1. Problem Statement
Build a device for use in research that compares the ability of young and old monkeys to sense tastes and smells (stimuli). Once the monkey has chosen a door based on the stimulus, the other door must be inactivated.

2. Design Objectives Flexible stimulus capability
Present two clearly distinct options
Choice must be final
Sensitivity
…To present stimuli -- Both tastes and smells
Allow monkey to choose between the two. One may be BLANK!
Both options must clearly be separate and correlate to a specific stimulus
* No “looking behind door #2” or getting a reward for a wrong choice!
If he’s right, gets a treat!
To facilitate fast and efficient testing of several monkeys
Sensitive enough for a monkey’s timid touch, but not so much that it can be tripped accidentally by a random bump or tap.
Constructed of metal; something that can be repeatedly washed and sterilized and can withstand abuse from operation and an occasional drop to the floor.
Simple for BOTH the monkey to use and for the researcher to reset.

3. Design Objectives Provide a reward Readily movable between cages
Durable, non-corrosive
Simple operation - as automated as possible

4. Past Accomplishments Constructed a working prototype
Mechanical door-locking mechanism
Moveable from cage to cage
Sized to fit cage
Durable construction

5. Past Accomplishments Problems Doors opened sideways
Cumbersome locking mechanisms to reset
Edge of doors could be harmful to monkeys

6. Mechanical Design

7. Mechanical Design (locked tripped)
Ta Da!!! The Mark-1 prototype (complete with Sarah’s gay 12-inch ruler from God knows where…) Body casing constructed of sheet aluminum. Components of the door-locking mechanism are made of brass. The mounting plate can be seen on the bottom half of the device.

8. Alterations to Mechanical Design
Switch door setup - hinge on top
Eliminate metal ‘lip’
Install an internal divider
Remove locking mechanism
Rounded door edges
Training device for use in teaching the monkeys how to operate the device (those 700 exposures we talked about) How to associate door with reward, etc… Complex locking mechanism is NOT crucial at this time… “Short Term” implies by next week…
Switch from side-opening to top-opening; Can do this simply by removing old doors and adding new ones.
Get rid of the sharp metal ‘lip’ between the bottom edge of each door opening and the floor of the device. Not only can it be dangerous, it can hinder the monkey’s ability to use the device.
Add an internal divider to prevent the monkey from reaching through to the other side: say, to the left-side cup from the right side door. They’re smart little buggers!

9. Electrical Design Same form as mechanical design Door hinges on top
Electrical locking mechanism
Photomicro sensors
Solenoid locks
Battery powered – 9 volt
Simple
Easy reset button
On/Off switch

10. Electrical Design
We found that the overall shape and dimensions were acceptable.
Do modifications to create a training device that can go into immediate use. (Move doors, cut off metal lip, add a divider.)
Long Term: What do we want to do??? Which avenue (mechanical? Electrical?) do we wish to pursue and why?

11. Comparison Mechanical Design
Advantages: No electrical demand, easy to fix, high durability
Disadvantages: Cumbersome device to reset, more moving parts
These are ideas to improve the LONG-TERM (testing) device. Feel free to remove any of these. Should probably pick three to go over with some level of detail (as much as we can spare during an 8-minute presentation)

12. Comparison Electrical Design
Advantages: Simplicity of operation, automatic
Disadvantages: Higher cost, electrical dependence

13. Future Work Attach mounting plate for cage
Add a divider plate and food trays
Indicator lights for correct door choice
Test the prototype with monkeys
Train and test monkeys with the product

14. Acknowledgements Special Thanks to:
Thomas Roberts – for assistance in prototype design and development
Clients:
Goran Hellekant, Vicktoria Danilova
Advisor:
Professor John Webster