When order matters: last-come first-served effect in sequential arithmetic operations.
Cognitive psychologists have relied on dual-task interference experiments to understand the low-capacity and serial nature of conscious mental operations. Two widely studied paradigms, the Attentional Blink (AB) and the Psychological Refractory Period (PRP) have demonstrated a first-come first-served policy; processing a stimulus either impedes conscious access (AB) or postpones treatment (PRP) of a concurrent stimulus. Here we explored the transition from dual-task paradigms to multi-step human cognition. We studied the relative weight of individual addends in a sequential arithmetic task, where number notation (symbolic/non-symbolic) and presentation speed were independently manipulated. For slow presentation and symbolic notation, the decision relied almost equally on all addends, whereas for fast or non-symbolic notation, the decision relied almost exclusively on the last item reflecting a last-come first-served policy. We suggest that streams of stimuli may be chunked in events in which the last stimuli may override previous items from sensory buffers.
Laboratory of Integrative Neuroscience, Physics Department, FCEyN UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires, Argentina. arielz@df.uba.ar
Ariel
A
Zylberberg
Juan E
JE
Kamienkowski
Andres R
AR
Farall
Mariano
M
Sigman
D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D006801:Humans; D008433:Mathematics