シンポジウム
06 エルゼビア/NSRシンポジウム
06 Elsevier/NSR Symposium
座長：Lau Chris Hak-wan（RIKEN Center for Brain Science）・Keogh Rebecca（Macquarie University） |
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| 2022年7月2日 9:00～9:10 ラグナガーデンホテル 羽衣：西 第10会場
3S10m-01
General introduction: Why we need new paradigms for studying consciousness
*Hakwan Lau(1)
1. RIKEN Center for Brain Science
Keyword: consciousness, qualia, attention, metacognition
In this short presentation, we will go through the basic rationale for having this symposium. In neuroscience and philosophy, consciousness research primarily concerns the study of subjective experience. To focus on this phenomenon and to isolate confounds such as sheer information processing capacity, we need to focus on selective manipulations and comparisons that target subjective experience itself. In this context, we will explain why studies of blindsight, aphantasia, peripheral vision, and metacognition, are essential phenomena for understanding consciousness. This does not imply that studies of anesthesia, coma, dreams, visual making, change blindness, inattentional blindness, motion-induced blindness, binocular rivalry, etc, are uninteresting. They certainly are, but they provide relatively general manipulations and comparisons. When subjective experiences change under these paradigms, the overall capacity for the relevant processing is also largely different. This sets the four focused phenomena apart, especially in terms of how they can constraint theories. Although the focus here is on experimental paradigms and laboratory studies, we will discuss one general theoretical implication of these studies too. To anticipate, the view these studies point to is that subjective experience may depend on a specific kind of implicit self-monitoring, which we call perceptual reality monitoring. It is implicit in the sense that it occurs automatically without effort, as subjective experience does. A computational model will link this process to reinforcement learning mechanisms. | | 2022年7月2日 9:10～9:32 ラグナガーデンホテル 羽衣：西 第10会場
3S10m-02
Neural circuits and cognitive capacity of blindsight macaques
*Tadashi Isa(1)
1. Grad Sch Med, Kyoto Univ, Kyoto Japan
Keyword: blindsight, extrageniculate visual pathway, awareness, nonhuman primate
Blindsight is a curious phenomenon in which subjects with damage to the primary visual cortex (V1) can perform visually guided behavior despite loss of visual awareness. Our laboratory has conducted a series of experimental studies on macaque monkeys with unilateral lesion of V1 (for review, see Isa and Yoshida, Neuroscience 469:138-161, 2021) to understand the neural circuits underlying the blindsight, and to unravel the visual cognitive functions retained in the blindsight conditions. It has been clarified that macaques with V1 lesion exhibit impaired ability to report their visual experience in Yes-No task settings, despite near complete performance in the forced choice condition (Cowey and Stoerig 1995, Yoshida and Isa 2015), suggesting impaired visual awareness in these animals and supporting the feasibility of these animals as a blindsight model. As for the visual pathway mediating the blindsight, two conflicting possibilities were suggested; one is the pathway from the lateral geniculate nucleus to extrastriate cortices (Schmid et al. 2010), and the other is the pathway from the superior colliculus to pulvinar, then to the extrastriate cortices (Diamond and Hall 1968). We have demonstrated that both pathways are critical after the V1 lesion by using pathway-selective blocking with viral vector and pharmacological inactivation techniques (Kinoshita et al. 2019; Takakuwa et al. 2021). Furthermore, as for the cortical regions responsible for blindsight, by combining noninvasive neuroimaging with PET, neuronal recording and pharmacological inactivation, we have demonstrated that the bilateral lateral intraparietal regions are critical for saccade control in blindsight condition (Kato et al. 2021). Furthermore, we have demonstrated that the dorsal premotor cortex critically mediates the visual signals to control conditioned manual response task in blindsight monkeys. As for the cognitive functions, we demonstrated that blindsight is not just a low-level reflex, but enables a variety of complex visually guided behaviors such as short term spatial memory (Takaura et al. 2011), classical conditioning and instrumental learning (Takakuwa et al. 2017; Kato et al. 2021), which may suggest that the V1-lesioned monkey may mimic Type-II blindsight patients who report “feeling something happening” rather than “seeing something” in their blind visual field. Thus, multiple visual pathways bypassing V1 might be able to access the centers for such higher cognitions. | | 2022年7月2日 9:32～9:54 ラグナガーデンホテル 羽衣：西 第10会場
3S10m-03
Measuring aphantasia and its impact on related cognitive functions
*Rebecca Keogh(1), Lachlan Kay(2), Joel Pearson(2)
1. Macquarie University, 2. UNSW
Keyword: Visual Imagery, Aphantasia, Individual Differences
Visual imagery is the ability to ‘see with the mind’s eye’. Neuroimaging work has shown that visual imagery recruits perceptual regions of the brain including early visual cortex. When individuals are asked to describe the subjective qualities of their mental imagery, for example, how vivid it is, a wide array of responses are given. Some people report that their visual imagery is very strong and akin to seeing an image, while others report that while they see an image it might be weak or blurry. It is often assumed that all people are able to visualise to some extent however a small proportion of the population report that when they attempt to visualise they do not see anything at all. This inability to visualise has been named aphantasia, and is sometimes also referred to as having a ‘blind mind’s eye’. Aphantasia provides a unique opportunity to understand and study differences in the conscious experience of our mental worlds. However, due to its inherently private nature, one of the main hurdles to overcome in visual imagery research is objectively and reliably measuring individual differences in the ability to visualise. In my presentation I will report on some behavioural (binocular rivalry) and physiological (pupillometry) measures that can be used to index visual imagery strength in the general population, as well as the lack of visual imagery in congenital aphantasia. I will also present data showing that, despite aphantasic individuals lacking the ability to visualise, they are still able to perform tasks that are thought to rely on visual imagery (visual working memory and mental rotation). I will end by discussing potential neural models that might explain what leads to aphantasia and how aphantasic individuals are still able to complete tasks that others report using visual imagery to perform. | | 2022年7月2日 9:54～10:16 ラグナガーデンホテル 羽衣：西 第10会場
3S10m-04
Peripheral vision in the central-peripheral dichotomy
*Li Zhaoping(1)
1. University of Tübingen and Max Planck Institute for Biological Cybernetics
Keyword: visual attention, visual recognition, visual illusion, visual search
Compared to central vision, peripheral vision has not only a lower spatial sampling resolution in the retina, but also, according to the recently proposed central-peripheral dichotomy (CPD, Zhaoping 2017, 2019), has a primary role for looking rather than seeing in vision. Furthermore, for seeing (i.e., recognizing and discriminating visual objects), CPD asserts that peripheral vision has a weaker or absent feedback component in the feedforward and feedback processes along the visual pathway from the primary visual cortex (V1) to higher visual areas. Due to an attentional bottleneck assumed to start from V1's output to downstream areas (Zhaoping 2019), visual recognition in higher visual areas relies on impoverished sensory information fed forward from V1. To aid recognition in challenging or ambiguous situations, in which the perceptual outcome from viewing a scene could be one of multiple non-trivial possibilities, central vision uses feedback from higher to lower visual areas such as V1 to query for additional information. This query uses brain's internal model of the visual world to disambiguate between the possibilities for an eventual perceptual outcome. Peripheral vision, with a weaker or absent feedback query according to CPD, is therefore vulnerable to visual illusions due to misleading V1 inputs. I will show two visual illusions predicted by CPD using our knowledge about V1's neural response properties. One is called the reversed depth illusion (Zhaoping & Ackermann 2018) in perceiving the 3-dimensional depth of a surface from a viewer. The other is called the flip tilt illusion (Zhaoping 2020) in perceiving the orientation of an item in an image. Usually, both illusions are only visible peripherally. A relative of the flip tilt illusion is a surprising prediction of a parallel advantage: in a special visual search task, it is faster to find a target that is parallel rather than perpendicular to uniformly oriented non-targets (Zhaoping 2022). As in typical visual search tasks, time needed for completing the task is largely determined by looking, which is the process of deciding where in the peripheral visual field to make a saccade to, until the target is located at the saccadic destination. Hence, this predicted parallel advantage highlights the role of peripheral vision in looking. Indeed, this parallel advantage is stronger for targets at the more peripheral visual fields. | | 2022年7月2日 10:16～10:38 ラグナガーデンホテル 羽衣：西 第10会場
3S10m-05
霊長類の未来の成績を予測するための知覚体験に対する展望的社会メタ認知
Social prospective metacognition of perceptual experience for prediction of future performance in primates
*宮本 健太郎(1)、Nadescha Trudel(2)、Nicholas Shea(3,4)、Matthew FS Rushworth(5,6)
1. 理化学研究所 脳神経科学研究センター
*Kentaro Miyamoto(1), Nadescha Trudel(2), Nicholas Shea(3,4), Matthew FS Rushworth(5,6)
1. RIKEN Center for Brain Science, Japan, 2. Max Planck UCL Centre, Comp Psych and Ageing Res, London, UK, 3. Institute Philosophy, Sch Advanced Study, Univ London, London, UK, 4. Faculty Philosophy, Univ of Oxford, Oxford, UK, 5. Dept Exp Psychology, Univ of Oxford, Oxford, UK, 6. Wellcome Center for Integrative Neuroimaging, Univ of Oxford, Oxford, UK
Keyword: Metacognition, Social cognition, Prospection, Imagination
Prediction and evaluation of future subjective experience both for the self and for others are important to enable cooperation between people to solve a difficult problem in a social setting. However, neural mechanisms mediating prospective metacognition in a social setting remain unknown. In the first part of the talk, we will present our study on the ability to predict one’s own future success in performing a task. We devised a behavioral paradigm with a metacognitive matching of estimates relating to both the self and the environment to be used for future decision making. We discovered that a neural signal in human alPFC could be measured which accumulated to predict prospective metacognitive decision-making but which had a limited role in other, more immediate, aspects of decision making. Disruption of this signal by TMS (cTBS) did not disrupt decision making performance but it did impair a metacognitive process before the decision – people’s ability to identify the best decisions to tackle. In the second part of the talk, we will present our study on the ability to compare predictions of future performance between oneself and a partner (with a higher or lower ability on the task). We adapted the metacognitive matching paradigm to examine comparisons of estimates of likely success between the self and other players. We found that human participants were able to estimate others’ performances in the same as they could estimate their own. Functional neuroimaging under the social metacognitive evaluation will reveal the neural mechanism that enables imagination of the subjective experience of others. | | 2022年7月2日 10:38～11:00 ラグナガーデンホテル 羽衣：西 第10会場
3S10m-06
Cognitive reality monitoring neural networks for reinforcement learning
*Mitsuo Kawato(1)
1. ATR BICR
Keyword: reinforcement learning, generative-inference model pairs, learning from a small sample, metacognition
Kawato and Cortese (2021) proposed a computational neuroscience model of metacognition. The model comprises a modular hierarchical reinforcement-learning architecture of parallel and layered, generative-inverse model pairs. In the prefrontal cortex, a distributed executive network called the “cognitive reality monitoring network” (CRMN) orchestrates conscious involvement of generative-inverse-model pairs in perception and action. Based on mismatches between computations by generative and inverse models, as well as reward prediction errors, CRMN computes a “responsibility signal” that gates selection and learning of pairs in perception, action, and reinforcement learning. A high responsibility signal is given to the pairs that best capture the external world, that are competent in movements (small mismatch), and that are capable of reinforcement learning (small reward-prediction error). CRMN selects pairs with higher responsibility signals as objects of metacognition, and consciousness is determined by the entropy of responsibility signals across all pairs. This model could lead to new-generation AI, which exhibits metacognition, consciousness, dimension reduction, selection of modules and corresponding representations, and learning from small samples. It may also lead to the development of a new scientific paradigm that enables the causal study of consciousness by combining CRMN and decoded neurofeedback. In this symposium, I discuss how CRMN can explain phenomena like blindsight, peripheral vision, metacognition, and aphantasia. | |
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