| dc.description.abstract | Initial experiences of control/uncontrollability may affect subsequent encounters with stressors. Here, 48 participants completed an S1-S2 task, in which they passively viewed a negative or neutral picture (S1); following S2 onset (same picture, different border), they could push a button to make the picture disappear under conditions of control. One group (n=25) experienced controllability (Control Block 1, C1), followed by loss of control (No Control, NC) and then resumption of control (Control Block 2, C2); another group (n=23) experienced uncontrollability (NC), followed by two control blocks (C1, C2). Event-related potential, the late positive potential (LPP) was used to index motivated attention to S1 and the post-imperative negative variation (PINV) was used to assess perceived changes in stimulus controllability following S2 onset. Group and block interacted, F(2,46) = 2.94, p <. 05, such that among participants who started with control, loss of control increased the LPP and this effect persisted even after restitution of control (i.e. NC M = 1.33, SD = 3.24 > C1, M = .09, SD = 3.50 < C2, M = 1.69, SD = 4.11). In addition, larger PINVs during the NC (M = 3.21, SD = 3.90) compared to control (C1, M = 5.34, SD = 5.00; C2, M = 4.97, SD = 4.45) conditions were observed for the early time window, 400-800 ms after S2 onset. During the late time window (1,000-2,000 ms after S2 onset), NC and C2 conditions elicited a larger PINV than C1 (i.e. NC M = 4.17, SD = 4.63 > C1, M = 6.64, SD = 6.98 < C2, M = 4.70, SD = 5.23). Therefore, among those with a contingent response-outcome history (i.e., participants who started with control), uncontrollable stress may lead to persistent increases in motivated picture processing (LPP). Additionally, the early PINV may be especially sensitive to uncontrollability, whereas the late PINV may reflect more elaborated processing of changes in stimulus controllability. | en |
