Does the experimenter presence affect working ... - Wiley Online Library

Ann. N.Y. Acad. Sci. ISSN 0077-8923

A N N A L S O F T H E N E W Y O R K A C A D E M Y O F SC I E N C E S Special Issue: Attention in Working Memory ORIGINAL ARTICLE

Does the experimenter presence affect working memory? Clement Belletier and Valerie Camos ´ ´ Departement de psychologie, Universite´ de Fribourg, Fribourg, Switzerland ´ Address for correspondence: Clement Belletier, Departement de psychologie, Universite´ de Fribourg, Rue P.A. de Faucigny, ´ ´ 2, 1700 Fribourg, Switzerland. [email protected]

Recent studies suggest that social presence undermines performance in difficult tasks because the presence of others would automatically capture the attention needed to achieve these tasks. Here, we tested whether this attentional capture (caused by the experimenter presence) affects working memory. Several models suggest that maintenance in working memory relies on an attentional mechanism. Besides this mechanism, another nonattentional verbal rehearsal could also maintain verbal information. In experiment 1, we varied the presence of the experimenter while participants had to memorize letters during a short retention interval. Moreover, a secondary task was introduced in some conditions to reduce the availability of attention. Experiment 2 replicated experiment 1 with the addition of a concurrent articulation to prevent the use of verbal rehearsal. The results showed that participants in the presence of the experimenter recalled fewer letters than participants who stayed alone in the cubicle, but only in experiment 2. These findings are the first evidence that social presence hinders attentional but not nonattentional maintenance in working memory. They have strong implications for understanding working memory and the impact of social presence, as well as important methodological implications. Keywords: working memory; experimenter presence; attention; rehearsal; audience effect

Introduction At school, at work, or during hobbies, the majority of our activities are done in the presence of others. This is probably why the social-presence effect, the elementary brick of social context, was one of the first issues examined by experimental psychologists.1 More than one century of research has led to the finding that the presence of conspecifics improves performance on easy or welllearned tasks and impairs performance on difficult or poorly learned tasks (for reviews, see Refs. 2–4). According to Zajonc’s classic view,5 the presence of others increases the drive (conceived as a physiological arousal) and the emission of dominant responses (those with the greatest habit strength), which are often correct in easy tasks and incorrect in difficult tasks. The widely accepted drive theory has found support in many studies using different species, from cockroaches to humans (for review, see Ref. 4). Nonetheless, if the dominant response hypothesis is plausible in some nonhuman species that may lack

the control mechanisms allowing the inhibition of dominant responses when required, it is less plausible in primates. Indeed, primates—and especially humans—benefit from evolved executive functions that provide flexibility, planning, and inhibition capacities to their cognitive system.6–8 Thus, according to this view, the social presence effect should be reduced or even absent in humans. However, this is not the case.4 To resolve this paradox, recent studies have alternatively suggested that the social presence reduces cognitive control.9–11 The social presence would undermine executive functioning because the presence of others would automatically capture attention, usually required to fuel executive functions. This conflict results in a depletion of attentional resource that would have been dedicated to the task at hand.12–15 This hypothesis, named the distractionconflict hypothesis, has been tested in several studies that showed poor performance in difficult tasks that especially rely on executive control.9,16 For example, the social presence negatively affects inhibition

doi: 10.1111/nyas.13627 C 2018 New York Academy of Sciences. Ann. N.Y. Acad. Sci. 00 (2018) 1–9

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in the Simon task,9 cognitive flexibility in a fluency task,10 and voluntary attention control in a visual search task.11 An interesting but never tested consequence of the distraction-conflict hypothesis is that the social presence should also have an impact on working memory. Working memory is the cognitive system in charge of storing and manipulating information over the short term. Working memory tasks are known for heavily relying on executive control to the point that some authors even considered working memory as one executive function.17 More specifically, this strong relationship between working memory and executive function has been demonstrated in a large life span study in which tests of working memory and executive function share a common underlying executive attention component.18 Accordingly, many working memory models suggest that executive attention is needed to maintain information in the short term. In Cowan’s embedded-processes model,19,20 working memory is the currently activated portion of long-term memory in which a limited amount of memory items is maintained through the focus of attention. Similarly, in Engle,7,21 attention preserves the maintained items from distraction, preventing their forgetting. In the time-based resource-sharing (TBRS) model, an executive loop that relies on attention is dedicated to the maintenance and processing of information.22 Finally, in Baddeley’s multicomponent model23 and its extension by Logie,24 memorization is constrained by a range of attentiondemanding executive functions (e.g., focusing and sustaining attention, updating, inhibition, encoding, and retrieval), which correspond to the central executive in previous versions of this model. To summarize, all these models assume an attentional component that helps or sustains maintenance. In consequence, they predict that any depletion of attention should lead to reduced recall performance in working memory tasks. This was verified in several studies in which introducing an attentiondemanding secondary task, such as the Stroop task or a choice reaction time task in the retention interval, resulted in reduced recall performance.22,25,26 In the present study, we expected that, according to the distraction-conflict hypothesis, the social presence of the experimenter would also deplete attention. Working memory performance should then decrease, as it is the case for the attention 2

depletion resulting from the introduction of a secondary task. This question is of particular importance for theoretical and methodological reasons and has implications for practice. First, models of working memory often overlook the impact of social variables. Second, in the experimental method, the presence or absence of experimenters during the testing is rarely considered as a meaningful variable, and many authors do not mention it in the method section. Finally, because working memory capacity is strongly linked with fluid intelligence and predicts academic achievement and high-level cognition,21,27,28 it is frequently assessed by practitioner psychologists without taking into account the potential impact of their presence on the evaluation. Experiment 1 The aim of the first experiment is thus to assess the impact of the experimenter presence on working memory and to compare it to the distraction induced by a secondary attention-demanding task. This allowed us to examine whether the distraction from these two different sources (social and cognitive) is susceptible to additive effects. In a Brown– Peterson paradigm, participants maintained series of memory items during a filled or unfilled retention interval, before recall. To induce an attentional capture, we introduced a choice reaction time task known for reducing recall performance: the parity judgment task.29,30 We predicted that participants in the experimenter presence would have less attention available for memorization and would therefore recall fewer letters than participants who stayed alone in the cubicle. Moreover, because the distraction-conflict hypothesis supposes that the attentional capture induced by the social presence is automatic, the effect of the experimenter presence could be additive to the effect of the secondary task. Method Participants. Participants were 54 undergraduate students (eight males; age: M = 21.46; SD = 2.10) at the University of Fribourg who received course credit or cinema vouchers for their participation. All had normal or corrected-to-normal vision. None of them were aware of the goals of the experiment that was presented as a study on memory. Material and procedure. Participants performed 21 trials in unfilled and 21 trials in filled conditions on a computer using Psychopy.31,32 In the

C 2018 New York Academy of Sciences. Ann. N.Y. Acad. Sci. 00 (2018) 1–9

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Figure 1. Method used in experiments 1 and 2. In experiment 2, participants performed a concurrent articulation during the letters presentation and the maintenance interval in both unfilled and filled trials.

unfilled condition, a ready signal was displayed for 1000 ms just before the to-be-memorized letters that appeared for 1000 ms, separated by a 1000-ms fixation cross (Fig. 1). The letters were always consonants chosen at random, with the exclusion of “W,” which is trisyllabic in French, and “Z,” because of possible confusions between Swiss and English keyboard layouts (some participants being used to one or the other layout). The number of letters to memorize varied from two to eight, with three trials for each of the seven lengths. After the presentation of letters, participants had to maintain the memoranda during a 12-s blank interval. At the end of each trial, participants had to recall the letters one at the time in correct order by typing them on keyboard. In the filled condition, the blank interval was replaced by a parity judgment task. In this task, participants saw a series of 15 digits (from 1 to 9 picked at random). Each digit appeared for 600 ms, with an interdigit interval of 200 milliseconds. The task was to press a yellow key (left arrow on keyboard) with the left hand if the digit was even and a blue key (right arrow on keyboard) with the right hand if the digit was odd. The participants were asked to make their decision as quickly as possible without sacrificing accuracy. In both conditions, stimuli were presented at the center of a standard CRT monitor in Lucida Console font with a height of 1.3° of visual angle, participants being seated at a comfortable distance from the screen (60 cm).

Social presence. Participants were randomly assigned to one of the two social-presence conditions. In the “alone” condition, the experimenter (always a woman) left the cubicle before the beginning of the task. In the “experimenter presence” condition, the experimenter remained in the cubicle and was positioned opposite the participant, in such a way that she could not see the participants’ ongoing task but watched them 60% of the time (which is an efficient social presence manipulation13,33 ). Training. Before the task completion, participants were trained on four trials including only the parity judgment task and four trials in the filled condition with two letters to memorize. Participants stayed alone in the cubicle during training. Results Parity judgment task. Two participants who did not reach 65% of correct responses in the parity judgment task were excluded from the analyses, because they did not comply with the instructions and did not pay enough attention to the completion of the secondary task. Among the remaining participants, 23 were in the alone condition and 29 in the experimenter-presence condition. To control for performance on the parity judgment task, an analysis of variance (ANOVA) on the reaction times was performed for the filled trials with presence (alone versus experimenter presence) as the


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between-subject factor. The effect of presence was not significant (F(1,50) = 0.36; P = 0.55). Proportions correct were analyzed using generalized estimating equations (GEEs) as suggested by Dixon,34 with presence as the between-subject predictor. As noted by Dixon,34 accuracy data do not conform to the assumptions of ANOVAs because performance is constrained between 0 and 1, which leads, for example, to unequal variance between conditions and possibly to confidence intervals (CIs) with limits larger than 1 or smaller than 0. In the case of repeated-measure designs, one possibility to address these issues is to use GEEs.34 In our results, odds ratios (ORs) were provided and accounted for the change between the two modalities, as predicted by the model. For example, an OR of 0.5 indicates a reduction by two of the performance between the two modalities. Similarly, an OR of 1 indicates no changes between the two modalities, and a CI including 1 indicates a nonsignificant effect.a The main effect of presence was not significant (Wald Z = 0.553; P = 0.457; OR = 0.90, with 95% CI = 0.68–1.19), indicating a similar accuracy in both conditions (alone: M = 0.81; SE = 0.02; experimenter presence: M = 0.83; SE = 0.01). Memory. GEEs were used to analyze the number of correctly recalled letters with the type of trials (unfilled versus filled trials) as a within-subject predictor and presence (alone versus experimenter presence) as a between-subject predictor. An additive model (with the two main effects) and a full factorial model (with the two main effects and the interaction of the two variables) were tested. Whereas the likelihood of the factorial model was slightly better (QICC = 96,685.40) than the likelihood of the additive model (QICC = 96,832.40), the interaction between type of trial and presence did not reach significance (P = 0.45). The additive model was therefore preferred, because it was more parsimonious. Consistent with the literature,3,26 the main effect of the type of trials was significant (Wald Z = 42.50; P < 0.001; OR = 0.63, with 95% CI = 0.55–0.72), indicating a better recall in the unfilled trials (M = 0.87; SE = 0.01) than in a

Note that ANOVAs were also performed and led to the similar conclusions as GEE analysis for all the statistics presented in experiments 1 and 2 (see Appendix, online only, for details).

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the filled trials (M = 0.80; SE = 0.02). Nonetheless, and contrary to our predictions, the main effect of presence was not significant (Wald Z = 1.52; P = 0.22; OR = 0.82, with 95% CI = 0.59–1.13) (Fig. 2).

Discussion To summarize, the detrimental effect of a secondary task was found on recall performance22,25,26 in experiment 1, as was expected, whereas our prediction on the detrimental effect of the experimenter presence was not confirmed. At first sight, these findings could suggest that working memory maintenance is immune to the detrimental effect of social presence, contrary to other attentiondemanding processes or executive functions. A way to understand this result is to assume that the effect of social presence does not rely on attentional capture but deteriorates performance on difficult tasks through a different mechanism. For example, one might propose that social presence increases arousal (as originally hypothesized by Zajonc5 ), self-awareness,36,37 or vigilance.4,38 Alternatively, it can be suggested that the experimenter presence captures attention, but that our participants were able to achieve the memory task without using attention. Several working memory models (i.e., the phonological loop in Baddeley’s,23 Logie’s,24 and TBRS22,39 models) agree on the existence of a specific verbal subsystem in which verbal memory items are maintained through articulatory rehearsal. Whatever the model, this mechanism is thought to be independent from the other maintenance mechanisms, to be preferentially used to maintain verbal items and to rely on nonattentional processes (for reviews, see Refs. 40 and 41). Given that the memoranda in experiment 1 were letters, participants may have used this verbal maintenance mechanism. If the social presence reduces performance by distracting attention away from the task at hand (i.e., the maintenance here), recall performance should not be impaired when participants are rehearsing but should be impaired when the use of articulatory rehearsal is prevented. This latter condition favors the use of attention to maintain memory items.42 To test this prediction, we asked participants to perform a concurrent articulation during the maintenance period to prevent the use of articulatory rehearsal.35,43,44 Hence, experiment 2 used the same paradigm as experiment 1, but with


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Figure 2. Percentage of correctly recalled letters in unfilled and filled trials as a function of the social context. Results are presented for experiment 1 (without concurrent articulation) and experiment 2 (with concurrent articulation). Error bars represent standard errors.

a concurrent articulation during the presentation of letters and the maintenance interval. Experiment 2 By preventing articulatory rehearsal, participants in experiment 2 would rely on attention to maintain memory traces, leading to an increased vulnerability to an attentional capture by the experimenter presence. We then predicted that the participants doing the task under concurrent articulation in the presence of the experimenter should exhibit poorer recall performance than the participants who stay alone in the cubicle. Method Participants. Participants were 60 undergraduate students (10 males; age: M = 21.68; SD = 1.70) at the University of Fribourg who received course credit or cinema vouchers for their participation. All had normal or corrected-to-normal vision. None of them participated in the previous experiment or were aware of the goals of this experiment, presented as a study on memory. Material and procedure. The procedure was similar to that of experiment 1, with the following exceptions. First, to induce a concurrent articulation, participants were instructed to repeat “-babi-bou” at the pace of one syllable every 500 ms during the parity judgment–task training. An audio metronome provided an example of the desired pace during instructions. Participants also performed the

concurrent articulation during the filled trials in the training. Finally, all participants performed the experimental trials with a concurrent articulation during the letter presentation and the retention interval in both unfilled and filled trials.

Results Parity judgment task. As in experiment 1, four participants who did not reach 65% of correct responses in the parity judgment task during the completion of the filled trials were excluded from the analyses. Among the remaining participants, 26 were in the alone condition and 30 in the experimenter-presence condition. To control for performance in the parity judgment task, an ANOVA on the reaction times was performed for the filled trials, with presence (alone versus experimenter presence) as between-subject predictor. Our results indicated a trending but nonsignificant effect of the social presence (F(1,54) = 2.98; P = 0.09; η2 p = 0.05), with slower reaction times in the alone condition (M = 404 ms; SE = 9.19) than in the presence of the experimenter (M = 389 ms; SE = 14.28). Proportions correct in parity judgments were analyzed using GEEs, with presence as the betweensubject predictor. The main effect of presence was not significant (Wald Z = 0.304; P = 0.582; OR = 1.06, with 95% CI = 0.86–1.32), indicating a similar accuracy in both conditions (alone: M = 0.80; SE = 0.01; experimenter presence: M = 0.79; SE = 0.01).


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Memory. The same analyses as in experiment 1 were performed with the additive and the full factorial models being tested. Whereas the likelihood of the factorial model was once more slightly better (QICC = 85,844.87) than for the additive model (QICC = 85,997.35), the interaction between type of trials and presence did not reach significance (P = 0.34). The additive model was therefore preferred, because it was more parsimonious. Consistently with the literature and experiment 1, the main effect of the type of trials was significant (Wald Z = 126.36; P < 0.001; OR = 0.58, with 95% CI = 0.53–0.64), indicating a better recall in unfilled trials (M = 0.70; SE = 0.01) than in the filled trials (M = 0.56; SE = 0.02). Moreover, the overall performance was worse than in experiment 1, which is congruent with the idea that the concurrent articulation did prevent articulatory rehearsal and therefore undermined recall performance. Critically, and contrary to what we observed in the previous experiment, the main effect of presence was significant (Wald Z = 6.47; P = 0.01; OR = 0.72, with 95% CI = 0.56– 0.93) (Fig. 2). As we predicted, the participants who did the task in the experimenter-presence condition recalled fewer letters (M = 0.60; SE = 0.02) than those who stayed alone in the cubicle (M = 0.67; SE = 0.02). Discussion Experiment 2 strengthened the findings of experiment 1, as we observed once more a detrimental effect on memory of the attentional capture resulting from the introduction of a secondary task. However, more interestingly for the purpose of this study and contrary to the findings of experiment 1, the presence of the experimenter undermined recall performance. In other words, the simple fact that participants had to produce a concurrent articulation was enough to change the pattern of findings and make the effect of experimenter presence appear. This is perfectly coherent with our hypothesis that participants relied mostly on a verbal mechanism of maintenance in experiment 1, a mechanism that was not affected by the social presence. This also provides evidence in favor of the distractorconflict hypothesis, which puts forward that social presence distracts attention away from task execution. Implications for working memory models and social presence theories are discussed in the general discussion. 6

General discussion The social presence is known for automatically capturing attention,12,13,15 which in turn is susceptible to deteriorate cognitive control.9,11 Here, we tested for the first time whether this attentional capture may also undermine maintenance in working memory, a mechanism known to be sensitive to cognitive distraction.22,25,26 In a first experiment, participants memorized letters during an interval either empty or filled with a secondary task that has been shown to capture attention.29,30 We replicated the detrimental effect of cognitive distraction, but, contrary to our expectations, the experimenter presence did not affect recall performance. We then hypothesized that participants were unaffected by the experimenter presence, because they relied mainly on articulatory rehearsal, which is a nonattentional maintenance mechanism.22–24,39 In a second experiment, participants performed the same task but while repeating nonsense syllables during the letter presentation and the retention interval to impair the use of rehearsal.45,46 Coherently with our prediction, the experimenter presence undermined recall in this second experiment, suggesting that social presence affects working memory maintenance when it specifically relies on attention. Our results have implications for understanding working memory and the impact of social presence. They also have important methodological implications. Put together, our results are consistent with the idea that (at least) two different mechanisms support maintenance in working memory.40,41 The first mechanism relies on attention and is susceptible to cognitive and social distraction. The second mechanism is verbal, impaired by concurrent articulation, and immune to the social-presence effect. Moreover, the detrimental effect of the experimenter presence observed in our second experiment also implies that the attention used to maintain information over a short delay is general enough to be captured by the social presence, as it is by the introduction of a secondary task. This is compatible with the hypothesis that working memory relies on a domain-general, multipurpose executive attention7,20,22 and not so much on domain-specific resources depending on the nature of the memory items.24,47 Nonetheless, further studies are needed, because the involvement of attention to maintain different types of memoranda is still under debate.48–50


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The present research also refines our understanding of the social-presence effect. First, it extends the wide range of tasks known to be affected by the social presence. This is an important step forward, because working memory is a central concept in psychology and is thought to be the hub of cognition,51,52 influencing numerous behaviors.21 Second, our results also strengthen the evidence that the presence of others automatically captures attention. Indeed, the effect of the experimenter presence in our second experiment was observed with or without a secondary task in the retention interval. This indicates that, even when participants had to share their attention between two tasks (memorizing letters and processing digits), they were vulnerable to social attention capture. Furthermore, our results allowed us to compare a cognitively induced distraction (the secondary task) with a socially induced distraction (the experimenter presence). The fact that the effect of the cognitive distraction was twice as great (a drop of 14% in recall accuracy) than the distraction by the social presence (7%) may be due to the fact that the social presence is not central to the task, contrary to the secondary task. Another interesting point is that the social presence seems to have shortened the reaction times in the secondary task, maybe because of the socially induced attention capture. If this is the case, this finding would be consistent with the hypothesis of a sharing of attention between processing and storage, both being susceptible to the same sources of attention distraction. Nonetheless, given that we found only a statistic trend, this effect on the secondary task should be further investigated in future research, for example, by varying the salience of the presence (e.g., making the presence more evaluative). Another important point in our results is the fact that articulatory-based maintenance seems to be immune to the social-presence effect. This argues against the idea that the presence of others hinders performance by triggering intrusive negative thoughts, as it has been demonstrated for other threatening social contexts (such as the stereotype threat53 ). Intrusive thoughts have an important verbal component54,55 that is susceptible to consuming working memory resources, especially by impairing verbal-based maintenance.53,55 The intrusion of language-based thoughts does not seem to be compatible with the present results, in which the verbal rehearsal may have been used by participants


to compensate for the attentional cost of the social presence. Further studies should nonetheless confirm this finding and investigate why the verbal rehearsal is unaffected by the social presence. In our study, there was no direct measurement or control of the pace of the concurrent articulation. Despite the reduction in recall performance in experiment 2 compared with experiment 1 that supports the notion that the articulatory suppression had worked, one can argue that participants produced more concurrent articulations in the presence of the experimenter than alone. Accordingly, the effect of the experimenter presence on recall would have been indirect, resulting from a stronger impairment of verbal rehearsal rather than from attention capture. Finally, our results also have important methodological implications. In experimental psychology, the presence of the experimenter during task completion is often overlooked and rarely mentioned in the method section of scientific papers. Even if our results do not indicate an interaction between cognitive distraction manipulation and the presence of the experimenter (but more research is needed to confirm this pattern), the fact that this presence deteriorates working memory maintenance calls for caution. First, the presence and behavior56 of the experimenter should be carefully maintained as constant within the same experiment to avoid unnecessary noise in the data. Second, this presence and behavior should be systematically reported to insure replicability. These recommendations should apply not only to the working memory field but also to experimental psychology in general, the audience effect being known to affect a very broad range of tasks.2–4 Moreover, because working memory is strongly linked with fluid intelligence, high-level cognition, self-regulation, and psychopathology,57 making its assessment a classic measure in applied psychology, our results invite one to be careful concerning the potential effect of the evaluator presence that may lead one to underestimate the capacities of the tested person. To conclude, this study provided first evidence that the social presence hinders attentional maintenance in working memory. This finding opens exciting new perspectives of research for both working memory and social presence fields of research and invites more integration between the cognitive and social factors in psychology.


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Acknowledgments We thank Christel Aichele and Cyrielle Goetschi for their help in collecting the data. Author contributions are as follows. C.B. and V.C. devised the experiment. C.B. programmed the experimental tasks. C.B. and V.C. supervised the data collection done by the two research assistants. C.B. analyzed the data and is responsible for their integrity. C.B. drafted the manuscript, and V.C. provided critical revisions. Both authors approved the final manuscript. Supporting Information Additional supporting information may be found in the online version of this article. Appendix. Additional analyses. Competing interests The authors declare no competing interests. References 1. Triplett, N. 1898. The dynamogenic factors in pacemaking and competition. Am. J. Psychol. 9: 507–533. 2. Bond, C.F. & L.J. Titus. 1983. Social facilitation: a metaanalysis of 241 studies. Psychol. Bull. 94: 265–292. 3. Geen, R.G. & J.J. Gange. 1977. Drive theory of social facilitation: twelve years of theory and research. Psychol. Bull. 84: 1267–1288. 4. Guerin, B. 1993. Social Facilitation. Cambridge: Cambridge University Press. 5. Zajonc, R.B. 1965. Social facilitation. Science 149: 269–274. 6. Bont´e, E., T. Flemming & J. Fagot. 2011. Executive control of perceptual features and abstract relations by baboons (Papio papio). Behav. Brain Res. 222: 176–182. 7. Engle, R.W. 2002. Working memory capacity as executive attention. Curr. Dir. Psychol. Sci. 11: 19–23. 8. Miller, E.K. 2000. The prefrontal cortex and cognitive control. Nat. Rev. Neurosci. 1: 59–65. 9. Belletier, C., K. Davranche, I. Tellier, et al. 2015. Choking under monitoring pressure: being watched by the experimenter reduces executive attention. Psychon. Bull. Rev. 22: 1410–1416. 10. Wagstaff, G.F., J. Wheatcroft, J.C. Cole, et al. 2008. Some cognitive and neuropsychological aspects of social inhibition and facilitation. Eur. J. Cogn. Psychol. 20: 828–846. 11. W¨uhr, P. & L. Huestegge. 2010. The impact of social presence on voluntary and involuntary control of spatial attention. Soc. Cogn. 28: 145–160. 12. Baron, R.S. 1986. Distraction–conflict theory: progress and problems. Adv. Exp. Soc. Psychol. 19: 1–40. 13. Huguet, P., M.P. Galvaing, J.M. Monteil, et al. 1999. Social presence effects in the Stroop task: further evidence for an attentional view of social facilitation. J. Pers. Soc. Psychol. 77: 1011–1025.

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