Cognitive performance will be studied over time using an iPad game interface called the nine choice human game (5CH) in normal volunteer subjects before during and after experimentally induced thermal (cold or warm) pain or control (no intervention).

Purpose: to assess the effects of pain on performance in a computer game interface of attention and memory and reliability of the repeated testing.

Rationale: The perioperative period may alter the ability to play an iPad game through changes in attention or memory as result of surgery, anesthesia, pain or medications. This study will describe and quantify and isolate any short term reduction in ability to focus and pay attention to the presence of thermal (cold or warm) pain.

Objectives: Determine if cognitive function is altered from thermal pain (cold or warm) using simple computer/ipad games of attentional performance and cognitive function.

Design and Outcomes: In group 1: no interventions will be used and the subjects will play the ipad game at baseline, 5 minutes later and 10 minutes later. In group 2: The subjects will play the ipad game, then 5 minutes later a thermal probe at 47 degrees C for 90 seconds on the arm or leg will be used while the game is being played. Following 10 minutes of recovery, the subject will play the game again, 5 minutes later the subject will have the foot placed in 10 degree water bath or body temperature water bath while the game is played, and the game will be played 10 minutes later after the foot is warm and dry. Visual analog scale (VAS) pain score from 0-10 will be used to assess discomfort. The subject will be able to stop the game or withdraw at any point. The primary outcome measures will be median cue duration (MCD) in the 9CH game. Secondary outcome measures will be number of correct, incorrect, omissions, time to finish trials, and time to quit for the 9CH. A total of 60 subjects will be studied, 20 subject warm probe/cold water, 20 subjects warm probe/body temperature water, and 20 normal subjects with no intervention.

Inclusion Criteria:

• Healthy male and non-pregnant female volunteers between the ages of 18-55.

Exclusion Criteria:

• Any reported learning disabilities, psychomotor impairment including diagnosis of ADD/ADHD, seizures, debilitating neurologic disorders (muscular dystrophy, multiple sclerosis, etc.), genetic diseases, heart disease, stroke, or memory deficits; anything that would impair the ability to hold the iPAD and perform the computer gaming tasks (i.e. blindness, color blindness, upper extremity dysfunction or pain). Also any history of cold induced impaired circulation, cold agglutinins or Raynaud's or insensitivity to cold.