• Top page
  • Timetable
  • Per session
  • Per presentation
  • How to
  • Meeting Planner



Volitional control of neural activity via neural operant conditioning and brain-machine interfaces

開催日 2014/9/11
時間 14:00 - 16:00
会場 Room F(302)
Chairperson(s) 櫻井 芳雄 / Yoshio Sakurai (京都大学大学院文学研究科 心理学研究室 / Department of Psychology, Kyoto University, Japan)
Eberhard Fetz (Department of Physiology & Biophysics, University of Washington, USA / Department of Physiology and Biophysics, University of Washington, USA)

Operant conditioning of neural activity in freely behaving monkeys using intracranial reinforcement

  • S1-F-2-4
  • Eberhard Fetz:1 Ryan Eaton:1 Tyler Libey:1 
  • 1:Univ of Washington, USA 

Operant conditioning of neural activity has typically been achieved under controlled conditions using food rewards and neurofeedback. To reinforce cell activity during unconstrained behavior in primates, we used intracranial sites in nucleus accumbens whose stimulation supported operant responding on a wrist target-tracking task. Initially, EMG activity of biceps was detected and rewarded with a head-fixed, autonomous recording and stimulating system programmed to deliver reinforcement for 5-minute "time in" periods [TI], alternating with 5-min. extinction periods [time out = TO]. The monkey generated substantially greater muscle activity during TI than TO for most periods. For neural conditioning we recorded activity of single motor cortex neurons with moveable microwires and rewarded increased firing rates with the monkey either seated in the training booth or moving freely in the cage. Spikes occurring above baseline rates triggered electrical pulses to n. accumbens [1 mA, 0.2 ms biphasic current pulses] for TI periods of 1-3 min. separated by TO periods of 3-10 min. During in-booth sessions feedback was often presented through cell-driven cursor movement and auditory clicks. During in-cage sessions audible clicks occurred during each spike-triggered stimulation event. In-booth conditioning produced increases in single-neuron firing rates during TI in most of the cells. Reinforced cell activity could rise above 5 times baseline TO activity, doubling in most sessions. In-cage conditioning produced significant increases in TI activity in a smaller proportion of the cells. During free behavior in the cage monkeys increased firing rates between 13 to 18 percent above TO activity. The smaller relative increase of operant responding in the cage could be due to more competing behaviors than in the booth and to higher levels of TO firing rates in the cage. Post-stimulus histograms showed that stimulation of the reinforcement site never evoked increased cell activity directly. These results indicate that neural activity can be operantly conditioned with intracranial reinforcement during free behavior, and opens the way toward testing volitional control of spatiotemporal firing patterns.

Copyright © Neuroscience2014. All Right Reserved.