An fMRI investigation into the effect of preceding stimuli during visual oddball tasks
| Authors | |
|---|---|
| Year of publication | 2015 |
| Type | Article in Periodical |
| Magazine / Source | Journal of Neuroscience Methods |
| MU Faculty or unit | |
| Citation | |
| Web | http://ac.els-cdn.com/S0165027015001788/1-s2.0-S0165027015001788-main.pdf?_tid=9a20bf90-8dfd-11e5-b99f-00000aab0f01&acdnat=1447855785_2848590d3bb6924b3aa3be243f10167e |
| Doi | http://dx.doi.org/10.1016/j.jneumeth.2015.05.005 |
| Field | Neurology, neurosurgery, neurosciences |
| Keywords | fMRI; Oddball; Stimulus sequence; Target; Parametric modulation; Attention |
| Attached files | |
| Description | Background: This study investigates the modulatory effect of stimulus sequence on neural responses to novel stimuli. A group of 34 healthy volunteers underwent event-related functional magnetic resonance imaging while performing a three-stimulus visual oddball task, involving randomly presented frequent stimuli and two types of infrequent stimuli targets and distractors. New method: We developed a modified categorization of rare stimuli that incorporated the type of preceding rare stimulus, and analyzed the event-related functional data according to this sequence categorization; specifically, we explored hemodynamic response modulation associated with increasing rare-to-rare stimulus interval. Results: For two consecutive targets, a modulation of brain function was evident throughout posterior midline and lateral temporal cortex, while responses to targets preceded by distractors were modulated in a widely distributed fronto-parietal system. As for distractors that follow targets, brain function was modulated throughout a set of posterior brain structures. For two successive distractors, however, no significant modulation was observed, which is consistent with previous studies and our primary hypothesis. Comparison with existing methods: The addition of the aforementioned technique extends the possibilities of conventional oddball task analysis, enabling researchers to explore the effects of the whole range of rare stimuli intervals. Conclusion: This methodology can be applied to study a wide range of associated cognitive mechanisms, such as decision making, expectancy and attention. (C) 2015 Elsevier B.V. All rights reserved. |
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