The REME scores still increased. The eyes appeared to “know” what the correct answer should be, even though the subject did not consciously return the correct answer. By “know,” I really mean that the neural regions were directing the eyes. At some level, the brain was aware of the correct answer all along. For whatever reason, the organ did not return the correct answer to the subject. It means that accurate memory retriev-al was evident in eye movement behavior even when the subject’s judgment was incorrect.
This is a bombshell of a finding. Even if the subject was unable to recall a learned relationship between the face and the background, it appeared that the eyes and the hippocampus retained some of the information. And the eyes still responded correctly. At the very least, these data demonstrate that something beyond the hippocampus is required to make a previously encountered memory conscious.
These results suggest other ways to measure hippocampal memory formation that don’t depend on the subject’s conscious reporting. What other brain regions might be needed? The clue may come from the differential communication with the PFC. The connections between cortex and hippocampus became far less lively when the subject made a mistake. Because the PFC is involved in decision-making processes, its recruitment is hardly a surprising find. The intriguing decrease was not expected, however. It suggests new experimental directions in attempting to understand what the brain goes through when mistakes are being made.
One has to be careful of data like these, of course. One factor not controlled for in these studies is whether the subjects were conscious of the correct selection at the same time their eyes lingered on the matching face. They may have been aware of the correct choice, but in the intervening brief time between seeing the picture and selecting a face, they second-guessed themselves.
That’s hardly a deal killer. The real contribution of this work is to show that there are other ways of retrieving accurate information than direct interrogation of the witness.
And that has some powerful implications, especially for law enforcement professionals. Hooked up to these machines, you as a witness may indeed be confronted with a lineup of suspects who may have fired the gun in the bar. Your conscious recollection is just as fuzzy as ever, and you report that you cannot positively ID anybody. Your eyes (unbeknown to you) are consistently drawn to the actual perpetrator, however, revealing the correct version of the event. The machine detects this and the perpetrator, in the face of overwhelming technological superiority, breaks down and confesses. Sound like a fantasy? In the future, that may only be true of the perpetrator’s reaction.