1 Modeling the N-back-M-pitch paradigm Ion Juvina*, Michael Qin^, & Christian Lebiere* *Department of Psychology, Carnegie Mellon University ^Naval Submarine Medical Research Laboratory

2 Outline Task Study Cognitive model Discussion Future work Task | Study | Model | Discussion | Future

3 Diving Breathing compressed air at depth Hyperbaric nitrogen narcosis lightheadedness, inattention, difficulty concentrating, poor judgment, decreased coordination Resembles ethanol intoxication Becomes noticeable at a depth of ~130 fsw (~5 ATA) Task | Study | Model | Discussion | Future

4 Performance impairment Task | Study | Model | Discussion | Future

5 N-Back Auditory N-back Acute effects of ethanol N-back M-Pitch (Qin et al., 2011) Same / different duration as 1-back Added pitch as a distracting feature Pitch variation Standard pitch: 700 Hz, p = 0.7 Slightly deviant: 750 Hz, p = 0.1 Moderately deviant: 900 Hz, p = 0.1 Widely deviant: 1200 Hz, p = 0.1 ISI = ~ 1s Task | Study | Model | Discussion | Future

6 N-Back M-Pitch Task | Study | Model | Discussion | Future

7 Method Participants: 5 US Navy trained divers Apparatus: Hyperbaric chambers to simulate diving Conditions: Pre-dive, Dive at 190 fsw, Post-dive Pre-dive, Dive at 280 fsw, Post-dive Task | Study | Model | Discussion | Future

8 Method Task | Study | Model | Discussion | Future

9 Results Performance decreases with dive depth The cognitive deficit associated with narcosis is temporary Task | Study | Model | Discussion | Future

10 Accuracy at 190 fsw Task | Study | Model | Discussion | Future

11 Accuracy at 280 fsw Task | Study | Model | Discussion | Future

12 Relative accuracy Task | Study | Model | Discussion | Future

13 Model assumptions Main challenge of the task: Maintaining focal attention in the face of distraction Distraction caused by low frequency of deviant pitches Diving reduces ability to deal with interference Task | Study | Model | Discussion | Future

14 Model description Correct performance Perceive current sound, encode sound length Retrieve previous sound Compare perceived and retrieved sounds Respond same / different Errors Retrieval of previous sound perturbed by distracting feature of stimulus: partial matching Performance deterioration at depth Parameters Pre- and post-dive: ans=0.1 ; mp = 1.0 Dive at 190 fsw: ans = 0.2 ; mp = 1.5 Dive at 280 fsw: ans = 0.25 ; mp = 2.0 Task | Study | Model | Discussion | Future

15 Correct performance Task | Study | Model | Discussion | Future Perceive current sound - Encode sound length Retrieve previous sound Compare sounds based on length Respond Same / Different

16 Errors Task | Study | Model | Discussion | Future Perceive current sound Encode sound length Encode sound pitch Retrieve previous sound Expect matching pitch Allow partial matching Compare sounds based on length Respond Same / Different

17 Deterioration at depth Task | Study | Model | Discussion | Future Perceive current sound - Encode sound length Retrieve previous sound Compare sounds based on length Respond Same / Different Perceive current sound Encode sound length Encode sound pitch Retrieve previous sound Expect matching pitch Allow partial matching Compare sounds based on length Respond Same / Different :ans = 0.1; 0.2; 0.25 :mp = 1.0; 1.5; 2.0

18 Model fit Task | Study | Model | Discussion | Future

19 Model predictions Task | Study | Model | Discussion | Future

20 Discussion Why 2 parameters and not just one Only activation noise (ans): No correlation pitch deviation – accuracy Only mismatch penalty (mp): No errors in standard pitch condition Needs data to check predictions What does the model tell us? Need to explain parameter change in mechanistic terms Task | Study | Model | Discussion | Future

21 Future research Learning Affective effects associated with performance decrement Anxiety, euphoria, overconfidence, etc. Transfer and generalization Brain imaging, brain stimulation Task | Study | Model | Discussion | Future

22 Learning Learning effects: Accuracy Ignore the distracting feature of stimulus No RT effect Fast paced Wait for sounds to finish Transfer to different tasks Task | Study | Model | Discussion | Future

23 Acknowledgements Data collection study funded by ONR Modeling study funded by NSMRL Thanks to Dan Bothell for changes to the ACT-R auditory module Thanks to Dario Salvucci and Frank Ritter for introducing me to Michael Qin Task | Study | Model | Discussion | Future

24 Thank you for your attention! Questions?