The encoding ability of 17 amnesics of mixed aetiology and 17 matched
normal controls was assessed directly using a novel procedure. On two
separate occasions, subjects were shown 60 complex drawings each conta
ining six pictures. On one occasion each drawing was shown for 6 sec,
and on the other occasion it was shown for 25 sec. Immediately after p
resentation of each drawing subjects were asked a single unpredictable
question about picture colours, location, size or semantic category.
Amnesics performed normally in the 6-sec exposure condition indicating
that all of the tested kinds of information were encoded at a normal
rate. Performance in this condition correlated with short-term, but no
t long-term memory in the amnesics indicating that it depended largely
on encoding and short-term memory. However, the amnesics were impaire
d in the 25-sec condition where performance should have depended on (l
ong-term) memory abilities at which they were impaired. The results ar
e inconsistent with available encoding deficit accounts of amnesia.