Title

Effects of encoding and retrieval on bimanual rhythmic coordination

Date of Completion

January 2002

Keywords

Psychology, Experimental

Degree

Ph.D.

Abstract

In 4 experiments, bimanual 1:1 rhythmic coordination was performed at the same time as encoding and/or retrieval and with manipulanda that produced equal or different preferred left and right frequencies. Effects of divided attention (DA) on coordination were indexed by changes in mean relative phase and its variability compared to coordination without memory activity. Effects of DA on memory were indexed by deficits in recall relative to memory activity (encoding or retrieving) without coordination. Experiments 1 and 2 found shifts in the equilibrium value of relative phase for DA at encoding to-be-remembered words and DA at retrieving those words, respectively, and a recall deficit that was larger for DA at encoding. Experiment 3 found shifts in coordination equilibria and recall deficits for DA during a semantic memory task, the retrieving of category members. Experiment 4 examined the effect of DA at timing relations of 2:1 and 3:1 between the coupled frequency and the encoding or retrieval pace on the assumption that DA might interact with “resonance constraints.” Relative phase was affected most by DA at retrieval in the less-stable 3:1 mode. In all experiments, DA effects on relative phase were restricted to the detuned condition of unequal left and right preferred frequencies and always included increases in variability as measured by recurrence quantification techniques. Results were discussed in terms of conventional resource limitation models of DA and alternative models based in dynamical systems theory. ^