Intranasal Oxytocin and Response Inhibition in Younger and Older Adults Diana S. Cortes1, Petri Laukka1, Martin Asperholm2, William Fredborg1, Lillian Döllinger1, Shanshan Xiao1, Lennart Högman1, Junghua Dang3 and Håkan Fischer1 of Psychology, Stockholm University, Stockholm, Sweden; 2Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden; 3Department of Psychology, Lund University, Lund, Sweden
2-14s
Conclusions
Background In normal aging, people are confronted with impairments in both socioemotional and cognitive abilities. Specifically, there are age-related declines in the inhibitory processes which regulate attention towards irrelevant material (Hasher et al., 1991). In recent years, intranasal administration of the neuropeptide OT has been related to improvements in social cognition, prosociality, and affective processing (Bartz et al., 2011) and it has been suggested that attention modulation mediates the beneficial effects of OT (e.g., Lischke et al., 2012). To date the effects of OT in aging remain largely unknown, but recent findings suggest that OT enhances performance in OA (Ebner et al., 2013), and especially emotion recognition in older men (Campell et al., 2013).
Aims In a randomized, double blind, placebo controlled, within-subjects study design, we investigated whether OT facilitates inhibitory processing in OA compared to YA. Specifically, we investigated whether previous effects on emotion recognition could also be extended to inhibitory control, and hypothesized that older men would benefit the most from the administration of OT compared to women and to their younger counterparts.
Method In total, 43 OA (21 women; M = 69.93, SD = 3.02; age range 65-75 years) and 42 YA (20 women; M = 24.90, SD = 2.99; age range 20-30 years) participated in the study two times, receiving a single intranasal dose of 40 IU of placebo and oxytocin in randomized order 40 minutes before starting the testing session and approximately 95 minutes before engaging in the Go/NoGo task. Participants were tested approximately one month apart and approximately at the same hour during both occasions. Inhibition was measured with a simple Go/NoGo task which included happy and neutral faces as targets (36 trials; Go stimuli) and distractors (12 trials; NoGo stimuli) shown on a computer screen. Participants were instructed to press a button whenever they saw a target and remain passive when encountering a distractor. Stimuli contained equally many female and male faces for each condition and no expresser identity appeared more than once in the task. The faces were retrieved from the KDEF database (Lundqvist et al., 1998; see Figure 1).
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Figure 1. Trials for happy targets condition. Fixation cross lasted 2-14 seconds while the faces were shown for 5 seconds.
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Results Separate mixed ANOVAs with age and gender as between-groups variables and treatment as repeated measure were conducted for each condition (e.g., go happy accuracy; go happy reaction time; no go happy accuracy; see Table 1). Preliminary results indicate a main effect of age for the reaction times for happy targets, which indicates that YA responded faster than OA (Figure 2). For happy distractors, a main effect of gender was observed, where women were more accurate at inhibiting responses compared to men (Figure 3). We did not find significant effects for happy target accuracy nor for any of the neutral conditions, and we did not observe effects of treatment in the different conditions (see Table 1). 700
Placebo
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Reaction times (ms)
Results showed that older adults (OA) are slower at reacting to happy targets compared to younger adults (YA) and that administration of oxytocin (OT) did not decrease reaction times. We also observed that women were more accurate inhibiting responses for happy distractors than men. Our findings suggest that age and gender can influence inhibition but their effects may depend on the displayed emotions. This suggests that the ability to inhibit interfering distractors may remain intact in old age, and that deficits in inhibition may be selective. The role of OT in inhibition needs further investigation because it is possible that it is context dependent.
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Figure
2.
Mean reaction times (milliseconds) for happy targets as a function of age. Error bars denote 95% CI
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Accuracy
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0 Old
1,1 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0
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Figure 3. Mean accuracy ratings for happy distractors as a function of gender. Error bars denote 95% CI.
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Table 1. Inferential statistics for reaction times and accuracy of happy and neutral targets and distractors as a function as age and gender. Condition
Statistics
F (1, 81) p Happy Targets Accuracy η p2 F (1, 81) p Happy Targets Reaction η p2 Times F (1, 81) Happy Distractors Accuracy p η p2 F (1, 81) p Neutral Targets Accuracy η p2 F (1, 81) p Neutral Targets Reaction η p2 Times F (1, 81) Neutral Distractors Accuracy p η p2
Treatment .36 .55 .004 .07 .80 .001 1.53 .22 .018 .15 .70 .002 1.98 .16 .024 .68 .41 .008
Age .25 .62 .003 4.04 .04 .047 1.27 .99 .000 1.53 .22 .018 1.05 .31 .013 3.47 .07 .041
Gender 3.06 .08 .036 .38 .54 .005 9.20 .003 .102 .63 .43 .008 2.80 .09 .033 .98 .33 .012
Treatment x Age 1.86 .18 .022 .79 .38 .010 1.66 .20 .020 .01 .91 .000 .26 .61 .003 2.67 .11 .032
Treatment x Gender .36 .55 .004 .88 .35 .011 2.20 .14 .026 1.33 .25 .016 .80 .37 .010 .01 .94 .000
Treatment x Age x Gender 2.12 .15 .025 1.45 .23 0.18 .15 .70 .002 .03 .87 .000 .03 .86 .000 .99 .32 .012
Age x Gender .06 .81 .001 .32 .57 .004 1.57 .21 .019 .77 .38 .009 .44 .51 .005 .29 .59 .004
References: Bartz, J., et al., Trends in Cogn Sci, 2011, 15, 301-309; Campbell, A., et al., Neurobio Aging, 2013, 35, 2246-2248; Ebner, N. C., et al., Front Hum Neurosci, 2013, 7; Hasher, L., et al., J Exp Psy: Learn, Mem, Cogn, 1991, 17, 163-169; Lischke, A., et al., Psychoneuroend, 2012, 37, 475–81.
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