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The neural encoding of guesses in the human brain

NEUROIMAGE 2012年第2期59卷 1924-1931页

作者： Bode, Stefan Bogler, Carsten Soon, Chun Siong Haynes, John-Dylan Univ Melbourne Parkville Vic 3010 Australia Max Planck Inst Human Cognit & Brain Sci D-04109 Leipzig Germany Otto Von Guericke Univ Dept Neurol D-39120 Magdeburg Germany Charite D-10115 Berlin Germany Bernstein Ctr Computat Neurosci Berlin D-10115 Berlin Germany Duke NUS Grad Med Sch Singapore 169857 Singapore Humboldt Univ Grad Sch Mind & Brain D-10099 Berlin Germany

Human perception depends heavily on the quality of sensory information. When objects are hard to see we often believe ourselves to be purely guessing. Here we investigated whether such guesses use brain networks involved in perceptual decision making or independent networks. We used a combination of fMRI and pattern classification to test how visibility affects the signals, which determine choices. We found that decisions regarding clearly visible objects are predicted by signals in sensory brain regions, whereas different regions in parietal cortex became predictive when subjects were shown invisible objects and believed themselves to be purely guessing. This parietal network was highly overlapping with regions, which have previously been shown to encode free decisions. Thus, the brain might use a dedicated network for determining choices when insufficient sensory information is available. (C) 2011 Elsevier Inc. All rights reserved.

关键词： Decision making Free decisions Guessing multivariate decoding Precuneus

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Spatially Invariant Coding of Numerical Information in Functionally Defined Subregions of Human Parietal Cortex

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CEREBRAL CORTEX 2015年第5期25卷 1319-1329页

作者： Eger, E. Pinel, P. Dehaene, S. Kleinschmidt, A. INSERM U992 Gif Sur Yvette France CEA DSV I2BM NeuroSpin Gif Sur Yvette France Univ Paris Sud Orsay France Univ Hosp HUG Dept Clin Neurosci CH-1211 Geneva Switzerland Univ Geneva CH-1211 Geneva Switzerland

Macaque electrophysiology has revealed neurons responsive to number in lateral (LIP) and ventral (VIP) intraparietal areas. Recently, fMRI pattern recognition revealed information discriminative of individual numbers in human parietal cortex but without precisely localizing the relevant sites or testing for subregions with different response profiles. Here, we defined the human functional equivalents of LIP (feLIP) and VIP (feVIP) using neurophysiologically motivated localizers. We applied multivariate pattern recognition to investigate whether both regions represent numerical information and whether number codes are position specific or invariant. In a delayed number comparison paradigm with laterally presented numerosities, parietal cortex discriminated between numerosities better than early visual cortex, and discrimination generalized across hemifields in parietal, but not early visual cortex. Activation patterns in the 2 parietal regions of interest did not differ in the coding of position-specific or position-independent number information, but in the expression of a numerical distance effect which was more pronounced in feLIP. Thus, the representation of number in parietal cortex is at least partially position invariant. Both feLIP and feVIP contain information about individual numerosities in humans, but feLIP hosts a coarser representation of numerosity than feVIP, compatible with either broader tuning or a summation code.

关键词： fMRI multivariate decoding number processing parietal cortex

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Discriminability of numerosity-evoked fMRI activity patterns in human intra-parietal cortex reflects behavioral numerical acuity

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CORTEX 2019年 114卷 90-101页

作者： Lasne, Gabriel Piazza, Manuela Dehaene, Stanislas Kleinschmidt, Andreas Eger, Evelyn INSERM U992 Gif Sur Yvette France CEA DSV I2BM Gif Sur Yvette France Univ Paris Sud Orsay France Univ Hosp HUG Dept Clin Neurosci Geneva Switzerland Univ Geneva Geneva Switzerland Univ Trento Ctr Mind Brain Sci Trento Italy Coll France Paris France

Areas of the primate intraparietal cortex have been identified as an important substrate of numerical cognition. In human fMRI studies, activity patterns in these and other areas have allowed researchers to read out the numerosity a subject is viewing, but the relation of such decodable information with behavioral numerical proficiency remains unknown. Here, we estimated the precision of behavioral numerosity discrimination (internal Weber fraction) in twelve adult subjects based on psychophysical testing in a delayed numerosity comparison task outside the scanner. FMRI data were then recorded during a similar task, to obtain the accuracy with which the same sample numerosities could be read out from evoked brain activity patterns, as a measure of the precision of the neuronal representation. Sample numerosities were decodable in both early visual and intra-parietal cortex with approximately equal accuracy on average. In parietal cortex, smaller numerosities were better discriminated than larger numerosities of the same ratio, paralleling smaller behavioral Weber fractions for smaller numerosities. Furthermore, in parietal but not early visual cortex, fMRI decoding performance was correlated with behavioral number discrimination acuity across subjects (subjects with a more precise behavioral Weber fraction measured prior to scanning showed greater discriminability of fMRI activity patterns in intraparietal cortex, and more specifically, the right LIP region). These results suggest a crucial role for intra-parietal cortex in supporting a numerical representation which is explicitly read out for numerical decisions and behavior. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： fMRI Parietal cortex Number processing multivariate decoding Human

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Orientation-dependency of perceptual surround suppression and orientation decoding of centre-surround stimuli are preserved with healthy ageing

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VISION RESEARCH 2020年 176卷 72-79页

作者： Nguyen, Bao N. Chan, Yu Man Bode, Stefan McKendrick, Allison M. Univ Melbourne Dept Optometry & Vis Sci Parkville Vic 3010 Australia Univ Melbourne Melbourne Sch Psychol Sci Parkville Vic Australia

A key visual neuronal property that is mirrored in human behaviour is centre-surround contrast suppression, which is orientation-dependent. When a target is embedded in a high-contrast surround, the centre appears reduced in contrast, the magnitude of which depends on the relative orientation between centre and surround. Previous reports demonstrate changes in perceptual surround suppression with ageing;however, whether the orientation-dependency of surround suppression is impacted by ageing has not been explored. Here, we tested 18 younger (aged 19-33) and 18 older (aged 60-77) adults. Perceptual surround suppression was stronger for parallel than orthogonal stimuli;however contrary to previous work, here we found no difference in perceptual suppression strength between age-groups. In the same participants, we measured event-related potentials (ERPs) and conducted multivariate pattern analysis to confirm that parallel and orthogonal centre-surround stimuli elicit distinguishable brain activity, predominantly over occipital areas. Despite a delay in the first prominent ERP component (P1) in response to each pattern, older adults showed similar decoding of orientation information (i.e. distinguish between parallel and orthogonal centre-surround stimuli from 70 ms post-stimulus onset) as younger adults. This suggests that sufficient information to distinguish orientation in centre-surround stimuli becomes available to the older human brain as early as in younger adults.

关键词： Orientation multivariate decoding Surround suppression Electroencephalography Event-related potentials Ageing

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decoding different roles for vmPFC and dlPFC in multi-attribute decision making

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NEUROIMAGE 2011年第2期56卷 709-715页

作者： Kahnt, Thorsten Heinzle, Jakob Park, Soyoung Q. Haynes, John-Dylan Charite Bernstein Ctr Computat Neurosci D-10115 Berlin Germany Humboldt Univ Berlin Sch Mind & Brain D-1086 Berlin Germany Free Univ Berlin Dept Educ & Psychol D-1000 Berlin Germany Max Planck Inst Human Cognit & Brain Sci Leipzig Germany

In everyday life, successful decision making requires precise representations of expected values. However, for most behavioral options more than one attribute can be relevant in order to predict the expected reward. Thus, to make good or even optimal choices the reward predictions of multiple attributes need to be integrated into a combined expected value. Importantly, the individual attributes of such multi-attribute objects can agree or disagree in their reward prediction. Here we address where the brain encodes the combined reward prediction (averaged across attributes) and where it encodes the variability of the value predictions of the individual attributes. We acquired fMRI data while subjects performed a task in which they had to integrate reward predictions from multiple attributes into a combined value. Using time-resolved pattern recognition techniques (support vector regression) we find that (1) the combined value is encoded in distributed fMRI patterns in the ventromedial prefrontal cortex (vmPFC) and that (2) the variability of value predictions of the individual attributes is encoded in the dorsolateral prefrontal cortex (dlPFC). The combined value could be used to guide choices, whereas the variability of the value predictions of individual attributes indicates an ambiguity that results in an increased difficulty of the value-integration. These results demonstrate that the different features defining multi-attribute objects are encoded in non-overlapping brain regions and therefore suggest different roles for vmPFC and dlPFC in multi-attribute decision making. (C) 2010 Elsevier Inc. All rights reserved.

关键词： Multi-attribute decision making Expected value Functional magnetic resonance imaging (fMRI) multivariate decoding Ventromedial prefrontal cortex (vmPFC) Dorsolateral prefrontal cortex (dlPFC)

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Visual information representation and rapid-scene categorization are simultaneous across cortex: An MEG study

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NEUROIMAGE 2016年 134卷 295-304页

作者： Ramkumar, Pavan Hansen, Bruce C. Pannasch, Sebastian Loschky, Lester C. Aalto Univ Brain Res Unit OV Lounasmaa Lab Sch Sci Espoo Finland Colgate Univ Dept Psychol Hamilton NY 13346 USA Colgate Univ Neurosci Program Hamilton NY 13346 USA Tech Univ Dresden Dept Psychol D-01062 Dresden Germany Kansas State Univ Dept Psychol Sci Manhattan KS 66506 USA

Perceiving the visual world around us requires the brain to represent the features of stimuli and to categorize the stimulus based on these features. Incorrect categorization can result either from errors in visual representation or from errors in processes that lead to categorical choice. To understand the temporal relationship between the neural signatures of such systematic errors, we recorded whole-scalp magnetoencephalography (MEG) data from human subjects performing a rapid-scene categorization task. We built scene category decoders based on (1) spatiotemporally resolved neural activity, (2) spatial envelope (SpEn) image features, and (3) behavioral responses. Using confusion matrices, we tracked how well the pattern of errors from neural decoders could be explained by SpEn decoders and behavioral errors, over time and across cortical areas. Across the visual cortex and the medial temporal lobe, we found that both SpEn and behavioral errors explained unique variance in the errors of neural decoders. Critically, these effects were nearly simultaneous, and most prominent between 100 and 250 ms after stimulus onset. Thus, during rapid-scene categorization, neural processes that ultimately result in behavioral categorization are simultaneous and co-localized with neural processes underlying visual information representation. (C) 2016 Elsevier Inc. All rights reserved.

关键词： Scene gist Timing of visual perception MEG multivariate decoding Spatial envelope Confusion matrices Multiple linear regression

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Human anterior prefrontal cortex encodes the 'what' and 'when' of future intentions

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NEUROIMAGE 2012年第1期61卷 139-148页

作者： Momennejad, Ida Haynes, John-Dylan Charite Univ Med Berlin Bernstein Ctr Computat Neurosc D-10115 Berlin Germany Humboldt Univ Berlin Sch Mind & Brain Berlin Germany Max Planck Inst Human Cognit & Brain Sci Leipzig Germany Berlin Ctr Adv Neuroimaging Berlin Germany

On a daily basis we form numerous intentions to perform specific actions. However, we often have to delay the execution of intended actions while engaging in other demanding activities. Previous research has shown that patterns of activity in human prefrontal cortex (PFC) can reveal our current intentions. However, two fundamental questions have remained unresolved: (a) how does the PFC encode information about future tasks while we are busy engaging in other activities, and (b) how does the PFC enable us to commence a stored task at the intended time? Here we investigate how the brain stores and retrieves future intentions during occupied delays, i.e. while a person is busy performing a different task. For this purpose, we conducted a neuroimaging study with a time-based prospective memory paradigm. Using multivariate pattern classification and fMRI we show that during an occupied delay, activity patterns in the anterior PFC encode the content of 'what' subjects intend to do next, and 'when' they intend to do it. Importantly, distinct anterior PFC regions store the 'what' and 'when' components of future intentions during occupied maintenance and self-initiated retrieval. These results show a role for anterior PFC activity patterns in storing future action plans and ensuring their timely retrieval. (C) 2012 Elsevier Inc. All rights reserved.

关键词： Prospective memory fMRI multivariate decoding Anterior prefrontal cortex Brodmann area 10 decoding PFC Future intention

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Cortical correlates of perceptual decision making during tactile spatial pattern discrimination

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HUMAN BRAIN MAPPING 2015年第9期36卷 3339-3350页

作者： Hegner, Yiwen Li Lindner, Axel Braun, Christoph Univ Tubingen MEG Ctr Tubingen Germany Univ Tubingen Inst Med Psychol & Behav Neurobiol Tubingen Germany Hertie Inst Clin Brain Res Dept Cognit Neurol Tubingen Germany Werner Reichardt Ctr Integrat Neurosci CIN Tubingen Germany Univ Trento Ctr Mind Brain Sci Trento Italy

Perceptual decision making involves a distributed cortical network including areas related to sensory feature extraction, decision formation, and finally signalling the decision through a motor response. Although these processing steps are supposed to occur in sequence, the seemingly instant mapping of a perceptual decision onto a motor response renders these processes almost indistinguishable. To dissociate cortical areas related to sensory decision making from areas that prepare the subsequent motor response, we performed functional magnetic resonance imaging during a tactile spatial pattern discrimination task with interleaved immediate and delayed response conditions. Decision difficulty was manipulated parametrically by adding spatial noise to the tactile patterns, resulting in a rise in decision time with increasing noise. We assumed that areas involved in making the decision should show a variation in their activation with decision time and irrespective of whether (immediate response condition) or not (delayed response condition) a motor response could be prepared in advance. To exhibit these putative decision areas, we used response time, as was obtained in the immediate response condition, as parametric predictor for the difficulty-dependent variations of blood oxygenation level-dependent (BOLD)-activity in both response conditions. BOLD activations in right (contralateral) postcentral sulcus, right intraparietal sulcus (IPS) and bilateral anterior insula (aINS) reflected this parametric modulation in both response conditions, suggesting a role of these areas in tactile decisions independent of decision-specific motor preparation. Furthermore, a multivariate pattern analysis performed on the BOLD responses in the delayed response condition for a single difficulty level independently validated IPS and aINS as decision-related areas. Hum Brain Mapp 36:3339-3350, 2015. (c) 2015 Wiley Periodicals, Inc.

关键词： anterior insula fMRI intraparietal sulcus multivariate decoding tactile discrimination somatosensory BOLD posterior parietal cortex human

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Auditory discrimination improvement predicts awakening of postanoxic comatose patients treated with targeted temperature management at 36 °C

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RESUSCITATION 2017年第0期118卷 89-95页

作者： Pfeiffer, Christian Nguissi, Nathalie Ata Nguepno Chytiris, Magali Bidlingmeyer, Phanie Haenggi, Matthias Kurmann, Rebekka Zubler, Frederic Oddo, Mauro Rossetti, Andrea O. De Lucia, Marzia Univ Hosp CHUV Lab Rech Neuroimagerie LREN Lausanne Switzerland Univ Lausanne Lausanne Switzerland Univ Bern Bern Univ Hosp Dept Intens Care Med Inselspital Bern Switzerland Univ Bern Bern Univ Hosp Dept Neurol Inselspital Bern Switzerland Univ Hosp CHUV Dept Intens Care Med Lausanne Switzerland Univ Hosp CHUV Neurol Serv Lausanne Switzerland

Background: Outcome prognostication in postanoxic comatose patients is more accurate in predicting poor than good recovery. Using electroencephalography recordings in patients treated with targeted temperature management at 33 degrees C (TTM 33), we have previously shown that improvement in auditory discrimination over the first days of coma predicted awakening. Given the increased application of a 36 degrees C temperature target (TTM 36), here we aimed at validating the predictive value of auditory discrimination in the TTM 36 setting. Methods: In this prospective multicenter study, we analyzed the EEG responses to auditory stimuli from 60 consecutive patients from the first and second coma day. A semiautomatic decoding analysis was applied to single patient data to quantify discrimination performance between frequently repeated and deviant sounds. The decoding change from the first to second day was used for predicting patient outcome. Results: We observed an increase in auditory discrimination in 25 out of 60 patients. Among them, 17 awoke from coma (68% positive predictive value;95% confidence interval: 0.46-0.85). By excluding patients with electroencephalographic epileptiform features, 15 of 18 exhibited improvement in auditory discrimination (83% positive predictive value;95% confidence interval: 0.59-0.96). Specificity of good outcome prediction increased after adding auditory discrimination to EEG reactivity. Conclusion: These results suggest that tracking of auditory discrimination over time is informative of good recovery independent of the temperature target. This quantitative test provides complementary information to existing clinical tools by identifying patients with high chances of recovery and encouraging the maintenance of life support. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Cardiac arrest Coma Targeted temperature management EEG Mismatch negativity multivariate decoding

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decoding and predicting intentions

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YEAR IN COGNITIVE NEUROSCIENCE 2011年第1期1224卷 9-21页

作者： Haynes, John-Dylan Charite Bernstein Ctr Computat Neurosci Berlin D-10115 Berlin Germany

There has been a long debate on the existence of brain signals that precede the outcome of decisions, even before subjects believe they are consciously making up their mind. The framework of multivariate decoding provides a novel tool for investigating such choice-predictive information contained in neural signals leading up to a decision. New results show that the specific outcome of free choices between different plans can be interpreted from brain activity, not only after a decision has been made, but even several seconds before it is made. This suggests that a causal chain of events can occur outside subjective awareness even before a subject makes up his/her mind. An important future line of research would be to develop paradigms that allow feedback of real-time predictions of future decisions to reveal whether such decisions can still be reverted. This would shed light on how tight the causal link is between early predictive brain signals and subsequent decisions.

关键词： intention prediction multivariate decoding free will decision

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