Bilateral eye movements enhance the retrieval of episodic memories.

Abstract

Two experiments examining effects of eye movements on episodic memory retrieval are reported. Thirty seconds of horizontal saccadic eye movements (but not smooth pursuit or vertical eye movements) preceding testing resulted in selective enhancement of episodic memory retrieval for laboratory (Experiment 1) and everyday (Experiment 2) events. Eye movements had no effects on implicit memory. Eye movements were also associated with more conservative response biases relative to a no eye movement condition. Episodic memory improvement induced by bilateral eye movements is hypothesized to reflect enhanced interhemispheric interaction, which is associated with superior episodic memory (S. D. Christman & R. E. Propper, 2001). Implications for neuropsychological mechanisms underlying eye movement desensitization and reprocessing (F. Shapiro, 1989, 2001), a therapeutic technique for posttraumatic stress disorder, are discussed.

Eye movements enhance memory for individuals who are strongly right-handed and harm it for individuals who are not

“…Given evidence that baseline hemispheric interaction is less in SR than in nSR individuals (Cowell et al, 1993;Habib et al, 1991;Witelson, 1985), the present results are partially supportive of the theory that eye movements enhance retrieval by increasing hemispheric interaction (Christman et al, 2003), because that theory predicts that eye movements should benefit SR individuals more than nSR individuals. This prediction was borne out: SR subjects benefited from eye movements on several measures, whereas nSR subjects benefited on none.…”

“…If eye movements enhance retrieval by increasing hemispheric interaction (Christman et al, 2003), then the manipulation should differentially affect groups that differ in baseline interaction. A group with less interaction, like SR individuals, may benefit from eye movements more than a group with greater interaction, like nSR individuals, because members of the former group have a larger margin for increases in interaction.…”

“…In one, subjects performed up-down/vertical eye movements, instead of left-right/horizontal ones, to determine whether both types of saccade enhance retrieval, or only horizontal ones. Christman et al's (2003) hemispheric interaction account assumes that only horizontal saccades increase bihemispheric activation and hence only they should enhance retrieval. In past research, the effect of vertical saccades on recognition has been mixed: In Parker and Dagnall (2007), they produced accuracy that did not differ from that for no movement and was significantly lower than that for horizontal movements, but, in duced numerically higher d .…”

The efficacy and psychophysiological correlates of dual-attention tasks in eye movement desensitization and reprocessing (EMDR)

“…Research has also shown that saccadic EMs have greater effects on memory processing over smooth pursuit EMs (Christman et al, 2003), but research is yet to examine to what extent different EM tasks create saccadic movements during EMDR. Future research should also examine how much these aspects of dual-attention tasks relate to EMDR treatment outcome.…”

Neurobiology and Stochastic Resonance: Going Deeper

“…EMs generate an increase in the vividness of episodic memory retrieval and expansion of association networks (Christman, Garvey, Propper, & Phaneuf, 2003) following 30 seconds of horizontal saccadic eye movements (but not smooth pursuit or vertical eye movements). 2.…”