Encoding ability is preserved in amnesia: evidence from a direct test of encoding.
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 containing 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 presentation 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 not long-term memory in the amnesics indicating that it depended largely on encoding and short-term memory. However, the amnesics were impaired in the 25-sec condition where performance should have depended on (long-term) memory abilities at which they were impaired. The results are inconsistent with available encoding deficit accounts of amnesia.
Mayes
A R
AR
Department of Psychology, University of Manchester, U.K.
Downes
J J
JJ
Shoqeirat
M
M
Hall
C
C
Sagar
H J
HJ
D000328:Adult; D000368:Aged; D000647:Amnesia / Q000523:psychology*; D001288:Attention; D001925:Brain Damage, Chronic / Q000523:psychology*; D003118:Color Perception; D003210:Concept Formation; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D009949:Orientation; D010364:Pattern Recognition, Visual; D011930:Reaction Time; D012153:Retention, Psychology; D012660:Semantics; D014888:Wechsler Scales