The macaque anterior cingulate cortex translates counterfactual choice value into actual behavioral change
E Fouragnan, BKH Chau, D Folloni, N Kolling, L Verhagen, Miriam Klein-Flügge, L Tankelevitch, GK Papageorgiou, JF Aubry, J Sallet, MFS Rushworth
2018 · 10.1101/336917
Abstract
The neural mechanisms mediating sensory-guided decision making have received considerable attention but animals often pursue behaviors for which there is currently no sensory evidence. Such behaviors are guided by internal representations of choice values that have to be maintained even when these choices are unavailable. We investigated how four macaque monkeys maintained representations of the value of counterfactual choices – choices that could not be taken at the current moment but which could be taken in the future. Using functional magnetic resonance imaging, we found two different patterns of activity co-varying with values of counterfactual choices in a circuit spanning hippocampus, anterior lateral prefrontal cortex, and anterior cingulate cortex (ACC). ACC activity also reflected whether the internal value representations would be translated into actual behavioral change. To establish the causal importance of ACC for this translation process, we used a novel technique, Transcranial Focused Ultrasound Stimulation, to reversibly disrupt ACC activity.
Abstract via europepmc.
Exposures
Exposure 1: ACC TUS
Target: pregenual anterior cingulate cortex — “rACC”
Device: Sonic Concepts · Sonic Concept, Bothell, WA, USA · H115-MR ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 250 | ✓✓✓ |
| Pulse duration (ms) | 30 | ✓✓✓ |
| Pulse repetition frequency (Hz) | 10 | ✓✓✓ |
| Duty cycle (%) | not reportedpulse duration × PRF gives 30% | |
| Sonication duration (s) | 40 | ✓✓✓ |
| Free-field pressure (kPa) | 1,152, 1,292swept | ✓✓✓⚑ |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | deratingmean or range across subjects | |
| In-situ pressure (kPa) | 760, 850swept | ✓✓✓ |
| In-situ Isppa (W/cm²) | not reported | |
| In-situ Ispta (W/cm²) | not reported |
30 ms bursts of ultrasound were generated every 100 ms (i.e., a pulse every 100 ms, converting to a 10 Hz pulse repetition rate) for an overall stimulation duration of 40 s, applied immediately prior to each of nine TUS testing sessions interleaved with nine sham sessions per monkey; sham sessions mirrored the TUS procedure except sonication was not triggered.
Exposure 2: lOFC TUS (anatomical specificity control)
Target: orbitofrontal cortex — “lateral orbitofrontal cortex (lOFC)”
Device: Sonic Concepts · Sonic Concept, Bothell, WA, USA · H115-MR ✓
| Waveform | not reported | |
|---|---|---|
| Fundamental frequency (kHz) | 250 | ✓✓✓ |
| Pulse duration (ms) | 30 | ✓✓✓⚑ |
| Pulse repetition frequency (Hz) | 10 | ✓✓✓ |
| Duty cycle (%) | not reportedpulse duration × PRF gives 30% | |
| Sonication duration (s) | 40 | ✓✓✓ |
| Free-field pressure (kPa) | 1,152, 1,292swept | ✓✓✓⚑ |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | not reported | |
| In-situ pressure (kPa) | 760, 850swept | ✓✓✓ |
| In-situ Isppa (W/cm²) | not reported | |
| In-situ Ispta (W/cm²) | not reported |
A control experiment applying the same TUS technique (250 kHz, cigar-shaped focal spot) to lateral orbitofrontal cortex instead of ACC, to test anatomical specificity; other timing/pressure parameters are not restated separately in the text for this control.
Flags from extraction
exposures[0].free_field.pressure_kpa— Paper writes 'MP' where MPa is presumably intended (unit abbreviation truncated/typo); value itself recorded as stated.exposures[1].timing.pulse_duration_ms— Timing and pressure parameters for the lOFC control exposure are not restated separately from the ACC protocol in the main text; left not_reported rather than assuming identical values.exposures[1].free_field.pressure_kpa— Not explicitly restated for lOFC exposure; general TUS methods paragraph (pressure/timing) is written in the context of the ACC experiment.direction_of_effect— Classified as inhibitory based on behavioral disruption of counterfactual-value-guided switching; paper does not report a direct neural excitatory/inhibitory measure for the TUS effect itself.n_subjects— Only 2 of the 4 macaques used in the main fMRI task received TUS; n_subjects reflects those exposed to ultrasound.