Publications by authors named "Alex Konkel"

Many theories of episodic memory posit that the subjective experience of recollection may be driven by the activation of stimulus-specific cortical regions during memory retrieval. This study examined cortical activation during associative memory retrieval to identify brain regions that support confidence judgments of source memory in stimulus-specific ways. Adjectives were encoded with either a picture of a face or a scene.

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Adaptively biasing recognition judgments in light of environmental cues improves net accuracy. Based on previous work suggesting that strategically shifting biases on a trial-wise basis should be cognitively demanding, the authors predicted that older adults would not achieve the same accuracy benefits from environmental cues as the young. However, despite showing clear declines in cognitive control as indexed by complex span, older adults demonstrated similar accuracy gains and similar alterations of response probabilities with cues of 75% reliability (Experiment 1) and more complex cues spanning 3 levels of reliability (Experiment 2).

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The role of lateral parietal cortex during recognition memory is heavily debated. We examined parietal activation during an Explicit Memory Cueing recognition paradigm that biases participants towards expecting novel or familiar stimuli on a trial-by-trial basis using anticipatory cues ("Likely Old", "Likely New"), compared to trials with neutral cues ("????"). Three qualitatively distinct patterns were observed in the left lateral parietal cortex.

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Because children are becoming overweight, unhealthy, and unfit, understanding the neurocognitive benefits of an active lifestyle in childhood has important public health and educational implications. Animal research has indicated that aerobic exercise is related to increased cell proliferation and survival in the hippocampus as well as enhanced hippocampal-dependent learning and memory. Recent evidence extends this relationship to elderly humans by suggesting that high aerobic fitness levels in older adults are associated with increased hippocampal volume and superior memory performance.

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Since the discovery of the importance of the hippocampus for normal memory, considerable research has endeavored to characterize the precise role played by the hippocampus. Previously we have offered the relational memory theory, which posits that the hippocampus forms representations of arbitrary or accidentally occurring relations among the constituent elements of experience. In a recent report we emphasized the role of the hippocampus in all manner of relations, supporting this claim with the finding that amnesic patients with hippocampal damage were similarly impaired on probes of memory for spatial, sequential, and associative relations.

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Relational memory theory holds that the hippocampus supports, and amnesia following hippocampal damage impairs, memory for all manner of relations. Unfortunately, many studies of hippocampal-dependent memory have either examined only a single type of relational memory or conflated multiple kinds of relations. The experiments reported here employed a procedure in which each of several kinds of relational memory (spatial, associative, and sequential) could be tested separately using the same materials.

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New learning often interferes with the production of older, previously learned responses. However, the original responses usually appear to spontaneously recover and regain their dominance after a delay. This article takes a new approach to questions of interference and recovery by examining performance on immediate and delayed tests using direct or indirect instructions.

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