The role of the frontal eye field in gating and maintaining object signals in short-term memory
Abstract/Contents
- Abstract
- Spatial attention is known to gate entry into short-term memory, and some evidence suggests that spatial signals may also play a role in binding features or protecting object representations during memory maintenance. To examine a potential role for spatial signals in maintaining object short-term memory, the activity of neurons in the Frontal Eye Field (FEF) of macaque monkeys was recorded during an object-based delayed match-to-sample (DMS) task. In this task monkeys were trained to remember an object identity over a brief delay, irrespective of the locations of the sample or target presentation. FEF neurons exhibited visual, delay, and target period activity, including selectivity for sample location and target location. Delay period activity represented the sample location throughout the delay, despite the irrelevance of spatial information for successful task completion. Furthermore, neurons continued to encode sample position in a variant of the task in which the matching stimulus never appeared in their response field. FEF neurons also exhibited target-position-dependent anticipatory activity immediately prior to target onset, suggesting that the monkeys can predict target position within blocks. These results show that FEF neurons maintain spatial information during short-term memory, even when that information is irrelevant for task performance. Despite the robust delay period activity we observed in FEF during the DMS task, we found little further evidence to support the theory that this activity contributes to object memory maintenance. Noise correlations were present between pairs of simultaneously recorded FEF and IT neurons during the sample and early delay periods, but did not persist into the second half of the delay period, despite the continued elevation of firing rates in both regions throughout the delay. The most direct method of assessing the contribution of the FEF delay period activity observed during the DMS task to object memory was the pharmacological elimination of that activity and evaluation of the impact on task performance. Inactivation of FEF with muscimol produced spatially localized deficits on the memory guided saccade task, but did not selectively impair object memory performance for sample stimuli appearing in the mnemonic scotoma.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Clark, Kelsey Lynne |
|---|---|
| Associated with | Stanford University, Neurosciences Program. |
| Primary advisor | Moore, Tirin, 1969- |
| Thesis advisor | Moore, Tirin, 1969- |
| Thesis advisor | Knudsen, Eric I |
| Thesis advisor | Newsome, William T |
| Thesis advisor | Wagner, Anthony David |
| Advisor | Knudsen, Eric I |
| Advisor | Newsome, William T |
| Advisor | Wagner, Anthony David |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Kelsey Lynne Clark. |
|---|---|
| Note | Submitted to the Neurosciences Program. |
| Thesis | Ph.D. Stanford University 2012 |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Kelsey Lynne Clark
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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