Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.


Psychological and Brain Sciences

Committee Chair

Lyle, Keith B.

Author's Keywords

Saccades; Saccade-induced retrieval enhancement; SIRE; Memory retrieval


Saccadic eye movements; Memory


Multiple studies have found that performing repetitive saccades for 30 s improves subsequent memory retrieval. Although the effect is well established, the mechanism by which saccades affect retrieval is currently unknown. Saccade-induced retrieval enhancement (SIRE) has been hypothesized to be a product of increasing: interaction between the hemispheres, interaction within the hemispheres, or attentional control. It is currently unknown which components of the saccade activity are necessary to produce SIRE. The saccade activity in previous SIRE research is similar to an orienting activity that produces predictive saccades. Predictive saccades begin as exogenous orienting to a rhythmically alternating target. After a few repetitions, the pattern is learned and saccades are endogenously guided by memory instead of by the visual onset of the target. The goal of Experiment 1 was to determine whether purely endogenous or exogenous orienting to a target without a predictable location produces SIRE on a paired-associates test. Neither type of orienting improved retrieval relative to fixating on a stationary point. Only the saccade activity used in previous research, which may have produced predictive saccades, improved performance. None of the theoretical accounts of SIRE can fully accommodate this pattern of results. An additional component of the standard saccade activity is that attention and the eyes move simultaneously. However, attention can also be shifted covertly, without moving the eyes. The goal of Experiment 2 was to determine whether overt orienting is necessary for retrieval enhancement. Neither covert orienting nor saccades improved retrieval relative to fixation. Differences between the novel orienting activities in Experiment 1 and the standard saccade activity are discussed in relation to the cortical activity that has previously been associated with these activities. The implications of these results for the various theoretical accounts of SIRE are also discussed.