Pupil dilation: a fingerprint of temporal selection during the "Attentional Blink"

ARIEL ZYLBERBERG; MANUEL OLIVA; MARIANO SIGMAN

Frontiers in Psycology

Frontiers

Año: 2012 p. 316 - 316

1664-1078

Pupil dilation indexes cognitive eventsof behavioral relevance, like thestorage of information to memory and the deployment of attention. Yet, given the slow temporal response of the pupil ilation, it is not known from  previous studies whether the pupil can index cognitive events in the short time scale of ~100ms. Here we measured the size of the pupil in the Attentional Blink (AB) experiment, a classic demonstration of attentional limitations in processing rapidly presented stimuli. In the AB, two targets embedded in a sequence have to be reported and the second stimulus is of ten missed if presented between 200 and 500 ms after the first. We show that pupil dilation can beused as a marker of cognitive processingin AB, revealing both the timing and amount of cognitive processing. Specifically, we found that in the time range where the AB is known to occur: (i) the pupil dilation was delayed, mimicking the pattern of response times in the Psychological Refractory Period (PRP) paradigm, (ii) the amplitude of the pupil was reduced relative to that of larger lags, even for correctly identified targets, and (iii) theamplitude of thepupil was smaller for missed tan for correctly reported targets. These results support two-stage  theories of the Attentional Blink where a second processing stage is delayed inside the interference regime, and indicate that the pupil dilation can be used as a marker of cognitive processing in the time scale of ~100ms. Furthermore, given the known relation between the pupil dilation and the activity of the locus coeruleus, our results also support theories that link the serial stage to the action of a specific neuromodulator, norepinephrine.