Cognitive Demands in Semantic Memory Retrieval
Pupillometry as a measure of the task- evoked cognitive load has been used in a myriad of studies over the past 20 years. Pupils diameter change is an autonomic reaction that occurs as a response to light, emotional stimuli, or high task demands. The modulations in the pupil constriction and dilation are driven by the locus coeruleus–norepinephrine system activity (Van der Wel & Van Steenbergen, 2018). A series of research have demonstrated the effect of pupil dilation as a consequence of higher cognitive effort. For example, retrieving taxonomically low-related word pairs yielded higher pupil dilation and cognitive load, as opposed to low and high semantically-related word pairs (Geller, Landrigan, & Mirman, 2019). Furthermore, overcoming automatic or dominant responses to provide a more appropriate response has shown a similar effect. In tasks like Go/No-Go or Stroop task, participants’ pupils exhibited a higher diameter on No-Go trials, as well as on incongruent Stroop task trials (Van der Wel & Van Steenbergen, 2018). This research is the first to address the cognitive demands pertaining to inhibition in semantic memory retrieval. Our goal is to assess whether the same effect as in previous research will be observed while the individuals generate free associations (the first related word that “pops” into the subject’s mind) as opposed to dissociation tasks since dissociative tasks are expected to yield a higher cognitive effort, due to inhibitory processes being utilized to suppress automatic associative responses.
In this study we used a within-subject research design, meaning that the same subjects were exposed to all conditions, with retrieval condition (A vs D) as independent variable, response time, intrusion, and pupil diameter as dependent variables. The participants were presented auditory verbal stimuli, to which they responded orally. The intrusion was detected through self-report measures, while pupil size was recorded using eye- trackers. We hypothesize that the retrieval condition exerting the demands on inhibition in dissociative tasks will yield higher latency and wider pupil diameter, compared to easy retrieval and control. As for intrusion, we hypothesize that it will be more often present on dissociative trials that have a high potency (strong associations to a single word), as opposed to those with low potency (many probable associations).
After excluding data of insufficient accuracy of measurement we have observed longer RT and more intrusions in dissociation than association trials, as predicted.
 P. van der Wel, H. van Steenbergen, “Pupil dilation as an index of effort in cognitive control task: a Review” Psychonomic Bulletin & Review vol.35 no. 25 pp. 2005–2015 2018
 L. Geller, J-F. Landrigan, D. Mirman “A Pupillometric Examination of Cognitive Control in Taxonomic and Thematic Semantic Memory.,” Journal of Cognition vol. 2 no. 1 pp. 6–6 2019