Is Attentional Bias To Idiosyncratic Stimuli Related To Borderline Symptomatology?

Background: In borderline personality disorder, attentional bias to emotional stimuli may be a fundamental component in their origin and maintenance. However, the authors seem divided between the hypothesis of hypervigilance for negative stimuli and the hypothesis of over-reactivity against any type of stimuli. Aims: We aimed to observe the association between borderline symptoms and the allocation of attention to neutral, idiosyncratic negative and general negative emotional words. Method: We tested thirty-ve portuguese university students, aged between 18 and 40 years old with an Emotional Stroop paradigm. Results: Our results suggest that a higher score of borderline symptoms are associated with a greater interference of idiosyncratic negative words in the colour identication task. Conclusions: These results support the hypervigilance hypotheses for idiosyncratic borderline stimuli. In other words, this study suggested that borderline sympotms is linked to an inability to disengage attention from negative words typically of borderline disorder. Based on these ndings, mood-dependent therapeutic interventions focusing on attentional processes may represent a useful contribute to established therapies in patients with BPD.


Introduction
Subjects with borderline symptoms tend to present an impaired emotional regulation competence regarding attentional development -the ability to direct attention to a neutral or positive emotional situation -and cognitive change, which is the capability to modify the way people assess the situation and its associated emotional signi cance. Attentional bias to threat -typically found on these individuals -leads to the maintenance of their symptoms and to emotional dysregulation ( Emotional Stroop is a useful approach to experimentally investigate the emotional regulation, more particularly the attentional bias for emotionally charged stimuli (Gross, 2014). This task is an adaptation of the original test (Stroop, 1935), in which the stimuli are coloured words with an emotional meaning for the subjects, thus taking more time in naming the colours in which those words are written, due to the interference of automatic emotional processes (Cabaco, 1998). Several studies have concluded that individuals with an emotional disorder have a selective processing for negative or idiosyncratic stimuli (i.e. related to their disorder), which will result in a delay in the naming colours task when faced with an Emotional Stroop ( The assessment of borderline subjects with the Emotional Stroop task was primarily made by Arntz and colleagues (2000), who demonstrate that borderline patients are slower in naming all negative emotional words, regardless of whether they are associated with their disorder or not, when compared to the control group; however, were not slower than other patients with others personality disorders. Hypervigilance was therefore directed to negative emotional words, although it wasn't restricted to borderline patients. On the other hand, Portella and colleagues (2011) failed to replicate this study, because borderline patients had longer response times than controls for all words, regardless of their valence. This result led the authors to speculate that these subjects present an over-reactivity to all emotional stimuli, rather than the speci c hypervigilance suggested by Arntz and colleagues (2000). In this way, confrontation with idiosyncratic words may trigger negative subjective experiences that persist during the test, impairing the reaction to subsequent words, whether neutral or positive -due to the inability in emotional regulation after seeing a personally relevant stimulus (Linehan, 1993;Portella et al., 2011).
Given the inconsistency between these two studies that used Words Emotional Stroop in patients with borderline disorder, we intended to investigate whether there is primacy of any hypotheses (hypervigilance vs. over-reactivity) relative to the attentional bias for emotion in subjects with borderline symptoms. Our main objective was to clarify the association between borderline personality symptoms and attentional processing of emotional and neutral words. BSL23 is a self-report questionnaire used to assess the presence and severity of borderline symptomatology, consisting of 23 items answered on a 5-point scale (from "1 -None" to 5 -Very Much"). This instrument has good psychometric properties (α = .94 to .97 for the original version and α = .96 for the portuguese version). The BSL23 is divided into seven subscales: Negative Self-Perception, Affective Regulation, Self-Destruction, Dysphoria, Solitude, Intrusions and Hostility. It also includes the Global Score, resulting from the sum of the results obtained in each subscale.
Task Emotional Stroop. The stimuli of the Emotional Stroop task were 15 words carefully selected from the study by Portella (2011), which are divided into three valences: borderline negative words (Depression, Suicide, Solitude, Abandonment and Lack of Control), generic negative words (Hate, Corpse, Sorrow, Failure and Catastrophe) and neutral words (Clock, Crossing, Custom, Mountain and Dancer). The words were randomly presented in four colours (yellow, red, green and blue), placed on a grey background screen. The answer was given using a box with a four-button keyboard (yellow, red, green and blue) placed in front of the participants. The presentation of the stimuli and the recording of responses and reaction times were done using Presentation 0.76 software. In agreement with previous studies, a block design was used (Shin et al., 2001). Four blocks were organized for each category, in a total of 12 blocks; in each of them, the ve words in that category appeared four times (once in each colour, resulting in 20 items per block). Words' presentation time within each block is shown in Fig. 1. Each block had a duration of approximately 30s.

Procedure
All participants signed an informed consent and completed the sociodemographic questionnaire, as well as the BSL23, to assess the subclinical symptoms of borderline personality. Finally, the Emotional Stroop task was administered in a laboratory room, ensuring a completely noise-free environment. The task procedure was explained verbally and there was a training phase to familiarize the patients before it started.
Statistical analysis was used to evaluate the association between borderline symptoms and the Stroop effect, assessing the interference of words' content in the response latency. To test these associations, Pearson correlations were made using SPSS (Statistical Package for the Social Sciences, version 20.0).

Effect of Emotional Stroop and association with BSL23 (global and subscales)
The effect of word content interference on the latency of colour identi cation responses (Emotional Stroop effect) was estimated. It was understood by effect of Emotional Stroop an increase in the colour identi cation time due to the interference of the emotional words' content. Thus, the difference between the response latency to the borderline words and the latency of the neutral word responses was calculated, this difference being a measure of the speci c interference effect of borderline stimuli; the difference between responses latency to negative words and responses latency to neutral words was calculated, this being an effect of generic negative stimuli interference; and the difference between the responses latency to borderline words and responses latency to the negative words was calculated, this difference being a measure of the speci c interference effect of the borderline stimuli against the generic negative stimuli.
Analysis of the association between the variations observed in the Stroop effect indicators and the borderline symptoms is shown in Table 1. Generally, there are signi cant positive coe cients only when the Stroop effect involves borderline words. There were positive correlations between the Stroop effects expressed by the comparison of borderline words with neutral words (r = .347; p = .04) and with negative words (r = .369; p = .03) and the overall score of BSL23. An equivalent interference pattern is observed for the scores on the Negative Self-perception, Dysphoria, Solitude and Intrusion subscales. These results show some consistency and suggest that more marked borderline symptoms are associated with a greater slowdown in responding to idiosyncratic words of this personality disorder (compared to negative and neutral words).

Discussion
Emotional dysregulation, associated with an attentional bias to threat, has been studied as a factor of origin and/or maintenance of borderline personality disorder. In this context, our objective was to evaluate if there was an association between the attentional bias for emotion and borderline symptoms -trying to identify the stimuli load that activated this bias.
Our results suggest that borderline symptoms are associated with an Emotional Stroop effect for idiosyncratic negative words. Negative words related to borderline symptoms (e.g, "Solitude" or "Abandonment") elicit slower colour identi cation responses in participants with borderline symptoms than when they are responding to neutral or generic negative words. These results seem to be partially coincident with the results obtained by Arntz and collaborators (2000), Linehan (1993) and Sieswerda, Arntz, Mertens and Vertommen (2007), in which it was possible to support that subjects with borderline symptoms develop an information processing bias, therefore suffering from a hypervigilance mediated by their cognitive schema directed toward negative signs associated with the disorder.
Another empirical evidence that seems to go toward our results concerns the absence of a signi cant association between the non-idiosyncratic Stroop effect and the borderline personality symptoms: the interference of generic negative words (as opposed to neutral words) seems to be a cross-sectional effect and not be heightened in participants with borderline symptoms. Once again, this result reinforces the hypothesis of a hypervigilance speci c for idiosyncratic stimuli.
In conclusion, the results of this investigation seem to reinforce the notion that Emotional Stroop is particularly relevant for borderline personality research, both in investigative and clinical perspectives, because it's an implicit measure that allows to determine the borderline diagnosis and its features. The results obtained with this task contribute to the discussion around attentional bias in subjects with borderline personality disorder, supporting the hypothesis that individuals with borderline symptoms present a speci c hypervigilance for words idiosyncratically associated with their disorder. Furthermore, based on these ndings, mood-dependent therapeutic interventions focusing on attentional processes may represent a useful contribute to established therapies in patients with BPD.
Despite the consistency of the results, this study presents some limitations. The reduced size of the sample and the disparity between sexes prevented more robust and generalizable analyses. As future work proposals, it would be interesting to evaluate a clinical group with borderline personality and to add psychophysiological measures (e.g. galvanic skin response and heart rate) to verify if the observed interference has repercussions at a physiological level.

Declarations
Ethical approval and consent to participate: The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Scienti c Committee of Faculty of Human and Social Sciences, Universidade of Algarve (Ethical approval code CC-24/2018). Informed consent was obtained from all subjects involved in the study.
Consent for publication: All authors read and agreed to the published version of the manuscript.
Availability of data and materials: The datasets generated during and analyzed during the current study are available from the corresponding author on reasonable request. Figure 1 Stimuli presentation time in each block (Emotional Stroop Task)