Educators and psychologists have extolled the benefits of active learning techniques such as organizing material, self-explaining, learning through experience, and practicing retrieval for years. Underlying these strategies is the generation effect, an encoding phenomenon in which actively generating rather than passively learning information improves the subsequent retrieval of item information. Despite rather extensive analysis of the generation effect, the processes underlying it are not fully understood. Theories suggest that active generation increases cognitive effort, conceptual processing, item distinctiveness, and semantic processing. Further, generation has also been shown to have varying positive, negative and null effects for contextual features such as order, color, and spatial location, prompting tradeoff and transfer-appropriate processing accounts. This dissertation investigates the positive and negative effects of generation, the universality of the generation effect, and its underlying neural mechanisms. Further, these studies test various explanations of the generation effect, and a transfer-appropriate processing account is considered in detail.
In the first set of studies, I used five experiments to investigate the ways in which active generation can influence memory for item information, related item information, and contextual information. Employing synonym (e.g., ACADEMIC - SCH_L_R), antonym (e.g., question - a____), idiom (e.g., it's raining cats and ( )), picture, and category-exemplar (e.g., animal - c_t) generation tasks, the positive generation effect for item memory was generally robust, and persisted over long periods of retention and in the face of cognitive distraction. However, negative generation effects were found for font color memory, while null effects were found for background color and location memory. Further, generation was found to impair memory for related items and even the items themselves under certain circumstances.
The second set of studies investigated the degree to which the positive generation effect translates to participants in China, a country that stresses a Confucian rather than Socratic learning style reminiscent of active generation. To address memory for contextual details in a culture that processes information in a field-dependent rather than field-independent manner as in the United States, we also examined the effect of generation on color and spatial location. American and Chinese participants read or generated idioms (e.g., it's raining cats and ( ); 倾家荡( )) presented in different colors or locations, and were tested for item and context memory. For both groups, generation improved item memory. However, American individuals exhibited a negative generation effect only for color memory, while Chinese individuals exhibited negative effects for both color and location memory. These experiments demonstrate the universality of the positive generation effect and the first negative generation effect for location memory to my knowledge.
Finally, I explored the neural basis of the generation effect in an fMRI study. During encoding, participants read or generated synonyms from cues (e.g., GARBAGE - W_ST_). Again, compared to simply reading target words, generating target words significantly improved later recognition memory performance. During encoding, this benefit was associated with a broad neural network that involved both prefrontal (inferior frontal gyrus, middle frontal gyrus) and posterior cortex (inferior temporal gyrus, lateral occipital cortex, parahippocampal gyrus, ventral posterior parietal cortex). These results leave open the possibility that active generation increases attention and cognitive effort (prefrontal and posterior cortical activation), conceptual and semantic processing (IFG and MTG), and item distinctiveness (LOC and ACC).
Overall, active generation proved to be a powerful encoding strategy, engaging a wide range of cognitive processes and broad networks of neural activity. Seemingly an almost effortless task, generation enhanced item memory for various stimuli under several conditions. However, active generation had limitations, as it impaired both item and context memory in certain situations. I propose that a transfer-appropriate processing account in which active generation promotes conceptual processing and reduces perceptual processing, ultimately enhancing memory for item information, impairing memory for intrinsic contextual information, and ignoring memory for extrinsic contextual information, best accounts for this pattern of positive and negative generation effects.
