Table 3.

Laboratory studies’ experimental design and outcomes.

Study	Distractions		Subjects	Task	Standard Measurements Used	Outcomes on Surgical Performance
	Timing	Process				Time to Task Completion/Speed	Economy of Motion	Errors/Accuracy
Feuerbacher (2012)	Intermittent	Visual or Auditory	Eighteen (18) inexperienced residents	Simulated laparoscopic cholecystectomy	Frequency of errors.	NA	NA	More participants made errors with auditory distractions (p=.02). Errors committed by both inexperienced and experienced residents. No effect from visual.
Szafranski (2009)	Intermittent over a Continuous	Visual, Auditory & Vibrate	Seven (7) inexperienced residents	Sensable Technologies VR ring transfer task	Economy of Movement (gesture level proficiency, hand movement smoothness, tool movement smoothness), Time elapsed, Cognitive errors.	Increased time by 125% under auditory distractions (p<.05). No effect from visual or vibration distractions.	Decreased proficiency (31%), hand movement (33%), and tool movement (26%) under auditory distractions (p<.05). No effect from visual or vibration distractions.	Increased errors by 97% under auditory distractions (p<.05). No effect from visual or vibration distractions.
Pluyter (2010)	Continuous	Visual & Auditory	Twelve (12) inexperienced residents	Clip & Cut module of Xitact LC 3.0 virtual reality simulator	Time to task completion, Task errors, Economy of movement.	No effect.	No effect.	Errors increased (mean 7.08 to 35.83) (z=−2162; p=.03).
Siu (2010a)	Continuous	Auditory	Twelve (12) inexperienced med students	Mesh alignments, suture tying, bimanual carrying (in order of decreasing difficulty).	Time to task completion, Total distance travelled.	Completion time increased by 23% (p=.046). Greater difference with increasing task difficulty (inc by 37%, p=.012).	Distance travelled increased by 8% (p=.011). Greater difference with increasing task difficulty (inc. by 14% p=.035).	NA
Siu (2010b)	Continuous	Auditory	Ten (10) inexperienced med students	Two dVSS tasks: mesh alignment and suture tying (in order of decreasing difficulty).	Time to task completion, Total distance travelled.	Faster with hip-hop (p=.036) and Jamaican music (p=.001) than no music for both tasks.	Shortest distance with Jamaican music than hip-hop or no music (p=.038) for both tasks.	NA
Moorthy (2004)	Continuous	Auditory	Twelve (12) experienced attending surgeons	Suture placement	Performance (number of movements, path traveled by hand, speed of hand movements); Expert rating (nonpurposeful movement, accuracy of suturing, quality of knots).	No difference	No difference	No difference
Suh (2010)	Continuous	Mental or Auditory	Ten (10) inexperienced med students & four (4) experienced residents and fellows	Suture-tying task	Time to task completion, Total distance traveled, Average speed.	Time to task completion increased from mental (math: p=.006, decision-making: p=.039, memory:p=.03). Speed decreased from mental (math: p=.008, decision-making: p=.015, memory: p=.03). No difference for auditory distractions. No difference between experience levels.	No differences.	NA
Conrad (2010)	Continuous	Mental or Auditory	Eight (8) experienced attending surgeons	Three (3) Surgical SIM VR, laparoscopic simulator, tasks (not specified)	Time to task completion, Task accuracy.	Time to task completion increased with dichotic music (6/8 participants) or mental loading (4/8 part.), but decreased with classical music (7/8 part.). *No inferential statistics presented.	NA	Accuracy increased with dichotic music (6/8 participants) or classical music (7/8 part.) but decreased with mental loading (6/8 part.). *No inferential statistics presented.
Conrad (2012)	Continuous	Mental or Auditory	Thirty-one (31) inexperienced surgeons	4 Surgical SIM VR tasks (lifting a structure and cutting below it; object targeting; feeding a rope; object alignment)	Time to task completion, Accuracy.	Speed decreased due to mental distractions (118% worse than silence, p<.001) and dichotic music (115% worse, p<.001). Classical music was not significantly different from silence.	NA	Accuracy decreased due to dichotic music (64% less accurate than silence, p<.05) and mental distractions (126% less, p<.001). Classical music was not significantly different from silence.
Hsu (2008)	Continuous	Mental	Thirty-one (31) inexperienced med students & residents, & nine (9) experienced fellows & attending surgeons	FLS peg transfer task	Simulation score (Speed, Errors).	No difference for inexperienced or experienced groups.	NA	No difference for inexperienced or experienced groups.
Goodell (2006)	Continuous	Mental	Thirteen (13) inexperienced med students & residents	MIST-VR tasks: acquire-place, withdraw-insert, diathermy, manipulate-diathermy, stitch start, half square knot	Time to task completion, Number of errors, Economy of motion.	Time to task completion increased for all six tasks (average of 35% increase, p<.05). Task type did not have an effect.	No difference	No difference.
Park (2011)	Continuous	Mental	Fourteen (14) inexperienced ophthalmic surgeons & seven (7) experienced ophthalmic surgeons	Intraocular object removal task	Total time, Errors (lens injury, corneal injury, operating without red reflex score), Economy of motion (odometer score).	No difference for experts or novices.	Decrease in odometer score (increase in distance travelled) by novices (p=.028). No difference for experts.	No difference for experts or novices.