Decoding the temporal dynamics of affective scene processing.

Area of Science:

• Neuroscience
• Cognitive Science
• Psychology

Background:

• Affective scenes activate widespread brain networks, including visual, temporal, and frontal cortices.
• Understanding the precise spatial and temporal dynamics of visual emotion processing remains a challenge.

Purpose of the Study:

• To characterize the spatiotemporal dynamics of neural representations during the processing of affective visual scenes.
• To investigate the temporal emergence and stability of affect-specific neural representations.

Main Methods:

• Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) were recorded during passive viewing of affective images (International Affective Picture System - IAPS).
• Multivariate pattern analysis (MVPA) was applied to EEG data for decoding.
• Representational Similarity Analysis (RSA) was used to fuse EEG and fMRI data.

Main Results:

• Perceptual processing of complex visual scenes initiated in early visual cortex around 80 ms, progressing to ventral visual cortex by 100 ms.
• Affect-specific neural representations emerged between 200-300 ms (pleasant: ~200 ms; unpleasant: ~260 ms), primarily supported by occipital and temporal cortices.
• These affect-specific representations were stable, lasting up to 2 seconds with temporally generalizable activity patterns.

Conclusions:

• Affective scene representations are formed in a valence-dependent manner over time.
• Sustained representations may involve recurrent neural interactions across distributed brain areas.
• The findings provide insights into the temporal dynamics of visual emotion processing.