Associative learning and cognitive control

Eddy J. Davelaar & Geoff Bird

Incongruent trials (><>) slower than congruent trials (<<<) flanker effectFlanker effect smaller if the previous trial was an incongruent trial Gratton effectExplained by a computational model that assumes that response conflict is monitored by the ACC, is increased for incongruent trials, and sharpens attention on the next trial.

Botvinick, et al., 2001Jones, et al., 2002Cho, et al., 2002Botvinick, et al., 2004Yeung, et al., 2004

However, the Gratton effect (the interaction) is only observed when target/response repeats across trialsPriming account of the Gratton effectMayr, et al., 2003; Nieuwenhuis, et al., 2006

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1) IF learning from array to response plan THEN stronger functional connectivity for iI and cC trials in repeats compared to non-repeats2) IF conflict-modulated attention THEN stronger connectivity between conflict area and attention area

This is a DCM study: 2-step process1) localise relevant voxels2) Apply DCM to those voxels

Stimuli:C: >>>>>, <<<<<I: <<><<, >><>> N: -->--, --<--

Localisers:Decision: I minus C (DLPFC)Identity: full-array adaptationConflict: I minus C (ACC/pre-SMA)Attention: I+C-N

Design:

# nonrepeat repeat

I C I C

i 36 36 36 36

c 36 36 36 36

n 36 36 36 36

72 null events

Scanning Parameters:

2 runs 19mins each separated by structural scan. Scanner time ~60mins per subject including set-up. 14 subjects (14hr scanner time in total).

Event-related design, Stimulus + response period (1.5s) blank ISI (mean 3s, 2-4s range). Random sequence of events.

Whole cortex coverage (no cerebellum). TR 2.7s, 30slices, 3.5mm, 10% gap.

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1.5sMean 3s

Conflict area (ACC/pre-SMA)

Decision area (DLPFC)

Attention area (PPC/FEF)

Stimulus area (temporal)

WL

WC

Wi = b1(previous trial-type) + b2(target/response repetition)

Priming account: b10, b2>0Conflict account: b1>0, b2=0