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Recent Submissions

Representation of linguistic information determines its susceptibility to memory interference
(MDPI, 2013-08-08) Fernandes, Myra A.; Wammes, Jeffrey D.; Hsiao, Janet H.
We used the dual-task paradigm to infer how linguistic information is represented in the brain by indexing its susceptibility to retrieval interference. We measured recognition memory, in bilingual Chinese-English, and monolingual English speakers. Participants were visually presented with simplified Chinese characters under full attention, and later asked to recognize them while simultaneously engaging in distracting tasks that required either phonological or visuo-spatial processing of auditorily presented letters. Chinese speakers showed significantly greater memory interference from the visuo-spatial than phonological distracting task, a pattern that was not present in the English group. Such a pattern suggests that retrieval of simplified Chinese characters differentially requires visuo-spatial processing resources in Chinese speakers; these are compromised under dual-task conditions when such resources are otherwise engaged in a distracting task. In a secondary analysis, we showed the complementary pattern in a group of English speakers, whose memory for English words was disrupted to a greater degree from the phonological than visuo-spatial distracting task. Together, these results suggest the mode of representation of linguistic information can be indexed behaviorally by susceptibility to retrieval interference that occurs when representations overlap with resources required in a competing task.
Long-term working memory deficits after concussion: Electrophysiological evidence
(Taylor & Francis, 2013-07-22) Ozen, Lana; Itier, Roxane J.; Preston, Frank F.; Fernandes, Myra A.
Background: Persistent complaints of lingering memory and concentration difficulties are common following a concussion, although the brain basis of these is unknown. Some suggest abnormalities can be found on the P300 event-related potential component, recorded using electroencephalography (EEG), despite unobservable cognitive impairments. Objective: To examine the P300 and cognitive performance following a remote concussion during an n-back task that varies in working memory load. Research design: Seventeen participants with a remote concussion and 17 controls performed a visual n-back task in which working memory demands were systematically increased by manipulating cognitive load. Participants also completed neuropsychological and self-report measures. Results: The concussion group showed a decrease in P300 amplitude compared to controls that was independent of working memory load on the n-back task. While no performance differences were observed between groups, P300 amplitude was negatively correlated with response times at higher loads in both groups. Conclusion: High functioning young adults with a remote concussion may have inefficient recruitment of processing resources for target identification, evident by the attenuated P300. The negative correlations between response time and P300 amplitude suggest that the time necessary to accurately respond to targets increases as the efficiency of allocating processing resources decreases during highly demanding working memory tasks.
Alpha Meals: Using Cognitive Psychology to Boost Restaurant Server Performance
(Sage, 2013-05-29) Fernandes, Myra A.; Miller, Ethan; Michela, John L.
Past research suggests that our ability to recall information increases when atypical items are presented within otherwise homogeneous sets. We investigated whether this effect applied to performance on practical, everyday tasks. In a computer-simulated restaurant scenario, participants acted as virtual servers, delivering “plates of food orders” to tables set up in different “rooms.” Plate destination was communicated using either a distinctive alphanumeric code or a homogeneous numeric code, both of which indicated the room and table number for delivery of food orders. We examined accuracy of plate delivery when two (low load) or three (high load) coded assignments were given per delivery trial. As expected, performance declined from the low- to high-load condition. Importantly, performance declined less with alphanumeric compared with all-numeric communication of assignments. Results suggest that increasing the distinctiveness of assignments, by using alphanumeric codes, can boost performance in real-life situations to significantly improve memory-related task performance, particularly when cognitive load is taxed.
Source-constrained retrieval influences the encoding of new information
(Springer, 2011-06-07) Danckert, Stacey L.; MacLeod, Colin M.; Fernandes, Myra A.
Jacoby, Shimizu, Daniels, and Rhodes (Psychonomic Bulletin & Review, 12, 852–857, 2005) showed that new words presented as foils among a list of old words that had been deeply encoded were themselves subsequently better recognized than new words presented as foils among a list of old words that had been shallowly encoded. In Experiment 1, by substituting a deep-versus-shallow imagery manipulation for the levels-of-processing manipulation, we demonstrated that the effect is robust and that it generalizes, also occurring with a different type of encoding. In Experiment 2, we provided more direct evidence for context-related encoding during tests of deeply encoded words, showing enhanced priming for foils presented among deeply encoded targets when participants made the same deep-encoding judgments on those items as had been made on the targets during study. In Experiment 3, we established that the findings from Experiment 2 are restricted to this specific deep judgment task and are not a general consequence of these foils being associated with deeply encoded items. These findings provide support for the source-constrained retrieval hypothesis of Jacoby, Shimizu, Daniels, and Rhodes: New information can be influenced by how surrounding items are encoded and retrieved, as long as the surrounding items recruit a coherent mode of processing.
Effects of "Diagnosis Threat" on Cognitive and Affective Functioning Long After Mild Head Injury
(Cambridge University Press, 2010-12-08) Ozen, Lana; Fernandes, Myra A.
Persistent cognitive complaints are common following a mild head injury (MHI), but deficits are rarely detected on neuropsychological tests. Our objective was to examine the effect of symptom expectation on self-report and cognitive performance measures in MHI individuals. Prior research suggests that when MHI participants are informed they may experience cognitive difficulties, they perform worse on neuropsychological tests compared to MHI participants who are uninformed. In this study, undergraduate students with and without a prior MHI were either informed that the study's purpose was to investigate the effects of MHI on cognitive functioning ("diagnosis threat" condition) or merely informed that their cognitive functioning was being examined, with no mention of status ("neutral" condition). "Diagnosis threat" MHIs self-reported more attention failures compared to "diagnosis threat" controls and "neutral" MHIs, and more memory failures compared to "diagnosis threat" controls. In the "neutral" condition, MHIs reported higher anxiety levels compared to controls and compared to "diagnosis threat" MHIs. Regardless of condition, MHIs performed worse on only one neuropsychological test of attention span. "Diagnosis threat" may contribute to the prevalence and persistence of cognitive complaints made by MHI individuals found in the literature, but may not have as strong of an effect on neuropsychological measures.