The effects of contextual information and gender on the prediction of hypnotic susceptibility

Council, Kirsch, and Hafner (1986) obtained empirical support for the hypothesis that significant correlations between questionnaire measures of absorption and hypnotic susceptibility are an artifact of subjects' beliefs about their own hypnotizability. We tested this hypothesis in a two-session experiment. During Session 1, subjects completed questionnaire measures of absorption, mystical experience, daydreaming frequency, and paranormal beliefs. During Session 2, subjects were tested for hypnotic susceptibility. Subjects were also exposed to one of three information manipulations: They were told about hypnotic testing either before or after filling out the questionnaires or were not told about hypnotic testing. The information manipulation moderated the prediction of susceptibility by the questionnaire measures for women, but not for men. For women, scores on the absorption questionnaire predicted susceptibility only when subjects were informed about hypnotic testing. In the told-after condition, this effect generalized to all of the remaining questionnaire measures. For men, none of the questionnaires was a reliable predictor of susceptibility.     

Children's perception of certain musical properties: scale and contour

Children's perception of scale and contour in melodies was investigated in five studies. Experimental tasks included judging transposed renditions of melodies (Studies 1 and 3), discriminating between transposed renditions of a melody (Study 2), judging contour-preserving transformations of melodies (Study 4), and judging similarity to a familiar target melody of transformations preserving rhythm or rhythm and contour (Study 5). The first and second studies showed that young children detect key transposition changes even in familiar melodies and they perceive similarity over key transpositions even in unfamiliar melodies. Young children also are sensitive to melodic contour over transformations that preserve it (Study 5), yet they distinguish spontaneously between melodies with the same contour and different intervals (Study 4). The key distance effect reported in the literature did not occur in the tasks of this investigation (Studies 1 and 3), and it may be apparent only for melodies shorter or more impoverished than those used here.     

The perception of an optical flow projected on the ground surface

In most experiments in which the importance of visual control on postural stability is studied, optical stimuli attached to vertical surfaces are used. Analyses of long-term standing readjustments generally involve back-and-forth movements of a visual scene or its projection on vertical circular screens. In a natural environment, however, visual information is largely available from the ground. The aim of the experiment reported was to assess the effect of a flow pattern simulating an open outdoor setting on motion perception and postural control. Subjects were presented with an optical texture projected onto the ground. Periods of motionless texture alternated with equivalent durations of unidirectional flows. The change of position of the subject's centre of gravity over time was recorded on a force platform. Results show that the direction of body sway corresponded with that of texture motion. Important aftereffects, as shown in linear vection experiments, were also observed. However, the latency of postural responses was much shorter than with prolonged unidirectional flows produced in other locations of the visual environment. The hypothesis of an ecological specificity of the flows perceived on the ground during terrestrial displacements is discussed.