburg theory of binocular visual space, the equation for a visual circle (an apparent circle) was derived to estimate the personal constants, o and K, in this theory. Using small points of light in an otherwise dark room, five observers were asked to construct a visual circle on the horizontal plane with a standard radius of 50 or 100 cm in the median plane. The observation distance for the small circle was 250, 450, or 700 cm, and that for the large circle was 700, 1,030, 1,300, or 1,600 cm. The personal constants calculated from the radii of six directions in each circle were found to be inconsistent with those expected from this theory. The os obtained were remarkably larger than those observed in earlier studies and increased systematically as the observation distance increased. Almost all Ks were negative, with most being less than minus one. Possible factors responsible for these inconsistencies are discussed with reference to the results of previous experiments.     

Velar movements during speech in two Wernicke aphasic patients

The articulatory gestures of the velum in two Wernicke aphasic patients were examined to compare their performances with those of an apraxic patient by means of the fiberoptic technique. In contrast to the marked variability in the apraxic performance in terms of velum height and segmental duration, the two fluent aphasic subjects showed a relatively high degree of consistency in velar movements throughout several repetitions of nonsense syllables and meaningful words. In addition, both patients exhibited a normal pattern of anticipatory coarticulation. Analyses of the velar movement patterns during the speech-sound error processes of both patients suggested that these errors were not due to an impairment at the level of articulatory programming but to an error in the selection of a target phoneme.