Wednesday, 18 March 2015

Getting Social at UoN

 Record numbers of social psychologists from Australia, New Zealand, and the rest of the world have submitted presentations to the Annual Meeting of the Society of Australasian Social Psychologists, which will be hosted by academics from the University of Newcastle in April this year. High profile international researchers include keynote speaker Professor John Dixon from the Open University in the UK.

Speaking about the unprecedented interest, conference organiser Dr Stefania Paolini said, “Australia has always punched above its weight in the area of social psychology, and it is great to see Newcastle taking an active role in supporting this important area.”

Social psychology is currently enjoying a great deal of success at Newcastle. Dr Paolini was recently awarded an Australian Research Council Discovery Project to investigate the social psychological bases of people’s interest in approaching versus avoiding social diversity. The University has also strengthened its commitment to the field, with the School of Psychology establishing a new Social and Organisational Psychology Research Group and appointing new staff in the area. The School is also currently recruiting high profile candidates for a Chair in Cross-Cultural Psychology.

Thursday, 12 March 2015

A stochastic adventure in RT modeling: From random walks to nonlinear dynamics. A talk by Dr. Rachel Heath in the Cognitive Research Group

On Thursday 19th March, 12-1pm, the Cognitive Research Group will host a talk by Dr. Rachel Heath. Dr. Heath has been at the forefront of cognitive science in Australia for 40 years, studying diverse topics from simple decision making to complex cognition.

TITLE: A stochastic adventure in RT modeling: From random walks to nonlinear dynamics.

WHERE: Keats room, AVLG17, v/c to Ourimbah Science Offices.

ABSTRACTIn a broad summary of RT modeling since 1975, I first discuss the basic premises of Relative Judgment Theory and show how this relatively simple sequential sampling model can explain many important features of RT data in a variety of psychological contexts. Next I present a general nonstationary stochastic extension that includes the drift diffusion model and the Ornstein-Uhlenbeck model as special cases. I show how this complex model can be simplified by a tandem random walk decision process, which serves as a useful approximation for tasks involving brief stimuli. The talk concludes with evidence of nonlinear dynamics in sequential RT data using conventional techniques and multifractal spectra.

See also: 
Link, S.W. & Heath, R.A. (1975). A sequential theory of psychological discrimination. Psychometrika, 40, 77-105.
Heath, R.A. (1981). A tandem random walk model for psychological discrimination. British Journal of Mathematical and Statistical Psychology, 34, 76-92.
Heath, R.A. (1992). Nonstationary diffusion models for two-choice decision making. Mathematical Social Sciences, 23, 283-309.
Link, S.W. (1992). The wave theory of difference and similarity. Mahwah, NJ: Lawrence Erlbaum & Associates.
Heath, R.A. (2000). Nonlinear dynamics: Techniques and applications in psychology. Mahwah, NJ: Lawrence Erlbaum & Associates.
Kelly, A., Heathcote, A., Heath, R., & Longstaff, M. (2001).Response-time dynamics: Evidence for linear and low-dimensional nonlinear structure in human choice sequences. Quarterly Journal of Experimental Psychology, 54, 805-840.

Wednesday, 11 March 2015

JUST PUBLISHED! Cognitive aging and workload capacity: how do older people process information from multiple sources?

The modern world bombards us with multiple sources of information. Our ability to cope with increasing amounts of information and behave adaptively in this complex environment is sometimes referred to as ‘workload capacity’. A recent article in the open-access journal PLoS-ONE tests whether this ability changes over the life span. More specifically, the study tested how young and old adults differ in the ability to process multiple visual signals.

In laboratory studies of simple decisions older adults tend to be slower than younger participants. However, the reason for this performance detriment is not entirely clear: Are older people genuinely worse, or simply more cautious? Or, could they be more sensitive to interference from contextual factors? Dr. Ami Eidels from the School of Psychology at the University of Newcastle, along with co-authors Dr. Boaz Ben David (IDC) and Dr. Chris Donkin (UNSW), compared performance of young adults (mean age = 22 years) and older adults (mean age = 72) in a visual detection task. Participants in the study were presented with one target signal (‘X’) or multiple signals. In another condition, distractors (‘O’) could also be presented for view but the participants had to ignore the distracting items and look for target signals.

Overall, older adults were slower to detect a target by about 15%, compared with their younger counterparts. Both groups were highly accurate (more than 98% correct), so a caution explanation is not very likely. Namely, if the elderly were slower only because they were sacrificing speed for accuracy, they should have been more accurate.  Ben David, Eidels, and Donkin used cognitive modeling techniques that employ both response-times and accuracy data to separate the effects of perceptual ability, caution, and the effects of distractors. They found that the major difference between the young and old was the inability of the latter to ignore distractor information. Put bluntly, in a complex and cluttered environment older adults may not be as efficient at blocking irrelevant information. These results have important implications concerning the way we design displays and interfaces for Australia’s aging population.

The paper is available  via Ami’s website,, or directly (and for free) via PLoS-ONE: 

Ben-David B.M., Eidels A., Donkin C. (2014). Effects of Aging and Distractors on Detection of Redundant Visual Targets and Capacity: Do Older Adults Integrate Visual Targets Differently than Younger Adults? PLoS ONE, 9(12): e113551. doi:10.1371/journal.pone.0113551

Acknowledgment: the study was partially supported by the Keats Endowment Research Fund to A.E.

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