Altered attentive bias towards interpersonal communication information across phases of schizophrenia: an eye-tracking study

Abstract

Background: Eye movement abnormality in schizophrenia has been studied for several decades. However, patient differences in eye movements across phases of schizophrenia from eye-tracking studies have not been well documented.

Aims: This pilot study used eye-tracking technology to investigate attentive bias towards interpersonal communication information across different clinical phases of schizophrenia.

Methods: This study included 78 persons at clinical high risk (CHR) for schizophrenia, 68 first-episode (FEZ) patients, and 39 chronically ill patients from the Shanghai At Risk for Psychosis Extending Project (SHARP Extending cohort) as well as 74 healthy controls (HCs). The experiment was an unguided-viewing task composed of 24 trials showing three types of pictures which varied in the degree of interpersonal communication. Type 1 was a scenery picture without people, type 2 was a picture with four people not communicating, and type 3 was a picture with four people communicating. We used two measures: (1) initial fixation duration and (2) total fixation duration.

Results: A ratio for both measures was calculated between measures for pictures with more or less interpersonal communication. The ratio of initial fixation duration for pictures with people communicating versus pictures with people not communicating was lowest in chronically ill patients (0.13 (0.34))compared with HCs (0.31 (0.36)), FEZ patients (0.31 (0.46)), and CHR patients (0.36 (0.42)). The difference in the ratios of initial fixation duration for type 2 and type 3 pictures was also significant for female participants (HCs vs chronically ill patients, t=2.706, p=0.009; CHR patients vs chronically ill patients, t=4.079, p<0.001). In addition, the ratio of initial fixation duration on pictures with people not communicating versus pictures without people negatively correlated with participants' high-risk symptoms (r=-0.35, p=0.002) among the CHR group and also correlated with the negative symptom subscore on the Positive and Negative Syndrome Scale (PANSS) among chronically ill patients (r=-0.33, p=0.037). The ratio of initial fixation duration between type 1 and type 3 pictures was associated with PANSS negative symptoms only in female patients with schizophrenia (r=-0.46, p=0.004).

Conclusions: These findings suggest an altered attentive bias towards pictures with a high degree of interpersonal communication information across different clinical phases in schizophrenia. The ratio of initial attentive orienting was associated with negative symptoms in female patients.

Keywords: Behavioural Research; Schizophrenia.

Figure 1

The flowchart for the participant recruitment. CHR, clinical high-risk; DSM-IV-IR, Diagnostic and Statistical Manual of Mental disorders-Fourth Edition, Text Revision; FEZ, first-episode; HCs, healthy controls; M.I.N.I., Mini-International Neuropsychiatric Interview; SCID-I/P, Structural Clinical Interview for DSM-IV-TR, Patient's version; SD, standard deviation; SIPS, Structured Interview for Prodromal Symptoms; SOPS, Scale of Prodromal Syndromes.

Figure 2

The graph depicts the experimental procedure that is fixed for each time with the sequence of cross fixation (1000 ms) and pictures (4000 ms). Two of the three types of pictures were presented in pairs on 24 trials linked between cross fixation.

Figure 3

Chronically ill patients showed a smaller ratio of initial fixation duration compared with FEZ patients (p=0.030), CHR patients (p=0.003) and HCs (p=0.009), as indicated by the result of post hoc analysis. This means that chronically ill patients invested less attentive processing resources on pictures with people communicating, while HCs, by contrast, invested more. CHR, clinical high-risk; FEZ, first-episode; HCs, healthy controls.

Figure 4

Spearman’s correlation yielded negative correlation between SIPS and the ratio of initial fixation duration between type 1 and type 2 pictures in CHR patients (r=−0.35, p=0.002). CHR, clinical high-risk; SIPS, Structured Interview for Prodromal Symptoms.

Figure 5

Spearman’s correlation revealed negative correlation between PANSS negative symptoms and the ratio of initial fixation duration between type 1 and type 3 pictures in chronically ill patients (r=−0.33, p=0.037) but not in FEZ patients (r=−0.14, p=0.266). FEZ, first-episode; PANSS, Positive and Negative Syndrome Scale.