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Registration is now open for the fourth international TVA meeting in Copenhagen on June 23ed to 24th at http://psychology.ku.dk/conferences/itva2016/. The 4th ITVA meeting also coinsides with the 25 year annerversary of Center for Visual Cognition, University of Copenhagen and we are happy to present the following list of confirmed speakers:

Edward Awh, University of Oregon, USA
Gordon D. Logan, Vanderbilt University, USA
James T. Townsend, Indiana University, USA
Jeremy M. Wolfe, Harvard University, USA
Jennifer Coull, Aix Marseille Université, France
John Duncan, Cognition and Brain Sciences Unit, Cambridge, UK
Thomas Espeseth, Oslo University, Norway
Kathrin Finke, Ludwig Maximillians University, Munich, Germany
Céline Gillebert, Oxford University, UK
Antje Kraft, Charite Universitäts Medizin, Berlin, Germany
Hermann J. Müller, Ludwig Maximillians University, Munich, Germany
Christian Olivers, Free University, Amsterdam, The Netherlands
Kimron L. Shapiro, University of Birmingham, UK
Jane E. Raymond, University of Birmingham, UK
Werner X. Schneider, Bielefeld University, Germany
Rik Vandenberghe, KU Leuven, Belgium
Susanne Ditlevsen, University of Copenhagen, Denmark
Steven Paul Blurton, University of Copenhagen, Denmark
Thomas Habekost, University of Copenhagen, Denmark
Søren Kyllingsbæk, University of Copenhagen, Denmark
Signe Vangkilde, University of Copenhagen, Denmark
Iris Wiegand, University of Copenhagen, Denmark

For more information please follow the link above – and see you in Copenhagen this summer.

 

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A recent study published online in PLoS ONE by Ásgeirsson et al. (2015) use TVA to analyse what attentional components are modulated by stimulus congruency in colour-grapheme synaesthesia. The authors report that processing speed is affected by stimulus congruency. Surprisingly, several TVA parameters such as the threshold for visual perception as well as attentional selectivity remain un affected by a manipulation of congruency. The authors argue that as well as yielding a more detailed understanding of how synaesthesia interact with cognitive components like attention.

The study is freely available online at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0134456

In a new study published in Journal of Experimental Psychology: Learning, Memory, and Cognition, Sørensen et al. (2015) investigate the effects of temporal expectation and how it modulate attentional TVA parameters. They demonstrate that the temporal expectancy paradigm modulate visual short-term memory, possibly through a tonic modulation of observer arousal akin to a hypothesis proposed by Easterbrook (1959). Sørensen et al. also present a novel analysis using the standard deviation of the attentional weights as a measure of how evenly an observer distribute their attentional resources. Hereby, it is possible to measure the scope of attentional focus in addition to the traditional TVA parameters.

Article available for download via APA on PsycNET

The 3rd bi-annual meeting in the International TVA network will be held in Copenhagen on June 12ed to June 13th 2014.

Venue and a detailed program will follow later in January, together with the meeting registration form. Abstracts on TVA can be submitted through the meeting registration form until the 25th of May. Abstracts should be no more than 200 words. Accepted abstracts will receive a confirmation letter prior to the meeting.

Gillebert et al. (2012) combined functional magnetic resonance imaging and TVA-based computational modeling to investigate the role of the parietal cortex in attentional selection and visual short-term memory.  The authors factorially varied target and distracter set size during a change detection task.  A significant interaction occurred in the middle segment of the intraparietal sulcus and the right temporoparietal junction. The right temporoparietal junction was involved in spotting target singletons. The response profile of the intraparietal sulcus reflected the combined effect of selection and access to visual short-term memory.

Article available for download through ScienceDirect

Thomas Alrik Sørensen will defend his thesis entitled:

Investigations into Capacity-limitations in Visual Processing of the Human Observer.

June 20th at the University of Copenhagen.

The defence will begin at 3 pm and will be conducted in Udvalgsværelse 3 Nørregade 10 and will be evaluated by:

  • Associate Professor, Thomas Habekost, Department of Psychology, University of Copenhagen, (chairman).
  • Professor, Werner X. Schneider, Universität Bielefeld, Fakultät für Psychologie und Sportwissenshaft, Germany.
  • Dr. rer. nat., Antje Kraft, Charité Universitätsmedizin Berlin, Klinik für Neurologie, Germany.

Thesis abstract

Navigating in the environment seems to offer the viewer a rich sensation containing a wealth of information about different objects. However, in a controlled experimental setting it is possible to demonstrate that the short-term memory is severely limited in a human observer. This rich experience is in sharp contrast with the three to four objects that can be retained in visual short-term memory. It has been known for a long time that the human visual short-term memory is limited and within the last 10-15 years a consensus on the number of objects that can be retained seems to have been reached. The focus on a limitation in terms of number of objects has probably formed the basis for a description of short-term memory as a store consisting of a limited number of slots where objects can be encoded. However, whether there is empirical evidence to support the hypothesis that the short-term memory consists of a fixed number of slots is still open for debate.

This thesis presents two studies that investigate how manipulations of training and expertise (Study 1) or the general level of activation (arousal; Study 2) influence the capacity limitation in short-term memory.

In Study 1 the effects of training are investigated. Since it is time consuming to achieve a level of expertise where effects conceivably would show, groups with different levels of expertise were studied in a change detection task. By contrasting stimulus material with which participants had received different levels of overt training with stimulus material that was novel for all participants, it was demonstrated that short-term memory capacity is affected by level of expertise. The results indicate that the number of objects that can be retained in visual short-term memory is influenced by the strength of the mental representations of the observer; as categories become more established fewer resources seem to be required (as reflected in a larger short-term memory capacity).

Study 2 is based on an experimental investigation of repeated measures of short-term memory and investigates whether modulation of arousal affects the number of objects maintained in short-term memory. This manipulation also appears to systematically influence the number of objects encoded into short-term memory. As arousal increases the number of objects that can be maintained in short-term memory is lowered. The data suggest that this effect reflects a change in the focus of attention, which seems to narrow during heightened arousal. Two mechanisms are proposed to account for how arousal influences attentional processes; the scaling mechanism and the accentuation mechanism.

Both studies suggest an embrace of the concept that objects are maintained in short-term memory. However, short-term memory should not be viewed as a static concept consisting of a fixed number of slots. The number of objects that can be maintained in short-term memory is determined partly by how well the object is known and partly by the general level of activation (arousal) in an observer.

A new study by Sørensen and Kyllingsbæk (2012) demonstrate an effect of expertise on visual short-term memory (VSTM) capacity. The study measured the change in VSTM capacity for letters and pictures in four age groups. Here an increase in VSTM capacity for letters with age but not for pictures is reported. The results indicate that VSTM capacity is dependent on the level of expertise for specific types of stimuli processed.

Article available for download through ScienceDirect