Biomedical subjects

Casey DeBuse

Publications and source records attributed to Casey DeBuse.

3 recordsLinked to original sources

PubMed2007

Conflict and criterion setting in recognition memory.

Recognition memory requires both retrieval processes and control processes such as criterion setting. Decision criteria were manipulated by offering different payoffs for correct "old" versus "new" responses. Criterion setting influenced the following late-occurring (1,000+ ms), conflict-sensitive event-related brain potential (ERP) components: the stimulus-locked late posterior negativity (LPN) and the response-locked error-related negativity (ERN). The LPN-ERN were most negative to hits under conservative payoff conditions involving conflict between the correct old response and the payoff for new responses. This same conservative-hit condition was most frequently associated with response reversals when fast initial judgments were followed by slower judgments. Postresponse ERP activity may index conflict-sensitive processes underlying postretrieval cognitive control mechanisms involved with assessing responses to current items and updating response criteria on later trials.

Brain↗

PubMed2006

Combined pharmacological and electrophysiological dissociation of familiarity and recollection.

Dual-process theories of recognition memory hypothesize separate underlying familiarity and recollection processes, but the necessity of multiple processes is debated. Previous research has suggested that scalp-recorded event-related brain potentials (ERPs) may index the activity of separate familiarity and recollection processes. Other research indicates that the amnestic drug midazolam impairs recollection more than familiarity. Here, we used a convergent pharmacological and electrophysiological approach to manipulate and monitor human brain activity and provide evidence for separate processes. Midazolam selectively influenced the putative ERP-correlate of recollection but not the putative ERP-correlate of familiarity. Under control conditions (saline), subjects' accuracy correlated with the recollection-related but not the familiarity-related ERP component, suggesting that recollection was dominant in driving memory. The opposite pattern was observed under midazolam administration, suggesting that when recollection fails, subjects may leverage familiarity to compensate. Thus, in contrast to perspectives holding that familiarity represents the default process, these results suggest that recollection was dominant until its impairment unveiled the influence of familiarity.

Adult↗

PubMed2005

An early electrophysiological response associated with expertise in letter perception.

Expertise with print is likely to optimize visual processes for recognizing characters of a familiar writing system. Although brain activations have been identified for words and letter strings in contrast with other stimuli, relatively little work has focused on the neural basis of single-letter perception. English readers and Chinese-English bilinguals participated in an ERP study and performed a 1-back identity judgment on Roman letters, Chinese characters, pseudofonts, and their string versions. The Chinese-English bilinguals showed an enhanced N170 for both Roman letters and Chinese characters relative to pseudofonts. For the non-Chinese readers, the N170 amplitude was larger for Roman letters relative to Chinese characters and pseudofonts. Our results suggest that changes in relatively early visual processes underlie expert letter perception.

Adult↗