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Song J, Ampatzis K, Ausborn J, El Manira A. A Hardwired Circuit Supplemented with Endocannabinoids Encodes Behavioral Choice in Zebrafish. Curr Biol 2015; 25:2610-20. [PMID: 26412127 DOI: 10.1016/j.cub.2015.08.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/19/2015] [Accepted: 08/20/2015] [Indexed: 12/25/2022]
Abstract
Animals constantly make behavioral choices to facilitate moving efficiently through their environment. When faced with a threat, animals make decisions in the midst of other ongoing behaviors through a context-dependent integration of sensory stimuli. In vertebrates, the mechanisms underlying behavioral selection are poorly understood. Here, we show that ongoing swimming in zebrafish is suppressed by escape. The selection of escape over swimming is mediated by switching between two distinct motoneuron pools. A hardwired circuit mediates this switch by acting as a clutch-like mechanism to disengage the swimming motoneuron pool and engage the escape motoneuron pool. Threshold for escape initiation is lowered and swimming suppression is prolonged by endocannabinoid neuromodulation. Thus, our results reveal a novel cellular mechanism involving a hardwired circuit supplemented with endocannabinoids acting as a clutch-like mechanism to engage/disengage distinct motor pools to ensure behavioral selection and a smooth execution of motor action sequences in a vertebrate system.
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Affiliation(s)
- Jianren Song
- Department of Neuroscience, Karolinska Institute, 171 77 Stockholm, Sweden
| | | | - Jessica Ausborn
- Department of Neuroscience, Karolinska Institute, 171 77 Stockholm, Sweden
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152
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Lorteije JAM, Zylberberg A, Ouellette BG, De Zeeuw CI, Sigman M, Roelfsema PR. The Formation of Hierarchical Decisions in the Visual Cortex. Neuron 2015; 87:1344-1356. [PMID: 26365766 DOI: 10.1016/j.neuron.2015.08.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 07/12/2015] [Accepted: 08/07/2015] [Indexed: 01/14/2023]
Abstract
Intelligence relies on our ability to find appropriate sequences of decisions in complex problem spaces. The efficiency of a problem solver depends on the speed of its individual decisions and the number of decisions it can explore in parallel. It remains unknown whether the primate brain can consider multiple decisions at the same time. We therefore trained monkeys to navigate through a decision tree with stochastic sensory evidence at multiple branching points and recorded neuronal activity in visual cortical areas V1 and V4. We found a first phase of decision making in which neuronal activity increased in parallel along multiple branches of the decision tree. This was followed by an integration phase where the optimal overall strategy crystallized as the result of interactions between local decisions. The results reveal how sensory evidence is integrated efficiently for hierarchical decisions and contribute to our understanding of the brain mechanisms that implement complex mental programs.
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Affiliation(s)
- Jeannette A M Lorteije
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands; Center for Neuroscience, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands
| | - Ariel Zylberberg
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands; Laboratory of Integrative Neuroscience, Physics Department, Buenos Aires University, Intendente Güiraldes 2160, 1428 Buenos Aires, Argentina; Institute of Biomedical Engineering, Faculty of Engineering, Buenos Aires University, Avenue Paseo Colón 850, 1063 Buenos Aires, Argentina; Laboratory of Applied Artificial Intelligence, Computer Science Department, Facultad de Ciencias Exactas y Naturales, Buenos Aires University, Intendente Güiraldes 2160, 1428 Buenos Aires, Argentina
| | - Brian G Ouellette
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Chris I De Zeeuw
- Cerebellar Coordination and Cognition Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands; Department of Neuroscience, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Mariano Sigman
- Laboratory of Integrative Neuroscience, Physics Department, Buenos Aires University, Intendente Güiraldes 2160, 1428 Buenos Aires, Argentina; Universidad Torcuato Di Tella, Almirante Juan Saenz Valiente 1010, C1428BIJ Buenos Aires, Argentina
| | - Pieter R Roelfsema
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands; Department of Integrative Neurophysiology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands; Psychiatry Department, Academic Medical Center, 1105 AC Amsterdam, the Netherlands.
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153
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Motion makes sense: an adaptive motor-sensory strategy underlies the perception of object location in rats. J Neurosci 2015; 35:8777-89. [PMID: 26063912 DOI: 10.1523/jneurosci.4149-14.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tactile perception is obtained by coordinated motor-sensory processes. We studied the processes underlying the perception of object location in freely moving rats. We trained rats to identify the relative location of two vertical poles placed in front of them and measured at high resolution the motor and sensory variables (19 and 2 variables, respectively) associated with this whiskers-based perceptual process. We found that the rats developed stereotypic head and whisker movements to solve this task, in a manner that can be described by several distinct behavioral phases. During two of these phases, the rats' whiskers coded object position by first temporal and then angular coding schemes. We then introduced wind (in two opposite directions) and remeasured their perceptual performance and motor-sensory variables. Our rats continued to perceive object location in a consistent manner under wind perturbations while maintaining all behavioral phases and relatively constant sensory coding. Constant sensory coding was achieved by keeping one group of motor variables (the "controlled variables") constant, despite the perturbing wind, at the cost of strongly modulating another group of motor variables (the "modulated variables"). The controlled variables included coding-relevant variables, such as head azimuth and whisker velocity. These results indicate that consistent perception of location in the rat is obtained actively, via a selective control of perception-relevant motor variables.
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154
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Lateralized delay period activity marks the focus of spatial attention in working memory: evidence from somatosensory event-related brain potentials. J Neurosci 2015; 35:6689-95. [PMID: 25926447 DOI: 10.1523/jneurosci.5046-14.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The short-term retention of sensory information in working memory (WM) is known to be associated with a sustained enhancement of neural activity. What remains controversial is whether this neural trace indicates the sustained storage of information or the allocation of attention. To evaluate the storage and attention accounts, we examined sustained tactile contralateral delay activity (tCDA component) of the event-related potential. The tCDA manifests over somatosensory cortex contralateral to task-relevant tactile information during stimulus retention. Two tactile sample sets (S1, S2) were presented sequentially, separated by 1.5 s. Each set comprised two stimuli, one per hand. Human participants memorized the location of one task-relevant stimulus per sample set and judged whether one of these locations was stimulated again at memory test. The two relevant pulses were unpredictably located on the same hand (stay trials) or on different hands (shift trials). Initially, tCDA components emerged contralateral to the relevant S1 pulse. Sequential loading of WM enhanced the tCDA after S2 was presented on stay trials. On shift trials, the tCDA's polarity reversed after S2 presentation, resulting in delay activity that was now contralateral to the task-relevant S2 pulse. The disappearance of a lateralized neural trace for the relevant S1 pulse did not impair memory accuracy for this stimulus on shift trials. These results contradict the storage account and suggest that delay period activity indicates the sustained engagement of an attention-based rehearsal mechanism. In conclusion, somatosensory delay period activity marks the current focus of attention in tactile WM.
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155
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Haas S, Brock C, Krogh K, Gram M, Lundby L, Drewes AM, Laurberg S. Abnormal neuronal response to rectal and anal stimuli in patients with idiopathic fecal incontinence. Neurogastroenterol Motil 2015; 27:954-62. [PMID: 25903483 DOI: 10.1111/nmo.12567] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/16/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND The pathophysiology behind idiopathic fecal incontinence (IFI) is poorly understood. We hypothesized abnormal sensory pathways along the brain-gut axis as a key player in this disease, reflected in cortical evoked potentials (CEP) from mechanical stimuli of the rectum and the anal canal. METHODS CEPs were recorded during repeated rapid balloon distensions of the rectum and anal canal in 19 women with IFI (mean age: 60 ± 14, mean Wexner score: 14.7 ± 2.9) and in 19 healthy women (mean age: 56 ± 11, mean Wexner score: 1.1 ± 1.3). Latencies, amplitudes and topography of CEPs elicited by rectal distension were compared between the groups. CEPs from both rectal and anal distensions were examined using spectral band analysis of single sweeps determining the relative amplitude of five spectral bands as a proxy of neuronal processing. KEY RESULTS Compared to controls IFI patients had prolonged latency of CEPs from rectal distension by up to 27% (p < 0.001) while amplitudes and topography were similar (all p > 0.7 and all p > 0.23). Spectral analysis of CEPs from rectal distensions showed no difference (all p > 0.1) between groups. However, analysis of CEPs following distension of the anal canal resulted in abnormally low activity in beta (8-12 Hz; p < 0.001) band and high activity in the gamma (32-70 Hz; p = 0.04) band in patients. CONCLUSIONS & INFERENCES IFI seems to be associated with impaired ano-rectal sensory functions in both the afferent fibers to the brain and the cortical processing of anal sensory pathways. This may play a central role for the pathogenesis of IFI.
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Affiliation(s)
- S Haas
- Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark
| | - C Brock
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark.,Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - K Krogh
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - M Gram
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - L Lundby
- Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark
| | - A M Drewes
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark.,Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - S Laurberg
- Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark
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156
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Ku Y, Zhao D, Bodner M, Zhou YD. Cooperative processing in primary somatosensory cortex and posterior parietal cortex during tactile working memory. Eur J Neurosci 2015; 42:1905-11. [PMID: 25980785 DOI: 10.1111/ejn.12950] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/25/2015] [Accepted: 05/13/2015] [Indexed: 10/23/2022]
Abstract
In the present study, causal roles of both the primary somatosensory cortex (SI) and the posterior parietal cortex (PPC) were investigated in a tactile unimodal working memory (WM) task. Individual magnetic resonance imaging-based single-pulse transcranial magnetic stimulation (spTMS) was applied, respectively, to the left SI (ipsilateral to tactile stimuli), right SI (contralateral to tactile stimuli) and right PPC (contralateral to tactile stimuli), while human participants were performing a tactile-tactile unimodal delayed matching-to-sample task. The time points of spTMS were 300, 600 and 900 ms after the onset of the tactile sample stimulus (duration: 200 ms). Compared with ipsilateral SI, application of spTMS over either contralateral SI or contralateral PPC at those time points significantly impaired the accuracy of task performance. Meanwhile, the deterioration in accuracy did not vary with the stimulating time points. Together, these results indicate that the tactile information is processed cooperatively by SI and PPC in the same hemisphere, starting from the early delay of the tactile unimodal WM task. This pattern of processing of tactile information is different from the pattern in tactile-visual cross-modal WM. In a tactile-visual cross-modal WM task, SI and PPC contribute to the processing sequentially, suggesting a process of sensory information transfer during the early delay between modalities.
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Affiliation(s)
- Yixuan Ku
- The Key Lab of Brain Functional Genomics, MOE & STCSM, Institute of Cognitive Neuroscience, 3663, North Zhongshan Road, School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China.,Departments of Neurology, Physiology and Psychiatry, University of California, San Francisco, CA, USA.,NYU-ECNU Institute of Brain and Cognitive Science, NYU Shanghai and Collaborative Innovation Center for Brain Science, Shanghai, China
| | - Di Zhao
- The Key Lab of Brain Functional Genomics, MOE & STCSM, Institute of Cognitive Neuroscience, 3663, North Zhongshan Road, School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China
| | | | - Yong-Di Zhou
- NYU-ECNU Institute of Brain and Cognitive Science, NYU Shanghai and Collaborative Innovation Center for Brain Science, Shanghai, China.,Krieger Mind/Brain Institute, Johns Hopkins University, 3400 N. Charles Street, 338 Krieger Hall, Baltimore, MA 21218, USA
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157
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Strait CE, Sleezer BJ, Hayden BY. Signatures of Value Comparison in Ventral Striatum Neurons. PLoS Biol 2015; 13:e1002173. [PMID: 26086735 PMCID: PMC4472856 DOI: 10.1371/journal.pbio.1002173] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 05/08/2015] [Indexed: 11/18/2022] Open
Abstract
The ventral striatum (VS), like its cortical afferents, is closely associated with processing of rewards, but the relative contributions of striatal and cortical reward systems remains unclear. Most theories posit distinct roles for these structures, despite their similarities. We compared responses of VS neurons to those of ventromedial prefrontal cortex (vmPFC) Area 14 neurons, recorded in a risky choice task. Five major response patterns observed in vmPFC were also observed in VS: (1) offer value encoding, (2) value difference encoding, (3) preferential encoding of chosen relative to unchosen value, (4) a correlation between residual variance in responses and choices, and (5) prominent encoding of outcomes. We did observe some differences as well; in particular, preferential encoding of the chosen option was stronger and started earlier in VS than in vmPFC. Nonetheless, the close match between vmPFC and VS suggests that cortex and its striatal targets make overlapping contributions to economic choice. A study of single neurons in the ventral striatum reveals signatures of value comparison and selection during a risky choice task, suggesting that the cortex and its striatal targets make overlapping contributions to the choice process. Read the accompanying Primer. The neural calculations underlying reward-based choice are closely associated with a network of brain areas including the ventral striatum (VS) and ventromedial prefrontal cortex (vmPFC). Most theories ascribe distinct roles to these two structures during choice, but these differences have yet to be confirmed at the level of single neurons. We compared responses of VS neurons to those of vmPFC neurons recorded in rhesus macaques choosing between potential gambles for water rewards. We found widespread similarities in the way that VS and vmPFC neurons fire during the choice process. Neurons in both areas encoded the value of the offered gamble, the difference in value between offered gambles, and the gamble outcome. Additionally, both areas showed stronger coding for the chosen gamble than for the unchosen one and predicted choice even when we controlled for offer value. Interestingly, preferential encoding of the chosen option was stronger and started earlier in VS than in vmPFC. Nonetheless, similarities between vmPFC and VS suggest that cortex and its striatal targets make overlapping contributions to reward-based choice.
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Affiliation(s)
- Caleb E. Strait
- Department of Brain and Cognitive Sciences and Center for Visual Science, University of Rochester, Rochester, New York, United States of America
- * E-mail:
| | - Brianna J. Sleezer
- Department of Brain and Cognitive Sciences and Center for Visual Science, University of Rochester, Rochester, New York, United States of America
- Neuroscience Graduate Program, University of Rochester, Rochester, New York, United States of America
| | - Benjamin Y. Hayden
- Department of Brain and Cognitive Sciences and Center for Visual Science, University of Rochester, Rochester, New York, United States of America
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158
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Kim J, Chung YG, Park JY, Chung SC, Wallraven C, Bülthoff HH, Kim SP. Decoding Accuracy in Supplementary Motor Cortex Correlates with Perceptual Sensitivity to Tactile Roughness. PLoS One 2015; 10:e0129777. [PMID: 26067832 PMCID: PMC4465937 DOI: 10.1371/journal.pone.0129777] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 05/13/2015] [Indexed: 11/20/2022] Open
Abstract
Perceptual sensitivity to tactile roughness varies across individuals for the same degree of roughness. A number of neurophysiological studies have investigated the neural substrates of tactile roughness perception, but the neural processing underlying the strong individual differences in perceptual roughness sensitivity remains unknown. In this study, we explored the human brain activation patterns associated with the behavioral discriminability of surface texture roughness using functional magnetic resonance imaging (fMRI). First, a whole-brain searchlight multi-voxel pattern analysis (MVPA) was used to find brain regions from which we could decode roughness information. The searchlight MVPA revealed four brain regions showing significant decoding results: the supplementary motor area (SMA), contralateral postcentral gyrus (S1), and superior portion of the bilateral temporal pole (STP). Next, we evaluated the behavioral roughness discrimination sensitivity of each individual using the just-noticeable difference (JND) and correlated this with the decoding accuracy in each of the four regions. We found that only the SMA showed a significant correlation between neuronal decoding accuracy and JND across individuals; Participants with a smaller JND (i.e., better discrimination ability) exhibited higher decoding accuracy from their voxel response patterns in the SMA. Our findings suggest that multivariate voxel response patterns presented in the SMA represent individual perceptual sensitivity to tactile roughness and people with greater perceptual sensitivity to tactile roughness are likely to have more distinct neural representations of different roughness levels in their SMA.
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Affiliation(s)
- Junsuk Kim
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea
| | - Yoon Gi Chung
- IBS Center for Neuroscience Imaging Research, Sungkyunkwan University, Suwon, Republic of Korea
| | - Jang-Yeon Park
- IBS Center for Neuroscience Imaging Research, Sungkyunkwan University, Suwon, Republic of Korea; Department of Global Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Soon-Cheol Chung
- School of Biomedical Engineering, Konkuk University, Chungju, Republic of Korea
| | - Christian Wallraven
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea
| | - Heinrich H Bülthoff
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea; Department of Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Sung-Phil Kim
- Department of Human and Systems Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
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159
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Belief states as a framework to explain extra-retinal influences in visual cortex. Curr Opin Neurobiol 2015; 32:45-52. [DOI: 10.1016/j.conb.2014.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/24/2014] [Accepted: 10/26/2014] [Indexed: 12/13/2022]
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160
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Hasson U, Chen J, Honey CJ. Hierarchical process memory: memory as an integral component of information processing. Trends Cogn Sci 2015; 19:304-13. [PMID: 25980649 PMCID: PMC4457571 DOI: 10.1016/j.tics.2015.04.006] [Citation(s) in RCA: 347] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/07/2015] [Accepted: 04/10/2015] [Indexed: 11/28/2022]
Abstract
Models of working memory (WM) commonly focus on how information is encoded into and retrieved from storage at specific moments. However, in the majority of real-life processes, past information is used continuously to process incoming information across multiple timescales. Considering single-unit, electrocorticography, and functional imaging data, we argue that (i) virtually all cortical circuits can accumulate information over time, and (ii) the timescales of accumulation vary hierarchically, from early sensory areas with short processing timescales (10s to 100s of milliseconds) to higher-order areas with long processing timescales (many seconds to minutes). In this hierarchical systems perspective, memory is not restricted to a few localized stores, but is intrinsic to information processing that unfolds throughout the brain on multiple timescales.
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Affiliation(s)
- Uri Hasson
- Department of Psychology and the Neuroscience Institute, Princeton University, NJ 08544-1010, USA.
| | - Janice Chen
- Department of Psychology and the Neuroscience Institute, Princeton University, NJ 08544-1010, USA
| | - Christopher J Honey
- Department of Psychology, University of Toronto, Toronto ON, M5S 3G3, Canada
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161
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Gurtubay-Antolin A, Rodriguez-Herreros B, Rodríguez-Fornells A. The speed of object recognition from a haptic glance: event-related potential evidence. J Neurophysiol 2015; 113:3069-75. [PMID: 25744887 PMCID: PMC4455565 DOI: 10.1152/jn.00836.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 02/27/2015] [Indexed: 11/22/2022] Open
Abstract
Recognition of an object usually involves a wide range of sensory inputs. Accumulating evidence shows that first brain responses associated with the visual discrimination of objects emerge around 150 ms, but fewer studies have been devoted to measure the first neural signature of haptic recognition. To investigate the speed of haptic processing, we recorded event-related potentials (ERPs) during a shape discrimination task without visual information. After a restricted exploratory procedure, participants (n = 27) were instructed to judge whether the touched object corresponded to an expected object whose name had been previously presented in a screen. We encountered that any incongruence between the presented word and the shape of the object evoked a frontocentral negativity starting at ∼175 ms. With the use of source analysis and L2 minimum-norm estimation, the neural sources of this differential activity were located in higher level somatosensory areas and prefrontal regions involved in error monitoring and cognitive control. Our findings reveal that the somatosensory system is able to complete an amount of haptic processing substantial enough to trigger conflict-related responses in medial and prefrontal cortices in <200 ms. The present results show that our haptic system is a fast recognition device closely interlinked with error- and conflict-monitoring processes.
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Affiliation(s)
- Ane Gurtubay-Antolin
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Department of Basic Psychology, Campus Bellvitge, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; and
| | - Borja Rodriguez-Herreros
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Department of Basic Psychology, Campus Bellvitge, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; and
| | - Antoni Rodríguez-Fornells
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Department of Basic Psychology, Campus Bellvitge, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain; and Catalan Institution for Research and Advanced Studies, Barcelona, Spain
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162
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Evidence accumulation in obsessive-compulsive disorder: the role of uncertainty and monetary reward on perceptual decision-making thresholds. Neuropsychopharmacology 2015; 40:1192-202. [PMID: 25425323 PMCID: PMC4349497 DOI: 10.1038/npp.2014.303] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 10/28/2014] [Accepted: 11/07/2014] [Indexed: 02/02/2023]
Abstract
The compulsive behaviour underlying obsessive-compulsive disorder (OCD) may be related to abnormalities in decision-making. The inability to commit to ultimate decisions, for example, patients unable to decide whether their hands are sufficiently clean, may reflect failures in accumulating sufficient evidence before a decision. Here we investigate the process of evidence accumulation in OCD in perceptual discrimination, hypothesizing enhanced evidence accumulation relative to healthy volunteers. Twenty-eight OCD patients and thirty-five controls were tested with a low-level visual perceptual task (random-dot-motion task, RDMT) and two response conflict control tasks. Regression analysis across different motion coherence levels and Hierarchical Drift Diffusion Modelling (HDDM) were used to characterize response strategies between groups in the RDMT. Patients required more evidence under high uncertainty perceptual contexts, as indexed by longer response time and higher decision boundaries. HDDM, which defines a decision when accumulated noisy evidence reaches a decision boundary, further showed slower drift rate towards the decision boundary reflecting poorer quality of evidence entering the decision process in patients under low uncertainty. With monetary incentives emphasizing speed and penalty for slower responses, patients decreased the decision thresholds relative to controls, accumulating less evidence in low uncertainty. These findings were unrelated to visual perceptual deficits and response conflict. This study provides evidence for impaired decision-formation processes in OCD, with a differential influence of high and low uncertainty contexts on evidence accumulation (decision threshold) and on the quality of evidence gathered (drift rates). It further emphasizes that OCD patients are sensitive to monetary incentives heightening speed in the speed-accuracy tradeoff, improving evidence accumulation.
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163
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Wohrer A, Machens CK. On the number of neurons and time scale of integration underlying the formation of percepts in the brain. PLoS Comput Biol 2015; 11:e1004082. [PMID: 25793393 PMCID: PMC4368836 DOI: 10.1371/journal.pcbi.1004082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 12/10/2014] [Indexed: 11/18/2022] Open
Abstract
All of our perceptual experiences arise from the activity of neural populations. Here we study the formation of such percepts under the assumption that they emerge from a linear readout, i.e., a weighted sum of the neurons’ firing rates. We show that this assumption constrains the trial-to-trial covariance structure of neural activities and animal behavior. The predicted covariance structure depends on the readout parameters, and in particular on the temporal integration window w and typical number of neurons K used in the formation of the percept. Using these predictions, we show how to infer the readout parameters from joint measurements of a subject’s behavior and neural activities. We consider three such scenarios: (1) recordings from the complete neural population, (2) recordings of neuronal sub-ensembles whose size exceeds K, and (3) recordings of neuronal sub-ensembles that are smaller than K. Using theoretical arguments and artificially generated data, we show that the first two scenarios allow us to recover the typical spatial and temporal scales of the readout. In the third scenario, we show that the readout parameters can only be recovered by making additional assumptions about the structure of the full population activity. Our work provides the first thorough interpretation of (feed-forward) percept formation from a population of sensory neurons. We discuss applications to experimental recordings in classic sensory decision-making tasks, which will hopefully provide new insights into the nature of perceptual integration. This article deals with the interpretation of neural activities during perceptual decision-making tasks, where animals must assess the value of a sensory stimulus and take a decision on the basis of their percept. A “standard model” for these tasks has progressively emerged, whence the animal’s percept and subsequent choice on each trial are obtained from a linear integration of the activity of sensory neurons. However, up to date, there has been no principled method to estimate the parameters of this model: mainly, the typical number of neurons K from the population involved in conveying the percept, and the typical time scale w during which these neurons’ activities are integrated. In this article, we propose a novel method to estimate these quantities from experimental data, and thus assess the validity of the standard model of percept formation. In the process, we clarify the predictions of the standard model regarding two classic experimental measures in these tasks: sensitivity, which is the animal’s ability to distinguish nearby stimulus values, and choice signals, which assess the amount of correlation between the activity of single neurons and the animal’s ultimate choice on each trial.
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Affiliation(s)
- Adrien Wohrer
- Group for Neural Theory, Laboratoire de Neurosciences Cognitives, INSERM U960, École Normale Supérieure, Paris, France
- * E-mail:
| | - Christian K. Machens
- Group for Neural Theory, Laboratoire de Neurosciences Cognitives, INSERM U960, École Normale Supérieure, Paris, France
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
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164
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Ku Y, Bodner M, Zhou YD. Prefrontal cortex and sensory cortices during working memory: quantity and quality. Neurosci Bull 2015; 31:175-82. [PMID: 25732526 DOI: 10.1007/s12264-014-1503-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 11/10/2014] [Indexed: 11/25/2022] Open
Abstract
The activity in sensory cortices and the prefrontal cortex (PFC) throughout the delay interval of working memory (WM) tasks reflect two aspects of WM-quality and quantity, respectively. The delay activity in sensory cortices is fine-tuned to sensory information and forms the neural basis of the precision of WM storage, while the delay activity in the PFC appears to represent behavioral goals and filters out irrelevant distractions, forming the neural basis of the quantity of task-relevant information in WM. The PFC and sensory cortices interact through different frequency bands of neuronal oscillation (theta, alpha, and gamma) to fulfill goal-directed behaviors.
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Affiliation(s)
- Yixuan Ku
- Key Laboratory of Brain Functional Genomics, Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, 200062, China,
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165
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Rombouts JO, Bohte SM, Roelfsema PR. How attention can create synaptic tags for the learning of working memories in sequential tasks. PLoS Comput Biol 2015; 11:e1004060. [PMID: 25742003 PMCID: PMC4351255 DOI: 10.1371/journal.pcbi.1004060] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 11/24/2014] [Indexed: 11/17/2022] Open
Abstract
Intelligence is our ability to learn appropriate responses to new stimuli and situations. Neurons in association cortex are thought to be essential for this ability. During learning these neurons become tuned to relevant features and start to represent them with persistent activity during memory delays. This learning process is not well understood. Here we develop a biologically plausible learning scheme that explains how trial-and-error learning induces neuronal selectivity and working memory representations for task-relevant information. We propose that the response selection stage sends attentional feedback signals to earlier processing levels, forming synaptic tags at those connections responsible for the stimulus-response mapping. Globally released neuromodulators then interact with tagged synapses to determine their plasticity. The resulting learning rule endows neural networks with the capacity to create new working memory representations of task relevant information as persistent activity. It is remarkably generic: it explains how association neurons learn to store task-relevant information for linear as well as non-linear stimulus-response mappings, how they become tuned to category boundaries or analog variables, depending on the task demands, and how they learn to integrate probabilistic evidence for perceptual decisions.
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Affiliation(s)
- Jaldert O. Rombouts
- Department of Life Sciences, Centrum Wiskunde & Informatica, Amsterdam, The Netherlands
| | - Sander M. Bohte
- Department of Life Sciences, Centrum Wiskunde & Informatica, Amsterdam, The Netherlands
| | - Pieter R. Roelfsema
- Department of Vision & Cognition, Netherlands Institute for Neurosciences, an institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands
- Department of Integrative Neurophysiology, Centre for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
- Psychiatry Department, Academic Medical Center, Amsterdam, The Netherlands
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166
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Ritter P, Born J, Brecht M, Dinse HR, Heinemann U, Pleger B, Schmitz D, Schreiber S, Villringer A, Kempter R. State-dependencies of learning across brain scales. Front Comput Neurosci 2015; 9:1. [PMID: 25767445 PMCID: PMC4341560 DOI: 10.3389/fncom.2015.00001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/06/2015] [Indexed: 01/09/2023] Open
Abstract
Learning is a complex brain function operating on different time scales, from milliseconds to years, which induces enduring changes in brain dynamics. The brain also undergoes continuous “spontaneous” shifts in states, which, amongst others, are characterized by rhythmic activity of various frequencies. Besides the most obvious distinct modes of waking and sleep, wake-associated brain states comprise modulations of vigilance and attention. Recent findings show that certain brain states, particularly during sleep, are essential for learning and memory consolidation. Oscillatory activity plays a crucial role on several spatial scales, for example in plasticity at a synaptic level or in communication across brain areas. However, the underlying mechanisms and computational rules linking brain states and rhythms to learning, though relevant for our understanding of brain function and therapeutic approaches in brain disease, have not yet been elucidated. Here we review known mechanisms of how brain states mediate and modulate learning by their characteristic rhythmic signatures. To understand the critical interplay between brain states, brain rhythms, and learning processes, a wide range of experimental and theoretical work in animal models and human subjects from the single synapse to the large-scale cortical level needs to be integrated. By discussing results from experiments and theoretical approaches, we illuminate new avenues for utilizing neuronal learning mechanisms in developing tools and therapies, e.g., for stroke patients and to devise memory enhancement strategies for the elderly.
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Affiliation(s)
- Petra Ritter
- Minerva Research Group BrainModes, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany ; Department of Neurology, Charité University Medicine Berlin Berlin, Germany ; Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin Berlin, Germany ; Berlin School of Mind and Brain & Mind and Brain Institute, Humboldt-Universität zu Berlin Berlin, Germany
| | - Jan Born
- Department of Medical Psychology and Behavioral Neurobiology & Center for Integrative Neuroscience (CIN), University of Tübingen Tübingen, Germany
| | - Michael Brecht
- Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin Berlin, Germany
| | - Hubert R Dinse
- Neural Plasticity Lab, Institute for Neuroinformatics, Ruhr-University Bochum Bochum, Germany ; Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-University Bochum Bochum, Germany
| | - Uwe Heinemann
- Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin Berlin, Germany ; NeuroCure Cluster of Excellence Berlin, Germany
| | - Burkhard Pleger
- Clinic for Cognitive Neurology, University Hospital Leipzig Leipzig, Germany ; Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Dietmar Schmitz
- Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin Berlin, Germany ; NeuroCure Cluster of Excellence Berlin, Germany ; Neuroscience Research Center NWFZ, Charité University Medicine Berlin Berlin, Germany ; Max-Delbrück Center for Molecular Medicine, MDC Berlin, Germany ; Center for Neurodegenerative Diseases (DZNE) Berlin, Germany
| | - Susanne Schreiber
- Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin Berlin, Germany ; Department of Biology, Institute for Theoretical Biology (ITB), Humboldt-Universität zu Berlin Berlin, Germany
| | - Arno Villringer
- Berlin School of Mind and Brain & Mind and Brain Institute, Humboldt-Universität zu Berlin Berlin, Germany ; Clinic for Cognitive Neurology, University Hospital Leipzig Leipzig, Germany ; Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Richard Kempter
- Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin Berlin, Germany ; Department of Biology, Institute for Theoretical Biology (ITB), Humboldt-Universität zu Berlin Berlin, Germany
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167
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168
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Kropotov JD, Ponomarev VA. Differentiation of neuronal operations in latent components of event-related potentials in delayed match-to-sample tasks. Psychophysiology 2015; 52:826-38. [PMID: 25639295 DOI: 10.1111/psyp.12410] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Revised: 10/31/2014] [Indexed: 11/30/2022]
Abstract
The goal of this study was to decompose ERPs into latent components associated with hypothetical processes of category discrimination, comparison to working memory and action-related operations. In five variants of the delayed match-to-sample s1-s2 task, instructions were varied for manipulation of the processes. The blind source separation was applied to the collection of ERPs. The category discrimination operation is attributed to three latent components with peak latencies of 130 to 170 ms, which are generated in different parts of the prestriate cortex. The comparison to working memory operation is attributed to a latent component that is generated in the temporal cortex and manifested in a positive deflection with a peak latency of 250 ms after s2. The category discrimination and comparison to working memory effects were dissociated spatially and temporally from attention and action selection effects.
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Affiliation(s)
- Juri D Kropotov
- N.P. Bechtereva Institute of the Human Brain of Russian Academy of Sciences, St. Petersburg, Russia.,Institute of Psychology, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neuropsychology, Andrzej Frycz Modrzewski Krakow University, Krakow, Poland
| | - Valery A Ponomarev
- N.P. Bechtereva Institute of the Human Brain of Russian Academy of Sciences, St. Petersburg, Russia
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169
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Sustained maintenance of somatotopic information in brain regions recruited by tactile working memory. J Neurosci 2015; 35:1390-5. [PMID: 25632117 DOI: 10.1523/jneurosci.3535-14.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To adaptively guide ongoing behavior, representations in working memory (WM) often have to be modified in line with changing task demands. We used event-related potentials (ERPs) to demonstrate that tactile WM representations are stored in modality-specific cortical regions, that the goal-directed modulation of these representations is mediated through hemispheric-specific activation of somatosensory areas, and that the rehearsal of somatotopic coordinates in memory is accomplished by modality-specific spatial attention mechanisms. Participants encoded two tactile sample stimuli presented simultaneously to the left and right hands, before visual retro-cues indicated which of these stimuli had to be retained to be matched with a subsequent test stimulus on the same hand. Retro-cues triggered a sustained tactile contralateral delay activity component with a scalp topography over somatosensory cortex contralateral to the cued hand. Early somatosensory ERP components to task-irrelevant probe stimuli (that were presented after the retro-cues) and to subsequent test stimuli were enhanced when these stimuli appeared at the currently memorized location relative to other locations on the cued hand, demonstrating that a precise focus of spatial attention was established during the selective maintenance of tactile events in WM. These effects were observed regardless of whether participants performed the matching task with uncrossed or crossed hands, indicating that WM representations in this task were based on somatotopic rather than allocentric spatial coordinates. In conclusion, spatial rehearsal in tactile WM operates within somatotopically organized sensory brain areas that have been recruited for information storage.
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170
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Zuo Y, Safaai H, Notaro G, Mazzoni A, Panzeri S, Diamond ME. Complementary contributions of spike timing and spike rate to perceptual decisions in rat S1 and S2 cortex. Curr Biol 2015; 25:357-363. [PMID: 25619766 DOI: 10.1016/j.cub.2014.11.065] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 10/20/2014] [Accepted: 11/28/2014] [Indexed: 10/24/2022]
Abstract
When a neuron responds to a sensory stimulus, two fundamental codes [1-6] may transmit the information specifying stimulus identity--spike rate (the total number of spikes in the sequence, normalized by time) and spike timing (the detailed millisecond-scale temporal structure of the response). To assess the functional significance of these codes, we recorded neuronal responses in primary (S1) and secondary (S2) somatosensory cortex of five rats as they used their whiskers to identify textured surfaces. From the spike trains evoked during whisker contact with the texture, we computed the information that rate and timing codes carried about texture identity and about the rat's choice. S1 and S2 spike timing carried more information about stimulus and about choice than spike rates; the conjunction of rate and timing carried more information than either code alone. Moreover, on trials when our spike-timing-decoding algorithm extracted faithful texture information, the rat was more likely to choose correctly; when our spike-timing-decoding algorithm extracted misleading texture information, the rat was more likely to err. For spike rate information, the relationship between faithfulness of the message and correct choice was significant but weaker. These results indicate that spike timing makes crucial contributions to tactile perception, complementing and surpassing those made by rate. The language by which somatosensory cortical neurons transmit information, and the readout mechanism used to produce behavior, appears to rely on multiplexed signals from spike rate and timing.
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Affiliation(s)
- Yanfang Zuo
- Tactile Perception and Learning Laboratory, International School for Advanced Studies, 34136 Trieste, Italy
| | - Houman Safaai
- Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Corso Bettini 31, 38068 Rovereto (TN), Italy
| | - Giuseppe Notaro
- Behavior and Brain Organization, Center of Advanced European Studies and Research, Ludwig-Erhard Allee 2, 53175 Bonn, Germany
| | - Alberto Mazzoni
- Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Corso Bettini 31, 38068 Rovereto (TN), Italy
| | - Stefano Panzeri
- Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Corso Bettini 31, 38068 Rovereto (TN), Italy.
| | - Mathew E Diamond
- Tactile Perception and Learning Laboratory, International School for Advanced Studies, 34136 Trieste, Italy.
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171
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Daikhin L, Ahissar M. Fast learning of simple perceptual discriminations reduces brain activation in working memory and in high-level auditory regions. J Cogn Neurosci 2015; 27:1308-21. [PMID: 25603023 DOI: 10.1162/jocn_a_00786] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Introducing simple stimulus regularities facilitates learning of both simple and complex tasks. This facilitation may reflect an implicit change in the strategies used to solve the task when successful predictions regarding incoming stimuli can be formed. We studied the modifications in brain activity associated with fast perceptual learning based on regularity detection. We administered a two-tone frequency discrimination task and measured brain activation (fMRI) under two conditions: with and without a repeated reference tone. Although participants could not explicitly tell the difference between these two conditions, the introduced regularity affected both performance and the pattern of brain activation. The "No-Reference" condition induced a larger activation in frontoparietal areas known to be part of the working memory network. However, only the condition with a reference showed fast learning, which was accompanied by a reduction of activity in two regions: the left intraparietal area, involved in stimulus retention, and the posterior superior-temporal area, involved in representing auditory regularities. We propose that this joint reduction reflects a reduction in the need for online storage of the compared tones. We further suggest that this change reflects an implicit strategic shift "backwards" from reliance mainly on working memory networks in the "No-Reference" condition to increased reliance on detected regularities stored in high-level auditory networks.
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172
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Lottem E, Gugig E, Azouz R. Parallel coding schemes of whisker velocity in the rat's somatosensory system. J Neurophysiol 2014; 113:1784-99. [PMID: 25552637 DOI: 10.1152/jn.00485.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The function of rodents' whisker somatosensory system is to transform tactile cues, in the form of vibrissa vibrations, into neuronal responses. It is well established that rodents can detect numerous tactile stimuli and tell them apart. However, the transformation of tactile stimuli obtained through whisker movements to neuronal responses is not well-understood. Here we examine the role of whisker velocity in tactile information transmission and its coding mechanisms. We show that in anaesthetized rats, whisker velocity is related to the radial distance of the object contacted and its own velocity. Whisker velocity is accurately and reliably coded in first-order neurons in parallel, by both the relative time interval between velocity-independent first spike latency of rapidly adapting neurons and velocity-dependent first spike latency of slowly adapting neurons. At the same time, whisker velocity is also coded, although less robustly, by the firing rates of slowly adapting neurons. Comparing first- and second-order neurons, we find similar decoding efficiencies for whisker velocity using either temporal or rate-based methods. Both coding schemes are sufficiently robust and hardly affected by neuronal noise. Our results suggest that whisker kinematic variables are coded by two parallel coding schemes and are disseminated in a similar way through various brain stem nuclei to multiple brain areas.
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Affiliation(s)
- Eran Lottem
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Erez Gugig
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Rony Azouz
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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173
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Vaportzis E, Georgiou-Karistianis N, Churchyard A, Stout JC. Effects of task difficulty during dual-task circle tracing in Huntington's disease. J Neurol 2014; 262:268-76. [PMID: 25371018 DOI: 10.1007/s00415-014-7563-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/24/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
Abstract
Huntington's disease (HD) is associated with impairments in dual-task performance. Despite that, only a few studies have investigated dual-tasking in HD. We examined dual-task performance in 15 participants in the early stages of HD and 15 healthy controls. Participants performed direct circle tracing (able to view arm) and indirect circle tracing (arm obscured) either on their own (single tasks) or paired with serial subtraction by twos or threes (dual tasks). Overall, our results suggested that HD participants were significantly slower and less accurate than controls. Both groups were slower and less accurate when performing indirect circle tracing compared with direct circle tracing. HD participants experienced greater dual-task interference in terms of accuracy when performing direct circle tracing compared with indirect circle tracing. Despite that, controls were more inclined to speed-accuracy trade-offs compared with HD participants. Importantly, unlike controls, HD participants were not disproportionately faster when performing direct circle tracing as a single task compared with the dual-task conditions. Our results suggest that simple tasks place greater attentional demands on HD participants compared with controls. These findings support that impaired automaticity may be responsible for some of the attentional deficits manifested in HD.
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Affiliation(s)
- Eleftheria Vaportzis
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Wellington Road, Clayton, VIC, 3800, Australia
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174
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Wheeler ME, Woo SG, Ansel T, Tremel JJ, Collier AL, Velanova K, Ploran EJ, Yang T. The strength of gradually accruing probabilistic evidence modulates brain activity during a categorical decision. J Cogn Neurosci 2014; 27:705-19. [PMID: 25313658 DOI: 10.1162/jocn_a_00739] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The evolution of neural activity during a perceptual decision is well characterized by the evidence parameter in sequential sampling models. However, it is not known whether accumulating signals in human neuroimaging are related to the integration of evidence. Our aim was to determine whether activity accumulates in a nonperceptual task by identifying brain regions tracking the strength of probabilistic evidence. fMRI was used to measure whole-brain activity as choices were informed by integrating a series of learned prior probabilities. Participants first learned the predictive relationship between a set of shape stimuli and one of two choices. During scanned testing, they made binary choices informed by the sum of the predictive strengths of individual shapes. Sequences of shapes adhered to three distinct rates of evidence (RoEs): rapid, gradual, and switch. We predicted that activity in regions informing the decision would modulate as a function of RoE prior to the choice. Activity in some regions, including premotor areas, changed as a function of RoE and response hand, indicating a role in forming an intention to respond. Regions in occipital, temporal, and parietal lobes modulated as a function of RoE only, suggesting a preresponse stage of evidence processing. In all of these regions, activity was greatest on rapid trials and least on switch trials, which is consistent with an accumulation-to-boundary account. In contrast, activity in a set of frontal and parietal regions was greatest on switch and least on rapid trials, which is consistent with an effort or time-on-task account.
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175
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Vo K, Rutledge RB, Chatterjee A, Kable JW. Dorsal striatum is necessary for stimulus-value but not action-value learning in humans. ACTA ACUST UNITED AC 2014; 137:3129-35. [PMID: 25273995 DOI: 10.1093/brain/awu277] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Several lines of evidence implicate the striatum in learning from experience on the basis of positive and negative feedback. However, the necessity of the striatum for such learning has been difficult to demonstrate in humans, because brain damage is rarely restricted to this structure. Here we test a rare individual with widespread bilateral damage restricted to the dorsal striatum. His performance was impaired and not significantly different from chance on several classic learning tasks, consistent with current theories regarding the role of the striatum. However, he also exhibited remarkably intact performance on a different subset of learning paradigms. The tasks he could perform can all be solved by learning the value of actions, while those he could not perform can only be solved by learning the value of stimuli. Although dorsal striatum is often thought to play a specific role in action-value learning, we find surprisingly that dorsal striatum is necessary for stimulus-value but not action-value learning in humans.
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Affiliation(s)
- Khoi Vo
- 1 Department of Psychology, University of Pennsylvania, 3720 Walnut St., Philadelphia, PA 19104, USA
| | - Robb B Rutledge
- 2 Wellcome Trust Centre for Neuroimaging, UCL, London WC1N 3BG, UK, and Max Planck UCL Centre for Computational Psychiatry and Ageing Research, London WC1B 5EH, UK
| | - Anjan Chatterjee
- 3 Department of Neurology, University of Pennsylvania, 3 West Gates, 3400 Spruce St., Philadelphia, PA 19104, USA
| | - Joseph W Kable
- 1 Department of Psychology, University of Pennsylvania, 3720 Walnut St., Philadelphia, PA 19104, USA
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176
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Garion L, Dubin U, Rubin Y, Khateb M, Schiller Y, Azouz R, Schiller J. Texture coarseness responsive neurons and their mapping in layer 2-3 of the rat barrel cortex in vivo. eLife 2014; 3:e03405. [PMID: 25233151 PMCID: PMC4166033 DOI: 10.7554/elife.03405] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 08/18/2014] [Indexed: 02/02/2023] Open
Abstract
Texture discrimination is a fundamental function of somatosensory systems, yet the manner by which texture is coded and spatially represented in the barrel cortex are largely unknown. Using in vivo two-photon calcium imaging in the rat barrel cortex during artificial whisking against different surface coarseness or controlled passive whisker vibrations simulating different coarseness, we show that layer 2-3 neurons within barrel boundaries differentially respond to specific texture coarsenesses, while only a minority of neurons responded monotonically with increased or decreased surface coarseness. Neurons with similar preferred texture coarseness were spatially clustered. Multi-contact single unit recordings showed a vertical columnar organization of texture coarseness preference in layer 2-3. These findings indicate that layer 2-3 neurons perform high hierarchical processing of tactile information, with surface coarseness embodied by distinct neuronal subpopulations that are spatially mapped onto the barrel cortex.
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Affiliation(s)
- Liora Garion
- Department of Physiology and Biophysics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Uri Dubin
- Department of Physiology and Biophysics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yoav Rubin
- Department of Physiology and Biophysics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Mohamed Khateb
- Department of Physiology and Biophysics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yitzhak Schiller
- Department of Physiology and Biophysics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rony Azouz
- Department of Physiology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Jackie Schiller
- Department of Physiology and Biophysics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
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177
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Mendoza G, Merchant H. Motor system evolution and the emergence of high cognitive functions. Prog Neurobiol 2014; 122:73-93. [PMID: 25224031 DOI: 10.1016/j.pneurobio.2014.09.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/15/2014] [Accepted: 09/05/2014] [Indexed: 11/26/2022]
Abstract
In human and nonhuman primates, the cortical motor system comprises a collection of brain areas primarily related to motor control. Existing evidence suggests that no other mammalian group has the number, extension, and complexity of motor-related areas observed in the frontal lobe of primates. Such diversity is probably related to the wide behavioral flexibility that primates display. Indeed, recent comparative anatomical, psychophysical, and neurophysiological studies suggest that the evolution of the motor cortical areas closely correlates with the emergence of high cognitive abilities. Advances in understanding the cortical motor system have shown that these areas are also related to functions previously linked to higher-order associative areas. In addition, experimental observations have shown that the classical distinction between perceptual and motor functions is not strictly followed across cortical areas. In this paper, we review evidence suggesting that evolution of the motor system had a role in the shaping of different cognitive functions in primates. We argue that the increase in the complexity of the motor system has contributed to the emergence of new abilities observed in human and nonhuman primates, including the recognition and imitation of the actions of others, speech perception and production, and the execution and appreciation of the rhythmic structure of music.
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Affiliation(s)
- Germán Mendoza
- Instituto de Neurobiología, UNAM, Campus Juriquilla, Mexico.
| | - Hugo Merchant
- Instituto de Neurobiología, UNAM, Campus Juriquilla, Mexico.
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178
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Arabzadeh E, Clifford CWG, Harris JA, Mahns DA, Macefield VG, Birznieks I. Single tactile afferents outperform human subjects in a vibrotactile intensity discrimination task. J Neurophysiol 2014; 112:2382-7. [PMID: 25143540 DOI: 10.1152/jn.00482.2014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We simultaneously compared the sensitivity of single primary afferent neurons supplying the glabrous skin of the hand and the psychophysical amplitude discrimination thresholds in human subjects for a set of vibrotactile stimuli delivered to the receptive field. All recorded afferents had a dynamic range narrower than the range of amplitudes across which the subjects could discriminate. However, when the vibration amplitude was chosen to be within the steepest part of the afferent's stimulus-response function the response of single afferents, defined as the spike count over the vibration duration (500 ms), was often more sensitive in discriminating vibration amplitude than the perceptual judgment of the participants. We quantified how the neuronal performance depended on the integration window: for short windows the neuronal performance was inferior to the performance of the subject. The neuronal performance progressively improved with increasing spike count duration and reached a level significantly above that of the subjects when the integration window was 250 ms or longer. The superiority in performance of individual neurons over observers could reflect a nonoptimal integration window or be due to the presence of noise between the sensory periphery and the cortical decision stage. Additionally, it could indicate that the range of perceptual sensitivity comes at the cost of discrimination through pooling across neurons with different response functions.
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Affiliation(s)
- Ehsan Arabzadeh
- School of Psychology, University of Sydney, Sydney, Australia; Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australia; ARC Centre of Excellence for Integrative Brain Function, Australian National University Node, Canberra, Australia;
| | - Colin W G Clifford
- School of Psychology, University of Sydney, Sydney, Australia; School of Psychology, UNSW Australia, Sydney, Australia
| | - Justin A Harris
- School of Psychology, University of Sydney, Sydney, Australia
| | - David A Mahns
- School of Medicine, University of Western Sydney, Sydney, Australia
| | - Vaughan G Macefield
- School of Medicine, University of Western Sydney, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia; and
| | - Ingvars Birznieks
- Neuroscience Research Australia, Sydney, Australia; and School of Science and Health, University of Western Sydney, Sydney, Australia
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179
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Engineer CT, Perez CA, Carraway RS, Chang KQ, Roland JL, Kilgard MP. Speech training alters tone frequency tuning in rat primary auditory cortex. Behav Brain Res 2014; 258:166-78. [PMID: 24344364 DOI: 10.1016/j.bbr.2013.10.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Previous studies in both humans and animals have documented improved performance following discrimination training. This enhanced performance is often associated with cortical response changes. In this study, we tested the hypothesis that long-term speech training on multiple tasks can improve primary auditory cortex (A1) responses compared to rats trained on a single speech discrimination task or experimentally naïve rats. Specifically, we compared the percent of A1 responding to trained sounds, the responses to both trained and untrained sounds, receptive field properties of A1 neurons, and the neural discrimination of pairs of speech sounds in speech trained and naïve rats. Speech training led to accurate discrimination of consonant and vowel sounds, but did not enhance A1 response strength or the neural discrimination of these sounds. Speech training altered tone responses in rats trained on six speech discrimination tasks but not in rats trained on a single speech discrimination task. Extensive speech training resulted in broader frequency tuning, shorter onset latencies, a decreased driven response to tones, and caused a shift in the frequency map to favor tones in the range where speech sounds are the loudest. Both the number of trained tasks and the number of days of training strongly predict the percent of A1 responding to a low frequency tone. Rats trained on a single speech discrimination task performed less accurately than rats trained on multiple tasks and did not exhibit A1 response changes. Our results indicate that extensive speech training can reorganize the A1 frequency map, which may have downstream consequences on speech sound processing.
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180
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Katus T, Grubert A, Eimer M. Electrophysiological Evidence for a Sensory Recruitment Model of Somatosensory Working Memory. Cereb Cortex 2014; 25:4697-703. [DOI: 10.1093/cercor/bhu153] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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181
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Simulating stimulus- and TMS-induced interference in short-term memory using a model of prefrontal cortex. BMC Neurosci 2014. [PMCID: PMC4125045 DOI: 10.1186/1471-2202-15-s1-p141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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182
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Keuken MC, Müller-Axt C, Langner R, Eickhoff SB, Forstmann BU, Neumann J. Brain networks of perceptual decision-making: an fMRI ALE meta-analysis. Front Hum Neurosci 2014; 8:445. [PMID: 24994979 PMCID: PMC4063192 DOI: 10.3389/fnhum.2014.00445] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 06/02/2014] [Indexed: 01/24/2023] Open
Abstract
In the recent perceptual decision-making literature, a fronto-parietal network is typically reported to primarily represent the neural substrate of human perceptual decision-making. However, the view that only cortical areas are involved in perceptual decision-making has been challenged by several neurocomputational models which all argue that the basal ganglia play an essential role in perceptual decisions. To consolidate these different views, we conducted an Activation Likelihood Estimation (ALE) meta-analysis on the existing neuroimaging literature. The results argue in favor of the involvement of a frontal-parietal network in general perceptual decision-making that is possibly complemented by the basal ganglia, and modulated in substantial parts by task difficulty. In contrast, expectation of reward, an important aspect of many decision-making processes, shows almost no overlap with the general perceptual decision-making network.
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Affiliation(s)
- Max C Keuken
- Faculty of Social and Behavioural Science, Cognitive Science Center Amsterdam, University of Amsterdam Amsterdam, Netherlands ; Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Christa Müller-Axt
- Faculty of Social and Behavioural Science, Cognitive Science Center Amsterdam, University of Amsterdam Amsterdam, Netherlands
| | - Robert Langner
- Institute of Clinical Neuroscience and Medical Psychology, Heinrich Heine University Düsseldorf Düsseldorf, Germany ; Research Centre Jülich, Institute of Neuroscience and Medicine (INM-1) Jülich, Germany
| | - Simon B Eickhoff
- Institute of Clinical Neuroscience and Medical Psychology, Heinrich Heine University Düsseldorf Düsseldorf, Germany ; Research Centre Jülich, Institute of Neuroscience and Medicine (INM-1) Jülich, Germany
| | - Birte U Forstmann
- Faculty of Social and Behavioural Science, Cognitive Science Center Amsterdam, University of Amsterdam Amsterdam, Netherlands ; Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Jane Neumann
- Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany ; Leipzig University Medical Center, IFB Adiposity Diseases Leipzig, Germany
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183
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Spitzer B, Goltz D, Wacker E, Auksztulewicz R, Blankenburg F. Maintenance and manipulation of somatosensory information in ventrolateral prefrontal cortex. Hum Brain Mapp 2014; 35:2412-23. [PMID: 23913849 PMCID: PMC6869731 DOI: 10.1002/hbm.22337] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 04/05/2013] [Accepted: 05/10/2013] [Indexed: 11/08/2022] Open
Abstract
Neuroimaging studies of working memory (WM) suggest that prefrontal cortex may assist sustained maintenance, but also internal manipulation, of stimulus representations in lower-level areas. A different line of research in the somatosensory domain indicates that neuronal activity in ventrolateral prefrontal cortex (VLPFC) may also represent specific memory contents in itself, however leaving open to what extent top-down control on lower-level areas is exerted, or how internal manipulation processes are implemented. We used functional imaging and connectivity analysis to study static maintenance and internal manipulation of tactile working memory contents after physically identical stimulation conditions, in human subjects. While both tasks recruited similar subareas in the inferior frontal gyrus (IFG) in VLPFC, static maintenance of the tactile information was additionally characterized by increased functional coupling between IFG and primary somatosensory cortex. Independently, during internal manipulation, a quantitative representation of the task-relevant information was evident in IFG itself, even in the absence of physical stimulation. Together, these findings demonstrate the functional diversity of activity within VLPFC according to different working memory demands, and underline the role of IFG as a core region in sensory WM processing.
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Affiliation(s)
- Bernhard Spitzer
- Dahlem Institute for Neuroimaging of Emotion, Freie Universität BerlinHabelschwerdter Allee 4514195BerlinGermany
- Center for Adaptive Rationality, Max Planck Institute for Human DevelopmentLentzeallee 9414195BerlinGermany
| | - Dominique Goltz
- Department of NeurologyMax Planck Institute for Human Cognitive and Brain SciencesStephanstr. 1a04103LeipzigGermany
- Department of Experimental Psychology and MethodsUniversity LeipzigNeumarkt 9-1004109LeipzigGermany
| | - Evelin Wacker
- Charité University MedicineSpandauer Damm 130, 14050 BerlinGermany
| | - Ryszard Auksztulewicz
- Dahlem Institute for Neuroimaging of Emotion, Freie Universität BerlinHabelschwerdter Allee 4514195BerlinGermany
- Berlin School of Mind and BrainHumboldt Universität zu BerlinUnter den Linden 6 10099 BerlinGermany
| | - Felix Blankenburg
- Dahlem Institute for Neuroimaging of Emotion, Freie Universität BerlinHabelschwerdter Allee 4514195BerlinGermany
- Center for Adaptive Rationality, Max Planck Institute for Human DevelopmentLentzeallee 9414195BerlinGermany
- Berlin School of Mind and BrainHumboldt Universität zu BerlinUnter den Linden 6 10099 BerlinGermany
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184
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Insabato A, Dempere-Marco L, Pannunzi M, Deco G, Romo R. The influence of spatiotemporal structure of noisy stimuli in decision making. PLoS Comput Biol 2014; 10:e1003492. [PMID: 24743140 PMCID: PMC3990472 DOI: 10.1371/journal.pcbi.1003492] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Decision making is a process of utmost importance in our daily lives, the study of which has been receiving notable attention for decades. Nevertheless, the neural mechanisms underlying decision making are still not fully understood. Computational modeling has revealed itself as a valuable asset to address some of the fundamental questions. Biophysically plausible models, in particular, are useful in bridging the different levels of description that experimental studies provide, from the neural spiking activity recorded at the cellular level to the performance reported at the behavioral level. In this article, we have reviewed some of the recent progress made in the understanding of the neural mechanisms that underlie decision making. We have performed a critical evaluation of the available results and address, from a computational perspective, aspects of both experimentation and modeling that so far have eluded comprehension. To guide the discussion, we have selected a central theme which revolves around the following question: how does the spatiotemporal structure of sensory stimuli affect the perceptual decision-making process? This question is a timely one as several issues that still remain unresolved stem from this central theme. These include: (i) the role of spatiotemporal input fluctuations in perceptual decision making, (ii) how to extend the current results and models derived from two-alternative choice studies to scenarios with multiple competing evidences, and (iii) to establish whether different types of spatiotemporal input fluctuations affect decision-making outcomes in distinctive ways. And although we have restricted our discussion mostly to visual decisions, our main conclusions are arguably generalizable; hence, their possible extension to other sensory modalities is one of the points in our discussion.
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Affiliation(s)
- Andrea Insabato
- Department of Information and Communication Technologies, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain
| | - Laura Dempere-Marco
- Department of Information and Communication Technologies, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain
| | - Mario Pannunzi
- Department of Information and Communication Technologies, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain
| | - Gustavo Deco
- Department of Information and Communication Technologies, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain
- ICREA, Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Ranulfo Romo
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, México DF, México
- El Colegio Nacional, México DF, México
- * E-mail:
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185
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Mohebi A, Oweiss KG. A fully automated rodent conditioning protocol for sensorimotor integration and cognitive control experiments. J Vis Exp 2014. [PMID: 24798582 DOI: 10.3791/51128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Rodents have been traditionally used as a standard animal model in laboratory experiments involving a myriad of sensory, cognitive, and motor tasks. Higher cognitive functions that require precise control over sensorimotor responses such as decision-making and attentional modulation, however, are typically assessed in nonhuman primates. Despite the richness of primate behavior that allows multiple variants of these functions to be studied, the rodent model remains an attractive, cost-effective alternative to primate models. Furthermore, the ability to fully automate operant conditioning in rodents adds unique advantages over the labor intensive training of nonhuman primates while studying a broad range of these complex functions. Here, we introduce a protocol for operantly conditioning rats on performing working memory tasks. During critical epochs of the task, the protocol ensures that the animal's overt movement is minimized by requiring the animal to 'fixate' until a Go cue is delivered, akin to nonhuman primate experimental design. A simple two alternative forced choice task is implemented to demonstrate the performance. We discuss the application of this paradigm to other tasks.
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Affiliation(s)
- Ali Mohebi
- Electrical and Computer Engineering, Michigan State University
| | - Karim G Oweiss
- Electrical and Computer Engineering, Michigan State University; Neuroscience Program, Michigan State University; Cognitive Science Program, Michigan State University;
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186
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Abstract
To explore the role of oscillatory dynamics of the somatosensory thalamocortical network in perception and decision making, we recorded the simultaneous neuronal activity in the ventral posterolateral nucleus (VPL) of the somatosensory thalamus and primary somatosensory cortex (S1) in two macaque monkeys performing a vibrotactile detection task. Actively detecting a vibrotactile stimulus and reporting its perception elicited a sustained poststimulus beta power increase in VPL and an alpha power decrease in S1, in both stimulus-present and stimulus-absent trials. These oscillatory dynamics in the somatosensory thalamocortical network depended on the behavioral context: they were stronger for the active detection condition than for a passive stimulation condition. Furthermore, contrasting stimulus-present vs. stimulus-absent responses, we found that poststimulus theta power increased in both VPL and S1, and alpha/beta power decreased in S1, reflecting the monkey's perceptual decision but not the motor response per se. Additionally, higher prestimulus alpha power in S1 correlated with an increased probability of the monkey reporting a stimulus, regardless of the actual presence of a stimulus. Thus, we found task-related modulations in oscillatory activity, not only in the neocortex but also in the thalamus, depending on behavioral context. Furthermore, oscillatory modulations reflected the perceptual decision process and subsequent behavioral response. We conclude that these early sensory regions, in addition to their primary sensory functions, may be actively involved in perceptual decision making.
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187
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Abstract
As we begin to acquire a new motor skill, we face the dual challenge of determining and refining the somatosensory goals of our movements and establishing the best motor commands to achieve our ends. The two typically proceed in parallel, and accordingly it is unclear how much of skill acquisition is a reflection of changes in sensory systems and how much reflects changes in the brain's motor areas. Here we have intentionally separated perceptual and motor learning in time so that we can assess functional changes to human sensory and motor networks as a result of perceptual learning. Our subjects underwent fMRI scans of the resting brain before and after a somatosensory discrimination task. We identified changes in functional connectivity that were due to the effects of perceptual learning on movement. For this purpose, we used a neural model of the transmission of sensory signals from perceptual decision making through to motor action. We used this model in combination with a partial correlation technique to parcel out those changes in connectivity observed in motor systems that could be attributed to activity in sensory brain regions. We found that, after removing effects that are linearly correlated with somatosensory activity, perceptual learning results in changes to frontal motor areas that are related to the effects of this training on motor behavior and learning. This suggests that perceptual learning produces changes to frontal motor areas of the brain and may thus contribute directly to motor learning.
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188
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Bancroft TD, Hogeveen J, Hockley WE, Servos P. TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex. Front Comput Neurosci 2014; 8:23. [PMID: 24634653 PMCID: PMC3942793 DOI: 10.3389/fncom.2014.00023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 02/10/2014] [Indexed: 11/13/2022] Open
Abstract
In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.
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Affiliation(s)
- Tyler D Bancroft
- Department of Psychology, Wilfrid Laurier University Waterloo, ON, Canada
| | - Jeremy Hogeveen
- Department of Psychology, Wilfrid Laurier University Waterloo, ON, Canada
| | - William E Hockley
- Department of Psychology, Wilfrid Laurier University Waterloo, ON, Canada
| | - Philip Servos
- Department of Psychology, Wilfrid Laurier University Waterloo, ON, Canada
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189
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Thiel SD, Bitzer S, Nierhaus T, Kalberlah C, Preusser S, Neumann J, Nikulin VV, van der Meer E, Villringer A, Pleger B. Hysteresis as an implicit prior in tactile spatial decision making. PLoS One 2014; 9:e89802. [PMID: 24587045 PMCID: PMC3935932 DOI: 10.1371/journal.pone.0089802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 01/27/2014] [Indexed: 11/19/2022] Open
Abstract
Perceptual decisions not only depend on the incoming information from sensory systems but constitute a combination of current sensory evidence and internally accumulated information from past encounters. Although recent evidence emphasizes the fundamental role of prior knowledge for perceptual decision making, only few studies have quantified the relevance of such priors on perceptual decisions and examined their interplay with other decision-relevant factors, such as the stimulus properties. In the present study we asked whether hysteresis, describing the stability of a percept despite a change in stimulus property and known to occur at perceptual thresholds, also acts as a form of an implicit prior in tactile spatial decision making, supporting the stability of a decision across successively presented random stimuli (i.e., decision hysteresis). We applied a variant of the classical 2-point discrimination task and found that hysteresis influenced perceptual decision making: Participants were more likely to decide ‘same’ rather than ‘different’ on successively presented pin distances. In a direct comparison between the influence of applied pin distances (explicit stimulus property) and hysteresis, we found that on average, stimulus property explained significantly more variance of participants’ decisions than hysteresis. However, when focusing on pin distances at threshold, we found a trend for hysteresis to explain more variance. Furthermore, the less variance was explained by the pin distance on a given decision, the more variance was explained by hysteresis, and vice versa. Our findings suggest that hysteresis acts as an implicit prior in tactile spatial decision making that becomes increasingly important when explicit stimulus properties provide decreasing evidence.
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Affiliation(s)
- Sabrina D. Thiel
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Department of Psychology, Faculty of Mathematics and Natural Sciences II, Humboldt-University, Berlin, Germany
- * E-mail:
| | - Sebastian Bitzer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Till Nierhaus
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Mind-Brain Institute and Berlin School of Mind and Brain, Charité – University Medicine Berlin and Humboldt-University, Berlin, Germany
| | - Christian Kalberlah
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Sven Preusser
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Jane Neumann
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, Leipzig, Germany
| | - Vadim V. Nikulin
- Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité - University Medicine Berlin, Berlin, Germany
- Centre for Cognition and Decision Making, National Research University Higher School of Economics, Moscow, Russia
| | - Elke van der Meer
- Mind-Brain Institute and Berlin School of Mind and Brain, Charité – University Medicine Berlin and Humboldt-University, Berlin, Germany
- Department of Psychology, Faculty of Mathematics and Natural Sciences II, Humboldt-University, Berlin, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, Leipzig, Germany
| | - Burkhard Pleger
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, Leipzig, Germany
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190
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Centanni TM, Sloan AM, Reed AC, Engineer CT, Rennaker RL, Kilgard MP. Detection and identification of speech sounds using cortical activity patterns. Neuroscience 2014; 258:292-306. [PMID: 24286757 PMCID: PMC3898816 DOI: 10.1016/j.neuroscience.2013.11.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 10/26/2022]
Abstract
We have developed a classifier capable of locating and identifying speech sounds using activity from rat auditory cortex with an accuracy equivalent to behavioral performance and without the need to specify the onset time of the speech sounds. This classifier can identify speech sounds from a large speech set within 40 ms of stimulus presentation. To compare the temporal limits of the classifier to behavior, we developed a novel task that requires rats to identify individual consonant sounds from a stream of distracter consonants. The classifier successfully predicted the ability of rats to accurately identify speech sounds for syllable presentation rates up to 10 syllables per second (up to 17.9 ± 1.5 bits/s), which is comparable to human performance. Our results demonstrate that the spatiotemporal patterns generated in primary auditory cortex can be used to quickly and accurately identify consonant sounds from a continuous speech stream without prior knowledge of the stimulus onset times. Improved understanding of the neural mechanisms that support robust speech processing in difficult listening conditions could improve the identification and treatment of a variety of speech-processing disorders.
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Affiliation(s)
| | - A M Sloan
- University of Texas at Dallas, United States
| | - A C Reed
- University of Texas at Dallas, United States
| | | | | | - M P Kilgard
- University of Texas at Dallas, United States
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191
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Does stimulus complexity determine whether working memory storage relies on prefrontal or sensory cortex? Atten Percept Psychophys 2014; 76:1954-61. [DOI: 10.3758/s13414-013-0604-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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192
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Abstract
Primates can store sensory stimulus parameters in working memory for subsequent manipulation, but until now, there has been no demonstration of this capacity in rodents. Here we report tactile working memory in rats. Each stimulus is a vibration, generated as a series of velocity values sampled from a normal distribution. To perform the task, the rat positions its whiskers to receive two such stimuli, "base" and "comparison," separated by a variable delay. It then judges which stimulus had greater velocity SD. In analogous experiments, humans compare two vibratory stimuli on the fingertip. We demonstrate that the ability of rats to hold base stimulus information (for up to 8 s) and their acuity in assessing stimulus differences overlap the performance demonstrated by humans. This experiment highlights the ability of rats to perceive the statistical structure of vibrations and reveals their previously unknown capacity to store sensory information in working memory.
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193
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Transcranial focused ultrasound modulates the activity of primary somatosensory cortex in humans. Nat Neurosci 2014; 17:322-9. [PMID: 24413698 DOI: 10.1038/nn.3620] [Citation(s) in RCA: 539] [Impact Index Per Article: 53.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/04/2013] [Indexed: 01/26/2023]
Abstract
Improved methods of noninvasively modulating human brain function are needed. Here we probed the influence of transcranial focused ultrasound (tFUS) targeted to the human primary somatosensory cortex (S1) on sensory-evoked brain activity and sensory discrimination abilities. The lateral and axial spatial resolution of the tFUS beam implemented were 4.9 mm and 18 mm, respectively. Electroencephalographic recordings showed that tFUS significantly attenuated the amplitudes of somatosensory evoked potentials elicited by median nerve stimulation. We also found that tFUS significantly modulated the spectral content of sensory-evoked brain oscillations. The changes produced by tFUS on sensory-evoked brain activity were abolished when the acoustic beam was focused 1 cm anterior or posterior to S1. Behavioral investigations showed that tFUS targeted to S1 enhanced performance on sensory discrimination tasks without affecting task attention or response bias. We conclude that tFUS can be used to focally modulate human cortical function.
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194
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Aagten-Murphy D, Iversen J, Williams C, Meck W. Novel Inversions in Auditory Sequences Provide Evidence for Spontaneous Subtraction of Time and Number. TIMING & TIME PERCEPTION 2014. [DOI: 10.1163/22134468-00002028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Animals, including fish, birds, rodents, non-human primates, and pre-verbal infants are able to discriminate the duration and number of events without the use of language. In this paper, we present the results of six experiments exploring the capability of adult rats to count 2–6 sequentially presented white-noise stimuli. The investigation focuses on the animal’s ability to exhibit spontaneous subtraction following the presentation of novel stimulus inversions in the auditory signals being counted. Results suggest that a subtraction operation between two opposite sensory representations may be a general processing strategy used for the comparison of stimulus magnitudes. These findings are discussed within the context of a mode-control model of timing and counting that relies on an analog temporal-integration process for the addition and subtraction of sequential events.
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Affiliation(s)
- David Aagten-Murphy
- Department of Psychology, Ludwig-Maximilians-Universität München, Münich, Germany
| | - John R. Iversen
- Swartz Center for Computational Neuroscience and Institute for Neural Computation, University of California, San Diego, La Jolla, CA, USA
| | | | - Warren H. Meck
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
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195
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Carlson TA, Ritchie JB, Kriegeskorte N, Durvasula S, Ma J. Reaction Time for Object Categorization Is Predicted by Representational Distance. J Cogn Neurosci 2014; 26:132-42. [DOI: 10.1162/jocn_a_00476] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
How does the brain translate an internal representation of an object into a decision about the object's category? Recent studies have uncovered the structure of object representations in inferior temporal cortex (IT) using multivariate pattern analysis methods. These studies have shown that representations of individual object exemplars in IT occupy distinct locations in a high-dimensional activation space, with object exemplar representations clustering into distinguishable regions based on category (e.g., animate vs. inanimate objects). In this study, we hypothesized that a representational boundary between category representations in this activation space also constitutes a decision boundary for categorization. We show that behavioral RTs for categorizing objects are well described by our activation space hypothesis. Interpreted in terms of classical and contemporary models of decision-making, our results suggest that the process of settling on an internal representation of a stimulus is itself partially constitutive of decision-making for object categorization.
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196
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Abstract
A decision is a commitment to a proposition or plan of action based on information and values associated with the possible outcomes. The process operates in a flexible timeframe that is free from the immediacy of evidence acquisition and the real time demands of action itself. Thus, it involves deliberation, planning, and strategizing. This Perspective focuses on perceptual decision making in nonhuman primates and the discovery of neural mechanisms that support accuracy, speed, and confidence in a decision. We suggest that these mechanisms expose principles of cognitive function in general, and we speculate about the challenges and directions before the field.
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Affiliation(s)
- Michael N Shadlen
- Howard Hughes Medical Institute, Kavli Institute and Department of Neuroscience, Columbia University, New York, NY 10038, USA.
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197
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Goltz D, Pleger B, Thiel S, Villringer A, Müller MM. Sustained spatial attention to vibrotactile stimulation in the flutter range: relevant brain regions and their interaction. PLoS One 2013; 8:e84196. [PMID: 24367642 PMCID: PMC3868580 DOI: 10.1371/journal.pone.0084196] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 11/13/2013] [Indexed: 11/18/2022] Open
Abstract
The present functional magnetic resonance imaging (fMRI) study was designed to get a better understanding of the brain regions involved in sustained spatial attention to tactile events and to ascertain to what extent their activation was correlated. We presented continuous 20 Hz vibrotactile stimuli (range of flutter) concurrently to the left and right index fingers of healthy human volunteers. An arrow cue instructed subjects in a trial-by-trial fashion to attend to the left or right index finger and to detect rare target events that were embedded in the vibrotactile stimulation streams. We found blood oxygen level-dependent (BOLD) attentional modulation in primary somatosensory cortex (SI), mainly covering Brodmann area 1, 2, and 3b, as well as in secondary somatosensory cortex (SII), contralateral to the to-be-attended hand. Furthermore, attention to the right (dominant) hand resulted in additional BOLD modulation in left posterior insula. All of the effects were caused by an increased activation when attention was paid to the contralateral hand, except for the effects in left SI and insula. In left SI, the effect was related to a mixture of both a slight increase in activation when attention was paid to the contralateral hand as well as a slight decrease in activation when attention was paid to the ipsilateral hand (i.e., the tactile distraction condition). In contrast, the effect in left posterior insula was exclusively driven by a relative decrease in activation in the tactile distraction condition, which points to an active inhibition when tactile information is irrelevant. Finally, correlation analyses indicate a linear relationship between attention effects in intrahemispheric somatosensory cortices, since attentional modulation in SI and SII were interrelated within one hemisphere but not across hemispheres. All in all, our results provide a basis for future research on sustained attention to continuous vibrotactile stimulation in the range of flutter.
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Affiliation(s)
- Dominique Goltz
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Institute of Psychology, University of Leipzig, Leipzig, Germany
| | - Burkhard Pleger
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
| | - Sabrina Thiel
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Berlin School of Mind and Brain, Humboldt-University Berlin, Berlin, Germany
| | - Matthias M. Müller
- Institute of Psychology, University of Leipzig, Leipzig, Germany
- * E-mail:
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198
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Carrillo JA, Cordier S, Deco G, Mancini S. Complexity reduction of rate-equations models for two-choice decision-making. PLoS One 2013; 8:e80820. [PMID: 24339885 PMCID: PMC3855154 DOI: 10.1371/journal.pone.0080820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/15/2013] [Indexed: 11/22/2022] Open
Abstract
We are concerned with the complexity reduction of a stochastic system of differential equations governing the dynamics of a neuronal circuit describing a decision-making task. This reduction is based on the slow-fast behavior of the problem and holds on the whole phase space and not only locally around the spontaneous state. Macroscopic quantities, such as performance and reaction times, computed applying this reduction are in agreement with previous works in which the complexity reduction is locally performed at the spontaneous point by means of a Taylor expansion.
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199
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Carnevale F, de Lafuente V, Romo R, Parga N. An optimal decision population code that accounts for correlated variability unambiguously predicts a subject's choice. Neuron 2013; 80:1532-43. [PMID: 24268419 DOI: 10.1016/j.neuron.2013.09.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2013] [Indexed: 10/26/2022]
Abstract
Decisions emerge from the concerted activity of neuronal populations distributed across brain circuits. However, the analytical tools best suited to decode decision signals from neuronal populations remain unknown. Here we show that knowledge of correlated variability between pairs of cortical neurons allows perfect decoding of decisions from population firing rates. We recorded pairs of neurons from secondary somatosensory (S2) and premotor (PM) cortices while monkeys reported the presence or absence of a tactile stimulus. We found that while populations of S2 and sensory-like PM neurons are only partially correlated with behavior, those PM neurons active during a delay period preceding the motor report predict unequivocally the animal's decision report. Thus, a population rate code that optimally reveals a subject's perceptual decisions can be implemented just by knowing the correlations of PM neurons representing decision variables.
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Affiliation(s)
- Federico Carnevale
- Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - Victor de Lafuente
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, 76230 Querétaro, México
| | - Ranulfo Romo
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, 04510 México, DF, México; El Colegio Nacional, 06020 México, DF, México.
| | - Néstor Parga
- Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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200
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Engineer CT, Perez CA, Carraway RS, Chang KQ, Roland JL, Sloan AM, Kilgard MP. Similarity of cortical activity patterns predicts generalization behavior. PLoS One 2013; 8:e78607. [PMID: 24147140 PMCID: PMC3797841 DOI: 10.1371/journal.pone.0078607] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 09/20/2013] [Indexed: 11/23/2022] Open
Abstract
Humans and animals readily generalize previously learned knowledge to new situations. Determining similarity is critical for assigning category membership to a novel stimulus. We tested the hypothesis that category membership is initially encoded by the similarity of the activity pattern evoked by a novel stimulus to the patterns from known categories. We provide behavioral and neurophysiological evidence that activity patterns in primary auditory cortex contain sufficient information to explain behavioral categorization of novel speech sounds by rats. Our results suggest that category membership might be encoded by the similarity of the activity pattern evoked by a novel speech sound to the patterns evoked by known sounds. Categorization based on featureless pattern matching may represent a general neural mechanism for ensuring accurate generalization across sensory and cognitive systems.
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Affiliation(s)
- Crystal T. Engineer
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
- * E-mail:
| | - Claudia A. Perez
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
| | - Ryan S. Carraway
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
| | - Kevin Q. Chang
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
| | - Jarod L. Roland
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
| | - Andrew M. Sloan
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
| | - Michael P. Kilgard
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America
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