Results and Discussion

6.4.4.1 Eye-movement Results

As can be seen in Graph 7 by looking at the difference between the red and the blue lines, experiment 3 replicated the main effect of action depiction in the Verb, Adverb, Verb-Adverb, NP2 and the Long region (F1 & F2, all ps <.05). Hence participants’ on-line sentence processing was facilitated when an action was depicted (vs. when no action was depicted). Thematic role-assignment was also anticipatory in nature as the significant main effects of action in the Verb and Adverb region show (cf., Graph 7:

the red lines show higher log ratio of looks towards the agent than the blue lines).

Crucially, we also found a marginal main effect for the prime in the Adverb (F2(1,15)= 3.083, p= .1), the Verb-Adverb (F1(1,39)= 2.984, p= .092, F2(1,15)= 3.003, p= .104) and in the Long region (F1(1,39)= 3.429, p= .072). !

Graph 7: Time course for the eye-movement results by condition (exp. 3).

Graph 8 shows that younger adults anticipated the agent, i.e., the sentential subject, more when they had been primed with the positive congruent than the incongruent natural facial expression. Hence, younger adults could quickly match the positive prime face to the positive facial expression of the target agent as soon as the adverb of the sentence revealed the positive sentence valence. This match in positive emotional valence quickly contributed to thematic role assignment independent of the action depiction.

-2.5 -1.5 -0.5 0.5 1.5 2.5 3.5 4.5

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5100 5200 5300 5400 5500

log ratio of looks agent over distractor

time in milliseconds

incongruent prime + no action incongruent prime + depicted action positive prime + no action positive prime + depicted action

Verb Adverb NP2

NP1 + 500 ms

!

Graph 8: Mean log ratio of looks for the main effect of prime in the Verb-Adverb region (F1,exp. 3). Error bars show the standard error.

Moreover, the fact that we did not find any visual context effects of the prime in the preNP1, NP1 or in the Verb region underlines that the effect of the natural positive facial expression is not just a mere emotional priming effect due to the matching valence between the prime face and the target agent’s facial expression. Crucially, this effect is mediated by the linguistic input, i.e., the positively valenced adverb.

Hence, the positive natural facial expression was integrated into sentence processing, and facilitated sentence processing of the OVS sentence by helping participants to anticipate the correct role filler before it was mentioned in the sentence.

However, we did not find a significant interaction between action and prime.

Nevertheless, an inspection of the means (Graph 9) shows that similar to experiment 1 and 2 the two-cue condition elicited more anticipatory looks towards the agent (vs.

the distractor) than the single-cue and no-cue condition. Thus, the natural positive prime face seemed to have a stronger facilitatory effect on thematic role assignment when an action had also been depicted.

One reason why the analyses did not reveal a significant action x prime interaction might be the low statistical power. There were only 160 observations in total, i.e., only 4 trials per subject could be used to determine an interaction effect.

0 0.5 1 1.5

positive prime incongruent prime

mean log ratio of looks

Main Effect of Prime (Verb-Adverb Region)

!

Graph 9: Mean log ratio of looks for the interaction between prime and action in the Verb-Adverb region (not sign., exp. 3). Error bars show the standard error.

6.4.4.2 Accuracy Results

The accuracy results underline the real-time data. We found a significant main effect of action (F1(1,39)= 3.857, p= .057, F2(1,15)= 10.385, p< .05) and a non-significant effect of prime (p> .103). Participants answered the passive comprehension question more accurately when an action was (MF1= 3.9, MF2= 9.75 vs. was not: MF1= 3.75, MF2= 9.375) depicted (Graph 10) and (descriptively) when the prime was positive (MF1= 3.785 vs. an incongruent prime: MF1= 3.775). The fact that these effects emerged in experiment 3 (but not in experiments 1 and 2) indicate that participants seemed to draw on the visual cues for answering the comprehension question only when the syntactic structure of the question was more challenging, i.e., passive compared to active questions.

However, potential stronger effects of depicted action and positive prime face might have been concealed since participants still performed at ceiling (< 95% correct answers regardless of condition). Participants answered 99.4 % of all face-recall questions correctly. The high accuracy means the subtle effect of the emotional prime cannot be due to participants ignoring the facial expression.

0 0.5 1 1.5 2

positive prime incongruent prime

mean log ratio of looks

Interaction Action x Prime (Verb-Adverb Region)

depicted action no action

!

Graph 10: Accuracy for the main effect of action (exp. 3). The y-axis displays the percentage of correctly answered trials averaged across participants. The percentages are shown in the center of each bar.

6.4.4.3 Effect Size Differences: Schematic vs. Natural Prime

We also compared the effect sizes for the prime and action effects in the eye-tracking data between experiments 2 and 3. These two experiments mainly differed in terms of prime presentation. Whereas participants in experiment 2 were primed with a dynamic happy looking schematic smiley (see Figure 4), participants in experiment 3 were primed with a natural dynamic happy facial expression (see Figure 5). In order to directly compare the magnitude of the effect of the schematic prime with the magnitude of the effect of the natural prime, we ran repeated measure ANOVAs on the generalized eta squared effect sizes (of the F1 and F2 analyses) separately for the prime and for the action effects of the Verb, Adverb, Verb-Adverb, NP2 and Long region together (N=10), using prime presentation (natural vs. schematic) as the fixed factor.

We used Generalized eta squared (ŋG²) over other effect size measures (e.g., partial eta squared) because it is better suited for comparisons across studies and can also be used to compare effect sizes in within-study designs. It takes inter-study variations such as differing methods and analyses into account and is well suited for experiments with subtle effects. It has to be noted however, that ŋG² cannot be interpreted in the same way as partial eta squared, meaning that the magnitude of an effect cannot be determined by looking at the value of the effect size but always should be interpreted in relation to another effect size (cf., Bakeman, 2005; Lakens, 2013).

98

94 90

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depicted action no action

percent accuracy

Main Effect of Action

!

As Graph 11 shows, ŋG² for the action effect is higher in experiment 2 in which the schematic prime was used compared to experiment 3 which used the natural prime. This difference is significant (F(1,9)= 15.093, p< .05) and hence indicates that participants in the schematic prime experiment used the depicted action to a greater extent than participants in the natural prime experiment. This result becomes interesting when looking at Graph 12, which shows the difference in effect size for the prime effect.

Graph 11: Mean generalized eta squared of the action effect (of the Verb, Verb-Adverb, NP2 and Long region) for the natural face (exp. 3) compared to the schematic face (exp. 2) of the real-time data. The mean effect size is displayed on the y-axis. Error bars show the standard error.

Graph 12: Mean generalized eta squared of the prime effect (of the Verb, Verb-Adverb, NP2 and Long region) for the natural face (exp. 3) compared to the schematic face (exp. 2) of the real-time data. The mean effect size is displayed on the y-axis. Error bars show the standard error.

0 0.05 0.1 0.15 0.2 0.25

natural schematic meanŋG2

Action Effect

0 0.005 0.01 0.015 0.02 0.025

natural schematic meanŋG2

Prime Effect

!

Graph 12 shows that the magnitude of the prime effect is significantly greater (F(1,9)= 5.636, p< .05) in experiment 3 (natural prime face) compared to experiment 2 (schematic prime face). Hence, participants made greater use of the natural compared to the schematic prime and at the same time reduced the use of the depicted action in experiment 3 arguably because they did not have to rely on the direct cue as much as in experiment 2 given the more accessible natural facial expression (vs. the schematic prime face).

However, effect sizes for the action effect were significantly higher than the effect sizes for the prime effect in both experiments 2 and 3 (independent two-tailed t-tests:

ps < .05). Given the strong and reliable main effects of action in the Verb, Adverb, Verb-Adverb, NP2 and the Long region in both studies and the present but marginal main effects of prime in experiment 3 this is not surprising. Nevertheless, regardless of effect size magnitude difference between the factors, the word region effect sizes for the individual regions for experiments 2 and 3 do not differ significantly from each other (independent two-tailed t-test: p= .346).