However, it is not clear how any such learned avoidance could produce the patterns of PCEs and NCEs shown in Experiment 2. In order for the NCE to be absent – perhaps due to motor selleck screening library processes
becoming weaker when unused, or due to tonic inhibition of responses in the alien hand – we would also expect the PCE to be similarly absent or reduced, which was not the case. Alternatively, perhaps learned avoidance resulted in a general difficulty in using the alien hand, especially when the stimulus primes a response in the opposite hand. This could contribute to affordance effects reported in Experiment 1 and the PCE in Experiment 2, but would also have been expected to generalise to spatial congruency effects, which was not supported by our data. Nevertheless, the best way to test for learned avoidance behaviour in AHS would be to follow a patient longitudinally from before diagnosis to discover whether such
effects emerge after the alien limb symptoms. While this was not possible with the patient reported in this paper because we did not assess her at the time of the very earliest symptoms, it may be a fruitful avenue for future research. Third, one Silmitasertib ic50 could argue that the absent NCE in the alien hand does not reflect absent automatic inhibition, and instead that the primed responses were so strongly activated that the (intact) inhibitory mechanisms were insufficient to prevent the primed response being executed. For this to explain the absent NCE in the alien hand, we would also have expected a larger PCE over the earliest RT bins compared to the non-alien hand (which was not the case here, see Fig. 5). Fourth, Adenosine triphosphate one could suggest that differences in stimulus presentation between the short- and long-SOA conditions in the masked priming task could have affected responses. For example, perhaps the delay between the mask and target in the long SOA condition may have allowed for better attentional disengagement
from the preceding mask relative to the short SOA condition. Such attentional disengagement would be expected to speed responses when SOAs were long. Similarly, perhaps crowding or flanking effects from the mask would have lengthened RTs to targets in the short SOA trials (where masks and targets were presented simultaneously) relative to the long SOA trials. Again, this would be expected to produce a global slowing of RT in the short SOA condition. However, both of these global effects on RT would not be expected to differentially affect compatible and incompatible trials, or left and right targets, so they cannot account for the observed effects reported here. Finally, perhaps differences in affordance and masked priming effects across the hands in Patient SA occurred by chance, and are not related to her neurological condition.