Spatially and Temporally Predictive Saccades and Their Neural Correlates
Loading...
Authors
Chang, Benedict
Date
2015-10-03
Type
thesis
Language
eng
Keyword
fMRI , Eye tracking , Prediction , Saccades
Alternative Title
Abstract
Prediction is needed to compensate for neural delays between a sensory input and an
appropriate motor output. We designed an eye movement task to clarify the behavioural control
and neural correlates that are involved in both temporal and spatial prediction. A task involving
temporally and spatially predictive and non-predictive saccades was employed in an MRI machine in which four conditions were tested: spatially/temporally predictive (ST-PRED), temporally predictive/spatially non-predictive (T-PRED), spatially predictive/ temporally non-predictive (S-PRED), and spatially/temporally non-predictive (NON).
Data from 24 normal human participants (mean age = 22.4 yrs) showed distinct behavioural
differences between conditions. All participants elicited primarily predictive saccades (saccadic
reaction time: SRT < 100ms) in the ST-PRED condition. The NON condition elicited primarily
reactive saccades (SRT > 100ms). The average SRT of the S-PRED condition fell between the
average of the ST-PRED and NON conditions, and no significant differences in SRT were
observed between the T-PRED and the NON conditions. Analysis of the functional imaging data
identified regions with activations that correlated to the predictive conditions.
Contrasts of predictive conditions isolating both spatially and temporally predictive areas
showed activation of the PEF, insular cortex, and DLPFC which may play a role in the control of predictive saccades. Contrasts that isolated spatially predictive areas also showed activation of the PEF, insular cortex, and DLPFC while contrasts that isolated temporally predictive areas showed select activation of the
cerebellum which may serve as the internal clock that drives the regular rhythmic behaviour
observed for the temporal aspect of predictive saccades. Surprisingly, activation or frontal areas
responsible for saccadic control such as the Frontal and Supplementary Eye fields were equal
among all conditions. The behavioural differences validated the activity of the contrasts to isolate
brain areas that are correlated with both spatial and temporal prediction. The results from these
contrasts indicated that brain activation in the ST-PRED and S-PRED conditions reflects
predictive responses to visual stimuli while brain activation in the T-PRED condition reflects
motor-timed responses. This suggests that utilizing a predictive saccade task is a valuable tool
for simultaneously testing both spatial and temporal prediction that involves fast internally-guided
responses.
Description
Thesis (Master, Neuroscience Studies) -- Queen's University, 2015-09-30 09:03:38.889
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
Creative Commons - Attribution - CC BY
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
Creative Commons - Attribution - CC BY
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.