151
|
Astle D, Nobre A, Scerif G. Attentional control constrains visual short-term memory: insights from developmental and individual differences. Q J Exp Psychol (Hove) 2011; 65:277-94. [PMID: 20680889 PMCID: PMC4152725 DOI: 10.1080/17470218.2010.492622] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The mechanisms by which attentional control biases mnemonic representations have attracted much interest but remain poorly understood. As attention and memory develop gradually over childhood and variably across individuals, assessing how participants of different ages and ability attend to mnemonic contents can elucidate their interplay. In Experiment 1, 7-year-olds, 10-year-olds, and adults were asked to report whether a probe item had been part of a previously presented four-item array. The initial array could either be uncued, be preceded ("precued"), or followed ("retrocued") by a spatial cue orienting attention to one of the potential item locations. Performance across groups was significantly improved by both cue types, and individual differences in children's retrospective attentional control predicted their visual short-term and working memory span, whereas their basic ability to remember in the absence of cues did not. Experiment 2 imposed a variable delay between the array and the subsequent orienting cue. Cueing benefits were greater in adults than in 10-year-olds, but they persisted even when cues followed the array by nearly 3 seconds, suggesting that orienting operated on durable short-term representations for both age groups. The findings indicate that there are substantial developmental and individual differences in the ability to control attention to memory and that in turn these differences constrain visual short-term memory capacity.
Collapse
Affiliation(s)
- D.E. Astle
- Department of Experimental Psychology University of Oxford
| | - A.C. Nobre
- Department of Experimental Psychology University of Oxford
| | - G. Scerif
- Department of Experimental Psychology University of Oxford
| |
Collapse
|
152
|
Olivers CNL, Peters J, Houtkamp R, Roelfsema PR. Different states in visual working memory: when it guides attention and when it does not. Trends Cogn Sci 2011; 15:327-34. [PMID: 21665518 DOI: 10.1016/j.tics.2011.05.004] [Citation(s) in RCA: 263] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 05/04/2011] [Accepted: 05/05/2011] [Indexed: 10/18/2022]
Abstract
Recent studies have revealed a strong relationship between visual working memory and selective attention, such that attention is biased by what is currently on our mind. However, other data show that not all memorized items influence the deployment of attention, thus calling for a distinction within working memory: whereas active memory items function as an attentional template and directly affect perception, other, accessory items do not. We review recent evidence that items compete for the status of 'attentional template' that contains only one object at a time. Neurophysiological results provide insight into these different memory states by revealing a more intricate organization of working memory than was previously thought.
Collapse
Affiliation(s)
- Christian N L Olivers
- Department of Cognitive Psychology, Vrije Universiteit Amsterdam, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
153
|
Doallo S, Raymond JE, Shapiro KL, Kiss M, Eimer M, Nobre AC. Response inhibition results in the emotional devaluation of faces: neural correlates as revealed by fMRI. Soc Cogn Affect Neurosci 2011; 7:649-59. [PMID: 21642353 DOI: 10.1093/scan/nsr031] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although it is well established that prior experience with faces determines their subsequent social-emotional evaluation, recent work shows that top-down inhibitory mechanisms, including response inhibition, can lead to social devaluation after even a single, brief exposure. These rapidly induced effects indicate interplay among perceptual, attentional, response-selection and social-emotional networks; yet, the brain mechanisms underlying this are not well understood. This study used functional magnetic resonance imaging (fMRI) to investigate the neural mechanism mediating the relationship between inhibitory control and emotional devaluation. Participants performed two tasks: (i) a Go/No-Go task in response to faces and (ii) a trustworthiness rating task involving the previously seen faces. No-Go faces were rated as significantly less trustworthy than Go faces. By examining brain activations during Task 1, behavioral measures and brain activations obtained in Task 2 could be predicted. Specifically, activity in brain areas during Task 1 associated with (i) executive control and response suppression (i.e. lateral prefrontal cortex) and (ii) affective responses and value representation (i.e. orbitofrontal cortex), systematically covaried with behavioral ratings and amygdala activity obtained during Task 2. The present findings offer insights into the neural mechanisms linking inhibitory processes to affective responses.
Collapse
Affiliation(s)
- Sonia Doallo
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
| | | | | | | | | | | |
Collapse
|
154
|
A gateway system in rostral PFC? Evidence from biasing attention to perceptual information and internal representations. Neuroimage 2011; 56:1666-76. [DOI: 10.1016/j.neuroimage.2011.02.056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 01/13/2011] [Accepted: 02/17/2011] [Indexed: 11/24/2022] Open
|
155
|
Lepsien J, Thornton I, Nobre AC. Modulation of working-memory maintenance by directed attention. Neuropsychologia 2011; 49:1569-77. [PMID: 21420421 DOI: 10.1016/j.neuropsychologia.2011.03.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/14/2010] [Accepted: 03/10/2011] [Indexed: 11/17/2022]
Abstract
Many current models of working memory (WM) emphasize a close relationship between WM and attention. Recently it was demonstrated that attention can be dynamically and voluntarily oriented to items held in WM, and it was suggested that directed attention can modulate the maintenance of specific WM representations. Here we used event-related functional magnetic resonance imaging to test the effects of orienting attention to a category of stimuli when participants maintained a variable number of faces and scenes in WM. Retro-cues that indicated the relevant stimulus type for the subsequent WM test modulated maintenance-related activity in extrastriate areas preferentially responsive to face or scene stimuli - fusiform and parahippocampal gyri respectively - in a categorical way. After the retro-cue, the activity level in these areas was larger for the cued category in a load-independent way, suggesting the modulation may also reflect anticipation of the probe stimulus. Activity in associative parietal and prefrontal cortices was also modulated by retro-cues, and additionally co-varied with the number of stimuli of the relevant stimulus category that was being maintained. The findings suggest that these associative areas participate in maintaining the relevant memoranda in a flexible and goal-directed way to guide future behaviour.
Collapse
Affiliation(s)
- Jöran Lepsien
- Brain & Cognition Laboratory, Department of Experimental Psychology, University of Oxford, United Kingdom.
| | | | | |
Collapse
|
156
|
Belopolsky AV, Theeuwes J. Selection within visual memory representations activates the oculomotor system. Neuropsychologia 2011; 49:1605-10. [PMID: 21315747 DOI: 10.1016/j.neuropsychologia.2010.12.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 11/09/2010] [Accepted: 12/02/2010] [Indexed: 11/24/2022]
Abstract
Humans tend to create and maintain internal representations of the environment that help guiding actions during the everyday activities. Previous studies have shown that the oculomotor system is involved in coding and maintenance of locations in visual-spatial working memory. In these studies selection of the relevant location for maintenance in working memory took place on the screen (selecting the location of a dot presented on the screen). The present study extended these findings by showing that the oculomotor system also codes selection of location from an internal memory representation. Participants first memorized two locations and after a retention interval selected one location for further maintenance. The results show that saccade trajectories deviated away from the ultimately remembered location. Furthermore, selection of the location from the memorized representation produced sustained oculomotor preparation to it. The results show that oculomotor system is very flexible and plays an active role for coding and maintaining information selected within internal memory representations.
Collapse
Affiliation(s)
- Artem V Belopolsky
- Department of Cognitive Psychology, Vrije Universiteit, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands.
| | | |
Collapse
|
157
|
Houtkamp R, Braun J. Cortical response to task-relevant stimuli presented outside the primary focus of attention. J Cogn Neurosci 2011; 22:1980-92. [PMID: 19702464 DOI: 10.1162/jocn.2009.21327] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Visual attention selectively enhances the neural response to a task-relevant item. But what happens when an item outside the primary focus of attention is also relevant to the task at hand? In a dual-task fMRI experiment, we studied the responses in retinotopically organized visual cortex in such a situation. Observers performed an attention-demanding task in the fovea while another, unmasked stimulus appeared in the visual periphery. With respect to this latter stimulus, observers attempted to perform either a less or a more attentionally demanding task. Both tasks increased the BOLD response to the peripheral stimulus. Behaviorally, however, only the less demanding task was performed well, whereas the demanding task was carried out near chance. What could explain the discrepancy between BOLD response and behavioral performance? A control experiment revealed that the report of the less demanding feature was severely disturbed by a mask. Moreover, the visual attributes queried by the demanding task had a significantly shorter iconic memory persistence. We conclude that, in the dual-task situation, the focus of attention initially remains with the foveal task, but subsequently shifts to the former location of the peripheral stimulus. Such a belated shift to a peripheral iconic memory (futile in one case, informative in the other) would reconcile the similar BOLD response with the disparate behavioral performance. In summary, our results show that an enhanced BOLD response is consistently associated with attentional modulation, but not with behavioral performance.
Collapse
Affiliation(s)
- Roos Houtkamp
- Otto-von-Guericke Universität, Department of Cognitive Biology, Magdeburg, Germany.
| | | |
Collapse
|
158
|
Tamber-Rosenau BJ, Esterman M, Chiu YC, Yantis S. Cortical mechanisms of cognitive control for shifting attention in vision and working memory. J Cogn Neurosci 2011; 23:2905-19. [PMID: 21291314 DOI: 10.1162/jocn.2011.21608] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Organisms operate within both a perceptual domain of objects and events, and a mnemonic domain of past experiences and future goals. Each domain requires a deliberate selection of task-relevant information, through deployments of external (perceptual) and internal (mnemonic) attention, respectively. Little is known about the control of attention shifts in working memory, or whether voluntary control of attention in these two domains is subserved by a common or by distinct functional networks. We used human fMRI to examine the neural basis of cognitive control while participants shifted attention in vision and in working memory. We found that these acts of control recruit in common a subset of the dorsal fronto-parietal attentional control network, including the medial superior parietal lobule, intraparietal sulcus, and superior frontal sulcus/gyrus. Event-related multivoxel pattern classification reveals, however, that these regions exhibit distinct spatio-temporal patterns of neural activity during internal and external shifts of attention, respectively. These findings constrain theoretical accounts of selection in working memory and perception by showing that populations of neurons in dorsal fronto-parietal network regions exhibit selective tuning for acts of cognitive control in different cognitive domains.
Collapse
|
159
|
Kuo BC, Yeh YY, Chen AJW, D'Esposito M. Functional connectivity during top-down modulation of visual short-term memory representations. Neuropsychologia 2011; 49:1589-96. [PMID: 21241721 DOI: 10.1016/j.neuropsychologia.2010.12.043] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 12/21/2010] [Accepted: 12/30/2010] [Indexed: 12/01/2022]
Abstract
Recent evidence has revealed that short-lived internal representations held in visual short-term memory (VSTM) can be modulated by top-down control via retrospective attention which impacts subsequent behavioral performance. However, the functional inter-regional interactions underlying these top-down modulatory effects are not fully characterized. Here we used event-related functional magnetic imaging to investigate whether the strength of functional connectivity between the frontal cortex and posterior visual areas varies with the efficacy of top-down modulation of memory traces. Top-down modulation was manipulated by the timing of retro-cuing (early or late) in a VSTM task. Univariate analyses revealed that more effective top-down modulation (early cueing vs. late cueing) increased activity in early visual areas. Importantly, coherency analyses revealed that top-down modulation produced stronger functional connectivity between frontal and posterior occipital regions. Also, participants with stronger functional connectivity exhibit better memory performance. These results suggest that augmented functional connectivity between frontal and posterior visual areas strengthens the VSTM representations of importance to behavioral goals.
Collapse
Affiliation(s)
- Bo-Cheng Kuo
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | | | | | | |
Collapse
|
160
|
Abstract
Perceptual salience improves the encoding of information into visual working memory (WM). However, the factors that contribute to this facilitation effect are not well understood. This study tested the influence of target familiarity on WM encoding. In each trial, participants were presented with either one or three targets and asked to encode their locations into WM. In Experiment 1, target familiarity was manipulated by presenting either an upright (familiar target) or upside-down (unfamiliar/novel target) A. Increasing the novelty of the targets led to improved performance in the spatial WM task. Experiment 2 showed that participants were faster in responding to novel versus familiar targets in a spatial detection task. Experiment 3 demonstrated that the beneficial effect of target novelty on WM encoding was not driven by differences in low-level features. Our results suggest that target novelty enhances the processes required for WM encoding, just as it facilitates perceptual processing.
Collapse
Affiliation(s)
- Jutta S. Mayer
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA
| | - Jejoong Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Sohee Park
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA
| |
Collapse
|
161
|
Astle DE, Scerif G. Interactions between attention and visual short-term memory (VSTM): what can be learnt from individual and developmental differences? Neuropsychologia 2010; 49:1435-45. [PMID: 21185321 DOI: 10.1016/j.neuropsychologia.2010.12.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 11/18/2010] [Accepted: 12/02/2010] [Indexed: 11/28/2022]
Abstract
An ever increasing amount of research in the fields of developmental psychology and adult cognitive neuroscience explores attentional control as a driver of visual short-term and working memory capacity limits ("VSTM" and "VWM", respectively). However, these literatures have thus far been disparate: they use different measures or different labels, and the constructs of interest often appear to be quite distinct. In the current review, we attempt to bridge these gaps across disciplines and explore the extent to which these two literatures might support one another. In order to do this, we explore five principal questions of interest to members of both communities: (1) To what extent are measures of VSTM, VWM and attentional control commensurate across the developmental and adult literatures? (2) To what extent do individual differences in attentional control account for why some children, just like some adults, show poorer VSTM and VWM capacity than others? (3) Can developmental improvements in VSTM and VWM capacity also be explained by differences in attentional control? (4) What novel insights can be gained by studying the developmental cognitive neuroscience of attention and VSTM and VWM? (5) Can visual short-term and working memory capacity be modulated by training and, if so, how can training effects inform the relationships between attention and VSTM? Throughout, we evaluate the central thesis that variability in attentional control, both between individuals and over development, is a driver of variability in VSTM and VWM capacity.
Collapse
Affiliation(s)
- Duncan E Astle
- Department of Experimental Psychology, University of Oxford, UK
| | | |
Collapse
|
162
|
Bledowski C, Kaiser J, Rahm B. Basic operations in working memory: Contributions from functional imaging studies. Behav Brain Res 2010; 214:172-9. [PMID: 20678984 DOI: 10.1016/j.bbr.2010.05.041] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 05/23/2010] [Indexed: 10/19/2022]
|
163
|
Peelen MV, Atkinson AP, Andersson F, Vuilleumier P. Emotional modulation of body-selective visual areas. Soc Cogn Affect Neurosci 2010; 2:274-83. [PMID: 18985133 DOI: 10.1093/scan/nsm023] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 05/14/2007] [Indexed: 11/13/2022] Open
Abstract
Emotionally expressive faces have been shown to modulate activation in visual cortex, including face-selective regions in ventral temporal lobe. Here, we tested whether emotionally expressive bodies similarly modulate activation in body-selective regions. We show that dynamic displays of bodies with various emotional expressions vs neutral bodies, produce significant activation in two distinct body-selective visual areas, the extrastriate body area and the fusiform body area. Multi-voxel pattern analysis showed that the strength of this emotional modulation was related, on a voxel-by-voxel basis, to the degree of body selectivity, while there was no relation with the degree of selectivity for faces. Across subjects, amygdala responses to emotional bodies positively correlated with the modulation of body-selective areas. Together, these results suggest that emotional cues from body movements produce topographically selective influences on category-specific populations of neurons in visual cortex, and these increases may implicate discrete modulatory projections from the amygdala.
Collapse
Affiliation(s)
- Marius V Peelen
- Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.
| | | | | | | |
Collapse
|
164
|
van Donkelaar P, Langan J, Rodriguez E, Drew A, Halterman C, Osternig LR, Chou LS. Attentional deficits in concussion. Brain Inj 2010; 19:1031-9. [PMID: 16263646 DOI: 10.1080/02699050500110363] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PRIMARY OBJECTIVE The purpose of the present study was to examine deficits in the alerting, orienting and executive components of attention in individuals who have recently suffered a concussion. RESEARCH DESIGN A group design was used in which the performance by individuals with concussion was compared to control subjects matched for age, height, weight and activity level. METHODS AND PROCEDURES Participants completed the Attentional Network Test (ANT) that breaks down attention into alerting, orienting and executive components. Reaction time and response accuracy were the dependent variables. MAIN OUTCOMES AND RESULTS It was found that only the orienting and executive components of attention were affected by concussion, whereas the alerting component was normal. Furthermore, participants with concussion required a significantly longer time than controls to initiate correct responses. CONCLUSIONS These results suggest that the orienting and executive components of attention are most susceptible to the effects of concussion.
Collapse
Affiliation(s)
- P van Donkelaar
- Department of Human Physiology, University of Oregon, Eugene, OR 97403-1240, USA.
| | | | | | | | | | | | | |
Collapse
|
165
|
Posterior parietal cortex mediates encoding and maintenance processes in change blindness. Neuropsychologia 2010; 48:1063-70. [DOI: 10.1016/j.neuropsychologia.2009.12.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 10/17/2009] [Accepted: 12/05/2009] [Indexed: 11/23/2022]
|
166
|
What "works" in working memory? Separate systems for selection and updating of critical information. J Neurosci 2009; 29:13735-41. [PMID: 19864586 DOI: 10.1523/jneurosci.2547-09.2009] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cognition depends critically on working memory, the active representation of a limited number of items over short periods of time. In addition to the maintenance of information during the course of cognitive processing, many tasks require that some of the items in working memory become transiently more important than others. Based on cognitive models of working memory, we hypothesized two complementary essential cognitive operations to achieve this: a selection operation that retrieves the most relevant item, and an updating operation that changes the focus of attention onto it. Using functional magnetic resonance imaging, high-resolution oculometry, and behavioral analysis, we demonstrate that these two operations are functionally and neuroanatomically dissociated. Updating the attentional focus elicited transient activation in the caudal superior frontal sulcus and posterior parietal cortex. In contrast, increasing demands on selection selectively modulated activation in rostral superior frontal sulcus and posterior cingulate/precuneus. We conclude that prioritizing one memory item over others invokes independent mechanisms of mnemonic retrieval and attentional focusing, each with its distinct neuroanatomical basis within frontal and parietal regions. These support the developing understanding of working memory as emerging from the interaction between memory and attentional systems.
Collapse
|
167
|
Goal-directed access to mental objects in working memory: The role of task-specific feature retrieval. Mem Cognit 2009; 37:1103-19. [PMID: 19933455 DOI: 10.3758/mc.37.8.1103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
168
|
Behavioral and neural correlates of memory selection and interference resolution during a digit working memory task. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2009; 9:249-59. [PMID: 19679761 DOI: 10.3758/cabn.9.3.249] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neuroimaging studies have shown the involvement of prefrontal and posterior parietal cortexes in regulating information processing. We conducted behavioral and fMRI experiments to investigate the relationship between memory selection and proactive interference (PI), using a delayed recognition task with a selection cue presented during the delay indicating which two of the four studied digits were relevant to the present test. PI was indexed by the response time differences between rejecting probes matching and not matching the no longer relevant digits. By varying the delay intervals, we found that the effect of PI did not diminish, even for cases in which the postcue interval was extended to 9 sec, but was stronger when the precue interval was lengthened to 5 sec. By examining the correlation between PI index and neural correlates of memory selection, we found that stronger PI is predicted by lower selection-related activity in the left inferior parietal lobe, the precuneus, and the dorsal middle frontal gyrus. Our results suggest that activity in the prefrontal-parietal network may contribute to one's ability to focus on the task-relevant information and may proactively reduce PI in working memory.
Collapse
|
169
|
Esterman M, Chiu YC, Tamber-Rosenau BJ, Yantis S. Decoding cognitive control in human parietal cortex. Proc Natl Acad Sci U S A 2009; 106:17974-9. [PMID: 19805050 PMCID: PMC2764943 DOI: 10.1073/pnas.0903593106] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Indexed: 11/18/2022] Open
Abstract
Efficient execution of perceptual-motor tasks requires rapid voluntary reconfiguration of cognitive task sets as circumstances unfold. Such acts of cognitive control, which are thought to rely on a network of cortical regions in prefrontal and posterior parietal cortex, include voluntary shifts of attention among perceptual inputs or among memory representations, or switches between categorization or stimulus-response mapping rules. A critical unanswered question is whether task set shifts in these different domains are controlled by a common, domain-independent mechanism or by separate, domain-specific mechanisms. Recent studies have implicated a common region of medial superior parietal lobule (mSPL) as a domain-independent source of cognitive control during shifts between perceptual, mnemonic, and rule representations. Here, we use fMRI and event-related multivoxel pattern classification to show that spatial patterns of brain activity within mSPL reliably express which of several domains of cognitive control is at play on a moment-by-moment basis. Critically, these spatiotemporal brain patterns are stable over time within subjects tested several months apart and across a variety of tasks, including shifting visuospatial attention, switching categorization rules, and shifting attention in working memory.
Collapse
Affiliation(s)
- Michael Esterman
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686, USA.
| | | | | | | |
Collapse
|
170
|
Dell'Acqua R, Sessa P, Toffanin P, Luria R, Jolicoeur P. Orienting attention to objects in visual short-term memory. Neuropsychologia 2009; 48:419-28. [PMID: 19804791 DOI: 10.1016/j.neuropsychologia.2009.09.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 09/27/2009] [Indexed: 11/19/2022]
Abstract
We measured electroencephalographic activity during visual search of a target object among objects available to perception or among objects held in visual short-term memory (VSTM). For perceptual search, a single shape was shown first (pre-cue) followed by a search-array, and the task was to decide whether the pre-cue was or was not in the search-array. For search of VSTM, a search-array was shown first followed by a single shape (post-cue), and the task was to decide whether the post-cue was or was not in the previously displayed search-array. We focused on early lateralized electrical brain activity over posterior and temporal areas time-locked to search-arrays in pre-cue trials and to post-cues in post-cue trials. In Experiment 1, search-arrays were composed of two lateralized shapes, displayed in the upper/lower two quadrants of the monitor. In Experiment 2, search-arrays were composed of four shapes, displayed at the corners of an imaginary square centered on fixation. In pre-cue trials, we observed an N2pc of about equal amplitude and latency for search-arrays composed of two or four shapes. In post-cue trials, we observed N2pc-like activity with search-arrays composed of two shapes, that was however substantially attenuated with search-arrays composed of four shapes. For many aspects, attending to a perceptual object was functionally and neurally analogous to attending to an object held in VSTM, suggesting that spatial selective attention biases search of objects during both ongoing perception and retention.
Collapse
|
171
|
Motes MA, Rypma B. Working memory component processes: isolating BOLD signal changes. Neuroimage 2009; 49:1933-41. [PMID: 19732840 DOI: 10.1016/j.neuroimage.2009.08.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 08/07/2009] [Accepted: 08/22/2009] [Indexed: 11/28/2022] Open
Abstract
The chronology of the component processes subserving working memory (WM) and hemodynamic response lags has hindered the use of fMRI for exploring neural substrates of WM. In the present study, however, participants completed full trials that involved encoding two or six letters, maintaining the memory set over a delay, and then deciding whether a probe was in the memory set or not. Additionally, they completed encode-only, encode-and-maintain, and encode-and-decide partial trials intermixed with the full trials. The inclusion of partial trials allowed for the isolation of BOLD signal changes to the different trial periods. The results showed that only lateral and medial prefrontal cortex regions differentially responded to the 2- and 6-letter memory sets over the trial periods, showing greater activation to 6-letter sets during the encode and maintain trial periods. Thus, the data showed the differential involvement of PFC in the encoding and maintenance of supra- and sub-capacity memory sets and show the efficacy of using fMRI partial trial methods to study WM component processes.
Collapse
Affiliation(s)
- Michael A Motes
- Center for BrainHealth and School of Behavioral and Brain Sciences, University of Texas at Dallas, TX 75235, USA.
| | | |
Collapse
|
172
|
Eimer M, Kiss M. An electrophysiological measure of access to representations in visual working memory. Psychophysiology 2009; 47:197-200. [PMID: 19674389 DOI: 10.1111/j.1469-8986.2009.00879.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous research has demonstrated that the maintenance of visual information in working memory is associated with a sustained posterior contralateral negativity. Here we show that this component is also elicited during the spatially selective access to visual working memory. Participants memorized a bilateral visual search array that contained two potential targets on the left and right side. The task-relevant side was signalled by post-cues that were presented either 150 ms after array offset or after a longer interval (700-1000 ms). Enhanced negativities at posterior electrodes contralateral to the cued side of a target were elicited in response to both early and late post-cues, suggesting that they reflect not only memory maintenance, but also processes involved in the access to stored visual working memory representations. Results provide new electrophysiological evidence for the retinotopic organization of visual working memory.
Collapse
Affiliation(s)
- Martin Eimer
- Department of Psychology, Birkbeck College, University of London, London, UK.
| | | |
Collapse
|
173
|
Abstract
Attention is a core property of all perceptual and cognitive operations. Given limited capacity to process competing options, attentional mechanisms select, modulate, and sustain focus on information most relevant for behavior. A significant problem, however, is that attention is so ubiquitous that it is unwieldy to study. We propose a taxonomy based on the types of information that attention operates over--the targets of attention. At the broadest level, the taxonomy distinguishes between external attention and internal attention. External attention refers to the selection and modulation of sensory information. External attention selects locations in space, points in time, or modality-specific input. Such perceptual attention can also select features defined across any of these dimensions, or object representations that integrate over space, time, and modality. Internal attention refers to the selection, modulation, and maintenance of internally generated information, such as task rules, responses, long-term memory, or working memory. Working memory, in particular, lies closest to the intersection between external and internal attention. The taxonomy provides an organizing framework that recasts classic debates, raises new issues, and frames understanding of neural mechanisms.
Collapse
Affiliation(s)
- Marvin M Chun
- Department of Psychology, Yale University, New Haven, Connecticut 06520, USA.
| | | | | |
Collapse
|
174
|
Oliveri M, Koch G, Caltagirone C. Spatial-temporal interactions in the human brain. Exp Brain Res 2009; 195:489-97. [PMID: 19458940 DOI: 10.1007/s00221-009-1834-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Accepted: 04/29/2009] [Indexed: 11/30/2022]
Abstract
The review summarises current evidence on the cognitive mechanisms for the integration of spatial and temporal representations and of common brain structures to process the where and when of stimuli. Psychophysical experiments document the presence of spatially localised distortions of sub-second time intervals and suggest that visual events are timed by neural mechanisms that are spatially selective. On the other hand, experiments with supra-second intervals suggest that time could be represented on a mental time-line ordered from left-to-right, similar to what is reported for other ordered quantities, such as numbers. Neuroimaging and neuropsychological findings point towards the posterior parietal cortex as the main site where spatial and temporal information converge and interact with each other.
Collapse
|
175
|
Nee DE, Jonides J. Common and distinct neural correlates of perceptual and memorial selection. Neuroimage 2009; 45:963-75. [PMID: 19280708 DOI: 10.1016/j.neuroimage.2009.01.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
A critical aspect of cognitive control is the ability to select goal-relevant information in the face of competing distraction. A popular account is that common top-down selection processes underlie the ability to select among competing percepts and memories. We test the degree to which selective attention and memorial selection recruit the same neural resources. We demonstrate that both functions elicit largely overlapping networks within the dorsolateral prefrontal cortex (DLPFC), frontal eye fields (FEF), premotor cortex, and superior parietal lobule (SPL). Despite the close commonalities of selective attention and memorial selection, our results demonstrate that the SPL and FEF show preferential involvement in selective attention, whereas left ventrolateral prefrontal cortex (VLPFC) is uniquely associated with memorial selection. Thus, the two sorts of selection are not identical. We show further that variations in shared selection circuits are associated with differences in behavioral performance, suggesting that economy of control is beneficial to performance.
Collapse
Affiliation(s)
- Derek Evan Nee
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1043, USA.
| | | |
Collapse
|
176
|
Phillips JS, Velanova K, Wolk DA, Wheeler ME. Left posterior parietal cortex participates in both task preparation and episodic retrieval. Neuroimage 2009; 46:1209-21. [PMID: 19285142 DOI: 10.1016/j.neuroimage.2009.02.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 01/29/2009] [Accepted: 02/23/2009] [Indexed: 12/01/2022] Open
Abstract
Optimal memory retrieval depends not only on the fidelity of stored information, but also on the attentional state of the subject. Factors such as mental preparedness to engage in stimulus processing can facilitate or hinder memory retrieval. The current study used functional magnetic resonance imaging (fMRI) to distinguish preparatory brain activity before episodic and semantic retrieval tasks from activity associated with retrieval itself. A catch-trial imaging paradigm permitted separation of neural responses to preparatory task cues and memory probes. Episodic and semantic task preparation engaged a common set of brain regions, including the bilateral intraparietal sulcus (IPS), left fusiform gyrus (FG), and the pre-supplementary motor area (pre-SMA). In the subsequent retrieval phase, the left IPS was among a set of frontoparietal regions that responded differently to old and new stimuli. In contrast, the right IPS responded to preparatory cues with little modulation during memory retrieval. The findings support a strong left-lateralization of retrieval success effects in left parietal cortex, and further indicate that left IPS performs operations that are common to both task preparation and memory retrieval. Such operations may be related to attentional control, monitoring of stimulus relevance, or retrieval.
Collapse
Affiliation(s)
- Jeffrey S Phillips
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | | | | | | |
Collapse
|
177
|
Pia L, Corazzini LL, Folegatti A, Gindri P, Cauda F. Mental number line disruption in a right-neglect patient after a left-hemisphere stroke. Brain Cogn 2009; 69:81-8. [DOI: 10.1016/j.bandc.2008.05.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 05/19/2008] [Accepted: 05/21/2008] [Indexed: 11/30/2022]
|
178
|
Di Martino A, Scheres A, Margulies DS, Kelly AMC, Uddin LQ, Shehzad Z, Biswal B, Walters JR, Castellanos FX, Milham MP. Functional connectivity of human striatum: a resting state FMRI study. Cereb Cortex 2008; 18:2735-47. [PMID: 18400794 DOI: 10.1093/cercor/bhn041] [Citation(s) in RCA: 852] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Classically regarded as motor structures, the basal ganglia subserve a wide range of functions, including motor, cognitive, motivational, and emotional processes. Consistent with this broad-reaching involvement in brain function, basal ganglia dysfunction has been implicated in numerous neurological and psychiatric disorders. Despite recent advances in human neuroimaging, models of basal ganglia circuitry continue to rely primarily upon inference from animal studies. Here, we provide a comprehensive functional connectivity analysis of basal ganglia circuitry in humans through a functional magnetic resonance imaging examination during rest. Voxelwise regression analyses substantiated the hypothesized motor, cognitive, and affective divisions among striatal subregions, and provided in vivo evidence of a functional organization consistent with parallel and integrative loop models described in animals. Our findings also revealed subtler distinctions within striatal subregions not previously appreciated by task-based imaging approaches. For instance, the inferior ventral striatum is functionally connected with medial portions of orbitofrontal cortex, whereas a more superior ventral striatal seed is associated with medial and lateral portions. The ability to map multiple distinct striatal circuits in a single study in humans, as opposed to relying on meta-analyses of multiple studies, is a principal strength of resting state functional magnetic resonance imaging. This approach holds promise for studying basal ganglia dysfunction in clinical disorders.
Collapse
Affiliation(s)
- A Di Martino
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, NYU Child Study Center, New York, NY 10016, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
179
|
Top-down and bottom-up attention to memory: a hypothesis (AtoM) on the role of the posterior parietal cortex in memory retrieval. Neuropsychologia 2008; 46:1828-51. [PMID: 18471837 DOI: 10.1016/j.neuropsychologia.2008.03.022] [Citation(s) in RCA: 393] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2007] [Revised: 03/14/2008] [Accepted: 03/21/2008] [Indexed: 11/24/2022]
Abstract
Recent neuroimaging studies have implicated the posterior parietal cortex in episodic memory retrieval, but there is uncertainty about its specific role. Research in the attentional domain has shown that superior parietal lobe (SPL) regions along the intraparietal sulcus are implicated in the voluntary orienting of attention to relevant aspects of the environment, whereas inferior parietal lobe (IPL) regions at the temporo-parietal junction mediate the automatic allocation of attention to task-relevant information. Here we propose that the SPL and the IPL play conceptually similar roles in episodic memory retrieval. We hypothesize that the SPL allocates top-down attention to memory retrieval, whereas the IPL mediates the automatic, bottom-up attentional capture by retrieved memory contents. By reviewing the existing fMRI literature, we show that the posterior intraparietal sulcus of SPL is consistently active when the need for top-down assistance to memory retrieval is supposedly maximal, e.g., for memories retrieved with low vs. high confidence, for familiar vs. recollected memories, for recognition of high vs. low frequency words. On the other hand, the supramarginal gyrus of IPL is consistently active when the attentional capture by memory contents is supposedly maximal, i.e., for strong vs. weak memories, for vividly recollected vs. familiar memories, for memories retrieved with high vs. low confidence. We introduce a model of episodic memory retrieval that characterizes contributions of posterior parietal cortex.
Collapse
|
180
|
Nobre AC, Griffin IC, Rao A. Spatial attention can bias search in visual short-term memory. Front Hum Neurosci 2008; 1:4. [PMID: 18958218 PMCID: PMC2525979 DOI: 10.3389/neuro.09.004.2007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 01/14/2008] [Indexed: 12/05/2022] Open
Abstract
Whereas top-down attentional control is known to bias perceptual functions at many levels of stimulus analysis, its possible influence over memory-related functions remains uncharted. Our experiment combined behavioral measures and event-related potentials (ERPs) to test the ability of spatial orienting to bias functions associated with visual short-term memory (VSTM), and to shed light on the neural mechanisms involved. In particular, we investigated whether orienting attention to a spatial location within an array maintained in VSTM could facilitate the search for a specific remembered item. Participants viewed arrays of one, two or four differently colored items, followed by an informative spatial (100% valid) or uninformative neutral retro-cue (1500–2500 ms after the array), and later by a probe stimulus (500–1000 ms after the retro-cue). The task was to decide whether the probe stimulus had been present in the array. Behavioral results showed that spatial retro-cues improved both accuracy and response times for making decisions about the presence of the probe item in VSTM, and significantly attenuated performance decrements caused by increasing VSTM load. We also identified a novel ERP component (N3RS) specifically associated with searching for an item within VSTM. Paralleling the behavioral results, the amplitude and duration of the N3RS systematically increased with VSTM load in neutral retro-cue trials. When spatial retro-cues were provided, this “retro-search” component was absent. Our findings clearly show that the influence of top-down attentional biases extends to mnemonic functions, and, specifically, that searching for items within VSTM can be under flexible voluntary control.
Collapse
Affiliation(s)
- Anna C Nobre
- Brain and Cognition Laboratory, Department of Experimental Psychology, University of Oxford Oxford, UK.
| | | | | |
Collapse
|
181
|
Loetscher T, Bockisch C, Brugger P. Looking for the answer: The mind's eye in number space. Neuroscience 2008; 151:725-9. [DOI: 10.1016/j.neuroscience.2007.07.068] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 07/18/2007] [Accepted: 07/27/2007] [Indexed: 11/28/2022]
|
182
|
Ruff CC, Kristjánsson A, Driver J. Readout from iconic memory and selective spatial attention involve similar neural processes. Psychol Sci 2007; 18:901-9. [PMID: 17894608 PMCID: PMC2440528 DOI: 10.1111/j.1467-9280.2007.01998.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Iconic memory and spatial attention are often considered separately, but they may have functional similarities. Here we provide functional magnetic resonance imaging evidence for some common underlying neural effects. Subjects judged three visual stimuli in one hemifield of a bilateral array comprising six stimuli. The relevant hemifield for partial report was indicated by an auditory cue, administered either before the visual array (precue, spatial attention) or shortly after the array (postcue, iconic memory). Pre- and postcues led to similar activity modulations in lateral occipital cortex contralateral to the cued side. This finding indicates that readout from iconic memory can have some neural effects similar to those of spatial attention. We also found common bilateral activation of a fronto-parietal network for postcue and precue trials. These neuroimaging data suggest that some common neural mechanisms underlie selective spatial attention and readout from iconic memory. Some differences were also found; compared with precues, postcues led to higher activity in the right middle frontal gyrus.
Collapse
Affiliation(s)
- Christian C Ruff
- Institute of Cognitive Neuroscience and Department of Psychology, University College London, London, United Kingdom.
| | | | | |
Collapse
|
183
|
Abstract
The different prefrontal cortical regions exert executive control over processing occurring in posterior cortical regions. We examined with the autoradiographic method, in the macaque monkey, the course and terminations of the efferent corticocortical connections of the rostral prefrontal region, the function of which is least understood. Three efferent streams of fibers organized into three distinct fasciculi convey rostral prefrontal influences on posterior cortical areas. These connections provide powerful insights into the cortical regions on which executive control is being exercised. The lateral stream of fibers via the extreme capsule targets the midsection of the auditory superior temporal region and the multisensory areas of the superior temporal sulcus, thus permitting control over the most integrated aspects of cognitive processing. The fibers coursing through the extreme capsule originating in areas 10 and 9 continue as part of the white matter of the superior temporal gyrus (i.e., the middle longitudinal fasciculus) to target the midportion of the superior temporal gyrus (areas TAa, TS2, and TS3) and adjacent multisensory area TPO within the upper bank of the superior temporal sulcus. Some of the fibers from areas 10 and 9 that enter the extreme capsule terminate in the ventral part of the insula. The dorsomedial limbic stream via the cingulate fasciculus targets the anterior and posterior cingulate cortex, as well as the retrosplenial cortex, allowing control over motivational and memory processes. A ventral limbic stream via the uncinate fasciculus targets the temporal proisocortex and the amygdala, indicating an additional powerful influence over the emotional motivational sphere.
Collapse
|
184
|
Is there continuity between categorical and coordinate spatial relations coding? Evidence from a grid/no-grid working memory paradigm. Neuropsychologia 2007; 46:576-94. [PMID: 18037455 DOI: 10.1016/j.neuropsychologia.2007.10.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 10/04/2007] [Accepted: 10/05/2007] [Indexed: 11/22/2022]
Abstract
We ask the question whether the coding of categorical versus coordinate spatial relations depends on different neural networks showing hemispheric specialization or whether there is continuity between these two coding types. The 'continuous spatial coding' hypothesis would mean that the two coding types rely essentially on the same neural network consisting of more general-purpose processes, such as visuo-spatial attention, but with a different weighting of these general processes depending on exact task requirements. With event-related fMRI, we have studied right-handed male subjects performing a grid/no-grid visuo-spatial working memory task inducing categorical and coordinate spatial relations coding. Our data support the 'continuous spatial coding' hypothesis, indicating that, while based on the same fronto-parieto-occipital neural network than categorical spatial relations coding, the coding of coordinate spatial relations relies more heavily on attentional and executive processes, which could induce hemispheric differences similar to those described in the literature. The results also show that visuo-spatial working memory consists of a short-term posterior store with a capacity of up to three elements in the parietal and extrastriate cortices. This store depends on the presence of a visible space categorization and thus can be used for the coding of categorical spatial relations. When no visible space categorization is given or when more than three elements have to be coded, additional attentional and executive processes are recruited, mainly located in the dorso-lateral prefrontal cortex.
Collapse
|
185
|
Krueger F, Fischer R, Heinecke A, Hagendorf H. An fMRI investigation into the neural mechanisms of spatial attentional selection in a location-based negative priming task. Brain Res 2007; 1174:110-9. [PMID: 17803973 DOI: 10.1016/j.brainres.2007.08.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 07/27/2007] [Accepted: 08/06/2007] [Indexed: 11/30/2022]
Abstract
Selective attention enables us to respond to objects and events that are relevant to our goals for adaptive interactions with the environment. Despite evidence from research addressing the selection of a target location, little is known about the neural mechanisms of attentional selection in situations in which the selection is biased in favor of the information in the irrelevant location. In this study, we combined event-related fMRI and a location-based negative priming paradigm with a prime-probe-trial design to investigate the neural mechanisms of spatial attentional selection. Participants were instructed to respond to the location of a pre-specified target while ignoring a distractor at an irrelevant location. The goal of this study was twofold. First, we identified brain regions that are linked to conflict resolution situations, in which the selection bias puts the irrelevant information in the probe trial on a selection advantage over the target. Second, we determined the mechanism of conflict resolution when the encoding conditions of stimuli are manipulated by presenting stimuli either abruptly (onset) or masked (no-onset). The results showed that the bottom-up-induced competition among stimuli in the target selection is stronger for onset than no-onset stimuli. The superior parietal lobule was sensitive to those changes in bottom-up-induced competition. Furthermore, the dorsolateral prefrontal cortex and inferior parietal lobe were activated to resolve the additional processing effort necessary to select the negatively biased target. In conclusion, the present study identified dissociable neural components needed to resolve the negative selection bias, which attentional modulation can be addressed in future studies by examining changes in the functional connectivity.
Collapse
Affiliation(s)
- Frank Krueger
- Cognitive Neuroscience Section, National Institute of Neurological Disorders and Stroke,National Institutes of Health, Bethesda, MD 20892-1440, USA.
| | | | | | | |
Collapse
|
186
|
Wallentin M, Roepstorff A, Burgess N. Frontal eye fields involved in shifting frame of reference within working memory for scenes. Neuropsychologia 2007; 46:399-408. [PMID: 17915262 DOI: 10.1016/j.neuropsychologia.2007.08.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 08/18/2007] [Accepted: 08/20/2007] [Indexed: 11/27/2022]
Abstract
Working memory (WM) evoked by linguistic cues for allocentric spatial and egocentric spatial aspects of a visual scene was investigated by correlating fMRI BOLD signal (or "activation") with performance on a spatial-relations task. Subjects indicated the relative positions of a person or object (referenced by the personal pronouns "he/she/it") in a previously shown image relative to either themselves (egocentric reference frame) or shifted to a reference frame anchored in another person or object in the image (allocentric reference frame), e.g. "Was he in front of you/her?" Good performers had both shorter response time and more correct responses than poor performers in both tasks. These behavioural variables were entered into a principal component analysis. The first component reflected generalised performance level. We found that the frontal eye fields (FEF), bilaterally, had a higher BOLD response during recall involving allocentric compared to egocentric spatial reference frames, and that this difference was larger in good performers than in poor performers as measured by the first behavioural principal component. The frontal eye fields may be used when subjects move their internal gaze during shifting reference frames in representational space. Analysis of actual eye movements in three subjects revealed no difference between egocentric and allocentric recall tasks where visual stimuli were also absent. Thus, the FEF machinery for directing eye movements may also be involved in changing reference frames within WM.
Collapse
Affiliation(s)
- Mikkel Wallentin
- Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark.
| | | | | |
Collapse
|
187
|
Burgess PW, Dumontheil I, Gilbert SJ. The gateway hypothesis of rostral prefrontal cortex (area 10) function. Trends Cogn Sci 2007; 11:290-8. [PMID: 17548231 DOI: 10.1016/j.tics.2007.05.004] [Citation(s) in RCA: 458] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 04/26/2007] [Accepted: 05/18/2007] [Indexed: 11/28/2022]
Abstract
Rostral prefrontal cortex (PFC) is a large brain region, and is unusually large in humans. Therefore, it seems likely that it might support functions that are central to cognition. However, until recently, almost nothing was known about what these functions might be. The 'gateway hypothesis' places these abilities at the centre of human mental processing. It maintains that rostral PFC supports mechanisms that enable us to attend, to a novel degree, either to environmental stimuli, or by contrast, to self-generated or maintained representations (i.e. the 'thoughts in our head'). In this way, investigations into the functions of rostral PFC will reveal key new insights into how human and non-human mental abilities differ.
Collapse
Affiliation(s)
- Paul W Burgess
- Institute of Cognitive Neuroscience & Psychology Department, University College London, London, WC1E 6BT, UK.
| | | | | |
Collapse
|
188
|
Mayer JS, Bittner RA, Nikolić D, Bledowski C, Goebel R, Linden DEJ. Common neural substrates for visual working memory and attention. Neuroimage 2007; 36:441-53. [PMID: 17462914 DOI: 10.1016/j.neuroimage.2007.03.007] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 02/16/2007] [Accepted: 03/06/2007] [Indexed: 11/17/2022] Open
Abstract
Humans are severely limited in their ability to memorize visual information over short periods of time. Selective attention has been implicated as a limiting factor. Here we used functional magnetic resonance imaging to test the hypothesis that this limitation is due to common neural resources shared by visual working memory (WM) and selective attention. We combined visual search and delayed discrimination of complex objects and independently modulated the demands on selective attention and WM encoding. Participants were presented with a search array and performed easy or difficult visual search in order to encode one or three complex objects into visual WM. Overlapping activation for attention-demanding visual search and WM encoding was observed in distributed posterior and frontal regions. In the right prefrontal cortex and bilateral insula blood oxygen-level-dependent activation additively increased with increased WM load and attentional demand. Conversely, several visual, parietal and premotor areas showed overlapping activation for the two task components and were severely reduced in their WM load response under the condition with high attentional demand. Regions in the left prefrontal cortex were selectively responsive to WM load. Areas selectively responsive to high attentional demand were found within the right prefrontal and bilateral occipital cortex. These results indicate that encoding into visual WM and visual selective attention require to a high degree access to common neural resources. We propose that competition for resources shared by visual attention and WM encoding can limit processing capabilities in distributed posterior brain regions.
Collapse
Affiliation(s)
- Jutta S Mayer
- Department of Psychiatry, Johann Wolfgang Goethe-University, Heinrich-Hoffmann-Str. 10, 60528 Frankfurt, Germany.
| | | | | | | | | | | |
Collapse
|
189
|
Freksa C, Bertel S. Eye movements and smart technology. Comput Biol Med 2007; 37:983-8. [PMID: 17296176 DOI: 10.1016/j.compbiomed.2006.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 11/23/2006] [Accepted: 12/13/2006] [Indexed: 11/19/2022]
Abstract
From a cognitive science/artificial intelligence perspective, this paper identifies the scanpath concept as the instantiation of a general sequencing principle that permeates the organization of spatial scene knowledge throughout the levels of mental processing. As such, it helps create methodologies to open up windows onto higher-level cognitive processes, particularly by relating shifts of visual focus to shifts of attention in mental reasoning. The paper argues that these methodologies form a robust basis for smart applications that employ eye movements to assess and to assist in diagrammatic problem solving.
Collapse
Affiliation(s)
- Christian Freksa
- Cognitive Systems Research Group & SFB/TR 8 Spatial Cognition, Universität Bremen, Cartesium 3.47, 28359 Bremen, Germany
| | | |
Collapse
|
190
|
Petrides M, Pandya DN. Efferent association pathways originating in the caudal prefrontal cortex in the macaque monkey. J Comp Neurol 2007; 498:227-51. [PMID: 16856142 DOI: 10.1002/cne.21048] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The efferent association fibers from the caudal part of the prefrontal cortex to posterior cortical areas course via several pathways: the three components of the superior longitudinal fasciculus (SLF I, SLF II, and SLF III), the arcuate fasciculus (AF), the fronto-occipital fasciculus (FOF), the cingulate fasciculus (CING F), and the extreme capsule (Extm C). Fibers from area 8Av course via FOF and SLF II, merging in the white matter of the inferior parietal lobule (IPL) and terminating in the caudal intraparietal sulcus (IPS). A group of these fibers turns ventrally to terminate in the caudal superior temporal sulcus (STS). Fibers from the rostral part of area 8Ad course via FOF and SLF II to the IPS and IPL and via the AF to the caudal superior temporal gyrus and STS. Some fibers from the rostral part of area 8Ad are conveyed to the medial parieto-occipital region via FOF, to the STS via Extm C, and to the caudal cingulate gyrus via CING F. Fibers from area 8B travel via SLF I to the supplementary motor area and area 31 in the caudal dorsal cingulate region and via the CING F to cingulate areas 24 and 23 and the cingulate motor areas. Fibers from area 9/46d course via SLF I to the superior parietal lobule and medial parieto-occipital region, via SLF II to the IPL. Fibers from area 9/46v travel via SLF III to the rostral IPL and the frontoparietal opercular region and via the CING F to the cingulate gyrus.
Collapse
Affiliation(s)
- M Petrides
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada.
| | | |
Collapse
|
191
|
Loetscher T, Brugger P. A disengagement deficit in representational space. Neuropsychologia 2007; 45:1299-304. [PMID: 17084423 DOI: 10.1016/j.neuropsychologia.2006.09.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 09/26/2006] [Accepted: 09/27/2006] [Indexed: 11/21/2022]
Abstract
Some patients with hemispatial neglect show a deficit of "disengagement", i.e., their left-sided inattention is largely a consequence of an inability to move the spotlight of attention away from right-sided stimuli. We report a neglect patient with a failure of disengagement in imagined space, a feature not previously described. The patient was repeatedly moved along a hallway and had to memorize 20 objects placed alongside the walls (alternating starting points). Each learning run was followed by a recall run, in which objects had to be named in their correct sequence from one imaginary starting point. Initially, when performance was still poor, only right-sided items were named, a response pattern mimicking a neglect of representational space. However, as recall improved over successive runs, left-sided objects were as well memorized as right-sided, but the latter were named before the former. By contrast, if photographs of single objects were presented in the center of a screen for laterality decisions, neither accuracy nor latency of the patient's decisions differentiated between left-sided and right-sided items. We interpret the sticking to the right side during initial periods of free recall, in the absence of side-differences during cued recognition, as a failure to disengage from the right side of a mental image. In view of the extensive cortical and subcortical lesions in our patient the current debate about the functional neuroanatomy of this deficit cannot be resolved. However, the present report adds to our understanding of the heterogeneous nature of deficiencies in the representation of space.
Collapse
Affiliation(s)
- Tobias Loetscher
- Department of Neurology, Unit of Neuropsychology, University Hospital Zurich, CH-8091 Zurich, Switzerland.
| | | |
Collapse
|
192
|
Girard TA, Martius DLMA, Cheyne JA. Mental representation of space: Insights from an oblique distribution of hallucinations. Neuropsychologia 2007; 45:1257-69. [PMID: 17113114 DOI: 10.1016/j.neuropsychologia.2006.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 10/10/2006] [Accepted: 10/13/2006] [Indexed: 11/27/2022]
Abstract
Three-dimensional spatial distributions of hypnagogic and hypnopompic hallucinations associated with sleep paralysis were used to investigate the internal representation of space. Left-right asymmetries in human preferences and abilities are well established. Parallel effects are also observed as lower-upper asymmetries. These parallels could reflect common underlying mechanisms or additive effects of independently evolved horizontal and vertical asymmetries. This study adds to the growing literature on multidimensional spatial biases in a context free from the influence of task-related factors. We present evidence of an oblique bias in the projection of both sensory and motor hallucinations toward lower-left and especially upper-right external space exceeding that accounted for by an additive model of separate horizontal and vertical biases. These observations are consistent with theories regarding a systematic functional relation of hemispheric with ventral and dorsal cerebral organization.
Collapse
Affiliation(s)
- Todd A Girard
- Department of Psychology, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 Canada.
| | | | | |
Collapse
|
193
|
Yeh YY, Kuo BC, Liu HL. The neural correlates of attention orienting in visuospatial working memory for detecting feature and conjunction changes. Brain Res 2006; 1130:146-57. [PMID: 17173876 DOI: 10.1016/j.brainres.2006.10.065] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Revised: 10/19/2006] [Accepted: 10/19/2006] [Indexed: 11/22/2022]
Abstract
The neural mechanisms of attentional orienting in visuospatial working memory for change detection were investigated. A spatial cue was provided with the onset time manipulated to allow more effective top-down control with an early cue than with a late cue. The change type was also manipulated so that accurate detection depended on color or the binding of color and location. The results showed that both the frontal and parietal regions subserved the change detection task without cueing. When data were collapsed over the two change types, early cueing increased activation in the right inferior frontal gyrus (IFG) and middle frontal gyrus (MFG) while late cueing increased activation in the right inferior parietal lobule (IPL) and temporoparietal junction (TPJ) as compared with the no-cue condition. The cue onset time led to different levels of enhancement in the frontal and posterior cortices related to top-down control and stimulus-driven orienting. For feature detection, early cueing increased activation in the right MFG and late cueing increased activation in the bilateral precuneus (PCu), right TPJ, and right cuneus. The neural correlates of conjunction detection involved the right PCu and cerebellum without cueing, were associated with the anterior MFG, left IFG, and the left STG with early cueing, and involved the right MFG, left IFG, and right IPL with late cueing. The left IFG was correlated with memory retrieval of the cued representation for conjunction detection, and the right posterior PCu was associated with maintenance and memory retrieval among competing stimuli.
Collapse
Affiliation(s)
- Yei-Yu Yeh
- Department of Psychology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei, Taiwan 106.
| | | | | |
Collapse
|
194
|
Mitchell DGV, Nakic M, Fridberg D, Kamel N, Pine DS, Blair RJR. The impact of processing load on emotion. Neuroimage 2006; 34:1299-309. [PMID: 17161627 PMCID: PMC1909754 DOI: 10.1016/j.neuroimage.2006.10.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2006] [Revised: 10/02/2006] [Accepted: 10/10/2006] [Indexed: 11/24/2022] Open
Abstract
This event-related fMRI study examined the impact of processing load on the BOLD response to emotional expressions. Participants were presented with composite stimuli consisting of neutral and fearful faces upon which semi-transparent words were superimposed. This manipulation held stimulus-driven features constant across multiple levels of processing load. Participants made either (1) gender discriminations based on the face; (2) case judgments based on the words; or (3) syllable number judgments based on the words. A significant main effect for processing load was revealed in prefrontal cortex, parietal cortex, visual processing areas, and amygdala. Critically, enhanced activity in the amygdala and medial prefrontal cortex seen during gender discriminations was significantly reduced during the linguistic task conditions. A connectivity analysis conducted to investigate theories of cognitive modulation of emotion showed that activity in dorsolateral prefrontal cortex was inversely related to activity in the ventromedial prefrontal cortex. Together, the data suggest that the processing of task-irrelevant emotional information, like neutral information, is subject to the effects of processing load and is under top-down control.
Collapse
Affiliation(s)
- D G V Mitchell
- Mood and Anxiety Disorders Program, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA.
| | | | | | | | | | | |
Collapse
|
195
|
Longo MR, Lourenco SF. Spatial attention and the mental number line: evidence for characteristic biases and compression. Neuropsychologia 2006; 45:1400-7. [PMID: 17157335 DOI: 10.1016/j.neuropsychologia.2006.11.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Revised: 11/02/2006] [Accepted: 11/04/2006] [Indexed: 11/21/2022]
Abstract
Numbers are often proposed to be represented spatially as lying along a mental number line. The present study examined whether the direction of spatial attention operates similarly in physical and numerical space. Participants bisected physical lines by indicating the perceived center and "bisected" the mental number line by estimating (without calculating) the number midway between two others. Healthy participants generally show a slight leftward bias (pseudoneglect) when bisecting physical lines. In the present study, pseudoneglect was also observed on mental number line bisection and, importantly, was greater for participants who showed stronger pseudoneglect on physical line bisection. This finding suggests that hemispheric asymmetries in spatial attention operate similarly in physical and numerical space. Furthermore, this bias increased with the average of the numbers, consistent with the proposal that the spatial representation of the mental number line is nonlinearly compressive, with pairs of numbers lying closer together as their magnitude increases.
Collapse
Affiliation(s)
- Matthew R Longo
- Department of Psychology, University of Chicago, Chicago, IL, USA.
| | | |
Collapse
|
196
|
Abstract
We investigated the role of object-based attention in modulating the maintenance of faces and scenes held online in working memory (WM). Participants had to remember a face and a scene, while cues presented during the delay instructed them to orient their attention to one or the other item. Event-related functional magnetic resonance imaging revealed that orienting attention in WM modulated the activity in fusiform and parahippocampal gyri, involved in maintaining representations of faces and scenes respectively. Measures from complementary behavioral studies indicated that this increase in activity corresponded to improved WM performance. The results show that directed attention can modulate maintenance of specific representations in WM, and help define the interplay between the domains of attention and WM.
Collapse
Affiliation(s)
- Jöran Lepsien
- Brain & Cognition Laboratory, Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
| | | |
Collapse
|
197
|
Lepsien J, Nobre AC. Cognitive control of attention in the human brain: Insights from orienting attention to mental representations. Brain Res 2006; 1105:20-31. [PMID: 16729979 DOI: 10.1016/j.brainres.2006.03.033] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 03/06/2006] [Accepted: 03/08/2006] [Indexed: 10/24/2022]
|
198
|
Affiliation(s)
- Onur Güntürkün
- Department of Biopsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr-University Bochum, Bochum, Germany.
| |
Collapse
|
199
|
Bao M, Li ZH, Chen XC, Zhang DR. Backward inhibition in a task of switching attention within verbal working memory. Brain Res Bull 2006; 69:214-21. [PMID: 16533672 DOI: 10.1016/j.brainresbull.2005.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 11/21/2005] [Accepted: 12/07/2005] [Indexed: 10/25/2022]
Abstract
Three experiments were conducted to examine the backward inhibition effect in attention switching within verbal working memory. Experiment one showed significant backward inhibition effect in a "tri-count task". Experiment two suggested that the effect was not due to a perceptual inhibition on the previously presented figure. Experiment three excluded the sequential expectancy explanation for this inhibition effect. Our results suggest that attention switching between working memory items is accompanied by inhibition of the previously attended working memory item. The findings are discussed in respect to the account of the executive function.
Collapse
Affiliation(s)
- Min Bao
- Hefei National Laboratory for Physical Science at Microscale, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | | | | | | |
Collapse
|
200
|
Summerfield JJ, Lepsien J, Gitelman DR, Mesulam MM, Nobre AC. Orienting Attention Based on Long-Term Memory Experience. Neuron 2006; 49:905-16. [PMID: 16543137 DOI: 10.1016/j.neuron.2006.01.021] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 11/29/2005] [Accepted: 01/11/2006] [Indexed: 11/24/2022]
Abstract
Attentional orienting and memory are intrinsically bound, but their interaction has rarely been investigated. Here we introduce an experimental paradigm using naturalistic scenes to investigate how long-term memory can guide spatial attention and thereby enhance identification of events in the perceptual domain. In the task, stable memories of objects embedded within complex scenes guide spatial orienting. We compared the behavioral effects and neural systems of memory-guided orienting with those in a more traditional attention-orienting task in which transient spatial cues guide attention. Memory-guided attention operated within surprisingly short intervals and conferred reliable and sizeable advantages for detection of objects embedded in scenes. Event-related functional magnetic resonance imaging showed that memory-guided attention involves the interaction between brain areas participating in retrieval of memories for spatial context with the parietal-frontal network for visual spatial orienting. Activity in the hippocampus was specifically engaged in memory-guided spatial attention and correlated with the ensuing behavioral advantage.
Collapse
Affiliation(s)
- Jennifer J Summerfield
- Brain and Cognition Laboratory, Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom
| | | | | | | | | |
Collapse
|