Article Figures & Data
Figures
- Figure 1.
Hardware and wiring for the LED matrices. The required wiring is shown for connecting the Arduino microcontroller (upper left) to the LED matrices (lower row) and the external control system that selects stimulus patterns based on TTL serial inputs. The version reported here allows for stimulus control by four distinct TTL inputs. Connectivity with the external control system can easily be arranged using a standard breakout board (upper right). Pins on the backpack controller for LED matrices are shown above the LED matrices.
- Figure 2.
Visual discrimination behavior using the LED matrices. A, Rats were trained and tested in an operant chamber with the LED matrices mounted above response ports on one side of the chamber and with a reward port containing a spout mounted on the opposite side of the chamber. Each trial was initiated by a nosepoke response in the center port to the “trial start” cue, followed by the presentation of either the high-luminance or low-luminance cue. Both cues were presented for discrimination trials. B, In detection trials, rats expressed a greater number of errors when detecting the low-luminance cue compared with the high-luminance cue. In discrimination trials, rats chose the high-luminance cue more often than the low-luminance cue. C, Rats responded more slowly on discrimination trials compared with detection trials. D, Reduced luminance testing. The test session started with one filter layer over the LED matrices and rats had to report the low-luminance cue on the left or right nosepoke port. After approximately every 30 trials, additional filter layers were added for a total of five layers. E, As each layer was added, the overall error percentage increased. F, Response latencies were stable over the level of luminance; *p < 0.05, **p < 0.01, ***p < 0.001. Error bars represent 95% confidence intervals.
Tables
Number of LED pixels illuminated Peak luminance (in μW) 1 6.2 2 9.3 4 18.5 8 30.2 16 58.0 - Table 2
Luminance levels for two illuminated pixels with 0–5 filters placed over the LED matrices
Number of filters over two LED pixels Peak luminance (in μW) 0 9.3 1 2.5 2 0.7 3 0.2 4 0.1 5 < 0.1
Extended Data 1
• README.txt, overview on files in the Extended Data 1.
• StimCodes.png, documentation on producing the visual patterns over three LED matrices as described in this manuscript.
• LEDMatrix-Addressing.png, documentation on addressing for the LED Backpacks.
• WiringDiagram.png, image showing specific wiring for the LED Backpacks, Arduno, and breadboard.
• FullSetUp.png, image showing wiring diagram for LED Backpacks, Arduino, breadboard, and relays to integrate with MedPC control system.
• nosepoke.stl and nosepoke-block.stl, design files for the optional nosepoke ports.
• LED-Matrix-Holder-Part1.stl and LED-Matrix-Holder-Part2.stl, design files for the 3D-printed holders for the LED matrices.
• VisualStimuli-Arduino-eNeuro.ino, Arduino code for the device.
The following files are included in the Extended Data, which can be found at https://github.com/LaubachLab/LED-matrices: Download Extended Data 1, ZIP file.
In this issue
