Feb 27, 2025
Non-human Primate Arm-reaching Behavioral Tasks
- Damien Pittard1,2,
- Adriana Galvan1,2,
- Thomas Wichmann1,2
- 1Emory University;
- 2ASAP
Protocol Citation: Damien Pittard, Adriana Galvan, Thomas Wichmann 2025. Non-human Primate Arm-reaching Behavioral Tasks. protocols.io https://dx.doi.org/10.17504/protocols.io.5jyl8d41rg2w/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: February 25, 2025
Last Modified: February 27, 2025
Protocol Integer ID: 123528
Keywords: ASAPCRN
Funders Acknowledgements:
ASAP
Grant ID: ASAP-020572
Abstract
This protocol describes procedures used for training and behavioral testing of non-human primates (NHPs) in simple arm-reaching behavioral tasks, used for evaluation of parkinsonian animals.
Guidelines
Introduction
Arm-reaching tasks are often used in NHPs to study their motor skills, to examine neuronal responses to behavioral events, and to study brain abnormalities in models of movement disorders. While monkeys have been shown to be able to learn highly complex motor tasks under healthy conditions, it has been difficult to study their performance in complex tasks in the parkinsonian state. Another limitation of behavioral testing in the parkinsonian state is that animals will perform even simple tasks only for a small number of trials. As we are interested in examining task responses under parkinsonian conditions, we chose a very simple task for our studies.
Materials
- Primate chair
- Head fixation via use of a thermoplastic molded helmet or a conventional head post
- Computer-controlled touchscreen display (GVision)
Safety warnings
This protocol needs prior approval from the users' Institutional Animal Care and Use Committee (IACUC), the Institutional Review Board (IRB), or equivalent ethics committee.
Procedure/Setting
Procedure/Setting
Train animals to accept being seated in a primate restraining chair, and to reduce their head movements through the use of a thermoplastic molded helmet (CIVCO medical solutions) (Drucker et al., 2015) or a surgically implanted head post.
Monkeys learn one of the arm-reaching tasks described below (implemented in MonkeyLogic v2.2 [NIMH]):
Position the animals facing a 17-inch touchscreen display (GVision) and use their right arm to perform one of the tasks.
Note
The animals are not specifically food- or water-restricted but receive drops of preferred juice as an incentive to perform the task.
Consider training is complete once the animal consistently performs at least 100 successful trials per session.
Note
The physical aspects of the tasks are described in the following sections, while Matlab code and parameter file information is provided in the Appendix.
One-target Task
One-target Task
3s
3s
Display a filled circle (~93 mm diameter) on the touch screen at randomly chosen intervals (see below), either at the center of the screen, or horizontally moved to either the left or right side of the screen (at the same vertical position).
The animal has to touch the circle to receive a juice reward.
At the moment of touch, the circle display will be switched off.
The target will be shown for a maximum of 00:00:03 .
- If the monkey fails to touch the screen during this period, the circle display will be switched off (without reward).
3s
A new trial will be initiated after a random inter-trial interval of 2-3 seconds.
- If the animal has touched the screen, the inter-trial interval will start following the release of the monkey's hand from the touch screen.
Note
The timing and template parameters for this program are presented in Appendix 1.
Two-target Task
Two-target Task
2s
2s
This task requires the monkey to touch two separate targets in succession on the screen, with the arm contralateral to the recording site.
The trial begins with the display of a filled center target circle (~52 mm diameter). The monkey is required to touch the center target on the touch screen within 00:00:01 of its appearance.
- If the animal fails to touch the target, the trial is aborted (without reward).
1s
If the monkey touches the center target, a similarly sized circular target on the left or right side of the screen (randomly chosen) appears, at an approximate distance of 117 mm (center – center) from the central target. The center target is extinguished when the side target appears.
Once the side target appears, the monkey has to touch the side target within 00:00:01 to receive a drop of juice for a successful trial.
- Failure to capture the peripheral target within the allotted time period aborts the trial.
Note
The timing and template parameters for this program are presented in Appendix 2.
1s
APPENDIX
APPENDIX
One-target task:
NIMH MonkeyLogic timing code (referred to as ‘ag_6n_TTL’ in the parameter file)
showcursor(false); % remove the touchscreen cursor
bhv_code(20,'Sample',40,'Go',50,'Reward',100,'TrialEnd'); % behavioral codes
sample = 1;
sound_sample = 2;
sample_time = 3000;
delay = 3000;
max_reaction_time = 1000;
itt_basic = 2000; % inter-trial intervals will not be any shorter than this time (in ms)
itt_rand = 3000; % random component added to inter-trial intervals (in ms)
hold_radius = 10; % fixation window (in degrees):
[~,button] = mouse_position();
while button(1) % if there is a mouse (=touch screen) input, task is stuck
[~,button] = mouse_position();
end
toggleobject([1 4], 'eventmarker',20); % turn on the target circle
ontarget = eyejoytrack('touchtarget',sample,hold_radius,sample_time);
if ontarget
toggleobject(3,'status','on');
idle(5); % duration of TTL pulse
toggleobject(3,'status','off');
toggleobject(2); % turn on sound
goodmonkey(300, 'juiceline',1, 'numreward',1, 'pausetime',700, 'eventmarker',50); % 300 ms
toggleobject(2);
trialerror(0); % good trial
else
trialerror(3); % bad trial
end
toggleobject([1 4],'eventmarker',100);
idle(itt_basic + rand(1)*itt_rand); % wait ...
NIMH MonkeyLogic parameter information
| A | B | C | D | E | F | G | H | |
| Condition | Frequency | Block | Timing File | TaskObject#1 | TaskObject#2 | TaskObject#3 | TaskObject#4 | |
| 1 | 1 | 1 | ag_6n_TTL | crc(5,[0 206 209],1,10,-5) | snd(sin,0.5,1000) | ttl(1) | ttl(2) | |
| 2 | 1 | 1 | ag_6n_TTL | crc(5,[0 206 209],1,0,-5) | snd(sin,0.5,1000) | ttl(1) | ttl(2) | |
| 3 | 1 | 1 | ag_6n_TTL | crc(5,[0 206 209],1,-10,-5) | snd(sin,0.5,1000) | ttl(1) | ttl(2) |
Two-target task:
NIMH MonkeyLogic timing code (referred to as ‘Ulrik_2target’) in the parameter file
bhv_code(15,'CenterOn',25,'CenterOff',30,'CenterCapture',40,'CenterHold',50,'TargetOn',60,'TargetOff',70,'CenterLeave',80,'TargetCapture',90,'RewardOn',100,'RewardOff'); % behavioral codes
% **** User parameters (times in ms, fixation_window size in degrees) ****
% Object 1 (center):
acquisition_time1=1000; % max time for the monkey to catch the center (ms)
hold_time1_min =100; % min time for which the center has to be touched (ms)
hold_time1_max =100; % min time for which the center has to be touched (ms)
release_time1 =1000; % max duration before the monkey has to let go of the center
hold_radius1 = 3; % determines the precision with which the center has to be hit
% Object 2 (peripheral target):
acquisition_time2= 1000; % max time for the monkey to catch the center (ms)
hold_radius2 = 3; % size of the side target
reward_dur = 200; % duration of solenoid activation
intertrial_interval_min = 1500; % minimal intertrial interval duration
intertrial_interval_max = 1800; % maximal intertrial interval duration
%calculate randomized parameters
intertrial_interval = intertrial_interval_min + rand*(intertrial_interval_max - intertrial_interval_min);
hold_time1 = hold_time1_min + rand*(hold_time1_max - hold_time1_min);
toggleobject([1 2 3],'status','off');
[~,button] = mouse_position();
while button(1) % if there is a mouse (=touch screen) input, task is stuck
[~,button] = mouse_position();
end
toggleobject([1],'status','on','eventmarker',15); % turn center object on
on_center = eyejoytrack('touchtarget',1,hold_radius1,acquisition_time1);
if~on_center % if center not hit within the appropriate time, the trial is being terminated
toggleobject([1 2 3],'status','off','eventmarker',25); % switch center off
trialerror(1); % report error type 1: did not touch center
return
end
eventmarker(30); % set eventmarker: CenterCapture
center_hold = eyejoytrack('releasetarget',1,hold_radius1,hold_time1);
if~center_hold % if the monkey relased the center too early ...
toggleobject([1 2 3],'status','off','eventmarker',25);
trialerror(2); % report error type 2: broke center target hold
return
end
eventmarker(40); % set eventmarker: CenterHold
toggleobject([1],'status','off','eventmarker',25); % turn center target off,
toggleobject([2],'status','on','eventmarker',50); % turn peripheral target on (= GO signal)
[center_release,rt] = eyejoytrack('releasetarget',1,hold_radius1,release_time1);
if center_release % if monkey has not reacted within the release_time1 window ...
toggleobject([1 2 3],'status','off','eventmarker',60);
trialerror(3); % report error type 3: did not react to target
return
end
eventmarker(70); % set eventmarker: CenterLeave
on_target = eyejoytrack('touchtarget',2,hold_radius2,acquisition_time2);
if ~on_target % if monkey has not acquired the peripheral target within the time allowed ...
toggleobject([1 2 3],'status','off','eventmarker',60);
trialerror(4); % report error type 4: did not capture target
return
end
eventmarker(80); % set eventmarker: TargetCapture
trialerror(0); % report error type 0: GoodTrial
toggleobject(3,'status','on'); % turn on sound
eventmarker(90); % set eventmarker: RewardOn
goodmonkey(200, 'juiceline',1, 'numreward',1, 'pausetime',500, 'eventmarker',80); % reward
eventmarker(60)
toggleobject([1 2 3],'status','off','eventmarker',100); % turn the lights off
idle(intertrial_interval); % wait ...
NIMH MonkeyLogic parameter information
| A | B | C | D | E | F | G | |
| Condition | Frequency | Block | Timing File | TaskObject#1 | TaskObject#2 | TaskObject#3 | |
| 1 | 1 | 1 | Ulrik_2target | crc(3,[256 256 256],1,0,-5) | crc(3,[256 256 256],1,-13,-5) | snd(sin,0.5,1000) | |
| 2 | 1 | 1 | Ulrik_2target | crc(3,[256 256 256],1,0,-5) | crc(3,[256 256 256],1,13,-5) | snd(sin,0.5,1000) |
Protocol references
Drucker, C.B., Carlson, M.L., Toda, K., DeWind, N.K., and Platt, M.L. (2015). Non-invasive primate head restraint using thermoplastic masks. J Neurosci Methods 253, 90-100.