The Cognitive Research Group is proud to host a talk by our visitors from Macquarie University:
Predicting Reaction Times from the Emerging Representation of Degraded Visual Objects.
Tijl Grootswagers, J. Brendan Ritchie, and Thomas Carlson
Macquarie University
ABSTRACT: Object
recognition is fast and reliable, and works even when our eyes are focused elsewhere.
The aim of our study was to examine how the visual system compensates for
degraded inputs in object recognition by looking at the time course of the
brain's processing of naturally degraded visual object stimuli. In Experiment
1, we degraded the images by varying the simulated focus so that each image was
equally recognizable. In Experiment 2, subjects categorized intact and degraded
images, while their brain activity was recorded using magnetoencephalography
(MEG). As expected, reaction times for the task were slower for the degraded
object stimuli. We assessed several neurally-based models to explain this
reaction time difference, including distance-based models, which predict
reaction times using distance from a decision bound through neural activation
space. We found that the distance-based models were the best predictors, which
we also related to the linear ballistic accumulator (LBA) model of choice and
reaction time behaviour.
WHEN: Thursday 16th April, 12-1pm.
WHERE: Aviation Building, room AVLG17, with audiovisual link to Ourimbah Science Offices.
