Motivated exercise (1) also starts in the PFC and the formulation of the performance goal. The formulation of the goal to be executed represents the top level of Dietrich’s [
70] hierarchical organization of consciousness and is localized to the dorsolateral part of the PFC [
72] while the MFC drives incentivized action selection [
73]. Anticipatory increases in performance anxiety/arousal [
135,
136] removes cortical override and upregulates the (2a) BCC and the (2b) BSC [
131,
132] independent of afferent feedback [
10,
44]. The BSC, located rostro-caudally from the (3) hypothalamus to the (4) midbrain, upregulates the skeletomotor, visceromotor and secretomotor systems [
132] during motivated behaviour via the release of a host of neurotransmitters and hormones [
136]. Specifically, the skeletomotor system is up-regulated via (4) midbrain DA neurons that release DA into the (5) striatum, thereby modulating the (6) striatal DA and ACh activities. These DA and ACh modulation changes facilitate the excitatory glutamatergic goal-directed drive in the continually updating (7) cortico-basoganglionic-thalamo-cortical circuits. These facilitated circuits serve to disinhibit both the motor cortex—with concomitant increase in (8) skeletal muscle recruitment—and (9) the PPT and CnF nuclei in the brainstem thereby upregulating locomotion, postural muscle tone and balance via the (9a) RS activation of the CPGs in the spine. This would serve to match the activity in the CPGs with the increase in (8) corticomotoneuronal recruitment of skeletal muscle. Increases in exercise intensity result in increases in homeostatic disturbances in the muscle and in afferent feedback, which lead to (10) increases in the RPE [
165]. Continual (11) cost : benefit analyses relative to the performance goal will up- or down regulate the DA release into the striatum and modulate the DA and ACh activities, and with it (12) the RPE. Additionally, (13) SIA [see Sect.
11] will also up- or down regulate the RPE.
ACh acetylcholine,
BCC behavioural control column,
BSC behavioural state controller,
CnF cuneiform,
CPGs central pattern generators,
DA dopamine,
MFC medial frontal cortex,
PFC pre-frontal cortex,
PPT pedunculopontine tegmental,
RPE ratings of perceived exertion,
RS reticulo-spinal tract,
SIA stress-induced analgesia,
SNc substantia nigra pars compacta, + indicates excitatory glutamate, − indicates inhibitory GABA