The Experts below are selected from a list of 99282 Experts worldwide ranked by ideXlab platform
Gregory Mccarthy - One of the best experts on this subject based on the ideXlab platform.
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opposing influences of emotional and non emotional distracters upon sustained prefrontal cortex activity during a delayed response working memory task
Neuropsychologia, 2008Co-Authors: Florin Dolcos, Paul Diazgranados, Lihong Wang, Gregory MccarthyAbstract:Performance in delayed-response working memory (WM) tasks is typically associated with sustained activation in the dorsolateral prefrontal cortex (dlPFC) that spans the delay between the Memoranda and the memory probe. Recent studies have demonstrated that novel distracters presented during the delay interval both affect sustained activation and impair WM performance. However, the effect of the performance-impairing distracters upon sustained dlPFC delay activity was related to the characteristics of the distracters: Memoranda-confusable distracters increased delay activity, whereas Memoranda-nonconfusable emotional distracters decreased delay activity. Because these different effects were observed in different studies, it is possible that different dlPFC regions were involved and the paradox is more apparent than real. To investigate this possibility, event-related fMRI data were recorded while subjects performed a WM task for faces with Memoranda-confusable (novel faces) and Memoranda-nonconfusable emotional (novel scenes) distracters presented during the delay interval. Consistent with previous findings, confusable face distracters increased dlPFC delay activity, while nonconfusable emotional distracters decreased dlPFC delay activity, and these opposing effects modulated activity in the same dlPFC regions. These results provide direct evidence that specific regions of the dlPFC are generally involved in mediating the effects of distraction, while showing sensitivity to the nature of distraction. These findings are relevant for understanding alterations in the neural mechanisms associated with both general impairment of cognitive control and with specific impairment in the ability to control emotional distraction, such as those observed in aging and affective disorders, respectively.
Benjamin J. Tamber-rosenau - One of the best experts on this subject based on the ideXlab platform.
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Reevaluating the sensory recruitment model by manipulating crowding in visual working memory representations
Psychonomic Bulletin & Review, 2020Co-Authors: Harun Yörük, Lindsay A. Santacroce, Benjamin J. Tamber-rosenauAbstract:The prominent sensory recruitment model argues that visual working memory (WM) is maintained via representations in the same early visual cortex brain regions that initially encode sensory stimuli, either in the identical neural populations as perceptual representations or in distinct neural populations. While recent research seems to reject the former (strong) sensory recruitment model, the latter (flexible) account remains plausible. Moreover, this flexibility could explain a recent result of high theoretical impact (Harrison & Bays, The Journal of Neuroscience, 38 (12), 3116-3123, 2018 ) – a failure to observe interactions between items held in visual WM – that has been taken to reject the sensory recruitment model. Harrison and Bays ( The Journal of Neuroscience, 38 (12), 3116-3123, 2018 ) tested the sensory recruitment model by comparing the precision of Memoranda in radially and tangentially oriented memory arrays. Because perceptual visual crowding effects are greater in radial than tangential arrays, they reasoned that a failure to observe such anisotropy in WM would reject the sensory recruitment model. In the present Registered Report or Replication, we replicated their study with greater sensitivity and extended their task by controlling a potential strategic confound. Specifically, participants might remap memory items to new locations, reducing interactions between proximal Memoranda. To combat remapping, we cued participants to report either a memory item or its precise location – with this report cue presented only after a memory maintenance period. Our results suggest that, similar to visual perceptual crowding, location-bound visual Memoranda interact with one another when remapping is prevented. Thus, our results support at least a flexible form of the sensory recruitment model.
Ezequiel Morsella - One of the best experts on this subject based on the ideXlab platform.
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Metacognition of Working Memory Performance: Trial-by-Trial Subjective Effects from a New Paradigm
Frontiers in Psychology, 2016Co-Authors: Andrew C. Garcia, Sabrina Bhangal, Anthony G. Velasquez, Mark W. Geisler, Ezequiel MorsellaAbstract:Investigators have begun to examine the fleeting urges and inclinations that subjects experience when performing tasks involving response interference and working memory. Building on this research, we developed a paradigm in which subjects, after learning to press certain buttons when presented with certain letters, are presented with two action-related letters (the Memoranda) but must withhold responding (4 s) until cued to emit the response associated with only one of the two letters. In the Congruent condition, the action corresponds to the cue (e.g., Memoranda = AB, cue = B, response = B); in the Incongruent condition, the action corresponds to the other item of the Memoranda (e.g., Memoranda = AB, cue = B, response = A). After each trial, subjects inputted a rating regarding their subjectively experienced “urge to err” on that trial. These introspection-based data revealed that, as found in previous research, urges to err were strongest for incongruent trials. Our findings reveal, first, that subjects can successfully perform this new task, even though it is more complex than that of previous studies, and second, that, in this new paradigm, reliable subjective, metacognitive data can be obtained on a trial-by-trial basis. We hope that our novel paradigm will serve as a foundation for future experimental projects on the relationship between working memory performance and consciousness—an under-explored nexus whose investigation is likely to reveal insights about working memory, cognitive control, and metacognition.
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Subjective aspects of working memory performance: Memoranda-related imagery.
Consciousness and Cognition, 2014Co-Authors: Tiffany K. Jantz, Jessica J. Tomory, Christina Merrick, Shanna Cooper, Adam Gazzaley, Ezequiel MorsellaAbstract:Although it is well accepted that working memory (WM) is intimately related to consciousness, little research has illuminated the liaison between the two phenomena. To investigate this under-explored nexus, we used an imagery monitoring task to investigate the subjective aspects of WM performance. Specifically, in two experiments, we examined the effects on consciousness of (a) holding in mind information having a low versus high memory load, and (b) holding Memoranda in mind during the presentation of distractors (e.g., visual stimuli associated with a response incompatible with that of the Memoranda). Higher rates of rehearsal (conscious imagery) occurred in the high load and distractor conditions than in comparable control conditions. Examination of the temporal properties of the rehearsal-based imagery revealed that, across subjects, imagery events occurred evenly throughout the delay. We hope that future variants of this new imagery monitoring task will reveal additional insights about WM, consciousness, and action control.
Vanessa M. Loaiza - One of the best experts on this subject based on the ideXlab platform.
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Where working memory meets long-term memory: The interplay of list length and distractors on memory performance.
Journal of Experimental Psychology: Learning Memory and Cognition, 2019Co-Authors: Vanessa M. Loaiza, Sindre C. HalseAbstract:Previous work regarding a counterintuitive benefit of increasing distractors on episodic long-term memory (LTM) has suggested that retrieval of Memoranda in working memory (WM) after attention has been distracted may confer benefits to episodic LTM. The current study investigated 2 conceptions of how this may occur: either as an attentional refreshing of active Memoranda within the focus of attention or as retrieval of a cohesive chunk of Memoranda from outside the central component of WM. Given the literature suggesting that increasing the number of items to maintain in WM, or list length, incurs an attentional cost, the current study investigated whether increasing list length may reduce the beneficial impact of distractors on episodic LTM. In a series of three experiments, we manipulated list length and the number of distractors following the Memoranda in a Brown-Peterson-like-span task. Despite profound negative effects of list length and distractors on initial recall, the results indicated that list length did not interact with the beneficial effect of distractors on final free recall of the items. Furthermore, final free recall was consistent across serial position, in line with the view that all of the Memoranda are retrieved as a chunk after each distractor. These findings emphasize the notion that recovering inactive information from outside of the central component of WM may impact its long-term retention. The theoretical implications regarding how retrieval may be a means by which LTM processes influence WM are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?
Advances in Cognitive Psychology, 2016Co-Authors: Vanessa M. Loaiza, Valérie CamosAbstract:The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented Memoranda in red or blue font that were immediately followed by two processing words that matched the Memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the Memoranda before a cue to recall them from WM. Participants also completed delayed recall of the Memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects.
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Long-term semantic representations moderate the effect of attentional refreshing on episodic memory
Psychonomic Bulletin & Review, 2014Co-Authors: Vanessa M. Loaiza, Kayla A. Duperreault, Matthew G. Rhodes, David P. MccabeAbstract:The McCabe effect (McCabe, Journal of Memory and Language 58:480-494, 2008) refers to an advantage in episodic memory (EM) retrieval for Memoranda studied in complex span versus simple span tasks, particularly for Memoranda presented in earlier serial positions. This finding has been attributed to the necessity to refresh Memoranda during complex span tasks that, in turn, promotes content-context binding in working memory (WM). Several frameworks have conceptualized WM as being embedded in long-term memory. Thus, refreshing may be less efficient when Memoranda are not well-established in long-term semantic memory (SM). To investigate this, we presented words and nonwords in simple and complex span trials in order to manipulate the long-term semantic representations of the Memoranda with the requirement to refresh the Memoranda during WM. A recognition test was administered that required participants to make a remember-know decision for each memorandum recognized as old. The results replicated the McCabe effect, but only for words, and the beneficial effect of refreshing opportunities was exclusive to recollection. These results extend previous research by indicating that the predictive relationship between WM refreshing and long-term EM is specific to recollection and, furthermore, moderated by representations in long-term SM. This supports the predictions of WM frameworks that espouse the importance of refreshing in content-context binding, but also those that view WM as being an activated subset of and, therefore, constrained by the contents of long-term memory.
John T. Serences - One of the best experts on this subject based on the ideXlab platform.
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Separating Memoranda in depth increases visual working memory performance
Journal of Vision, 2019Co-Authors: Chaipat Chunharas, Rosanne L. Rademaker, Thomas C. Sprague, Timothy F. Brady, John T. SerencesAbstract:Visual working memory is the mechanism supporting the continued maintenance of information after sensory inputs are removed. Although the capacity of visual working memory is limited, Memoranda that are spaced farther apart on a 2-D display are easier to remember, potentially because neural representations are more distinct within retinotopically organized areas of visual cortex during memory encoding, maintenance, or retrieval. The impact on memory of spatial separability in depth is less clear, even though depth information is essential to guiding interactions with objects in the environment. On one account, separating Memoranda in depth may facilitate performance if interference between items is reduced. However, depth information must be inferred indirectly from the 2-D retinal image, and less is known about how visual cortex represents depth. Thus, an alternative possibility is that separation in depth does not attenuate between-items interference; it may even impair performance, as attention must be distributed across a larger volume of 3-D space. We tested these alternatives using a stereo display while participants remembered the colors of stimuli presented either near or far in the 2-D plane or in depth. Increasing separation in-plane and in depth both enhanced performance. Furthermore, participants who were better able to utilize stereo depth cues showed larger benefits when Memoranda were separated in depth, particularly for large memory arrays. The observation that spatial separation in the inferred 3-D structure of the environment improves memory performance, as is the case in 2-D environments, suggests that separating Memoranda in depth might reduce neural competition by utilizing cortically separable resources.
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Separating Memoranda in depth increases visual working memory performance
2018Co-Authors: Chaipat Chunharas, Rosanne L. Rademaker, Thomas C. Sprague, Timothy F. Brady, John T. SerencesAbstract:Visual working memory is the mechanism supporting the continued maintenance of information after sensory inputs are removed. Although the capacity of visual working memory is limited, Memoranda that are spaced farther apart on a 2D display are easier to remember, potentially because neural representations are more distinct within retinotopically-organized areas of visual cortex during memory encoding, maintenance, and/or retrieval. The impact of spatial separability in depth on memory is less clear, even though depth information is essential to guide interactions with objects in the environment. On one account, separating Memoranda in depth may facilitate performance if interference between items is reduced. However, depth information must be inferred indirectly from the 2D retinal image, and less is known about how visual cortex represents depth. Thus, an alternative possibility is that separation in depth does not attenuate between-item interference; separation in depth may even impair performance, as attention must be distributed across a larger volume of 3D space. We tested these alternatives using a stereo display while participants remembered the colors of stimuli presented either near or far in the 2D plane or in depth. Increasing separation in-plane and in depth both enhanced performance. Furthermore, participants who were better able to utilize stereo depth cues showed larger benefits when Memoranda were separated in depth, particularly for large memory arrays. The observation that spatial separation in the inferred 3D structure of the environment improves memory performance, as is the case in 2D environments, suggests that separating Memoranda in depth might reduce neural competition by utilizing cortically separable resources.
