Current Research
NEURAL DYNAMICS OF PERCEPTION ACTION COUPLING
The neural mechanisms for actions influence on perception: It is well established that perception can influence action planning and execution, in part by triggering motor related representations of perceptual stimuli mediated by the human mirror neuron system. Following the early insights of James (1890) and Gibson (1979) among others, there has been renewed appreciation of the converse relationship; namely the ability of motor planning and execution to influence visual perception. Our research seeks to uncovering the neural mechanisms by which action can influence perception in order to contribute to the establishment of general principles of action perception coupling proposed by a number of theoretical approaches (Hommel et al., 2001; Schütz-Bosbach & Prinz, 2007).
In a number of studies we have adopted an ambiguous apparent motion paradigm used to illustrate the influence of action on perception in previous behavioral studies (Wohlschläger, 2000). You can try this by viewing the central cross on the ambiguous apparent motion display below. You should see the dots progressing in either a clockwise or counter-clockwise direction. The direction will change if you look long enough. Now make a rotate your hand in a clockwise direction (as if it is on a turntable) and you should see the display rotate in the same direction. Now changed directions and see what happens.
Although the apparent motion display is equally likely to be perceived as rotating clockwise or counter-clockwise, action primes the perception of participants, who tend to judge the direction of the apparent motion stimulus to be the same as the direction of manual rotation. This finding reflects a bidirectional link between perception and action.
Our research (Jantzen et al., 2012) has uncovered a network of brain areas critical for the influence of action on perception (figure 1). Motor, parietal and visual regions show greater activity when action influences perception compared to a number of controls. Moreover, we observed an increase in the coupling between these brain regions when action is influencing perception. Phase coherence (a measure of neural coupling) in the gamma band increases between sensorimotor cortex and a number of key occipital and parietal regions known to be involved in the perception of apparent motion. The increase in coupling was not observed when viewing non-ambiguous apparent motion in the same direction as manual rotation, indicating that the neural coupling reflects the influence of motor activity on visual processing.
Current Research in the lab continues to investigate critical questions for understanding the nature of shared perceptual and motor representations include: (1) What brain regions or circuits underlie action priming of perception? (2) How does activity in regions comprising this circuit change during action priming of perception? (3) How is long-range functional connectivity between brain regions altered during action priming of perception?
Figure 1. (A) A single independent component pattern. Black spheres indicate EEG electrode locations. (B) A left parietal cluster of equivalent current dipoles (ECD) projected onto MRI slices. Each ECD is computed from an independent components of one participant. (C) Time–frequency plots computed from the time series of the independent components comprising the cluster in (B). The log power for frequencies in the range from 3 to 50 Hz is shown in a time window from 1 s before to 6 s after the first onset of the visual stimulus array. Blue colors indicate a decrease in oscillatory power from the pre-stimulus period and red colors indicate an increase in oscillatory power. Standard frequency bands are shown for reference (α: alpha, 8–12 Hz; low β: low beta, 12–20 Hz; high β: high beta, 20–30 Hz; γ: gamma, 30–50 Hz). It is clear from the data in this figure that the the greatest neural activity occurs during the ambiguous apparent motion condition , in which action influences perception. Comparison conditions are when perception is not ambiguous and occurs in the same direction as action (Determined) when the participants moves in the absence of apparent motion (Move Only) and when the participant views apparent motion in the absence of action (Stim Only).