Abstract
In the present EEG study we investigated whether semantic knowledge for object use is represented in motor-related brain areas. Subjects were required to perform actions with everyday objects and to maintain either a meaningful or a meaningless end posture with the object. Analysis of the EEG data focused on the beta-frequency band, as previous studies have indicated that the maintenance of a posture is reflected in stronger beta-oscillations. Time frequency analysis indicated that the execution of actions resulting in a meaningless compared to a meaningful end posture was accompanied by a stronger beta-desynchronization towards the end of the movement and a stronger subsequent beta-rebound after posture-onset. The effect in the beta-frequency band was localized to premotor, parietal and medial frontal areas and could not be attributed to differences in timing or movement complexity between meaningful and meaningless actions. Together these findings directly show that the motor system is differentially activated during the execution and maintenance of semantically correct or incorrect end postures. This suggests that semantic object knowledge is indeed represented in motor-related brain areas, organized around specific end postures associated with the use of objects.
Highlights
By brushing your teeth twice a day, at the age of 30 you have brought a toothbrush towards your mouth for more than 20,000 times! given that on average people drink about three cups of coffee a day and assuming that it takes 10 sips to empty a cup, the number of times that you have brought a cup towards your mouth exceeds the 150,000! These numbers illustrate that throughout our lives we have profound experience with using objects
time frequency representation (TFR) RESULTS DURING MOVEMENT PREPARATION AND EXECUTION As can be seen in Figure 4, the onset of the picture cue resulted in a gradual suppression in both the mu power (8–12 Hz; mu ERD) and the beta power (16–24 Hz; beta ERD) that was found maximal around the time of object grasping
TFR RESULTS DURING THE POSTURE INTERVAL As can be seen in Figure 5, the onset of the end posture with the object resulted in a gradual increase in beta power (16–24 Hz; post-movement beta rebound) that reached its maximum around 1500 ms after termination of the movement
Summary
By brushing your teeth twice a day, at the age of 30 you have brought a toothbrush towards your mouth for more than 20,000 times! given that on average people drink about three cups of coffee a day and assuming that it takes 10 sips to empty a cup, the number of times that you have brought a cup towards your mouth exceeds the 150,000! These numbers illustrate that throughout our lives we have profound experience with using objects. By brushing your teeth twice a day, at the age of 30 you have brought a toothbrush towards your mouth for more than 20,000 times! Given that on average people drink about three cups of coffee a day and assuming that it takes 10 sips to empty a cup, the number of times that you have brought a cup towards your mouth exceeds the 150,000! The importance of conceptual knowledge for action planning is especially apparent in neuropsychological patients showing specific deficits in object-directed actions. Patients with semantic dementia are often impaired in using objects in a correct fashion (e.g. using a remote control as a telephone; Hodges et al, 2000). These patient studies indicate that object use can be impaired at different levels and suggest that different brain areas are involved in using objects meaningfully
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
