m8ta
You are not authenticated, login.
text: sort by
tags: modified
type: chronology
[0] Isoda M, Hikosaka O, Switching from automatic to controlled action by monkey medial frontal cortex.Nat Neurosci 10:2, 240-8 (2007 Feb)

{183}
hide / / print
ref: Isoda-2007.02 tags: SMA saccade basal_forebrain executive function 2007 microstimulation SUA cortex sclin date: 10-03-2008 17:12 gmt revision:2 [1] [0] [head]

PMID-17237780[0] Switching from automatic to controlled action by monkey medial frontal cortex.

  • SCLIN's blog entry
  • task: two monkeys were trained to saccade to one of two targets, left/right pink/yellow. the choice was cued by the color of the central fixation target; when it changed, they should saccade to the same-colored target.
    • usually, the saccade direction remained the same; sometimes, it switched.
    • the switch could either occur to the same side as the SUA recording (ipsilateral) or to the opposite (contralateral).
  • found cells in the pre-SMA that would fire when the monkey had to change his adapted behavior
    • both cells that increased firing upon an ipsi-switch and contra-switch
  • microstimulated in SMA, and increased the number of correct trials!
    • 60ua, 0.2ms, cathodal only,
    • design: stimulation simulated adaptive-response related activity in a slightly advanced manner
    • don't actually have that many trials of this. humm?
  • they also did some go-nogo (no saccade) work, in which there were neurons responsive to inhibiting as well as facilitating saccades on both sides.
    • not a hell of a lot of neurons here nor trials, either - but i guess proper statistical design obviates the need for this.
  • I think if you recast this in tems of reward expectation it will make more sense and be less magical.
  • would like to do shadlen-similar type stuff in the STN
questions
  1. how long did it take to train the monkeys to do this?
  2. what part of the nervous system looked at the planned action with visual context, and realized that the normal habitual basal-ganglia output would be wrong?
    1. probably the whole brain is involved in this.
    2. hypothetical path of error trials: visual system -> cortico-cortico projections + context activation -> preparatory motor activity -> basal ganglia + visual context (is there anatomical basis for this?) -> activation of some region that detects the motor plan is unlikely to result in reward -> SMA?

____References____