The Effect of Electronic Cigarette Liquid Characteristics in Smokers.

Plasma Nicotine Concentration

Change in plasma nicotine concentration. Changes in plasm nicotine concentration during puff bout are considered to be the more relevant and accurate values so analysis and results reporting will focus on change from baseline to immediately following 10-puff bout.

Time frame: Blood will be taken 4 times in each session to examine changes from baseline (approx 70 minutes) to immediately following a ten-puff bout (approx 80 minutes), and immediately before (approx 140 minutes) and after the PRT (approx 180 minutes).

Progressive Ratio Task - Breakpoint

The progressive ratio task (PRT) is a self-administration task that will take 30-minutes to complete. It will begin by requiring ten computer key presses to earn the first puff of the session product, and this requirement will increase by 30% (i.e., 10, 13, 17, etc.) after each reinforcer (puff) is earned and consumed. The PRT will have three outcome measures (1) breakpoint (maximum number of key presses completed to earn a puff), (2) number of puffs, and (3) latency (sec) to initiate key pressing. Breakpoint is reported here.

Time frame: This task will begin approximately an hour and ten minutes after the 10-puff directed product use bout.

Progressive Ratio Task - Number of Puffs

The progressive ratio task (PRT) is a self-administration task that will take 30-minutes to complete. It will begin by requiring ten computer key presses to earn the first puff of the session product, and this requirement will increase by 30% (i.e., 10, 13, 17, etc.) after each reinforcer (puff) is earned and consumed. The PRT will have three outcome measures (1) breakpoint (maximum number of key presses completed to earn a puff), (2) number of puffs, and (3) latency (sec) to initiate key pressing. Number of puffs is reported here.

Time frame: This task will begin approximately an hour and ten minutes after the 10-puff directed product use bout.

Progressive Ratio Task - Latency

The progressive ratio task (PRT) is a self-administration task that will take 30-minutes to complete. It will begin by requiring ten computer key presses to earn the first puff of the session product, and this requirement will increase by 30% (i.e., 10, 13, 17, etc.) after each reinforcer (puff) is earned and consumed. The PRT will have three outcome measures (1) breakpoint (maximum number of key presses completed to earn a puff), (2) number of puffs, and (3) latency (milliseconds) to initiate key pressing. Latency is reported here.