Det finns olika metoder som kan användas för att komma ihåg instuderat material. Det har visats att resultatet på ett minnestest förbättras avsevärt om man under inlärning har testats på instuderat material, jämfört med att enbart ha studerat materialet utan testning, detta kallas testeffekten. Syftet med föreliggande studie var att undersöka hur viktigt svarsformatet är för testeffekten där 38 försöksdeltagare fick studera 48 ordpar för att sedan bli testade vid två olika tillfällen (efter 5 minuter respektive 1 vecka). Svarsformatet manipulerades vid både inlärning (covert/overt) och slutlig testning, enligt teorin om transfer-appropriate processing (kongruent/inkongruent). Resultatet visade en signifikant huvudeffekt av svarsformat, sådan att overt framplockning ledde till bättre minnesprestation än covert framplockning. Kongruensen mellan svarsformaten vid inlärning respektive slutlig testning (TAP) gav inga signifikanta effekter. Möjliga förklaringar till resultatet, och de slutsatser som kan dras därav, diskuteras.

Source memory is defined as memory for not only the core aspect of some event, but additional contextual detail about that core aspect, or item. Source memory tasks are marked by their engagement of prefrontal cortex in addition to the brain circuits required by other episodic memory tasks. The dissertation examines the relationships among source memory accuracy, concurrent brain activity, and general cognitive principles derived from the study of episodic memory more generally. Electrical measures of brain activity (event-related potentials, ERPs) were recorded while manipulating factors hypothesized to improve or worsen source memory accuracy.The first experiment manipulated the task assigned during the encoding phase and its match to the retrieval demands of remembering objects (depicted in drawings) and their colors. As predicted by the principle of transfer-appropriate processing, source accuracy was higher when the encoding task fostered integration of the item (object) and source (color) attributes. Prefrontal activity during the retrieval phase was greatly reduced when retrieval could benefit from transfer-appropriate processing.In associative memory tasks, poor memory performance is observed when the to-be-retained stimuli share elements with other studied stimuli, as in a variety of interference paradigms. The second experiment thus examined the impact of feature overlap on source recognition by varying the quantitative mapping between the shape and color of an object depicted in a drawing. The results showed two frontal processes supporting source retrieval: an early differentiation between stimuli identical to those encoded and those that switch colors from study to test, and a later effect reflecting prolonged memory search that was truncated by reinstating unique object-color pairings at test.The final experiment compared conjunctions of "intra-item" versus "extra-item" features, by placing the features within a single visual object or distributing them across two visual objects. Source accuracy was worse when shape and color were spatially separated, but prefrontal activity did not vary. The insensitivity of prefrontal ERPs to this perceptual manipulation of difficulty stands in contrast to their sensitivity to encoding task. Individual variability in parietal ERPs was strongly correlated with source accuracy, and likely reflects a contribution of visual working memory to long-term memory.

Transfer-appropriate processing (TAP) proposes that retrieval success is based on the match between processing at encoding and retrieval. We propose that the processing described by TAP determines the contextual cues that are encoded with an event. At retrieval, the presence or absence of contextual cues matching the encoding cues will influence success. To implement these principles as a strategy to improve memory, the nature of future retrieval processing or cues must be known during encoding. As this is unlikely in real-world memory function, we propose that increased encoding variability – increasing the range of encoded cues – increases the likelihood of TAP when the retrieval scenario is unknown. The larger the set of encoded cues, the more likely those cues will recur during retrieval and therefore achieve TAP. Preliminary research in our lab (Diana, unpublished data) has found that increased encoding variability improves memory for item information in a novel retrieval context. To test whether this benefit to memory is due to the increased likelihood of TAP, the current experiment compared the effects of encoding variability under conditions that emphasize TAP to conditions that reduce TAP. We found main effects of encoding variability and TAP, but no interaction between the two. Planned comparisons between high and low variability encoding contexts within matching and non-matching retrieval contexts did not produce a significant difference between high and low variability when encoding-retrieval processing matched. We conclude that further studies are necessary to determine whether encoding variability has mechanisms that benefit memory beyond TAP. / M.S. / It is well accepted within the episodic memory literature that successful memory retrieval is often driven by context cues. Specifically, the cues that are stored with the memory of the event. To develop a better understanding of how episodic memory works, we must understand how manipulating context cues changes memory performance. One way to investigate the effects of context manipulation is using encoding variability, which refers to the amount of variability (i.e., change) in context cues from one repetition of an item or event, to the next. Preliminary research in our lab (Diana, unpublished data) has found that increased encoding variability improves memory retrieval in a novel context, but it is unclear why this is the case. We proposed that the mental processing described by transfer-appropriate processing (TAP) – a principle stating that memory retrieval success is determined by the match, or overlap, between the mental processing at encoding (i.e., memory formation) and memory retrieval – determines the contextual cues that are stored with the memory at encoding. We hypothesized that encoding variability works even when TAP has already been achieved by matching the processing and cues at encoding to those at retrieval. Alternatively, we hypothesized that encoding variability works by specifically achieving TAP, so that encoding variability is only helpful when the encoding and retrieval contexts do not match. Results indicated partial support for the alternative hypothesis, suggesting that encoding variability works by achieving TAP. However, these results were not sufficiently conclusive, and it is likely that there are other mechanisms that allow for encoding variability to improve memory. This study establishes the groundwork for future work examining encoding variability and its effects on memory.

The current project is an examination of the effectiveness of decision-support graphics in a simulated real-world task, and of the role those graphics should play in training. It is also an attempt to apply a theoretical account of memory performance-transfer-appropriate processing-to naturalistic decision making. The task in question is a low-fidelity air traffic control simulation. In some conditions, that task includes decision-support graphics designed to explicitly represent elements of the task that normally must be mentally represented-namely, trajectory and relative altitude. The assumption is that those graphics will encourage a type of processing different from that used in their absence. If so, then according to the theory of transfer-appropriate processing (TAP), the best performance should occur in conditions in which the graphics are present either during both training and testing, or else not at all. For other conditions, the inconsistent presence or absence of the graphics should lead to mismatches in the type of processing used during training and testing, thus hurting performance. A sample of 205 undergraduate students were randomly assigned to four experimental and two control groups. The results showed that the support graphics provided immediate performance benefits, regardless of their presence during training. However, presenting them during training had an apparent overshadowing effect, in that removing them during testing significantly hurt performance. Finally, although no support was found for TAP, some support was found for the similar but more general theory of identical elements.

The current project is an examination of the effectiveness of decision-support graphics in a simulated real-world task, and of the role those graphics should play in training. It is also an attempt to apply a theoretical account of memory performance-transfer-appropriate processing-to naturalistic decision making. The task in question is a low-fidelity air traffic control simulation. In some conditions, that task includes decision-support graphics designed to explicitly represent elements of the task that normally must be mentally represented-namely, trajectory and relative altitude. The assumption is that those graphics will encourage a type of processing different from that used in their absence. If so, then according to the theory of transfer-appropriate processing (TAP), the best performance should occur in conditions in which the graphics are present either during both training and testing, or else not at all. For other conditions, the inconsistent presence or absence of the graphics should lead to mismatches in the type of processing used during training and testing, thus hurting performance. A sample of 205 undergraduate students were randomly assigned to four experimental and two control groups. The results showed that the support graphics provided immediate performance benefits, regardless of their presence during training. However, presenting them during training had an apparent overshadowing effect, in that removing them during testing significantly hurt performance. Finally, although no support was found for TAP, some support was found for the similar but more general theory of identical elements.