Friedemann Pulvermüller - Grounding meaning in actions and perceptions: A role for logical circuits

It has been argued that embodiment of information about actions and perceptions is sufficient for explaining meaning and concepts. I will review neuroscience evidence for grounding of referential semantics in action- and perception knowledge. When understanding action words, the motor cortex lights up instantaneously, and, critically, this motor activation reflects referential features of action-related language. The motor system is also relevant for processing action-related words, as magnetic stimulation and neurological disease affecting the motor system demonstrate. Similar points can be made for sensory brain systems and words with object reference. So a semantic embodiment perspective has solid neuroscientific grounding. (1-8) However, mechanistically speaking, embodiment is not enough for meaning. When I learn what a square is, I may encounter a range of very different perceptions and may become involved in numerous different actions. These may provide some “embodied” information relevant to the referential meaning of the word, but there is need for computational devices linking features and separating relevant from irrelevant ones. A mechanism for dynamically linking perceptual and action features in semantic processing is offered by the Logical Embodiment Model. This model describes neurons as logical elements that compute NON, AND, OR or XOR functions from sensory and motor features. As they are located just anterior to action and perception systems, inferior and dorsolateral prefrontal, and anterior temporal and parahippocampal cortex, respectively, are particularly well-suited for housing XOR neurons operating on actions and perceptions. The extraction of complex action and perception features is proposed as a critical component of the brain basis of abstract semantic processing.(9)

1.   F. Pulvermüller, Behavioral and Brain Sciences 22,253-336 (1999).

2.   F. Pulvermüller, M. Härle, F. Hummel, NeuroReport 11, 2789-2793 (2000).

3.   B. Neininger, F. Pulvermüller, Neuropsychologia 41, 53-70 (2003).

4.   O. Hauk, I. Johnsrude, F. Pulvermüller, Neuron 41, 301-307 (2004).

5.   Y. Shtyrov, O. Hauk, F. Pulvermüller, European Journal of Neuroscience 19, 1083-92 (2004).

6.   F. Pulvermüller, O. Hauk, V. V. Nikulin, R. J. Ilmoniemi, European Journal of Neuroscience 21, 793-7 (2005).

7.   F. Pulvermüller, Nature Reviews Neuroscience 6, 576-582 (2005).

8.   T.H. Bak et al., Brain 129, 321-32(2006).

9.   F. Pulvermüller, O. Hauk, Cerebral Cortex16, 1193-201 (2006).