Sensory-processing sensitivity versus the sensory-processing theory: Convergence and divergence

The development and validation of the "SENSE" - Sensory and Behavioral Modulation Questionnaire for adults

Sensory modulation is critical for interacting with the physical and social environment. When sensory input from the environment is not properly perceived and modulated, it may elevate arausability, avoidant behavior, impair function and wellbeing. Sensory modulation difficulties (SMD) are mainly reported during childhood and are related to neurodevelopmental conditions such as Attention-Deficit Hyperactivity Disorder (ADHD). SMD in adulthood further deteriorate function and emotional status, hence should be screened and treated. Nonetheless, relevant measures of SMD for adults are limited. This study aims to establish the psychometric properties of the "SENSE" - Sensory and Behavioral Modulation Questionnaire for adults. Based on theoretical/clinical knowledge the SENSE measures sensitivity/arousability, habituation and avoidance. After establishing content and face validity, 663 participants aged 18-65 completed a sociodemographic and health questionnaire, the Adult ADHD Scale-5 (ASRS-5), the SENSE and the Highly Sensitive Person Scale (HSPS). Factor analysis approved the determination of SENSE scales. Medium- high internal consistency was found. SENSE discriminated between adults with/without ADHD and correlated with HSPS scores, confirming concurrent validity. CONCLUSIONS: SENSE has good psychometric properties and may be feasible for screening sensory-behavioral modulation difficulties in adults. Studies should further examine SENSE applicability to clinical populations.

Gender differences in the relationship between neuroticism and odor memory

Given the indications on the relationship between neuroticism and various olfactory functions as well as the emotionality of odor memory, it is surprising that no research so far has investigated whether neuroticism corresponds with odor memory performance. Thus, the purpose of our study was to address this question in the context of gender differences. Participants (73 men) completed the 60-items NEO Five Factor Inventory and participated in 32-items "Test for odor memory". In the separate analyses conducted for men and women, we demonstrated that women outperformed men regarding the number of correct odor recognitions in the odor memory test and had higher neuroticism level than men. Spearman correlation showed further that neuroticism was positively associated with D-prime (R = 0.3, p = .021) and the number of correct odor recognitions in women (R = 0.32, p = .014). This effect was, respectively, moderately (B10 = 5.2) and strongly confirmed using the Bayesian approach (B10 = 8). However, Bonferroni post-hoc correction for multiple comparisons further revealed that in case of neuroticism and the number of hits, as well as D-prime, alpha level was below significance, indicated by p = .006. The correlation between neuroticism level and odor memory performance was significantly higher in women compared to men (Z = 1.8, p = .038), while in case of neuroticism and D-prime, it was on a trend level (Z = 1.5, p = .074). Overall, the present results indicate that neuroticism might be linked to conscious odors' remembering for women, which can be explained by the warning role of odor memory and its connection to limbic structures, as well as by the higher level of neuroticism and odor memory performance in women compared to men.

Neurophysiological signatures of sensory-processing sensitivity

Background

Sensory processing sensitivity is mainly captured based on questionnaires and it's neurophysiological basis is largely unknown. As hitherto no electroencephalography (EEG) study has been carried out, the aim of this work was to determine whether the self-reported level of SPS correlates with the EEG activity in different frequency bands.

Methods

One hundred fifteen participants were measured with 64-channel EEG during a task-free resting state. After artifact correction, a power spectrum time series was calculated using the Fast Fourier Transform (FFT) for the following frequency bands: Delta: 1-3.5 Hz, theta: 4-7.5 Hz, alpha1: 8-10 Hz, alpha2: 10.5-12 Hz, beta1: 12.5-15 Hz, beta2: 15.5-25 Hz, gamma: 25.5-45 Hz, global: 1-45 Hz. Correlations with the 'Highly Sensitive Person Scale' (HSPS-G) scores were determined. Then, the lowest and the highest 30% of the cohort were contrasted as polar opposites. EEG features were compared between the two groups applying a paired two-tailed t-test.

Results

The HSPS-G scores correlated statistically significantly positive with beta 1 and 2, and global EEG power during resting with eyes open, but not during resting with eyes closed. The highly sensitive group revealed higher beta power (4.38 ± 0.32 vs. 4.21 ± 0.17, p = 0.014), higher gamma power (4.21 ± 0.37 vs. 4.00 ± 0.25, p = 0.010), and increased global EEG power (4.38 ± 0.29 vs. 4.25 ± 0.17, p = 0.041). The higher EEG activity in the HSP group was most pronounced in the central, parietal, and temporal region, whereas lower EEG activity was most present in occipital areas.

Conclusion

For the first time, neurophysiological signatures associated with SPS during a task free resting state were demonstrated. Evidence is provided that neural processes differ between HSP and non-HSP. During resting with eyes open HSP exhibit higher EEG activity suggesting increased information processing. The findings could be of importance for the development of biomarkers for clinical diagnostics and intervention efficacy evaluation.