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Training Monkeys By Linc-8 Computer
TRAINING MONKEYS BY LINC-B COMPUTER G. Ettlinger (The Institute of Psychiatry, London, S.E.5)
INTRODUCTION
Solid-state automatic trammg equipment can not compete with the general purpose laboratory computer in flexibility. Its sole advantage, low cost, can be matched by the computer when the latter is able to control the training of more than one animal at a time. Methods of training monkeys under control of a small computer are described in this note. For details of a different system which also uses a computer to present stimuli and process responses made in an "automated discrimination apparatus" see Pribram, Gardner, Pressman and Bagshaw (1962) and Pribram(1969).
THE COMPUTER
A standard Linc-8 computer (Digital Equipment Corporation) with 4K memory store is used but its successor the PDP12 (DEC) would be equally suitable. Separate programmes control the training of monkeys at: 2-choice simultaneous discrimination, 2-choice successive discrimination (with or without symmetrical reward) and spatial alternation. (Programmes for the control of time- instead of cuedependent behaviour could also be written.) Programmes are stored on magnetic tape and loaded into the computer by typing the name of the programme. All programmes are intended for use with either one monkey at a time or up to 4 monkeys at a time. These latter programmes were largely written by Dr. C. Rashbass: each animal can be set an in-
Training monkeys by computer
411
dividual criterion, trained with individual stimuli and be out of step with the other animals in the number of trials on the task, but all 4 animals must be on one task (e.g., simultaneous, vs. successive, training.) Some special features of the programmes are: each animal's performance is displayed, trial by trial, on the computer's screen as training proceeds; at the end of a training session (i.e., after a predetermined number of trials during that session, or when all animals have met criterion) the computer prints the day's performance for each animal showing various cumulative totals across all sessions on this task, various totals for this session and the outcome of every trial this session; any criterion level can be set and the computer determines after every response whether the criterion has been met. With 2-choice simultaneous training, position habits are corrected (this is shown in the print-out) and trials on which the animal failed to respond within 5 sec. of the stimulus presentation are recorded. With 2-choice successive training, response latencies can (optionally) be printed to the nearest 20 msec. for every trial of each animal, and separate totals are recorded for correct responses to positive and negative stimuli, and incorrect responses to positive and negative stimuli. With spatial alternation, a "zero" trial is given, and incorrect responses are conected. The computer can also terminate training when an "adjusted" criterion has been reached, i.e. account is taken, trial by trial, of the number of trials that have been given without meeting criterion in setting the criterion (which therefore changes as training proceeds).
THE PERIPHERAL APPARATUS
The major components of the peripheral apparatus are: control circuits responsive to the relays or relay register of the computer; stimulus projectors, one for each response panel, able to project 12-25 different shapes, colours or intensities; response panels on which the stimuli are projected, and which the monkey presses to respond; micro-switches attached to the panels to sense the monkey's response and inform the computer; locks to lock/unlock the response panels; a means of distributing a peanut-reward to any designated panel; and a clock giving timing pulses to the computer. Figure 1 shows the peripheral apparatus currently in use. The
c.
412
Ettlinger
pneumatic delivery unit
~-_peanut
translucent hinged panels
o
E
projected stimulus
DO
o
o r-
".
0.5 m
Fig. 1 -
~---0.5
m---+
Side and front view of peripheral apparatus (schematic).
upper or lower pairs of panels can be used for 2-choice simultaneous, the central panel for 2-choice successive discrimination; these 5 panels in combination for matching from sample; and the central pair, excluding the middle one, for simultaneous discrimination with an
Training monkeys by computer
413
micro switch tray illumination lamp
actuated by loose member pressure adjusting screw on loose member actuated by hinged door
I-~----------I
I
J
I I
translucent panel
teflon-roller lock
I I
I I
return spring
D
,... solenoid . release
spring to keep roller in open door position when unlocked
--+--+-plastic pipe
Fig. 2 (schematic) .
Rear and side view of response panel, and of tray receiving peanuts
animal seated in a chair. The projectors (Counting Instrument Ltd.) allow a shape, colour or intensity to be projected centrally on each panel by applying a voltage to an individual lamp for each of the 12-25 stimuli. The response panels are made of translucent plastic;
G. Ettlinger
414
supply
sectional view of funnel
50 positions pneumatic rotary ~1!r---1t- switch
lIi~~:;e=~=~:S~~~peanut
selection _ solenoids
holder
....--ttl
plastic pipes to panel trays
Fig. 3 - Side view of peanut holder, of air e;ection mechanism and of selector mechanism to direct peanut to intended tray (schematic).
they are hinged at the top, spring loaded to shut, and are locked by the rotation of a solenoid-retained cam at the bottom (see Figure 2).
Training monkeys by computer
415
Micro-switches are fixed above the panels (see Figure 2); a press against the spring-loaded panel operates the switch even though a panel when locked can be displaced by only 1-2 mm. The locks are made of PTFE (Teflon) so that they can return to their normally unlocked position by the action of their spring (should the monkey have rotated them into the locked position) against the pressure of the panel closing spring, thus permitting the panel to close fully before the locks are locked by the computer. Peanuts are stored in 50 individual holders, and ejected, one at a time, into a funnel by a blast of air after a correct response (see Figure 3); a selector mechanism then ensures that the peanut falls to the tray behind the predetermined panel (see Figure 3). A mains-operated reed relay giving 50 cycles of operation per sec. serves as a clock for programmes intended for only one animal; a Digitimer (Devices Instruments Ltd.) giving a 0.1 msec. pulse every 10 msec. serves as a clock for programmes intended for up to 4 animals.
OPERATION
The programme of choice is loaded into the computer and the animal(s) brought to the peripheral apparatus(es). The animal(s) to be trained is identified to the computer by typing a number. Stimuli appear on the response panel(s). The monkey does/does not respond, and this is interpreted as correct/incorrect by the computer. If correct, the panel unlocks, a yellow light illuminates the tray to which a peanut is delivered behind the panel where the correct response was made. If incorrect, the stimulus/stimuli are extinguished and a 5 sec. inter-trial interval ensues. In this way 40 trials are given unless the animal either meets criterion or fails to respond 40 times since its previous response. Using these procedures for a period of one year, learning scores have been found to be remarkably low and uniform. "Shaping" takes 1-7 days, mostly 2-3 days. Pattern discriminations are learnt in about half as many trials or less than would be required in a WGTA with comparable pattern stimuli on plaques or lids. Details of performance scores are to be published elsewhere.
G. Ettlinger
416
SUMMARY
A method of training monkeys to perform cue-dependent tasks under control of a standard small laboratory computer is described. Acknowledgements. The computer was made available through the generosity of the M.R.C. The cost of training animals was defrayed by a grant from the Research Fund of the Maudsley Hospital. Dr. C. Rashbass gave invaluable help throughout. The peripheral apparatus was built with great ingenuity by Mr. R. Reeves. Programmes are available from the author on request.
REFERENCES
K. H. (1969) DADTA III: An on-line computerised system for the experimental analysis of behavior, "Percept. Mot. Skills," 29, 599-608. GARDNER, K. W., PRESSMAN, G. L., and BAGSHAW, M. (1962) An automated discrimination apparatus for discrete trial analysis (DADTA) , "Psycho!. Rep.," 11, 247-250.
PRIBRAM, -,
Dr. G. Ettlinger, The Institute of Psychiatry, De Crespigny Park, Denmark Hill, London S.E.5.
INTRODUCTION
Solid-state automatic trammg equipment can not compete with the general purpose laboratory computer in flexibility. Its sole advantage, low cost, can be matched by the computer when the latter is able to control the training of more than one animal at a time. Methods of training monkeys under control of a small computer are described in this note. For details of a different system which also uses a computer to present stimuli and process responses made in an "automated discrimination apparatus" see Pribram, Gardner, Pressman and Bagshaw (1962) and Pribram(1969).
THE COMPUTER
A standard Linc-8 computer (Digital Equipment Corporation) with 4K memory store is used but its successor the PDP12 (DEC) would be equally suitable. Separate programmes control the training of monkeys at: 2-choice simultaneous discrimination, 2-choice successive discrimination (with or without symmetrical reward) and spatial alternation. (Programmes for the control of time- instead of cuedependent behaviour could also be written.) Programmes are stored on magnetic tape and loaded into the computer by typing the name of the programme. All programmes are intended for use with either one monkey at a time or up to 4 monkeys at a time. These latter programmes were largely written by Dr. C. Rashbass: each animal can be set an in-
Training monkeys by computer
411
dividual criterion, trained with individual stimuli and be out of step with the other animals in the number of trials on the task, but all 4 animals must be on one task (e.g., simultaneous, vs. successive, training.) Some special features of the programmes are: each animal's performance is displayed, trial by trial, on the computer's screen as training proceeds; at the end of a training session (i.e., after a predetermined number of trials during that session, or when all animals have met criterion) the computer prints the day's performance for each animal showing various cumulative totals across all sessions on this task, various totals for this session and the outcome of every trial this session; any criterion level can be set and the computer determines after every response whether the criterion has been met. With 2-choice simultaneous training, position habits are corrected (this is shown in the print-out) and trials on which the animal failed to respond within 5 sec. of the stimulus presentation are recorded. With 2-choice successive training, response latencies can (optionally) be printed to the nearest 20 msec. for every trial of each animal, and separate totals are recorded for correct responses to positive and negative stimuli, and incorrect responses to positive and negative stimuli. With spatial alternation, a "zero" trial is given, and incorrect responses are conected. The computer can also terminate training when an "adjusted" criterion has been reached, i.e. account is taken, trial by trial, of the number of trials that have been given without meeting criterion in setting the criterion (which therefore changes as training proceeds).
THE PERIPHERAL APPARATUS
The major components of the peripheral apparatus are: control circuits responsive to the relays or relay register of the computer; stimulus projectors, one for each response panel, able to project 12-25 different shapes, colours or intensities; response panels on which the stimuli are projected, and which the monkey presses to respond; micro-switches attached to the panels to sense the monkey's response and inform the computer; locks to lock/unlock the response panels; a means of distributing a peanut-reward to any designated panel; and a clock giving timing pulses to the computer. Figure 1 shows the peripheral apparatus currently in use. The
c.
412
Ettlinger
pneumatic delivery unit
~-_peanut
translucent hinged panels
o
E
projected stimulus
DO
o
o r-
".
0.5 m
Fig. 1 -
~---0.5
m---+
Side and front view of peripheral apparatus (schematic).
upper or lower pairs of panels can be used for 2-choice simultaneous, the central panel for 2-choice successive discrimination; these 5 panels in combination for matching from sample; and the central pair, excluding the middle one, for simultaneous discrimination with an
Training monkeys by computer
413
micro switch tray illumination lamp
actuated by loose member pressure adjusting screw on loose member actuated by hinged door
I-~----------I
I
J
I I
translucent panel
teflon-roller lock
I I
I I
return spring
D
,... solenoid . release
spring to keep roller in open door position when unlocked
--+--+-plastic pipe
Fig. 2 (schematic) .
Rear and side view of response panel, and of tray receiving peanuts
animal seated in a chair. The projectors (Counting Instrument Ltd.) allow a shape, colour or intensity to be projected centrally on each panel by applying a voltage to an individual lamp for each of the 12-25 stimuli. The response panels are made of translucent plastic;
G. Ettlinger
414
supply
sectional view of funnel
50 positions pneumatic rotary ~1!r---1t- switch
lIi~~:;e=~=~:S~~~peanut
selection _ solenoids
holder
....--ttl
plastic pipes to panel trays
Fig. 3 - Side view of peanut holder, of air e;ection mechanism and of selector mechanism to direct peanut to intended tray (schematic).
they are hinged at the top, spring loaded to shut, and are locked by the rotation of a solenoid-retained cam at the bottom (see Figure 2).
Training monkeys by computer
415
Micro-switches are fixed above the panels (see Figure 2); a press against the spring-loaded panel operates the switch even though a panel when locked can be displaced by only 1-2 mm. The locks are made of PTFE (Teflon) so that they can return to their normally unlocked position by the action of their spring (should the monkey have rotated them into the locked position) against the pressure of the panel closing spring, thus permitting the panel to close fully before the locks are locked by the computer. Peanuts are stored in 50 individual holders, and ejected, one at a time, into a funnel by a blast of air after a correct response (see Figure 3); a selector mechanism then ensures that the peanut falls to the tray behind the predetermined panel (see Figure 3). A mains-operated reed relay giving 50 cycles of operation per sec. serves as a clock for programmes intended for only one animal; a Digitimer (Devices Instruments Ltd.) giving a 0.1 msec. pulse every 10 msec. serves as a clock for programmes intended for up to 4 animals.
OPERATION
The programme of choice is loaded into the computer and the animal(s) brought to the peripheral apparatus(es). The animal(s) to be trained is identified to the computer by typing a number. Stimuli appear on the response panel(s). The monkey does/does not respond, and this is interpreted as correct/incorrect by the computer. If correct, the panel unlocks, a yellow light illuminates the tray to which a peanut is delivered behind the panel where the correct response was made. If incorrect, the stimulus/stimuli are extinguished and a 5 sec. inter-trial interval ensues. In this way 40 trials are given unless the animal either meets criterion or fails to respond 40 times since its previous response. Using these procedures for a period of one year, learning scores have been found to be remarkably low and uniform. "Shaping" takes 1-7 days, mostly 2-3 days. Pattern discriminations are learnt in about half as many trials or less than would be required in a WGTA with comparable pattern stimuli on plaques or lids. Details of performance scores are to be published elsewhere.
G. Ettlinger
416
SUMMARY
A method of training monkeys to perform cue-dependent tasks under control of a standard small laboratory computer is described. Acknowledgements. The computer was made available through the generosity of the M.R.C. The cost of training animals was defrayed by a grant from the Research Fund of the Maudsley Hospital. Dr. C. Rashbass gave invaluable help throughout. The peripheral apparatus was built with great ingenuity by Mr. R. Reeves. Programmes are available from the author on request.
REFERENCES
K. H. (1969) DADTA III: An on-line computerised system for the experimental analysis of behavior, "Percept. Mot. Skills," 29, 599-608. GARDNER, K. W., PRESSMAN, G. L., and BAGSHAW, M. (1962) An automated discrimination apparatus for discrete trial analysis (DADTA) , "Psycho!. Rep.," 11, 247-250.
PRIBRAM, -,
Dr. G. Ettlinger, The Institute of Psychiatry, De Crespigny Park, Denmark Hill, London S.E.5.