**3.11 Motor components (RP, LRP, MP, RAP)**

402 Neuroimaging – Cognitive and Clinical Neuroscience

**3.10 Error-Related Negativity (ERN) and Feedback Error-Related Negativity (fERN)**  The ERN is a component observed 50 to 100 ms after a response characterized as being of high conflict in which a dominant response is inconsistent with respect to the correct response (Hohnsbein, Falkenstein and Hoormann, 1995 and others). The ERN is an index for the general sensitivity of the conflict monitoring system, which can be used to predict successful patterns of control (Yeung, Botvinick, and Cohen, 2004). Feedback error-related negativity (fERN) has been referred to as a negative deflection in the event-related potential (ERP), which distinguishes between wins/losses or correct/error trials in terms of expected and unexpected outcomes (e.g., San Martin et al., 2010). In correct (ERN) or win trials (fERN), similar components have been named Correct Related Negativity (CRN) and

Fig. 2. Motor potential (MP and RAP) modulated by compatibility with semantic stimuli. A) Verbal stimuli used in an action-sentence compatibility paradigm. B) Participants' open- and close-hand responses. C) Scalp topography of the motor response at baseline, zero-time response and 200 ms after the response. D) Motor potential (MP and RAP) modulated by the compatibility between the participant motor responses (open or close) and the semantic stimuli (sentences containing open- or close-hand actions). Modified from Aravena et al., 2010. The movement-related cortical potentials (MRCP) associated with self-paced movements are considered to be a measure of motor cortex excitability and allow the exploration of cortical changes related to motor preparation and execution. The readiness potential (RP, or in its original German name, Bereitschaftspotential) precedes voluntary muscle movement and represents the cortical contribution to the pre-motor planning of volitional movement. The RP was first described in 1964 by Hans Helmut Kornhuber and Lüder Deecke. The lateralized readiness potential (LRP) is a particular form of RP in response to certain movements of one side (left or right) of the body. Being related to RP, another negativity measured over Cz beginning shortly before the response onset (-90 ms) has been named the motor potential (MP) or late motor-related potential (late MRP; Aravena et al., 2010). The MP is likely to represent pyramidal neuron activity in the primary cortex (M1) at motor execution. MP amplitude modulation has been associated with the rapidness and precision of movement and also with short-term training effects. Finally, another component with a peak over Cz after movement onset (200-300 ms) has been named the re-afferent potential (RAP). RAP is an index of movement-related sensory feedback to the primary sensorymotor cortex and is considered an indicator of attention (Aravena et al., 2010, see Figure 2).
