Building the Lie Detector Kit

I built a simple lie detector circuit. The lie detector kit from Maplin demonstrates the basic principles of lie detection: the change in skin resistance in the presence of perspiration.
Components required are:

1. PCB
2. 1N006 Diode
3. 8-pin DIL Socket
4. LM358
5. Jumper wires
6. Green LED
7. Red LED
8. BC538 transistor (2)
9. Resistors:
10. R1-R3: 560K (3)
11. R4-R5: 10K (2)
12. R6-R7: 1.5K (2)
13. R8-R9: 680R (2)
14. Slider switch
15. PP3 battery box
16. Self taping screw
17. 9V battery (not included in the kit)

Circuit Diagram is given below

Soldered circuit is:

The circuit in operation is given by the YouTube video