1
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Zhao YJ, Zhang X, Ku Y. Divergent roles of early visual cortex and inferior frontal junction in visual working memory. Brain Stimul 2024; 17:713-720. [PMID: 38839040 DOI: 10.1016/j.brs.2024.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 05/31/2024] [Accepted: 06/02/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND Recent studies indicate that both prefrontal and visual regions play critical roles in visual working memory (VWM), with prefrontal regions mainly associated with executive functions, and visual cortices linked to representations of memory contents. VWM involves the selective filtering of irrelevant information, yet the specific contributions of the prefrontal regions and visual cortex in this process remain unclear. OBJECTIVE To understand the dynamic causal roles of prefrontal and visual regions in VWM. METHODS The differentiation of VWM components was achieved using a computational model that incorporated a swap rate for non-target stimuli. Single-pulse magnetic transcranial stimulation (spTMS) was delivered to the early visual cortex (EVC) and the inferior frontal junction (IFJ) across different phases of an orientation recall task that with or without distractors. RESULTS Our results indicate that spTMS over the EVC and IFJ influences VWM particularly when distractors are present. VWM precision can be impacted by spTMS applied to either region during the early retention, while spTMS effect is especially prominent when EVC is stimulated during the late retention phase and when directed at the ipsilateral EVC. Conversely, the probability of accurately recalling the target exhibited comparable patterns when spTMS was administered to either the EVC or IFJ. CONCLUSIONS We highlight the "sensory recruitment" of VWM characterized by critical involvement of EVC particularly in the information-filtering process within VWM. The maintenance of memory content representations necessitates ongoing communication between the EVC and IFJ throughout the entirety of the VWM process in a dynamic pattern.
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Affiliation(s)
- Yi-Jie Zhao
- Clinical Research Center for Mental Disorders, Shanghai Pudong New Area Mental Health Center, School of Medicine, Tongji University, Shanghai, China
| | - Xinying Zhang
- School of Psychology and Cognitive Science, East China Normal University, Shanghai, China; Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Yixuan Ku
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Department of Psychology, Sun Yat-sen University, Guangzhou, China; Peng Cheng Laboratory, Shenzhen, China.
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2
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Barton AU, Valle-Inclán F, Cowan N, Hackley SA. Unconsciously registered items reduce working memory capacity. Conscious Cogn 2022; 105:103399. [PMID: 36108591 DOI: 10.1016/j.concog.2022.103399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 08/09/2022] [Accepted: 08/09/2022] [Indexed: 01/27/2023]
Abstract
The assumption that the contents of consciousness correspond to those of working memory (WM) is challenged by evidence that stimuli masked from awareness can be retained for several seconds (Soto et al., 2011; Bergström & Eriksson, 2015). To assess whether conscious and unconscious items compete in a unitary WM store we conducted an experiment in which some of the memory items in an array were masked from conscious sight using continuous flash suppression (CFS) while others remained visible. After a retention interval, participants decided whether the probed item (either masked or visible) had changed its orientation. Behavioral results indicated that change detection for visible items was significantly impaired when masked items were present, suggesting that masked items either displaced or reduced the precision of visible items in WM. However, change detection for masked items was at chance levels, indicating that these items were not stored. The unsuccessful attempt to encode them may have drawn upon a common pool of attentional resources needed to retain or retrieve visible items. Contralateral Delay Activity, an EEG index of net WM load, failed to temporally localize this interference.
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Affiliation(s)
- Amy U Barton
- Northwest Missouri State University, United States.
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3
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Sensory recruitment in visual short-term memory: A systematic review and meta-analysis of sensory visual cortex interference using transcranial magnetic stimulation. Psychon Bull Rev 2022; 29:1594-1624. [PMID: 35606595 DOI: 10.3758/s13423-022-02107-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2022] [Indexed: 11/08/2022]
Abstract
Sensory visual areas are involved in encoding information in visual short-term memory (VSTM). Yet it remains unclear whether sensory visual cortex is a necessary component of the brain network for maintenance of information in VSTM. Here, we aimed to systematically review studies that have investigated the role of the sensory visual cortex in VSTM using transcranial magnetic stimulation (TMS) and to quantitatively explore these effects using meta-analyses. Fourteen studies were identified and reviewed. Eight studies provided sufficient data for meta-analysis. Two meta-analyses, one regarding the VSTM encoding phase (17 effect sizes) and one regarding the VSTM maintenance phase (15 effect sizes), two meta-regressions (32 effect sizes in each), and one exploratory meta-analysis were conducted. Our results indicate that the sensory visual cortex is similarly involved in both the encoding and maintenance VSTM phase. We suggest that some cases where evidence did not show significant TMS effects was due to low memory or perceptual task demands. Overall, these findings support the idea that sensory visual areas are part of the brain network responsible for successfully maintaining information in VSTM.
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4
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Beynel L, Appelbaum LG, Luber B, Crowell CA, Hilbig SA, Lim W, Nguyen D, Chrapliwy NA, Davis SW, Cabeza R, Lisanby SH, Deng ZD. Effects of online repetitive transcranial magnetic stimulation (rTMS) on cognitive processing: A meta-analysis and recommendations for future studies. Neurosci Biobehav Rev 2019; 107:47-58. [PMID: 31473301 PMCID: PMC7654714 DOI: 10.1016/j.neubiorev.2019.08.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/28/2019] [Accepted: 08/22/2019] [Indexed: 01/03/2023]
Abstract
Online repetitive transcranial magnetic stimulation (rTMS), applied while subjects are performing a task, is widely used to disrupt brain regions underlying cognition. However, online rTMS has also induced "paradoxical enhancement". Given the rapid proliferation of this approach, it is crucial to develop a better understanding of how online stimulation influences cognition, and the optimal parameters to achieve desired effects. To accomplish this goal, a quantitative meta-analysis was performed with random-effects models fitted to reaction time (RT) and accuracy data. The final dataset included 126 studies published between 1998 and 2016, with 244 total effects for reaction times, and 202 for accuracy. Meta-analytically, rTMS at 10 Hz and 20 Hz disrupted accuracy for attention, executive, language, memory, motor, and perception domains, while no effects were found with 1 Hz or 5 Hz. Stimulation applied at and 10 and 20 Hz slowed down RTs in attention and perception tasks. No performance enhancement was found. Meta-regression analysis showed that fMRI-guided targeting and short inter-trial intervals are associated with increased disruptive effects with rTMS.
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Affiliation(s)
- Lysianne Beynel
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Lawrence G Appelbaum
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Bruce Luber
- Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Courtney A Crowell
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Susan A Hilbig
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Wesley Lim
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Duy Nguyen
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Nicolas A Chrapliwy
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Simon W Davis
- Department of Neurology, Duke University School of Medicine, Durham, NC, United States
| | - Roberto Cabeza
- Center for Cognitive Neuroscience, Duke University, Durham, NC, United States
| | - Sarah H Lisanby
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States; Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Zhi-De Deng
- Departments of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, United States; Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States.
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5
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Hilbert S, McAssey M, Bühner M, Schwaferts P, Gruber M, Goerigk S, Taylor PCJ. Right hemisphere occipital rTMS impairs working memory in visualizers but not in verbalizers. Sci Rep 2019; 9:6307. [PMID: 31004125 PMCID: PMC6474855 DOI: 10.1038/s41598-019-42733-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 04/04/2019] [Indexed: 01/26/2023] Open
Abstract
Distinguishing between verbal and visual working memory processes is complicated by the fact that the strategy used is hard to control or even assess. Many stimuli used in working memory tasks can be processed via verbal or visual coding, such as the digits in the digit span backwards task (DSB). The present study used repetitive transcranial magnetic stimulation (rTMS) to examine the use of visual processing strategies in the DSB. A total of 47 German university students took part in the study, 23 spontaneously using a verbal processing strategy and 24 using a visual strategy. After rTMS to the right occipital cortex, visualizers showed a significantly stronger mean performance decrease compared to verbalizers. The results indicate that the visual cortex is more critical for visualizers compared to verbalizers in the DSB task. Furthermore, the favored processing modality seems to be determined by the preference for a cognitive strategy rather than the presentation modality, and people are aware of the applied strategy. These findings provide insight into inter-individual differences in working memory processing and yield important implications for laboratory studies as well as clinical practice: the stimulus does not necessarily determine the processing and the participant can be aware of that.
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Affiliation(s)
- Sven Hilbert
- Faculty of Psychology, Educational Science, and Sport Science, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Michaela McAssey
- Department of Neurology, University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neuroscience, Research Training Group 2175, Ludwig-Maximilians-University, Leopoldstraße 13, 80802, München, Germany
| | - Markus Bühner
- Department of Psychology, Psychological Methods and Assessment, LMU Munich, Leopoldstraße 13, 80802, München, Germany
| | - Patrick Schwaferts
- Institute of Statistics, Methodological Foundations of Statistics and its Applications, Ludwigstraße 33, 80539, München, Germany
| | - Monika Gruber
- Department of Psychology, Psychological Methods and Assessment, LMU Munich, Leopoldstraße 13, 80802, München, Germany
| | - Stephan Goerigk
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Nußbaumstraße 7, 80336, Munich, Germany
- Hochschule Fresenius, University of Applied Sciences, Infanteriestraße 11A, 80797, Munich, Germany
| | - Paul Christopher John Taylor
- Department of Neurology, University Hospital, LMU Munich, Munich, Germany
- German Center for Vertigo and Balance Disorders, University Hospital, LMU Munich, Munich, Germany
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6
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Characterizing the Impact of Distracting Input on Visual Working Memory Representations. J Neurosci 2018; 38:10589-10591. [PMID: 30541768 DOI: 10.1523/jneurosci.1969-18.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/19/2018] [Accepted: 10/23/2018] [Indexed: 11/21/2022] Open
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7
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Widhalm ML, Rose NS. How can transcranial magnetic stimulation be used to causally manipulate memory representations in the human brain? WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2018; 10:e1469. [DOI: 10.1002/wcs.1469] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 04/21/2018] [Accepted: 05/14/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Morgan L. Widhalm
- Department of Psychology University of Notre Dame Notre Dame Indiana
| | - Nathan S. Rose
- Department of Psychology University of Notre Dame Notre Dame Indiana
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8
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Gayet S, Paffen CLE, Van der Stigchel S. Visual Working Memory Storage Recruits Sensory Processing Areas. Trends Cogn Sci 2017; 22:189-190. [PMID: 29050827 DOI: 10.1016/j.tics.2017.09.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 09/15/2017] [Accepted: 09/21/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Surya Gayet
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
| | - Chris L E Paffen
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
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9
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Abstract
In complex environments, there are costs to both ignorance and perception. An organism needs to track fitness-relevant information about its world, but the more information it tracks, the more resources it must devote to perception. As a first step towards a general understanding of this trade-off, we use a tool from information theory, rate-distortion theory, to study large, unstructured environments with fixed, randomly drawn penalties for stimuli confusion ('distortions'). We identify two distinct regimes for organisms in these environments: a high-fidelity regime where perceptual costs grow linearly with environmental complexity, and a low-fidelity regime where perceptual costs are, remarkably, independent of the number of environmental states. This suggests that in environments of rapidly increasing complexity, well-adapted organisms will find themselves able to make, just barely, the most subtle distinctions in their environment.
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Affiliation(s)
- Sarah E Marzen
- Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Redwood Center for Theoretical Neuroscience, and Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Simon DeDeo
- Department of Social and Decision Sciences, Carnegie Mellon University, 5000 Forbes Avenue, BP 208, Pittsburgh, PA 15213, USA
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
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10
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Rademaker RL, van de Ven VG, Tong F, Sack AT. The impact of early visual cortex transcranial magnetic stimulation on visual working memory precision and guess rate. PLoS One 2017; 12:e0175230. [PMID: 28384347 PMCID: PMC5383271 DOI: 10.1371/journal.pone.0175230] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 03/22/2017] [Indexed: 11/18/2022] Open
Abstract
Neuroimaging studies have demonstrated that activity patterns in early visual areas predict stimulus properties actively maintained in visual working memory. Yet, the mechanisms by which such information is represented remain largely unknown. In this study, observers remembered the orientations of 4 briefly presented gratings, one in each quadrant of the visual field. A 10Hz Transcranial Magnetic Stimulation (TMS) triplet was applied directly at stimulus offset, or midway through a 2-second delay, targeting early visual cortex corresponding retinotopically to a sample item in the lower hemifield. Memory for one of the four gratings was probed at random, and participants reported this orientation via method of adjustment. Recall errors were smaller when the visual field location targeted by TMS overlapped with that of the cued memory item, compared to errors for stimuli probed diagonally to TMS. This implied topographic storage of orientation information, and a memory-enhancing effect at the targeted location. Furthermore, early pulses impaired performance at all four locations, compared to late pulses. Next, response errors were fit empirically using a mixture model to characterize memory precision and guess rates. Memory was more precise for items proximal to the pulse location, irrespective of pulse timing. Guesses were more probable with early TMS pulses, regardless of stimulus location. Thus, while TMS administered at the offset of the stimulus array might disrupt early-phase consolidation in a non-topographic manner, TMS also boosts the precise representation of an item at its targeted retinotopic location, possibly by increasing attentional resources or by injecting a beneficial amount of noise.
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Affiliation(s)
- Rosanne L. Rademaker
- Psychology Department, University of California San Diego, San Diego, California, United States of America
- Cognitive Neuroscience Department, Maastricht University, Maastricht, The Netherlands
- * E-mail:
| | - Vincent G. van de Ven
- Cognitive Neuroscience Department, Maastricht University, Maastricht, The Netherlands
| | - Frank Tong
- Psychology Department, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Alexander T. Sack
- Cognitive Neuroscience Department, Maastricht University, Maastricht, The Netherlands
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11
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Chiau HY, Muggleton NG, Juan CH. Exploring the contributions of the supplementary eye field to subliminal inhibition using double-pulse transcranial magnetic stimulation. Hum Brain Mapp 2016; 38:339-351. [PMID: 27611342 DOI: 10.1002/hbm.23364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/22/2016] [Accepted: 08/22/2016] [Indexed: 11/09/2022] Open
Abstract
It is widely accepted that the supplementary eye fields (SEF) are involved in the control of voluntary eye movements. However, recent evidence suggests that SEF may also be important for unconscious and involuntary motor processes. Indeed, Sumner et al. ([2007]: Neuron 54:697-711) showed that patients with micro-lesions of the SEF demonstrated an absence of subliminal inhibition as evoked by masked-prime stimuli. Here, we used double-pulse transcranial magnetic stimulation (TMS) in healthy volunteers to investigate the role of SEF in subliminal priming. We applied double-pulse TMS at two time windows in a masked-prime task: the first during an early phase, 20-70 ms after the onset of the mask but before target presentation, during which subliminal inhibition is present; and the second during a late phase, 20-70 ms after target onset, during which the saccade is being prepared. We found no effect of TMS with the early time window of stimulation, whereas a reduction in the benefit of an incompatible subliminal prime stimulus was found when SEF TMS was applied at the late time window. These findings suggest that there is a role for SEF related to the effects of subliminal primes on eye movements, but the results do not support a role in inhibiting the primed tendency. Hum Brain Mapp 38:339-351, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Hui-Yan Chiau
- Institute of Cognitive Neuroscience, National Central University, Jhongli, Taiwan.,Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Neil G Muggleton
- Institute of Cognitive Neuroscience, National Central University, Jhongli, Taiwan.,Institute of Cognitive Neuroscience, University College London, London, United Kingdom.,Department of Psychology, Goldsmiths, University of London, New Cross, London, United Kingdom
| | - Chi-Hung Juan
- Institute of Cognitive Neuroscience, National Central University, Jhongli, Taiwan
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12
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Soto D, Silvanto J. Is conscious awareness needed for all working memory processes? Neurosci Conscious 2016; 2016:niw009. [PMID: 30109128 PMCID: PMC6084557 DOI: 10.1093/nc/niw009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/25/2016] [Accepted: 05/31/2016] [Indexed: 11/30/2022] Open
Abstract
Stein and colleagues argue there is no yet conclusive evidence for nonconscious working memory (WM) and that is critical to probe WM while ensuring null sensitivity to memory cues. While this stringent approach reduces the likelihood of nonconscious signaling for WM, we discuss existing work meeting this null sensitivity criteria, and, related work on nonconscious cognition in keeping with WM/awareness dissociations on the basis of a functional operational definition of WM. Further, because it is likely that WM is a nonunitary functional construct and visual awareness a gradual phenomenon, we propose that delineating the neural mechanisms for distinct WM types across different levels of awareness may prove the most fruitful approach for understanding the interplay between WM and consciousness.
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Affiliation(s)
- David Soto
- Basque Center on Cognition, Brain and Language, San Sebastian, Spain
- Basque Foundation for Science, Ikerbasque, Bilbao, Spain; and
| | - Juha Silvanto
- Department of Psychology, Faculty of Science and Technology, University of Westminster, London, UK
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13
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Non-invasive Human Brain Stimulation in Cognitive Neuroscience: A Primer. Neuron 2015; 87:932-45. [DOI: 10.1016/j.neuron.2015.07.032] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 06/07/2015] [Accepted: 07/16/2015] [Indexed: 11/21/2022]
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14
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Jacobs C, Silvanto J. How is working memory content consciously experienced? The 'conscious copy' model of WM introspection. Neurosci Biobehav Rev 2015; 55:510-9. [PMID: 26054793 DOI: 10.1016/j.neubiorev.2015.06.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 04/14/2015] [Accepted: 06/03/2015] [Indexed: 10/23/2022]
Abstract
We address the issue of how visual information stored in working memory (WM) is introspected. In other words, how do we become aware of WM content in order to consciously examine or manipulate it? Influential models of WM have suggested that WM representations are either conscious by definition, or directly accessible for conscious inspection. We propose that WM introspection does not operate on the actual memory trace but rather requires a new representation to be created for the conscious domain. This conscious representation exists in addition and in parallel to the actual memory representation. The existence of such a separate representation is revealed by and reflected in the qualitatively different functional characteristics between the actual memory trace and its conscious experience, and their distinct interactions within external visual input. Our model differs from state-based models in that WM introspection does not involve a change in the state of WM content, but rather involves the creation of a new, second representation existing in parallel to the original memory trace.
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Affiliation(s)
- Christianne Jacobs
- Department of Psychology, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, W1W 6UW London, UK.
| | - Juha Silvanto
- Department of Psychology, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, W1W 6UW London, UK.
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15
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Saad E, Wojciechowska M, Silvanto J. Partial dissociation in the neural bases of VSTM and imagery in the early visual cortex. Neuropsychologia 2015; 75:143-8. [PMID: 26026256 PMCID: PMC4542523 DOI: 10.1016/j.neuropsychologia.2015.05.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 05/22/2015] [Accepted: 05/25/2015] [Indexed: 11/23/2022]
Abstract
Visual short-term memory (VSTM) and visual imagery are believed to involve overlapping neuronal representations in the early visual cortex. While a number of studies have provided evidence for this overlap, at the behavioral level VSTM and imagery are dissociable processes; this begs the question of how their neuronal mechanisms differ. Here we used transcranial magnetic stimulation (TMS) to examine whether the neural bases of imagery and VSTM maintenance are dissociable in the early visual cortex (EVC). We intentionally used a similar task for VSTM and imagery in order to equate their assessment. We hypothesized that any differential effect of TMS on VSTM and imagery would indicate that their neuronal bases differ at the level of EVC. In the “alone” condition, participants were asked to engage either in VSTM or imagery, whereas in the “concurrent” condition, each trial required both VSTM maintenance and imagery simultaneously. A dissociation between VSTM and imagery was observed for reaction times: TMS slowed down responses for VSTM but not for imagery. The impact of TMS on sensitivity did not differ between VSTM and imagery, but did depend on whether the tasks were carried concurrently or alone. This study shows that neural processes associated with VSTM and imagery in the early visual cortex can be partially dissociated. Both VSTM and visual imagery are believed to involve early visual cortex (EVC). TMS was used to investigate whether their neural bases can be dissociated. TMS dissociated VSTM and imagery at the level of reaction times. No differences in the effect of TMS on task sensitivity.
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Affiliation(s)
- Elyana Saad
- Brain Research Unit, O.V. Lounasmaa Laboratory, School of Science, Aalto University, 00076 Espoo, Finland; Institute of Behavioral Sciences, University of Helsinki, 00014 Helsinki, Finland.
| | - Maria Wojciechowska
- Department of Biomedical Engineering and Computational Science BECS, Aalto University, 02150 Espoo, Finland
| | - Juha Silvanto
- Brain Research Unit, O.V. Lounasmaa Laboratory, School of Science, Aalto University, 00076 Espoo, Finland; Department of Psychology, Faculty of Science and Technology, University of Westminster, 309 Regent Street, London W1B 2HW, UK
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16
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Wildegger T, Myers NE, Humphreys G, Nobre AC. Supraliminal but not subliminal distracters bias working memory recall. J Exp Psychol Hum Percept Perform 2015; 41:826-39. [PMID: 25867502 PMCID: PMC4445384 DOI: 10.1037/xhp0000052] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Information of which observers are not consciously aware can nevertheless influence perceptual processes. Whether subliminal information might exert an influence on working memory (WM) representations is less clear, and relatively few studies have examined the interactions between subliminal and supraliminal information in WM. We present 3 experiments examining this issue. Experiments 1a and b replicated the finding that orientation stimuli can influence behavior subliminally in a visuomotor priming task. Experiments 2 and 3 used the same orientation stimuli, but participants had to remember a target orientation and report it back by adjusting a probe orientation after a memory delay. Before or after presentation of the target orientation, a subliminal or supraliminal distracter orientation was presented that was either irrelevant for task completion and never had to be reported (Experiment 2), or was relevant for task completion because it had to be reported on some trials (Experiment 3). In both experiments, presentation of a supraliminal distracter influenced WM recall of the target orientation. When the distracter was presented subliminally, however, there was no bias in orientation recall. These results suggest that information stored in WM is protected from influences of subliminal stimuli, while online information processing is modulated by subliminal information.
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Affiliation(s)
| | | | - Glyn Humphreys
- Department of Experimental Psychology, University of Oxford
| | - Anna C Nobre
- Department of Experimental Psychology, University of Oxford
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17
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Hsu TY, Tseng P, Liang WK, Cheng SK, Juan CH. Transcranial direct current stimulation over right posterior parietal cortex changes prestimulus alpha oscillation in visual short-term memory task. Neuroimage 2014; 98:306-13. [DOI: 10.1016/j.neuroimage.2014.04.069] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 04/11/2014] [Accepted: 04/23/2014] [Indexed: 11/25/2022] Open
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18
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Reappraising the relationship between working memory and conscious awareness. Trends Cogn Sci 2014; 18:520-5. [PMID: 25070269 DOI: 10.1016/j.tics.2014.06.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 05/27/2014] [Accepted: 06/16/2014] [Indexed: 11/22/2022]
Abstract
Classically, the operation of working memory (WM) has been strongly coupled with conscious states; it is thought that WM operates on conscious input and that we are conscious of the contents and operations of WM. Here, we re-evaluate the relationship between WM and conscious awareness in light of current data and question the views that awareness is mandatory for the operation of WM and that WM contents are necessarily linked to experiential states that are consciously accessible for perceptual report. We propose a novel framework for the relationship between WM and conscious awareness.
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Bona S, Silvanto J. Accuracy and confidence of visual short-term memory do not go hand-in-hand: behavioral and neural dissociations. PLoS One 2014; 9:e90808. [PMID: 24663094 PMCID: PMC3963844 DOI: 10.1371/journal.pone.0090808] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 02/04/2014] [Indexed: 11/18/2022] Open
Abstract
Currently influential models of working memory posit that memory content is highly accessible to conscious inspection. These models predict that metacognition of memory performance should go hand-in-hand with the accuracy of the underlying memory representation. To test this view, we investigated how visual information presented during the maintenance period affects VSTM accuracy and confidence. We used a delayed cue-target orientation discrimination task in which participants were asked to hold in memory a grating, and during the maintenance period a second memory cue could be presented. VSTM accuracy of the first memory cue was impaired when the orientation of the second memory cue was sufficiently different. However, participants' response confidence was reduced whenever the second memory cue was presented; thus VSTM accuracy and confidence were dissociated. In a second experiment, we applied transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (DLPFC) to investigate the causal role of this region in VSTM metacognition. Relative to the sham condition, anodal tDCS induced a general reduction in confidence ratings but did not affect VSTM accuracy. Overall, these results indicate that our metacognition of memory performance is influenced by factors other than the accuracy of the underlying memory representation.
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Affiliation(s)
- Silvia Bona
- Brain Research Unit, O.V. Lounasmaa Laboratory, School of Science, Aalto University, Espoo, Finland
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland
- Department of Behavioural Sciences, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Juha Silvanto
- Brain Research Unit, O.V. Lounasmaa Laboratory, School of Science, Aalto University, Espoo, Finland
- Department of Psychology, Faculty of Science and Technology, University of Westminster, London, United Kingdom
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Abstract
Emerging evidence suggests that items held in working memory (WM) might not all be in the same representational state. One item might be privileged over others, making it more accessible and thereby recalled with greater precision. Here, using transcranial magnetic stimulation (TMS), we provide causal evidence in human participants that items in WM are differentially susceptible to disruptive TMS, depending on their state, determined either by task relevance or serial position. Across two experiments, we applied TMS to area MT+ during the WM retention of two motion directions. In Experiment 1, we used an "incidental cue" to bring one of the two targets into a privileged state. In Experiment 2, we presented the targets sequentially so that the last item was in a privileged state by virtue of recency. In both experiments, recall precision of motion direction was differentially affected by TMS, depending on the state of the memory target at the time of disruption. Privileged items were recalled with less precision, whereas nonprivileged items were recalled with higher precision. Thus, only the privileged item was susceptible to disruptive TMS over MT+. By contrast, precision of the nonprivileged item improved either directly because of facilitation by TMS or indirectly through reduced interference from the privileged item. Our results provide a unique line of evidence, as revealed by TMS over a posterior sensory brain region, for at least two different states of item representation in WM.
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Sreenivasan KK, Curtis CE, D'Esposito M. Revisiting the role of persistent neural activity during working memory. Trends Cogn Sci 2014; 18:82-9. [PMID: 24439529 DOI: 10.1016/j.tics.2013.12.001] [Citation(s) in RCA: 286] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/01/2013] [Accepted: 12/03/2013] [Indexed: 10/25/2022]
Abstract
What are the neural mechanisms underlying working memory (WM)? One influential theory posits that neurons in the lateral prefrontal cortex (lPFC) store WM information via persistent activity. In this review, we critically evaluate recent findings that together indicate that this model of WM needs revision. We argue that sensory cortex, not the lPFC, maintains high-fidelity representations of WM content. By contrast, the lPFC simultaneously maintains representations of multiple goal-related variables that serve to bias stimulus-specific activity in sensory regions. This work highlights multiple neural mechanisms supporting WM, including temporally dynamic population coding in addition to persistent activity. These new insights focus the question on understanding how the mechanisms that underlie WM are related, interact, and are coordinated in the lPFC and sensory cortex.
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Affiliation(s)
- Kartik K Sreenivasan
- Division of Science and Mathematics, New York University Abu Dhabi, 19 Washington Square North, New York, NY 10011, USA.
| | - Clayton E Curtis
- Department of Psychology, and Center for Neural Science, New York University, 6 Washington Place, New York, NY 10003, USA
| | - Mark D'Esposito
- Helen Wills Neuroscience Institute, and Department of Psychology, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA
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The importance of perceptual experience in the esthetic appreciation of the body. PLoS One 2013; 8:e81378. [PMID: 24324689 PMCID: PMC3852268 DOI: 10.1371/journal.pone.0081378] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 10/13/2013] [Indexed: 11/29/2022] Open
Abstract
Several studies suggest that sociocultural models conveying extreme thinness as the widespread ideal of beauty exert an important influence on the perceptual and emotional representation of body image. The psychological mechanisms underlying such environmental influences, however, are unclear. Here, we utilized a perceptual adaptation paradigm to investigate how perceptual experience modulates body esthetic appreciation. We found that the liking judgments of round bodies increased or decreased after brief exposure to round or thin bodies, respectively. No change occurred in the liking judgments of thin bodies. The results suggest that perceptual experience may shape our esthetic appreciation to favor more familiar round body figures. Importantly, individuals with more deficits in interoceptive awareness were less prone to increase their liking ratings of round bodies after exposure, suggesting a specific risk factor for the susceptibility to the influence of the extreme thin vs. round body ideals of beauty portrayed by the media.
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Visual short-term memory for global motion revealed by directional and speed-tuned masking. Neuropsychologia 2013; 51:809-17. [PMID: 23454262 DOI: 10.1016/j.neuropsychologia.2013.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 02/02/2013] [Accepted: 02/08/2013] [Indexed: 11/20/2022]
Abstract
Neurobehavioral research with non-human primates has shown that different attributes of motion stimuli, such as direction and speed can be stored in visual short-term memory (VSTM) with a high degree of accuracy. We examined VSTM for global motion with a memory masking paradigm to determine which stimulus attributes are important in the storage process. We presented in two visual quadrants global motion random dot kinematograms (RDKs), whereas in the two remaining visual quadrants we presented random-motion RDKs. This pattern of stimulation was displayed in two distinct temporal intervals, i.e., sample and test stimuli (duration: 200 ms), separated in time by a 3.2-s delay period. During the delay period a random- or directional-motion mask was presented briefly (200 ms) either at the beginning, in the middle or at the end of the delay period. The results showed that the mask mainly interferes with performance when displayed 200 ms after the offset of the sample and when it had a coherent direction rather than random directions. Moreover, the mask is significantly more effective when its direction and speed matched that of the remembered sample. These results support the notion that the memory representation of global motion is selective for direction and speed, being compromised by intervening directional stimuli presented immediately after the encoding phase. Moreover, this selectivity suggests that the same neural mechanisms involved in the processing of global motion may be recruited for its storage.
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Bona S, Cattaneo Z, Vecchi T, Soto D, Silvanto J. Metacognition of Visual Short-Term Memory: Dissociation between Objective and Subjective Components of VSTM. Front Psychol 2013; 4:62. [PMID: 23420570 PMCID: PMC3572424 DOI: 10.3389/fpsyg.2013.00062] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/28/2013] [Indexed: 11/13/2022] Open
Abstract
The relationship between the objective accuracy of visual short-term memory (VSTM) representations and their subjective conscious experience is unknown. We investigated this issue by assessing how the objective and subjective components of VSTM in a delayed cue-target orientation discrimination task are affected by intervening distracters. On each trial, participants were shown a memory cue (a grating), the orientation of which they were asked to hold in memory. On approximately half of the trials, a distracter grating appeared during the maintenance interval; its orientation was either identical to that of the memory cue, or it differed by 10° or 40°. The distracters were masked and presented briefly, so they were only consciously perceived on a subset of trials. At the end of the delay period, a memory test probe was presented, and participants were asked to indicate whether it was tilted to the left or right relative to the memory cue (VSTM accuracy; objective performance). In order to assess subjective metacognition, participants were asked indicate the vividness of their memory for the original memory cue. Finally, participants were asked rate their awareness of the distracter. Results showed that objective VSTM performance was impaired by distracters only when the distracters were very different from the cue, and that this occurred with both subjectively visible and invisible distracters. Subjective metacognition, however, was impaired by distracters of all orientations, but only when these distracters were subjectively invisible. Our results thus indicate that the objective and subjective components of VSTM are to some extent dissociable.
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Affiliation(s)
- Silvia Bona
- Brain Research Unit, O.V. Lounasmaa Laboratory, School of Science, Aalto University Aalto, Finland
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van de Ven V, Sack AT. Transcranial magnetic stimulation of visual cortex in memory: Cortical state, interference and reactivation of visual content in memory. Behav Brain Res 2013; 236:67-77. [DOI: 10.1016/j.bbr.2012.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 08/01/2012] [Indexed: 12/27/2022]
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