Subliminal perception is continuous with conscious vision and can be predicted from prestimulus EEG activity

Subliminal perception can be predicted from prestimulus activity

10.1101/2020.01.06.896803 ◽

2020 ◽

Author(s):

Henry Railo ◽

Roberto Piccin ◽

Karolina M. Lukasik

Keyword(s):

Low Frequency ◽

Discrimination Accuracy ◽

Electrophysiological Response ◽

Eeg Activity ◽

Subliminal Perception ◽

Low Contrast ◽

Subliminal Stimulus ◽

Eeg Power ◽

Evoked Activity ◽

Complex Manner

AbstractHumans sometimes make accurate guesses about stimuli they report not consciously seeing—this phenomenon is known as “subliminal perception.” We asked participants (N = 31) to discriminate the location of a briefly presented low-contrast visual stimulus, and then rate how well they saw the stimulus. The behavioral accuracy of discriminating the location of a subjectively subliminal stimulus could be predicted in a trial-by-trial manner from lateralized low frequency (1–15 Hz) electroencephalographic (EEG) activity before the stimulus. This effect was observed up to 1 s before the stimulus was presented. Lateralized occipital prestimulus EEG power modulated the stimulus-evoked activity in a complex manner, but the amplitude of the stimulus-evoked electrophysiological response was not strongly modulated by subliminal objective discrimination accuracy. Signal detection analyses indicated that the participants’ capacity to discriminate subliminal stimuli lay on the same continuum as conscious vision. The results suggest that subliminal perception is not an automatic stimulus-evoked process but relies on perceptual decisions about weak perceptual signals that may be available for introspection.

Download Full-text

Variations Across the Menstrual Cycle in EEG Activity During Thinking and Mental Relaxation

Journal of Psychophysiology ◽

10.1027//0269-8803.13.3.163 ◽

1999 ◽

Vol 13 (3) ◽

pp. 163-172 ◽

Cited By ~ 7

Author(s):

R. Krug ◽

M. Mölle ◽

H.L. Fehm ◽

J. Born

Keyword(s):

Menstrual Cycle ◽

Divergent Thinking ◽

Spectral Power ◽

Plasma Concentrations ◽

Task Demands ◽

Menstrual Phase ◽

Convergent Thinking ◽

Eeg Activity ◽

Dimensional Complexity ◽

Mental Relaxation

Abstract Previous studies have indicated: (1) peak performance on tests of divergent creative thinking during the ovulatory phase of the menstrual cycle; (2) compared to convergent analytical thinking, divergent thinking was found to be associated with a distinctly increased dimensional complexity of ongoing EEG activity. Based on these findings, we hypothesized that cortical information processing during the ovulatory phase is characterized by an increased EEG dimensionality. Each of 16 women was tested on 3 occasions: during the ovulatory phase, the luteal phase, and menses. Presence of the phases was confirmed by determination of plasma concentrations of estradiol, progesterone, and luteinizing hormone. The EEG was recorded while the women performed: (1) tasks of divergent thinking; (2) tasks of convergent thinking; and (3) during mental relaxation. In addition to EEG dimensional complexity, conventional spectral power analysis was performed. Behavioral data confirmed enhanced creative performance during the ovulatory phase while convergent thinking did not vary across cycle phases. EEG complexity was higher during divergent than convergent thought, but this difference remained unaffected by the menstrual phase. Influences of the menstrual phase on EEG activity were most obvious during mental relaxation. In this condition, women during the ovulatory phase displayed highest EEG dimensionality as compared with the other cycle phases, with this effect being most prominent over the central and parietal cortex. Concurrently, power within the alpha frequency band as well as theta power at frontal and parietal leads were lower during the luteal than ovulatory phase. EEG results indicate that task demands of thinking overrode effects of menstrual cycle. However, with a less demanding situation, an ovulatory increase in EEG dimensionality became prominent suggesting a loosening of associative habits during this phase.

Download Full-text

Investigation of the Effect of Mode and Tempo on Emotional Responses to Music Using EEG Power Asymmetry

Journal of Psychophysiology ◽

10.1027/0269-8803/a000099 ◽

2013 ◽

Vol 27 (3) ◽

pp. 142-148 ◽

Cited By ~ 11

Author(s):

Konstantinos Trochidis ◽

Emmanuel Bigand

Keyword(s):

Left Hemisphere ◽

Right Hemisphere ◽

Emotional Responses ◽

Interactive Effects ◽

Eeg Activity ◽

Musical Excerpt ◽

Major Mode ◽

Musical Modes ◽

Slow Tempo ◽

The Right

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.

Download Full-text