Friday, 26 June 2015

JUST PUBLISHED: Task uncertainty can account for mixing and switch costs in task-switching.

Our everyday world is bubbling with information; from commuter timetables and text messages to advertisements and infotainment. How do our brains sieve through this information and select where to allocate precious cognitive resources? PhD students in the School of Psychology, Patrick Cooper and Jaime Rennie, and Honours student, Paul Garrett, are certain that uncertainty plays an important part. In this paper, they mathematically quantified the amount of uncertainty present in different stimuli and examined whether this affected the resources needed to process these stimuli. They then applied this algorithm to many different studies. Regardless of the source of uncertainty, similar levels of equivocation affected performance in the same way, with more ‘uncertain’ stimuli requiring more cognitive resources. These findings suggest that a simple and parsimonious process of resolution of uncertainty may help explain how the brain allocates cognitive resources.

Patrick S. Cooper, Paul M. Garrett, Jaime L. Rennie & Frini Karayanidis (2015). Task uncertainty can account for mixing and switch costs in task-switching. PLoS ONE 10(6): e0131556. doi: 10.1371/journal.pone.0131556

The article is published in the open access journal PlosONE, and can be accessed directly here:

Wednesday, 24 June 2015

Early Carreer Award for an Affiliate Member of the UoN Social Psychology Lab by Sylvie Graf

On 2nd June, Sylvie Graf - an Affiliate Member of the UoN Social Psychology Lab - received an Otto Wichterle Award from the Academy of Sciences of the Czech Republic, her home institution. You may not know Otto Wichterle but you probably do know about his invention – soft contact lenses. Otto Wichterle lent his name to an honorary recognition for “selected, exceptionally outstanding, promising young scientists at the Czech Academy of Sciences for their remarkable contributions to the advancement of scientific knowledge in a given area of science”.

Sylvie describes the festive event:
"The laureates attended Vila Lana, a representative building of the Czech Academy of Sciences, to receive the Award during an official ceremony. Unlike Oscar winners, we were not given space to thank those who contributed to our award. Here, I would like to express how much indebted I feel to two UoN academics – Dr Stefania Paolini and Dr Mark Rubin. I was lucky to collaborate with Drs Paolini and Rubin during my 9-month stay at the University of Newcastle, starting in October 2012. The collaboration has decisively boosted my knowledge, skills and orientation in the field. Drs Paolini and Rubin were always prepared to contribute with an immense share of work to our joint projects or help with key advice. I am sure I would not have been a candidate for the prize without their continuous kind support.

Our collaboration has not ended with my departure from Newcastle and I’m happy to continue with exciting joint projects. Currently, we are preparing an article about the role of intimate contacts in the effect of negative and positive intergroup interactions on prejudice reduction, another article about ambivalent contact experiences and a book chapter about valence in intergroup contact. Our collaboration has generated many thrilling ideas and the Otto Wichterle Award is yet another indicator of how fruitful it has been."

Friday, 5 June 2015

A Guest Presentation by Steve Blurton, Carsten Søren Nielsen, and Søren Kyllingsbæk, on visual identification.

The Cognitive Research Group is proud to present a talk by some research guests, Steve Blurton and Carsten Søren Nielsen (University of Copenhagen).

TITLE: A Poisson Random Walk Model for Response Time and Pure Accuracy Tasks

WHEN: Thursday 11th June 12-1pm.

WHERE: Keats Reading Room (AVLG17)

ABSTRACT: Based on a simple ‘what first comes to mind’ rule, a Theory of Visual Attention (TVA; Bundesen, 1990) has been successful in explaining human performance in pure accuracy tasks with non-confusable stimuli. However, for mutually confusable a ‘what has the most evidence’ rule is more suited (Kyllingsbæk et al., 2012). Based on this work we propose and test a common model of the time course of visual identification of mutually confusable single stimuli in two-alternative, response time and pure accuracy tasks. The central model assumption is that during the analysis of a single stimulus in the visual field, tentative evidence for one of two categorizations of the stimulus is generated by a Poisson process at a constant rate in such a way that a tentative categorization automatically counts against the other categorization. Visual identification is thus assumed to follow a simple random walk with exponential distributed interstep times. An identification is conclusively made if and when evidence reaches one of two thresholds. If a threshold is not reached before the analysis is stopped, then an informative guess will be made based on ‘what has the most evidence’. One important question that is to be addressed in an application of the model is whether it is possible to identify invariances of model parameters across conditions of pure accuracy task and speeded responses. With Poisson rate estimates being in the same range across conditions our common model provides a close fit to individual data on identification of Gabor patches in a two-alternative, response time and pure accuracy task.