University of Sydney
Current Students Future Students Research Clinical Staff Resources Staff Directory Contact Us Search  
Home › Recently Published Research
Archive of Research Publications
RECENTLY PUBLISHED RESEARCH

  • Curran, W., Clifford, C.W.G. & Benton, C.P. (2009). The hierarchy of directional interactions in visual motion processing. Proceedings of the Royal Society of London, Series B: Biological Sciences, 276, 263-268.

    ABSTRACT
    It is well known that context influences our perception of visual motion direction. For example, spatial and temporal context manipulations can be used to induce two well-known motion illusions: direction repulsion and the direction after-effect (DAE). Both result in inaccurate perception of direction when a moving pattern is either superimposed on (direction repulsion), or presented following adaptation to DAE, another pattern moving in a different direction. Remarkable similarities in tuning characteristics suggest that common processes underlie the two illusions. What is not clear, however, is whether the processes driving the two illusions are expressions of the same or different neural substrates. Here we report two experiments demonstrating that direction repulsion and the DAE are, in fact, expressions of different neural substrates. Our strategy was to use each of the illusions to create a distorted perceptual representation upon which the mechanisms generating the other illusion could potentially operate. We found that the processes mediating direction repulsion did indeed access the distorted perceptual representation induced by the DAE. Conversely, the DAE was unaffected by direction repulsion. Thus parallels in perceptual phenomenology do not necessarily imply common neural substrates. Our results also demonstrate that the neural processes driving the DAE occur at an earlier stage of motion processing than those underlying direction repulsion.

  • Costa, D.S.J & Boakes, R.A. (2009). Context blocking in rat autoshaping: Sign-tracking versus goal-tracking. Learning and Motivation, 40, 178-185.

    ABSTRACT
    Prior experience of unsignaled food can interfere with subsequent acquisition by birds of autoshaped key-pecking at a signal light. This has been understood to indicate that unsignaled food results in context conditioning, which blocks subsequent learning about the keylight-food relationship. In the present experiment with rats lever insertion as the conditioned stimulus (CS) preceded sucrose delivery as the unconditioned stimulus (US). Half the rats initially received unsignaled USs in the conditioning context, while the remainder did not. Both lever-presses (sign-tracking) and magazine-entries (goal-tracking) were recorded. Under immediate reinforcement conditions, prior unsignaled US interfered with sign- tracking, but had no effect on goal-tracking. In two further groups, a trace condition prevented development of sign-tracking. In this case, prior context conditioning interfered with goal-tracking. These results suggest that interference with sign-tracking may re?ect response competition, while interference with goal-tracking under trace conditions may reflect failure to acquire a CS-US association.

  • Collins-Tracey, S., Clayton, J. M., Kirsten, L., Butow, P. N., Tattersall, M. H. N. and Chye, R. (2009). Contacting bereaved relatives: The views and practices of palliative care and oncology health care professionals. Journal of Pain Symptom Management, 37: 807 - 822.

    ABSTRACT
    There are few data on the interactions of health care professionals with bereaved relatives. The objective of this study was to explore the current practice of health care professionals in oncology and palliative care in contacting bereaved relatives, and to elicit their views regarding the purpose, the optimal means, the format, timing, and content of these contacts. We conducted 28 in-depth, semi-structured inter views with health care professionals in Australia working in palliative care and oncology. The inter views were audiotaped and transcribed. Further inter views were conducted until no additional themes were raised. The narratives were analyzed using qualitative methodology. Most participants were in favor of contacting bereaved relatives after the death of a patient they had cared for. Some barriers to implementing these contacts were identified, including time constraints, institutional factors, and personal barriers. Contacts ranged from a personal phone call to a standardized letter. Timing of contacts varied from immediately after the death of the patient to several weeks later. Participants used words and phrases in these contacts that ranged from personal and individualized messages to standard phrases. Health care professionals emphasized the importance of contacting bereaved relatives after the death of a patient for whom they had cared. The format and content of current contacts vary widely, and there does not seem to be a gold standard approach. This area has been relatively unexplored and lacks adequate models for health care professionals. This study provides some insight into current practice and hopes to facilitate further discussion of this topic.

  • Craddock, A.E., Church, W., & Sands, A. (2009). Family of origin characteristics as predictors of perfectionism. Australian Journal of Psychology, 61, 3, 136 -144.

    ABSTRACT
    This study investigated perceptions of family of origin (parental style and family system characteristics) as predictors of dysfunctional and functional perfectionism (as measured by Khawaja and Armstrong's shortened Australian version of the Frost Multidimensional Perfectionism Scale) in a sample of 264 Australian first-year Psychology students at the University of Sydney. Regression analyses showed that dysfunctional perfectionism was predicted by extreme family enmeshment and by parenting styles that were highly authoritarian and high on psychological control. Functional perfectionism was also predicted by extreme family enmeshment and authoritarian parenting style, but not by high parental psychological control. An implication of these findings for counselling and remedial education programs for students working with dysfunctional perfectionist tendencies is that such programs need to include consideration of the possible influence of unhelpful controlling family processes that appear to be associated with the development of dysfunctional perfectionism.

  • Allen, K., Alais, D., Carlile, S. (2009). Speech intelligibility reduces over distance from an attended location: Evidence for an auditory spatial gradient of attention. Attention, Perception, & Psychophysics, 71 (1), 164-173.

    ABSTRACT
    Speech reception thresholds (SRTs) were measured at a central focus of attention and at 20°, 40°, and 60° locations distant in azimuth. Measurements were taken with one target collocated with two maskers, or with maskers flanking the target by 20°. For 80% of trials, the target was played from the attended location ("expected"), and 20% came from another ("unexpected") location. For collocated stimuli, SRTs worsened with increasing distance from the expected location by 2.1 dB over the 60° azimuth and by 5.1 dB for spatially separated target and maskers. In spatially separated conditions, a 2.9-dB change was still found when gaze was away from the attended location. Spatial attention appears to increase speech intelligibility against interferers, with gain decreasing with distance from the focus of attention. Spatial release from masking (RFM) was only found for the attended location. Further experiments suggest that target location uncertainty prevented RFM at unattended locations.