Empirical studies on cognitive resources in interpreting

Despite the apparent complexity of the interpreting task, most interpreters manage to interpret simultaneously successfully most of the time. A number of more recent studies have thus considered which skills interpreters may have, or may have acquired, in order to carry out the interpreting task. These studies often focus on non-language-related skills thought to be involved in the interpreting task, for instance working memory (Chincotta &

Underwood, 1998; Chmiel, 2016; Padilla, Bajo, & Macizo, 2005; Signorelli, Haarmann, &

Obler, 2012; Timarová et al., 2014). Researchers have often favoured between-group studies to identify experience-related differences (Babcock & Vallesi, 2015, 2017; Chmiel, 2016; Dong & Xie, 2014; Köpke & Nespoulous, 2006; Nour, Struys, & Stengers, 2020; Tzou, Eslami, Chen, & Vaid, 2012), although some longitudinal studies exist (Babcock & Vallesi, 2017; Dong & Liu, 2016; Dong, Liu, & Cai, 2018).

The hypothesis underlying behavioural studies in interpreting is that the extreme form of language control required in simultaneous interpreting seems likely to entail a greater overlap between language-specific and domain-general processes (Hervais-Adelman

& Babcock, 2019) than bilingual language processing (Bialystok, 2015; Bialystok, Craik, &

Freedman, 2007; Bialystok & Viswanathan, 2009; Costa & Sebastián-Gallés, 2014), although note that evidence of the relationship between language control and executive control is

mixed (Paap, 2014; Paap & Sawi, 2014). Simultaneous interpreting requires a specific combination of verbal and executive components, potentially setting it apart from other types of bilingual processing (García, Muñoz, & Kogan, 2019).

Table 2 shows several relatively recent studies of component skills in interpreting using behavioural methods, and whether or not the study found cognitive enhancement for interpreters in various domains. Column 5 of Table 2 shows whether between-group studies have reported better scores in interpreters (p < .05) than all other groups in the tasks used to measure different skills and subskills. As shown in the table, between-group approaches have found some evidence in support of a short-term memory advantage in interpreters, a working memory advantage for some sub-processes, and inhibition under specific

conditions. Short-term memory is associated with maintaining information in memory (and measured using simple span tasks), while working memory is associated with the

maintenance and manipulation of information (and measured using complex span tasks) (Aben, Stapert, & Blokland, 2012), but this separation of function and associated measure is not always clearly stated in the literature (e.g., Chmiel, 2016). Inhibition, or inhibitory control, refers to suppressing goal-irrelevant stimuli or responses (Tiego, Testa, Bellgrove, Pantelis, & Whittle, 2018). The evidence presented in Table 2 points towards an association between interpreting and working memory, short-term memory and inhibition skills.

Authors Skill Sub-skill Test Interpreter

advantage?

Babcock & Vallesi

(2017) Short-term

memory Letter span task Yes

Matrix span task Yes Working memory Verbal WM Operation span

task Yes

Spatial WM Operation

orienting network ANT No

Task-switching Transient control Task-switching task (with three trial types)

No

Sustained control Yes

Babcock and

Vallesi (2015) Inhibition Language switching n-2 word

repetition task No

orienting network ANT No

Köpcke and

Phonologically-related word span

No

Storage and

processing Free recall After listening No After

Listening span L1 word recall No*

Attention Stroop task No*

Morales, Padilla, Gómez-Ariza &

Bajo (2015)

Working memory Updating skills n-back test Yes

Attention conflict ANTI_V test

(variation of flanker)

No

orientation No

alertness No

Chmiel (2016) Working memory L2 reading span No

L1 reading span Yes L1 listening span Yes Christoffels, de

Groot & Kroll (2006)**

Lexical retrieval Picture naming No

Translation No

Control Vocabulary test No

Flanker No

Memory Reading span Yes

Speaking span Yes Word span Yes

Table 2. Studies on skills thought to be developed by simultaneous interpreting, the skills thought to sub-serve them, tests used and whether or not an interpreter advantage was found compared to all other groups included in the study.

* “Novice” interpreters performed better than “expert” interpreters and bilingual controls

**We include only Experiment 2 in this comparison, as participants in Experiment 1 differed significantly in their level of English proficiency.

It is worth highlighting two potential shortfalls of these studies. The first is theoretical. We do not know to what extent the processes measured sub-serve the

interpreting task (Seeber, 2015), nor do we know the relative weighting of the different sub-processes, and which of the different processes are specific to interpreting, as compared to bilingual communication. García et al. (2019) suggest that only specific functions directly taxed in simultaneous interpreting benefit from simultaneous interpreting experience, but it is difficult to say this conclusively, due to a lack of methodologically sound and sufficiently powered longitudinal studies with significant findings. In addition, there is a lack of detailed understanding of the processes involved in simultaneous interpreting (Van Paridon et al., 2019), and a resultant lack of understanding of the ways in which interpreting differs from other forms of bilingual comprehension. This in turn is linked to a lack of consensus in the bilingualism literature about whether bilinguals have superior executive functioning

compared to monolinguals (Lehtonen et al., 2018). Even if we were to accept that bilinguals had superior executive functioning, it would be difficult to make a compelling case for this as a consequence of bilingualism (it could also be a cause, for example). To sum up, there are multiple known unknowns. This has resulted in a lack of theoretical consensus about exactly which functions should be tested. Recently, steps have been taken to remedy this.

Dong and Li (2019) propose that language control and processing control are both required for simultaneous interpreting. They attempt to define the relationships between divided attention, coordination and working memory in the context of processing control in interpreting, and propose that language control consists of divided attention and language processing efficiency. Further, they suggest tasks that could be used to measure the different domains specified in their model.

The second shortfall is validity. We do not always know to what extent the tasks used actually relate to the domain they are supposed to measure, an issue which becomes particularly acute when ad-hoc tests are employed (García et al., 2019). Furthermore, as previously mentioned, many studies have small sample sizes, or compare populations that are not matched on key criteria (e.g., age) (Köpke & Signorelli, 2012). In spite of this, in consulting Table 2 we can see that interpreters sometimes perform better on some measures of short-term and working memory than non-interpreters. This lends some support to models of the interpreting process which ascribe a key role to memory (Gerver, 1976; Moser, 1978; Paradis, 1994).

Cognitive enhancement in interpreters has been further investigated in longitudinal studies, in which students are tested before and after training, and there is evidence that interpreting training leads to advantages in switching and working memory updating (Dong

& Liu, 2016) and measures associated with short-term memory (Babcock, Capizzi, Arbula, &

Vallesi, 2017). Chmiel (2016) found that trainee interpreters obtained higher scores on a reading span task in their L2 after training than before. She interpreted this as evidence that trainees develop a working memory advantage due to interpreter training. However, it is important to note, on the one hand, that higher scores in an L2 span test could be the result of improved L2 language proficiency, rather than improved working memory, and, on the other hand, that classifying individuals into memory span groups on the basis of only one measure has been found to yield highly inconsistent results (Waters & Caplan, 2003).

Other longitudinal studies have found null results. For instance, Nour, Struys and Strengers (2020) detected no differences in short-term memory and working memory in translation and interpreting students either pre or post training. However, they found that

professional interpreters scored higher in a working memory task than students of

translation pre-training, and higher in a short-term memory task than translation students post-training. They suggest that changes in short-term memory and working memory may take some time to manifest – equally these results might suggest that those with higher working memory decide to study interpreting (rather than translation), and those with even higher working memory continue into the profession after their studies.

Training-related changes have been more reliably detected in neural studies

(Hervais-Adelman & Babcock, 2019; Hervais-Adelman, Moser-Mercer, Murray, & Golestani, 2017). For example, Van de Putte et al. (2018) administered behavioural tasks designed to measure working memory and inhibition to a group of translation trainees and a group of interpreting trainees before and after 9 months of training, and took neural measures.

There were no behavioural between-group differences either before or after training.

However, after training, there were some neural differences between the two groups (that had not previously been present). Most importantly, interpreting trainees showed increased connectivity in two structural subnetworks as compared to translation trainees. The authors consider that the increased connectivity found in these subnetworks confirms the link between language and domain general control, and claim that the increased subnetwork connectivity in interpreting trainees must be due to control processes required in

simultaneous interpreting and not in translation (while conceding that further research is needed to establish what these processes are).

To summarise, we must be relatively circumspect in any conclusions we draw on the basis of current evidence. Studies in this area have various theoretical and methodological shortcomings, and even setting these aside, findings are mixed. There is limited evidence to

suggest that interpreters might have enhanced cognitive abilities in domains related to the interpreting process, in particular, in working memory and short-term memory. However, robust empirical research based on updated theoretical models seems necessary to

investigate whether interpreters use different processing strategies compared to bilinguals untrained in interpreting when comprehending and producing language. It is possible that prediction, which is posited to be central to the simultaneous interpreting process, is

increased by interpreting experience or in experienced interpreters. We test this hypothesis in Chapters 3 and 4.