Browsing by Subject "pupillometry"

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  • Szibor, Annett; Lehtimäki, Jarmo; Ylikoski, Jukka; Aarnisalo, Antti A.; Mäkitie, Antti; Hyvärinen, Petteri (2018)
    Affective processing appears to be altered in tinnitus, and the condition is to a large extent characterized by the emotional reaction to the phantom sound. Psychophysiological models of tinnitus and supporting brain imaging studies have suggested a role for the limbic system in the emergence and maintenance of tinnitus. It is not clear whether the tinnitus-related changes in these systems are specific for tinnitus only, or whether they affect emotional processing more generally. In this study, we aimed to quantify possible deviations in affective processing in tinnitus patients by behavioral and physiological measures. Tinnitus patients rated the valence and arousal of sounds from the International Affective Digitized Sounds database. Sounds were chosen based on the normative valence ratings, that is, negative, neutral, or positive. The individual autonomic response was measured simultaneously with pupillometry. We found that the subjective ratings of the sounds by tinnitus patients differed significantly from the normative ratings. The difference was most pronounced for positive sounds, where sounds were rated lower on both valence and arousal scales. Negative and neutral sounds were rated differently only for arousal. Pupil measurements paralleled the behavioral results, showing a dampened response to positive sounds. Taken together, our findings suggest that affective processing is altered in tinnitus patients. The results are in line with earlier studies in depressed patients, which have provided evidence in favor of the so-called positive attenuation hypothesis of depression. Thus, the current results highlight the close link between tinnitus and depression.
  • Kaakinen, Johanna; Simola, Jaana (2020)
    Thirty-nine participants listened to 28 neutral and horror excerpts of Stephen King short stories while constantly tracking their emotional arousal. Pupil size was measured with an Eyelink 1000+, and participants rated valence and transportation after each story. In addition to computing mean pupil size across 1-sec intervals, we extracted blink count and used detrended fluctuation analysis (DFA) to obtain the scaling exponents of long-range temporal correlations (LRTCs) in pupil size time-series. Pupil size was expected to be sensitive also to emotional arousal, whereas blink count and LRTC’s were expected to reflect cognitive engagement. The results showed that self-reported arousal increased, pupil size was overall greater, and the decreasing slope of pupil size was flatter for horror than for neutral stories. Horror stories induced higher transportation than neutral stories. High transportation was associated with a steeper increase in self-reported arousal across time, stronger LRTCs in pupil size fluctuations, and lower blink count. These results indicate that pupil size reflects emotional arousal induced by the text content, while LRTCs and blink count are sensitive to cognitive engagement associated with transportation, irrespective of the text type. The study demonstrates the utility of pupillometric measures and blink count to study literature reception.