See what you've done! Active touch affects the number of perceived visual objects

Area of Science:

• Cognitive Neuroscience
• Multisensory Perception
• Human Sensorimotor Control

Background:

• Sensory information from different modalities, such as sound, can influence visual perception.
• Typically, vision dominates when combined with touch, a phenomenon termed visual capture.
• Cross-modal interactions between senses are crucial for understanding perception.

Purpose of the Study:

• To investigate the cross-modal interaction between active touch (finger movements) and vision.
• To determine if sensorimotor activity affects the perception of visual events.
• To explore the conditions under which this sensorimotor illusion occurs.

Main Methods:

• Participants performed concurrent finger movements (keypresses) and observed brief visual stimuli (flashes).
• The number of perceived visual flashes was recorded in relation to the number of executed finger movements.
• The temporal proximity between movement execution and visual stimulus presentation was manipulated.

Main Results:

• The perceived number of visual flashes was significantly affected by the number of concurrently performed finger movements.
• This sensorimotor illusion persisted even with unambiguous visual stimuli.
• A close temporal link between movement and visual perception was essential for the illusion.

Conclusions:

• Active touch and sensorimotor activity can modulate visual perception, challenging the dominance of vision in cross-modal interactions.
• This study reveals a novel sensorimotor illusion where motor actions influence visual event perception.
• The findings highlight the intricate temporal coupling between motor execution and visual processing in the brain.