My dissertation presents two lines of research that examine motivation-cognition interactions. The first focuses on the effects of gain and loss incentive on attentional performance in young and older adults, examines which aspects of attention/cognitive control may be most sensitive to incentive manipulations, and takes steps towards elucidating the cognitive-motivational states and traits that may mediate those effects. When monetary incentives were offered throughout the experiments, they tended to have no effect or a small beneficial effect on the focused attention of young adults, and decreased young adults’ subjective reports of mind-wandering. In contrast, older adults had worse performance and more mind-wandering under incentive, especially loss incentive. Monetary incentives offered in alternating runs reduced the overall performance of both young and older adults compared to groups for which incentive was not offered at all, whereas within the alternating-run groups, performance was worse on the runs without incentive. Additional results from self-report measures suggest that for young adults, decreased performance under incentive may be the result of distraction. In contrast, older adults were more intrinsically motivated, and decreases in motivation under external incentive may underlie their reduced performance. In short, these results demonstrate that incentives may sometimes paradoxically reduce, rather than increase, performance, and that the direction and underlying mechanisms of incentive effects are influenced by factors including age (young vs old) and incentive structure (between- or within-subject manipulation).
The second line of research investigates how outcome probability and valence may influence learning as well as subsequent explicit memory. Participants first learned to associate scenes with wins or losses that occurred at high or low probability, with probability thought to influence the “motivational salience” of the scene. The task objective was to maximize the reward (points or points and money) earned in each trial, and the optimal choices are the high probability win scene and the low probability loss scene. Contrary to the common assumption that win and loss outcome associations are learned equally, win associations were learned better than loss associations, suggesting an advantage for learning outcomes with a positive valence. A subsequent recognition task assessed explicit knowledge of the learned value associations. Regardless of learning level or incentive conditions, memory for the association between a scene and its valence and motivational salience was superior for scenes that had previously been the optimal choice (high probability win and low probability loss). However. accurate recognition was significantly better for optimal win scenes than optimal loss scenes. These findings indicate that learning to select the optimal choice is dissociable from explicit knowledge about the outcome contingencies, especially for loss and low probability outcomes. Moreover, motivational salience is represented differentially in explicit memory for win and loss outcomes.
Together, this research examines several common assumptions about incentives and motivation in attention, learning, and memory in previous research studies, and demonstrates that the effects are more complex than currently realized. The discussion considers the implications for understanding the mechanisms underlying incentive effects on different types of cognition, as well as the effects of incentive in everyday life.PHDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/146000/1/ziyong_1.pd
