School of Psychology - Recently Published Research

Holcombe, A.O. (2009). Temporal binding favors the early phase of color changes, but not of motion changes, yielding the color-motion asynchrony illusion. Visual Cognition, 17(1-2), 232-253.

ABSTRACT
How our binding mechanism judges features as simultaneous remains mysterious. When moving dots alternate in colour and motion direction, reports of the perceived colour and motion pairing reveal an asynchrony in temporal binding: The motion change best precedes the associated colour change by about 150 ms. Here the durations of the motion and colour were independently varied. Regardless of motion duration, pairing reports were most consistent when the midpoint of the motion interval occurred at a particular time relative to the colour, suggesting no differential weighting of early versus late portions of the motion interval. In contrast, as colour duration increased, the best time of its midpoint shifted later, indicating that it is best to align the early part of the colour with the motion. Thus, the colour motion asynchrony phenomenon appears to result from the binding process favouring the early phase of the colour but not the early part of the motion.

Khatibi, A., Dehghani, M., Sharpe, L., Asmundsen, G. & Pouretemad, H. (2009). Selective attention towards painful faces amongst chronic pain patients: evidence from a modified version of the dot-probe. Pain, 142, 102-107.

ABSTRACT
Evidence that patients with chronic pain selectively attend to pain-related stimuli presented in modified Stroop and dot-probe paradigms is mixed. The pain-related stimuli used in these studies have been primarily verbal in nature (i.e., words depicting themes of pain). The purpose of the present study was to determine whether patients with chronic pain, relative to healthy controls, show selective attention for pictures depicting painful faces. To do so, 170 patients with chronic pain and 40 age- and education-matched healthy control participants were tested using a dot-probe task in which painful, happy, and neutral facial expressions were presented. Selective attention was denoted using the mean reaction time and the bias index. Results indicated that, while both groups shifted attention away from happy faces (and towards neutral faces), only the control group shifted attention away from painful faces. Additional analyses were conducted on chronic pain participants after dividing them into groups on the basis of fear of pain/(re)injury. The results of these analyses revealed that while chronic pain patients with high and low levels of fear both shifted attention away from happy faces, those with low fear shifted attention away from painful faces, whereas those with high fear shifted attention towards painful faces. These results suggest that patients with chronic pain selectively attend to facial expressions of pain and, importantly, that the tendency to shift attention towards such stimuli is positively influenced by high fear of pain/(re)injury. Implications of the findings and future research directions are discussed.

Hart, G., Harris, J. A., Westbrook, R. F. (2009). Systemic or intra-amygdala injection of a benzodiazepine (midazolam) impairs extinction but spares re-extinction of conditioned fear responses. Learning & Memory, 16, 53-61.

ABSTRACT
Rats were subjected to one or two cycles of fear conditioning and extinction, injected with a benzodiazepine, midazolam, before the first or second extinction, and tested for long-term inhibition of fear responses (freezing). In Experiment 1, inhibition of context-conditioned fear was spared when midazolam was injected before the second extinction, but impaired when injected before the first. In Experiment 2, it was spared when midazolam was injected before the second extinction, but only if vehicle had been injected before the first: Inhibition was impaired when the drug was injected before both. In Experiment 3, inhibition of a discrete conditioned stimulus (CS A) was spared when midazolam was injected before its second extinction, but impaired when injected before extinction of CS A in rats that had undergone extinction of CS B. In Experiment 4, inhibition was spared when midazolam was injected into the basolateral amygdala before the second extinction, but impaired when injected before the first extinction of context-conditioned fear. The results show that midazolam impairs learning, but not relearning to inhibit fear responses, and are discussed in terms of state dependency, error correction, and memory retrieval, whereby the drug's anxiolytic effects on the second extinction reactivate and strengthen the original inhibitory memory.

Hargreaves GA, Quinn H, Kashem MA, Matsumoto I, McGregor IS (2009). Proteomic analysis demonstrates adolescent vulnerability to lasting hippocampal changes following chronic alcohol consumption. Alcoholism: Clinical and Experimental Research, 33, 86-94.

ABSTRACT
Background: Excessive teenage alcohol consumption is of great concern because alcohol may adversely alter the developmental trajectory of the brain. The aim of the present study was to assess whether chronic intermittent alcohol intake during the adolescent period alters hippocampal protein expression to a greater extent than during adulthood.
Methods: Adolescent [postnatal day (PND) 27] and adult (PND 55) male Wistar rats were given 8 hours daily access to beer (4.44% ethanol v / v) in addition to ad libitum food and water for 4 weeks. From a large subject pool, subgroups of adolescent and adult rats were selected that displayed equivalent alcohol intake (average of 6.1 g / kg / day ethanol). The 4 weeks of alcohol access were followed by a 2-week alcohol-free washout period after which the hippocampus was analyzed using 2-DE proteomics.
Results: Beer consumption by the adult group resulted in modest hippocampal changes relative to alcohol naive adult controls. The only changes observed were an up-regulation of citrate synthase (a precursor to the Krebs cycle) and fatty acid binding protein (which facilitates fatty acid metabolism). In contrast, adolescent rats consuming alcohol showed more widespread hippocampal changes relative to adolescent controls. These included an increase in cytoskeletal protein T-complex protein 1 subunit epsilon (TCP-1) and a decrease in the expression of 10 other proteins, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), triose phosphate isomerise, alphaenolase, and phosphoglycerate kinase 1 (all involved in glycolysis); glutamate dehydrogenase 1 (an important regulator of glutamate); methylmalonate-semialdehyde dehydrogenase (involved in aldehyde detoxification); ubiquitin carboxyl-terminal hydrolase isozyme L1 (a regulator of protein degradation); and synapsin 2 (involved in synaptogenesis and neurotransmitter release).
Conclusions: These results suggest the adolescent hippocampus is more vulnerable to lasting proteomic changes following repeated alcohol exposure. The proteins most affected include those related to glycolysis, glutamate metabolism, neurodegeneration, synaptic function, and cytoskeletal structure.

Goodwin, R & Mullan, BA (2009). Predictors of undergraduates' intention to incorporate glycaemic index into dietary behaviour. Nutrition and dietetics, 66(1), 54-59.

ABSTRACT
Aim: The present study used an extension of the theory of planned behaviour to analyse undergraduates' intention to perform behaviour related to the glycaemic index of food. The extended model incorporated measures of past behaviour and pre-existing knowledge about glycaemic index.
Methods: Seventy-two participants read an academic journal article about glycaemic index and completed questionnaires measuring predictor components of the theory of planned behaviour model.
Results: Subjective norm and attitude were generally observed to be the best predictors of intention. Pre-existing knowledge about glycaemic index and attitude towards restrained eating were generally found to be poor predictors of intention. Past behaviour exhibited a positive relationship with intention.
Conclusions: Interventions that focus on dietary behaviour related to the glycaemic index of food should involve individuals who have relationships of influence with the target demographic, such as friends and family, and will need to address modifying ingrained patterns of behaviour.

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.