modeling the n-back-m-pitch paradigm

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Modeling the N-back-M-pitch paradigm

Ion Juvina*, Michael Qin^, & Christian Lebiere*

*Department of Psychology, Carnegie Mellon University

^Naval Submarine Medical Research Laboratory

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Outline Task

Study

Cognitive model

Discussion

Future work

Task | Study | Model | Discussion | Future

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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)


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Performance impairment


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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


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N-Back M-Pitch


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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


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Method


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Results Performance decreases with dive depth

The cognitive deficit associated with narcosis is temporary


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Accuracy at 190 fsw


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Accuracy at 280 fsw


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Relative accuracy


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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


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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


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Correct performance


Perceive current sound- Encode sound length

Retrieve previous sound

Compare sounds based on length

Respond Same / Different

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Errors


Perceive current soundEncode sound length Encode sound pitch

Retrieve previous soundExpect matching pitchAllow partial matching



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Deterioration at depth


Perceive current sound- Encode sound length

Retrieve previous sound



Perceive current soundEncode sound length Encode sound pitch

Retrieve previous soundExpect matching pitchAllow partial matching



:ans = 0.1; 0.2; 0.25 :mp = 1.0; 1.5; 2.0

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Model fit


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Model predictions


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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


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Future research Learning

Affective effects associated with performance decrement Anxiety, euphoria, overconfidence, etc.

Transfer and generalization

Brain imaging, brain stimulation


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Learning Learning effects:

Accuracy Ignore the distracting feature of stimulus

No RT effect Fast paced

Wait for sounds to finish

Transfer to different tasks


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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


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Thank you for your attention! Questions?

modeling the n-back-m-pitch paradigm

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