5pm on Thursday 30th August, Room 305, 26 Bedford Way.
http://www.ucl.ac.uk/psychlangsci/contactus
Investigating numerosity perception and its applications for studying development and clinical populations
David Aagten-Murphy
University of Florence, Italy
A common challenge, particularly in developmental or clinical testing, is ensuring subjects’ best performance throughout the experiment. Here we present several game-like paradigms, used for examining numerosity perception with typically-developing children and children with autism, designed to keep subjects attentive and motivated throughout testing. While these game-like interfaces can boost subject compliance, techniques such as adaptation still require monotonous repetition, a prohibitively large number of trials and prolonged fixation. Through a series of studies with adults, examining the psychophysical properties of number adaptation, we developed a rapid-adaptation paradigm whereby substantial adaptation can occur with adaptation periods as short as 1 s (compared with the typical 30–60s adaptation). This brief adaptation produces large effects in perceived numerosity that last over extended delays (10–20s) between adaptation and test, with measurable effects persisting for hours after initial adaptation. These results implicate a highly plastic mechanism for numerosity perception and suggest a quick and efficient paradigm for use in clinical testing of numerosity. Finally, in a preliminary fMRI study in adults we used this novel paradigm to investigate the impact that adaptation has on brain regions associated with numerosity.
Alan Johnston
Research Strategy Director, CoMPLEX
Professor of Psychology
Cognitive, Perceptual and Brain Sciences
University College London
Tel +44 (0)20 7679 5310 (x25310)
