Project: New treatment for Alzheimer’s please help.

Hello, I'm not yet a great coder but I'm kinda good at the hardware part. I have a family member that is starting to exhibit the beginning of Alzheimers. I came across this article Article HERE where Using LED lights flickering at a specific frequency, MIT researchers have shown that they can substantially reduce the beta amyloid plaques seen in Alzheimer’s disease, in the visual cortex of mice. I did some more research and found others who have created lights like the one I want to build. video HERE I found a video that shows how to change the frequency of the light video HERE
I don't know the correct questions to ask. I want to run the program of different frequencys for a certain amount of time like the one shown in the video. I have already downloaded the Zip file for the pwm and plugged it in but I don't know how to even start.

you can Email me @ clcburdine@yahoo.com or here on the forum.

Hi,
If you want an LED to simply blink on and off at a given frequency you can use the tone() function like:

  pinMode( LED_BUILTIN, OUTPUT );
  tone( LED_BUILTIN, 40 );   // flash LED at 40Hz

see: tone() reference

If you want the LED to be, for example, ON longer than OFF at a given frequency, then you would have to use PWM or, since the frequency is fairly low, you could turn it on and off in software with delays
e.g.

  pinMode( LED_BUILTIN, OUTPUT );
  for( int i=0; i<80; i++ ){            // flash LED 80 times at approx 40Hz (2 seconds)
    digitalWrite( LED_BUILTIN, HIGH );  // 20mS ON and 5mS OFF
    delay( 20 );
    digitalWrite( LED_BUILTIN, LOW );
    delay( 5 );
  }

Yours,
TonyWilk