The Fraser illusion: complex figures

The cause of the Fraser illusion, which occurs when a line made up of tilted segments itself appears tilted, is examined further. In this series of experiments, we used figures that resembled the original Fraser illusion; they were more complex than those reported on in our previous paper (Stuart & Day, 1988). The figures were used to explore two theories of the Fraser illusion further: that it is the result of interactions between orientation selective units, and that it is a consequence of the local, distributed processing of orientation. The presence of background elements like those used in the original illusion led to an increase in the strength of the illusion, but the shape of these elements had no differential effect on illusion strength. There was a differential effect of the background on the assimilative and contrast illusions, owing respectively to small and large tilts of the inducing elements. The illusion was markedly reduced at small visual angles when the background was absent, but it was only slightly affected when the background was present. All these findings are difficult to explain in terms of interactions between single units, either at the same or at different scales in the image. The effects of luminance contrast and isoluminance on the illusion were not consistent with either theory, but they indicated that researchers need to consider the role of figure-ground organization in this illusion.     

Extraversion and attitude towards capital punishment

Male and female Canadian undergraduate students identified as extraverts or introverts on the basis of the Eysenck Personality Inventory were administered a questionnaire measuring attitude towards Capital Punishment. Both effects of sex and personality were significant, males and extraverts reporting stronger beliefs in Capital Punishment than females and introverts. These results were interpreted as providing support for Eysenck's proposal that the social attitude dimension of Toughmindedness reflects the personality trait of Extraversion.     

Computer-Assisted Careers Counselling: A New Approach

This paper describes the outcome of a research and development project concerned to construct a computer aid for careers advisers and career decision-makers which differs in basic philosophy and design from others currentiy in the field. The resulting Careers Decision Aiding System (CDAS) is principally concerned with improving the quality of the decision-making strategy employed by clients by raising their awareness of the way in which their career choice is made, ratherthan with employing computer technology to attempt to match people to careers. The use of the CDAS by clients and careers advisers is illustrated by two case-studies.     

Auditory adaptation to gradual rise or fall in intensity of a tone

The auditory system adapts to gradual changes of intensity. After listening to a gradually loudening (or softening) tone, a steady test tone appeared to be growing gradually softer (or louder). “Tuning curves” for these aftereffects were measured by adapting to one audio frequency and testing at another. Softening tones produced larger aftereffects, which were more sharply tuned for audiofrequency, than did loudening tones.     

The effects of alcohol and extreme provocation on the use of a highly noxious electric shock

Intoxicated and nonintoxicated subjects were given the opportunity to administer a potentially injurious level of shock to an opponent who behaved in either a provocative or an extremely provocative manner. The provocative opponent attempted to administer high-intensity shocks to the subject. The extremely provocative opponent attempted to administer high-intensity shocks and the potentially injurious level of shock. The intoxicated subjects in the extreme provocation condition evidenced the greatest increase in the use of the potentially injurious shock. It was concluded that aggression is a function of the interaction of alcohol consumption and level of provocation.     

Tune recognition with reduced pitch and interval information

Twenty subjects were tested on their ability to recognize simple tunes from which rhythm information had been removed. Only the first phrase of each tune was presented. The purpose of the experiment was (a) to determine whether stimuli containing only high harmonics can evoke a sense of musical pitch, and (b) to provide a set of data in normal subjects with which the performance of deaf subjects whose auditory nerve is stimulated electrically can be compared. Each subject was tested on five sets of stimuli presented in a counterbalanced order. These stimuli were (I) pulse trains high-pass filtered at 2 kHz, with repetition rates in the range of 100-200 p.p.s.; (2) as in (I) but high-pass filtered at 4 kHz; (3) sinusoids with musical intervals compressed, so that the “octave” was a ratio of I:I·3; (4) sinusoids with the musical intervals expanded, so that the “octave” was a ratio of I:4; (5) sinusoids of a constant frequency in which the normal frequency changes were translated into intensity changes, each semitone being represented by a 3 dB change in level. The results indicate that a pattern of intensity changes does not support tune recognition, and that, although the pitch contour alone allows reasonable performance, subjects do use musical interval information in recognizing tunes. Stimuli containing only high harmonics can provide such interval information, and thus can evoke a sense of musical pitch. Preliminary results from a deaf subject stimulated electrically with an electrode on the surface of the cochlea indicate that such stimulation can also evoke a sense of musical pitch. It is concluded that musical pitch information can be carried in the time-pattern of nerve impulses in the auditory nerve.     

Prediction of success or failure in birth planning: An approach to prevention of individual and family stress

Following the view that individual future time perspective is an outcome of the socialization process, it was hypothesized that good contraceptors would display significantly longer future time extension than poor contraceptors. In a Planned Parenthood agency, 25 subjects from each group, constituting nearly the whole clinic population in these categories for a 3-month period, were given the Future Events Test during their clinic visits. The major hypothesis was confirmed, and also a significant tendency towards viewing future events more negatively was found among the poor contraceptors. Demographic data did not discriminate clearly between the two groups, though the poor contraceptors were somewhat younger and had a somewhat higher weekly family income. Use of personality variables in predicting birth-planning success or failure seems more promising than continued reliance solely on the sociocultural approach. Implications for screening and prevention in the interest of the individual, the family, and the community are discussed.     

The effect of social feedback contingent upon a non-social response in seven- and ten-month-old infants

Summary Acquisition of a manipulative response under contingent and non-contingent maternal social stimulation was examined in seven- and ten-month-old infants. Response acquisition was reliably deomonstrated in the case of the ten-month-old infants, but not in the case of the seven-month-old infants. However, despite no acquisition, the performance of the younger infants did differ from that obtained under non-contingent scheduling Examination of visual behaviour to the manipulandum and the feedback source revealed comparable profiles for both ages. The findings are interpreted in terms of the greater difficulty of mixed social/non-social contingency situations and discussed in the context of cognitive constraints on response acquisition in infancy.The conduct of this study was supported by a grant from the United Kingdom Social Science Research Council to H.R. Schaffer, and undertaken whilst the author was a Research Fellow in Psychology at the University of Strathclyde, Glasgow, Scotland.The author is grateful to W.M. Cheyne for advice and to Norman Sharp and Margaret Hunter who assisted with the data collection and analysis.     

The effects of verbal labelling on recognition memory for schematic faces

Four experiments investigated the effects of labelling on the encoding and recognition of schematic faces. In Experiments I and II, hard-to-label (H) faces were recognized better after labelling than after observing, whereas easy-to-label (E) faces were not significantly affected. However, E faces were recognized better after labelling when subjects were instructed to attend carefully to all features of the faces during viewing. In Experiments III and IV, which dealt with each kind of face separately, both E and H faces were recognized better after labelling than after observing. An additional improvement in recognition all of faces was found when labelling subjects knew which label was relevant on each recognition trial and were instructed to use it. It was concluded that (a) a verbal label functions mainly to direct attention to specific facial features during viewing, (b)the effect of the label on recognition is positive or negative depending on whether or not it directs attention to features which are functional for the recognition test, (c) the label also forms part of the representation of the face in memory, and (d) a label may serve as a mediator at the time of testing, but only in the presence of specific cues.     

Figure embeddedness depends on contour orientation

The “oblique effect” was studied using an embedded figures task in which complex patterns and hidden forms were rotated into different orientations. One set of stimuli (Series I) used patterns consisting either entirely of depending on rotation) horizontal and vertical line segments or entirely of obliques. A second set of stimuli (Series II) used patterns composed of horizontal, vertical, and oblique segments in equal proportions. With Series I, both form and complex pattern orientations changed with rotation. In Series II, rotation changed the orientation of the hidden forms, but not the relative proportion of contour orientations in the complex patterns. Significantly longer search times were required to find forms embedded within the obliquely oriented patterns of Series I. There were no significant differences in Series II. These results are discussed in terms of the role contextual contours may play in the detection of differently oriented form.