Pre-stimulus activities affect subsequent visual processing: Empirical evidence and potential neural mechanisms.

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Human information processing heavily relies on visual stimuli.
• Pre-stimulus brain activity can modulate the perception of subsequent visual information.
• Cognitive functions like attention and arousal may initiate before stimulus onset.

Purpose of the Study:

• To review proposed mechanisms explaining the impact of pre-stimulus brain activity on cognitive functions.
• To evaluate evidence for and against documented mechanisms.
• To explore how pre-stimulus cognitive functions interact.

Main Methods:

• Literature review of studies investigating pre-stimulus oscillatory activities (power, phase, connectivity).
• Analysis of proposed mechanisms for pre-stimulus cognitive functions.
• Examination of evidence supporting or refuting these mechanisms.

Main Results:

• Pre-stimulus brain activity involves changes in oscillatory activities across various frequency bands.
• Multiple cognitive functions, including spatial attention, feature-based attention, temporal attention, arousal, and mental imagery, can commence before stimulus presentation.
• A combination of these cognitive functions often begins prior to stimulus onset in many studies.

Conclusions:

• No single mechanism fully explains the influence of pre-stimulus brain activity on later processing.
• Multiple mechanisms likely operate in concert to guide pre-stimulus brain activity.
• Differentiating between various pre-stimulus cognitive functions is challenging, necessitating refined experimental designs.