Memory of Learning Facilitates Saccadic Adaptation in the Monkey

“Two rhesus monkeys (Macaca mulatta, male; 4.5 and 6.8 kg) were prepared for eye movement recording by the magnetic search coil method (Fuchs and Robinson, 1966).”

“The oculo - motor vermis and the fastigial oculomotor region ( FOR ) of the cerebellum have been shown to be key players in saccadic adap - tation ( Optican and Robinson , 1980 ; Takagi et al .”

“Adaptive changes in saccade amplitude were induced by a conventional intrasaccadic target step paradigm (McLaughlin, 1967).”

“The oculomotor vermis and the fastigial oculomotor region (FOR) of the cerebellum have been shown to be key players in saccadic adaptation (Optican and Robinson, 1980; Takagi et al., 1998; Barash et al., 1999; Scudder, 2002; Inaba et al., 2003; Scudder and McGee, 2003).”

“Recent results describe a previously unrecognized form of long-term potentiation in the cerebellar cortex (Lev-Ram et al., 2002) and a synaptic depotentiation in the hippocampus (Montgomery and Madison, 2002).”

“This is because the saccadic gain (saccade amplitude divided by target eccentricity) is constantly recalibrated by a learning mechanism called saccadic adaptation (for review, see Hopp and Fuchs, 2004).”

“The oculomotor vermis and the fastigial oculomotor region (FOR) of the cerebellum have been shown to be key players in saccadic adaptation (Optican and Robinson, 1980; Takagi et al., 1998; Barash et al., 1999; Scudder, 2002; Inaba et al., 2003; Scudder and McGee, 2003).”

“In the subsequent recovery block, the cortical plasticity decreases back to and possibly beyond the preadaptation level, as has been suggested for the extinction of eye blink conditioning (Medina et al., 2001), but the nuclear plasticity remains potentiated.”

“There is good evidence that saccadic adaptation is a form of motor learning driven by visual error immediately after the end of saccades (Wallman and Fuchs, 1998; Shafer et al., 2000; Noto and Robinson, 2001).”

“Adaptation is fairly specific to the amplitude and direction of adapted saccades and does not generalize fully to those with different vectors (Straube et al., 1997; Wallman and Fuchs, 1998; Noto et al., 1999; Watanabe et al., 2000).”

“This phenomenon has been observed in a wide range of paradigms (Rescorla, 2004;Kojima et al., 2004;Stollhoff et al., 2005).”

“A recent model 79 based on this idea of temporal credit assignment can account for a number of phenomena that are related to reach movement adaptation to perturbations as well as saccadic adaptation 98 .”

“observed in their saccade adaptation experiment following a period of darkness [3].”