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Characterization of affective states by pupillary dynamics and autonomic correlates.

Onorati F, Barbieri R, Mauri M, Russo V, Mainardi L - Front Neuroeng (2013)

Bottom Line: ECG, RESP, and PD data from 13 normal subjects were recorded during a memory recall paradigm, and processed with spectral and cross-spectral analysis.A strong linear coupling was found between the variables, due to the influence of RESP on both PD and HRV within the High Frequency (HF) band, from 0.15 to 0.45 Hz.Most importantly, our results point at PD features as possible candidates for characterizing basic emotional stimuli.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano Milan, Italy ; Massachusetts Institute of Technology Cambridge, MA, USA ; Massachusetts General Hospital Boston, MA, USA ; Behavior and Brain Lab, IULM University Milan, Italy.

ABSTRACT
With the recent advent of new recording devices and an easier access to signal processing tools, researchers are increasingly exploring and studying the Pupil Dilation (PD) signal. Recently, numerous studies pointed out the relations between PD dynamics and psychophysiological states. Although it is well known that PD is controlled by the Autonomic Nervous System (ANS), and ANS responses are related to emotional events/stimuli, the relationship between emotional states and PD is still an open issue. The aim of this study is to define the statistical properties of the PD signal, to understand its relation with ANS correlates such as Heart Rate Variability (HRV) and respiration (RESP), and to explore if PD could provide information for the evaluation of the psychophysiological response of ANS to affective triggering events. ECG, RESP, and PD data from 13 normal subjects were recorded during a memory recall paradigm, and processed with spectral and cross-spectral analysis. Our results demonstrate that variability indices extracted from fast PD oscillations, not observable through standard cardiorespiratory identification in the frequency domain, would be able to discern psychophysiological responses elicited by basic emotional stimuli. A strong linear coupling was found between the variables, due to the influence of RESP on both PD and HRV within the High Frequency (HF) band, from 0.15 to 0.45 Hz. Most importantly, our results point at PD features as possible candidates for characterizing basic emotional stimuli.

No MeSH data available.


Related in: MedlinePlus

Mean values and standard errors of GResp→ PD (at the top, in blue) and of GRESP→ RR (at the bottom, in red).
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Figure 7: Mean values and standard errors of GResp→ PD (at the top, in blue) and of GRESP→ RR (at the bottom, in red).

Mentions: Only GRESP→PD shows significant differences [F(3, 36) = 4.9, p-value < 0.05] within groups. The post-hoc analysis reveals significant differences between “Baseline” and “Happiness” (p-value < 0.016). This index is the only bivariate index showing high significance for the experimental conditions of our protocol, and it's the only one which distinguishes emotional states with an opposite connotation. The results of the analysis between PD and the RR signal indicate weak coupling. At LF the rate of subjects showing nDC above threshold for both the transfer functions was low and in some conditions none of the subjects showed above threshold nDC (results not shown). At HF no clear directionality in the linear coupling can be stated: nDC is above threshold on average for the same number of subjects for both the transfer functions. As expected, in the analysis for PD and RESP, a higher number of subjects shows nDCRESP→PD above threshold. Moreover, GRESP→PD shows an interesting trend in Figure 7: once compared with GRR→RESP, GRESP→PD shows higher values during “Happiness” with respect to the other conditions, in particular to “Anger” and “Sadness”.


Characterization of affective states by pupillary dynamics and autonomic correlates.

Onorati F, Barbieri R, Mauri M, Russo V, Mainardi L - Front Neuroeng (2013)

Mean values and standard errors of GResp→ PD (at the top, in blue) and of GRESP→ RR (at the bottom, in red).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3818468&req=5

Figure 7: Mean values and standard errors of GResp→ PD (at the top, in blue) and of GRESP→ RR (at the bottom, in red).
Mentions: Only GRESP→PD shows significant differences [F(3, 36) = 4.9, p-value < 0.05] within groups. The post-hoc analysis reveals significant differences between “Baseline” and “Happiness” (p-value < 0.016). This index is the only bivariate index showing high significance for the experimental conditions of our protocol, and it's the only one which distinguishes emotional states with an opposite connotation. The results of the analysis between PD and the RR signal indicate weak coupling. At LF the rate of subjects showing nDC above threshold for both the transfer functions was low and in some conditions none of the subjects showed above threshold nDC (results not shown). At HF no clear directionality in the linear coupling can be stated: nDC is above threshold on average for the same number of subjects for both the transfer functions. As expected, in the analysis for PD and RESP, a higher number of subjects shows nDCRESP→PD above threshold. Moreover, GRESP→PD shows an interesting trend in Figure 7: once compared with GRR→RESP, GRESP→PD shows higher values during “Happiness” with respect to the other conditions, in particular to “Anger” and “Sadness”.

Bottom Line: ECG, RESP, and PD data from 13 normal subjects were recorded during a memory recall paradigm, and processed with spectral and cross-spectral analysis.A strong linear coupling was found between the variables, due to the influence of RESP on both PD and HRV within the High Frequency (HF) band, from 0.15 to 0.45 Hz.Most importantly, our results point at PD features as possible candidates for characterizing basic emotional stimuli.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano Milan, Italy ; Massachusetts Institute of Technology Cambridge, MA, USA ; Massachusetts General Hospital Boston, MA, USA ; Behavior and Brain Lab, IULM University Milan, Italy.

ABSTRACT
With the recent advent of new recording devices and an easier access to signal processing tools, researchers are increasingly exploring and studying the Pupil Dilation (PD) signal. Recently, numerous studies pointed out the relations between PD dynamics and psychophysiological states. Although it is well known that PD is controlled by the Autonomic Nervous System (ANS), and ANS responses are related to emotional events/stimuli, the relationship between emotional states and PD is still an open issue. The aim of this study is to define the statistical properties of the PD signal, to understand its relation with ANS correlates such as Heart Rate Variability (HRV) and respiration (RESP), and to explore if PD could provide information for the evaluation of the psychophysiological response of ANS to affective triggering events. ECG, RESP, and PD data from 13 normal subjects were recorded during a memory recall paradigm, and processed with spectral and cross-spectral analysis. Our results demonstrate that variability indices extracted from fast PD oscillations, not observable through standard cardiorespiratory identification in the frequency domain, would be able to discern psychophysiological responses elicited by basic emotional stimuli. A strong linear coupling was found between the variables, due to the influence of RESP on both PD and HRV within the High Frequency (HF) band, from 0.15 to 0.45 Hz. Most importantly, our results point at PD features as possible candidates for characterizing basic emotional stimuli.

No MeSH data available.


Related in: MedlinePlus