修士 慶應義塾大学社会学研究科 実験心理学
PhD ケンブリッジ大学 実験心理学
Society for Neuroscience
Poulter, S., Austen, J. M., Kosaki, Y., Dachtler, J., Lever, C., & McGregor, A.
Behavioural Brain Research査読有り369p.111936 (online first publication)2019年-
Kosaki, Y., Pearce, J. M., & McGregor, A.
Hippocampus査読有りOnline First Publication2018年-
概要：Previous studies have suggested that spatial navigation can be achieved with at least two distinct learning processes, involving either cognitive map‐like representations of the local environment, referred to as the “place strategy”, or simple stimulus‐response (S‐R) associations, the “response strategy”. A similar distinction between cognitive/behavioral processes has been made in the context of non‐spatial, instrumental conditioning, with the definition of two processes concerning the sensitivity of a given behavior to the expected value of its outcome as well as to the response‐outcome contingency (“goal‐directed action” and “S‐R habit”). Here we investigated whether these two versions of dichotomist definitions of learned behavior, one spatial and the other non‐spatial, correspond to each other in a formal way. Specifically, we assessed the goal‐directed nature of two navigational strategies, using a combination of an outcome devaluation procedure and a spatial probe trial frequently used to dissociate the two navigational strategies. In Experiment 1, rats trained in a dual‐solution T‐maze task were subjected to an extinction probe trial from the opposite start arm, with or without prefeeding‐induced devaluation of the expected outcome. We found that a non‐significant preference for the place strategy in the non‐devalued condition was completely reversed after devaluation, such that significantly more animals displayed the use of the response strategy. The result suggests that the place strategy is sensitive to the expected value of the outcome, while the response strategy is not. In Experiment 2, rats with hippocampal lesions showed significant reliance on the response strategy, regardless of whether the expected outcome was devalued or not. The result thus offers further evidence that the response strategy conforms to the definition of an outcome‐insensitive, habitual form of instrumental behavior. These results together attest a formal correspondence between two types of dual‐process accounts of animal learning and behavior.
Bouchekioua, Y., Tsutsui-Kimura, I., Sano, H., Koizumi, M., Tanaka, K. F., Yoshida, K., Kosaki, Y., Watanabe, S., & Mimura, M.
Neuroscience Research査読有りEpub ahead of print2017年-
概要：Pharmacological intervention in the substantia nigra is known to induce repetitive behaviors in rodents, but a direct causal relationship between a particular neural circuit and repetitive behavior has not yet been established. Here we demonstrate that acute excitation in dopamine D1 receptor-expressing MSNs terminals in the substantia nigra pars reticulata by optogenetics resulted in sustained and chronic repetitive behaviors. These data show for the first time that activation of the striatonigral direct pathway is sufficient to generate motor stereotypies.
Shimbo, A., Kosaki, Y., Ito, I., & Watanabe, S.
Behavioural Brain Research査読有り336p.156 - 1652018年-
概要：Left-right asymmetry is known to exist at several anatomical levels in the brain and recent studies have provided further evidence to show that it also exists at a molecular level in the hippocampal CA3-CA1 circuit. The distribution of N-methyl-d-aspartate (NMDA) receptor NR2B subunits in the apical and basal synapses of CA1 pyramidal neurons is asymmetrical if the input arrives from the left or right CA3 pyramidal neurons. In the present study, we examined the role of hippocampal asymmetry in cognitive function using β2-microglobulin knock-out (β2m KO) mice, which lack hippocampal asymmetry. We tested β2m KO mice in a series of spatial and non-spatial learning tasks and compared the performances of β2m KO and C57BL6/J wild-type (WT) mice. The β2m KO mice appeared normal in both spatial reference memory and spatial working memory tasks but they took more time than WT mice in learning the two non-spatial learning tasks (i.e., a differential reinforcement of lower rates of behavior (DRL) task and a straight runway task). The β2m KO mice also showed less precision in their response timing in the DRL task and showed weaker spontaneous recovery during extinction in the straight runway task. These results indicate that hippocampal asymmetry is important for certain characteristics of non-spatial learning.
Kosaki, Y., & Watanabe, S.
Neurobiology of learning and memory査読有り134p.304 - 3162016年-
概要：Autism-spectrum disorder (ASD) is a multi-aspect developmental disorder characterised by various social and non-social behavioural abnormalities. Using BTBR T+ tf mouse strain (BTBR), a promising animal model displaying a number of behavioural and neural characteristics associated with ASD, we tested the hypothesis that at the core of various symptoms of ASD lies a fundamental deficit in predictive learning between events. In five experiments, we conducted a variety of Pavlovian conditioning tasks, some requiring the establishment of associations between temporally phasic events and others involving static events. BTBR mice were impaired in the acquisition of conditioned magazine approach responses with an appetitive unconditioned stimulus (US) (Experiment 1) and conditioned freezing with an electric shock US (Experiment 2). Both of these tasks had temporally phasic conditioned stimuli (CSs). Conversely, these mice showed normal acquisition of conditioned place preference (CPP), whether the US was a systemic injection of methamphetamine (Experiment 3A) or the presence of food (Experiment 3B). Experiment 4 showed normal acquisition of conditioned taste aversion (CTA) to a flavour-taste compound CS, although BTBR mice still exhibited an abnormal stimulus selection when learning for each element of the compound CS was assessed separately. Experiment 5 revealed a weaker latent inhibition of CTA in BTBR mice. The BTBR mouse's impaired predictive learning between phasic events and intact associations between static events are discussed in terms of dysfunctional contingency-based, but not contiguity-based learning, which may accompany abnormal selective attention to relevant cues. We propose that such dysfunctional contingency learning mechanisms may underlie the development of various social and non-social symptoms of ASD.
Kosaki, Y., & Watanabe, S.
Behavioral Neuroscience査読有り130p.182 - 1952016年-
概要：Oxytocin (OT) has been implicated in a variety of mammalian reproductive and social behaviors, and the use of intranasal OT for clinical purposes is on the rise. However, basic actions of OT, including the rewarding or reinforcing properties of the drug, are currently not fully understood. In this study, the authors investigated whether intranasally administered OT has different reinforcing properties for social and nonsocial stimuli and whether such effects are variable between male and female subjects. Conditioned social preference (CSP) and conditioned place preference (CPP) paradigms were used to examine social and nonsocial reinforcing properties of OT. In CSP, the presence of a same-sex unfamiliar conspecific was repeatedly paired with intranasal OT, while a different conspecific was associated with saline. The reinforcing effect of OT was assessed in a postconditioning choice test under a drug-free condition. In CPP, the 2 conspecifics were replaced with nonsocial black and white compartments. The authors found that intranasal OT (12 μg) in females supported the formation of CSP (Experiment 1) but not CPP (Experiment 3). Neither CSP (Experiment 2) nor CPP (Experiment 4) was formed in males. Extended conditioning with higher dose OT (36 μg), however, abolished the initial CSP in females and produced an aversion to the OT-paired stimulus mouse. Experiment 5 indicated that it was the repeated administrations rather than the higher dose that produced the abolition of the original preference. Overall, the current results demonstrate for the first time a sex- and stimulus-dependent reinforcing property of intranasal OT in mice.
Kosaki, Y., & Pearce, J. M.
Journal of Experimental Psychology: Animal Learning and Cognition査読有り41p.266 - 2762015年-
概要：Two groups of rats in Experiment 1 were required to escape from a square pool by swimming to 1 of 2 submerged platforms that were situated beside the centers of 2 opposite walls. To help rats find a platform, black panels of equal width were pasted to the middle of the walls that were adjacent to the platforms. The width of the 2 panels was 50 cm for Group 50, and 100 cm for Group 100. Test trials were then conducted in the same pool, but with the platforms removed and with a 50-cm panel on 1 wall and a 100-cm panel on the opposite wall. Group 50 expressed a stronger preference for the 100-cm than the 50-cm panel during the test, whereas Group 100 expressed a similar preference for both panels. Thus the degree of generalization from the short to the long panel was greater than from the long to the short panel. Experiments 2 and 3 pointed to the same conclusion. They were of a similar design to Experiment 1, except that the lengths of the panels for the 2 groups were 25 and 50 cm in Experiment 2, and 25 and 100 cm in Experiment 3. The results are explained by assuming the original training results in the walls without black panels entering into inhibitory associations. This inhibition is then assumed to generalize more to the short than the long test panels and thereby result in an asymmetry in the gradients of generalization between the different lengths.
Dumont, J. R., Jones, P. M., Pearce, J. M., & Kosaki, Y.
Journal of Experimental Psychology: Animal Learning and Cognition査読有り41p.91 - 1042015年-
概要：In 4 experiments, rats had to discriminate between the lengths of 2 objects of the same color, black or white, before a test trial with the same objects but of opposite color. The experiments took place in a pool from which rats had to escape by swimming to 1 of 2 submerged platforms. For Experiments 1 and 2, the platforms were situated near the centers of panels of 1 length, but not another, that were pasted onto the gray walls of a square arena. The acquired preference for the correct length was eliminated by changing the color of the panels. In Experiment 3, the platforms were situated near the middle of the long walls of a rectangular pool, and in Experiment 4 they were situated in 1 pair of diagonally opposite corners of the same pool. Changing the color of the walls markedly disrupted the effects of the original training in both experiments. The results indicate that rats represent the length of objects not by their abstract, geometric attributes but in a more concrete fashion such as by a mental snapshot or by the amount of color stimulation they provide.
Kosaki, Y., Poulter, S. L., Austen, J. M., & McGregor, A.
Learning & Memory査読有り22p.179 - 1912015年-
概要：In three experiments, the nature of the interaction between multiple memory systems in rats solving a variation of a spatial task in the water maze was investigated. Throughout training rats were able to find a submerged platform at a fixed distance and direction from an intramaze landmark by learning a landmark-goal vector. Extramaze cues were also available for standard place learning, or "cognitive mapping," but these cues were valid only within each session, as the position of the platform moved around the pool between sessions together with the intramaze landmark. Animals could therefore learn the position of the platform by taking the consistent vector from the landmark across sessions or by rapidly encoding the new platform position on each session with reference to the extramaze cues. Excitotoxic lesions of the dorsolateral striatum impaired vector-based learning but facilitated cognitive map-based rapid place learning when the extramaze cues were relatively poor (Experiment 1) but not when they were more salient (Experiments 2 and 3). The way the lesion effects interacted with cue availability is consistent with the idea that the memory systems involved in the current navigation task are functionally cooperative yet associatively competitive in nature.
Kosaki, Y., Lin, T. C. E., Horne, M. R., Pearce, J. M., & Gilroy, K. E.
Hippocampus査読有り24p.1633 - 16522014年-
概要：Rats with lesions of the hippocampus or sham lesions were required in four experiments to escape from a square swimming pool by finding a submerged platform. Experiments 1 and 2 commenced with passive training in which rats were repeatedly placed on the platform in one corner-the correct corner-of a pool with distinctive walls. A test trial then revealed a strong preference for the correct corner in the sham but not the hippocampal group. Subsequent active training of being required to swim to the platform resulted in both groups acquiring a preference for the correct corner in the two experiments. In Experiments 3 and 4, rats were required to solve a discrimination between different panels pasted to the walls of the pool, by swimming to the middle of a correct panel. Hippocampal lesions prevented a discrimination being formed between panels of different lengths (Experiment 3), but not between panels showing lines of different orientations (Experiment 4); rats with sham lesions mastered both problems. It is suggested that an intact hippocampus is necessary for the formation of stimulus-goal associations that permit successful passive spatial leaning. It is further suggested that an intact hippocampus is not necessary for the formation of stimulus-response associations, except when they involve information about length or distance.
Kosaki, Y., Jones, P. M., & Pearce, J. M.
Journal of Experimental Psychology: Animal Behavior Processes査読有り39p.342 - 3562013年-
概要：The ability of rats to solve a discrimination between two objects that differ in length was investigated in five experiments. Using a rectangular swimming pool, Experiment 1 revealed it is easier to locate a submerged platform when it is near the center of a long rather than a short wall. For Experiments 2-4, the objects were black or white panels pasted onto the gray walls of a square pool, with two long panels pasted to two opposing walls and two short panels pasted to the remaining walls. The platform was easier to locate when it was placed near the middle of a long rather than a short panel. This effect was found when the long panels were twice (Experiments 2-4) or four times the length of the short panels (Experiment 4). Experiment 5 demonstrated that rats can solve a discrimination between panels of length 15 and 45 cm more readily than when they are 70 and 100 cm. The results are consistent with the claim that generalization gradients based on stimulus magnitude are steeper for stimuli that are weaker rather than stronger than the stimulus used for the original training.
Austen, J. M., Kosaki, Y., & McGregor, A.
Journal of Experimental Psychology: Animal Behavior Processes査読有り39p.259 - 2722013年-
概要：In three experiments, rats were trained to locate a submerged platform in one of the base corners of a triangular arena above each of which was suspended one of two distinctive landmarks. In Experiment 1, it was established that these landmarks differed in their salience by the differential control they gained over behavior after training in compound with geometric cues. In Experiment 2, it was shown that locating the platform beneath the less salient landmark potentiated learning based on geometry compared with control rats for which landmarks provided ambiguous information about the location of the platform. The presence of the more salient landmark above the platform for another group of animals appeared to have no effect on learning based on geometry. Experiment 3 established that these landmark and geometry cues entered into within-compound associations during compound training. We argue that these within-compound associations can account for the potentiation seen in Experiment 2, as well as previous failures to demonstrate overshadowing of geometric cues. We also suggest that these within-compound associations need not be of different magnitudes, despite the different effects of each of the landmarks on learning based on geometry seen in Experiment 2. Instead, within-compound associations appear to mitigate the overshadowing effects that traditional theories of associative learning would predict.
Kosaki, Y., Austen, J. M., & McGregor, A.
Journal of Experimental Psychology: Animal Behavior Processes査読有り39p.126 - 1392013年-
Poulter, S. L., Kosaki, Y., Easton, A., & McGregor, A.
Journal of Experimental Psychology: Animal Behavior Processes査読有り39p.93 - 982013年-
概要：Studies of spontaneous behavior to assess memory are widespread, but often the relationships of objects to contexts and spatial locations are poorly defined. We examined whether object-location memory was maintained following global, but not local, changes to the geometric shape of an arena. Rats explored two trial-unique objects in a distinctively shaped arena before being exposed to two identical copies of one of these objects in a different shape in a different physical location. Rats preferentially explored objects that were novel in relation to their local geometric context rather than identifying both locations as novel in the global geometric context.
Kosaki, Y., & Watanabe, S.
Behavioural Brain Research査読有り227p.81 - 902012年-
概要：Contributions of different limbic cortical areas to mediation of behavioural flexibility were examined using repeated acquisition of three-choice discrimination in operant chambers. Rats were trained on a series of positional discrimination tasks with three levers, where position of the correct lever remained the same within a task but shifted across tasks. Ibotenic acid lesions of the medial prefrontal cortex impaired acquisition of each discrimination task by increasing errors specifically in the early phase of each task. These errors were characterised by perseveration to the previously correct lever. By contrast, lesions of the anterior cingulate cortex resulted in the impairment of discrimination in general without inducing perseveration; the impairment was instead characterised by disruption of general error-correction processes. Hippocampal lesions severely impaired learning by increasing perseverative tendencies that were present throughout the learning stages in each task. These results extend our understanding of the contributions of the different nodes of the limbic cortico-striatal circuit to different aspects of behavioural flexibility.
Kosaki, Y., & Dickinson, A.
Journal of Experimental Psychology: Animal Behavior Processes査読有り36p.334 - 3422010年-
概要：In two experiments hungry rats received extensive training to lever press for food outcomes before one outcome was devalued by aversion conditioning and responding tested in extinction. If the rats were trained on a concurrent schedule in which two responses yielded different outcomes, performance during the extinction test was reduced by devaluation of the associated outcome. By contrast, if a single response was trained concurrently with the noncontingent presentations of the other outcome, test performance was insensitive to devaluation of the contingent outcome. This finding demonstrates that training on a schedule that offers a choice between responses that yield different outcomes prevents the onset of behavioral autonomy.
Jonkman, S., Kosaki, Y., Everitt, B. J., & Dickinson, A.
Behavioural Processes査読有り83p.276 - 2812010年-
概要：Different groups of rats received different amounts of training to lever press for a food reinforcer before an aversion was conditioned to the food. This devaluation of the reinforcer reduced responding in both subsequent extinction and reinforced tests of responding to a degree that was independent of the amount of instrumental training. Moreover, interpolating context extinction between aversion conditioning and the extinction test reduced the magnitude of the devaluation effect, thereby indicating that Pavlovian contextual conditioning may play a role in the instrumental devaluation effect.
de Wit, S., Kosaki, Y., Balleine, B. W., & Dickinson, A.
Journal of Neuroscience査読有り26p.5224 - 52292006年-
概要：The capacity for goal-directed behavior requires not only the encoding of the response-outcome relationship but also the ability to resolve conflict induced by competing responses. Recent neuroimaging studies have identified the prefrontal cortex as critical for resolving conflict between competing responses. At present, however, much of this evidence is indirect, and the necessity of dorsomedial prefrontal cortex (dmPFC) function for the resolution of conflict in goal-directed behavior has not been assessed. Here, we develop a rodent paradigm to investigate response conflict caused by the concurrent activation of a correct and incorrect response. In this paradigm, the outcome of one response also acts as a discriminative stimulus signaling that the other response is correct. Whereas rats with a functional dmPFC are able to resolve this conflict, inactivation of dmPFC using an infusion of muscimol produced a deficit by selectively interfering with their ability to inhibit the incorrect, competing response.
神前裕, 時暁聴, 松井大, 新保彰大, 藤巻峻
基礎心理学研究査読有り34p.60 - 772015年-
概要：Throughout the history of research on animal learning, it has been widely acknowledged that the temporal relationship between events exerts a critical influence on the acquisition of a conditioned response. Until more recently, however, no explicit and systematic studies had investigated how animals learn the temporal relationship itself. In this article, we first review some basic functions of temporal information in classical conditioning. We then focus on one influential learning theory, temporal coding hypothesis, which posits that animals can automatically encode temporal relationships between events and express learned behaviour through integration of multiple temporal relationships acquired across contexts. After reviewing basic results supporting the temporal coding hypothesis, we present an alternative explanation of some temporal coding-like phenomena on the basis of AESOP model combined with the potentially different contributions of motivational and sensory US representations in higher-order conditioning. In a second article (Fujimaki, Shimbo, Matsui, Shi, & Kosaki, 2015), we will discuss interval timing in operant conditioning and neural substrates of timing behaviour.
藤巻峻, 新保彰大, 松井大, 時暁聴, 神前裕
基礎心理学研究査読有り34p.78 - 902015年-
概要：In the previous article (Kosaki, Shi, Matsui, Shimbo, & Fujimaki, 2015) we reviewed studies regarding how animals represent temporal information in classical conditioning. In this article, we first review various issues pertaining to interval timing in operant conditioning, with the main goal of providing a concise summary of procedural and theoretical developments in interval timing research. In the remainder of the article, we will review recent empirical findings and theories about the neural substrates underlying timing mechanisms both in classical and operant conditioning, and discuss how the hippocampus and striatum might contribute to different aspects of temporal information processing during conditioning. We then argue that the potentially different timing mechanisms implemented by the hippocampus and the striatum, as evidenced by the recent discovery of time cells in the hippocampus and consistent findings regarding involvement of the striatum in interval timing, might each be considered to constitute a part of functionally dissociable multiple memory systems that have been described elsewhere in the literature, particularly in the context of spatial learning and the organisation of voluntary behaviour.
心理学評論査読有り58p.276 - 2942015年-
心理学評論58p.318 - 3232015年-
Watanabe, S., & Kosaki, Y.(分担執筆)
単行本（学術書）担当ページ数：pp. 273-299 (Chapter 13)ISBN：978-4-431-56559-8
Keio University Press2004年-
研究成果概要：自閉症スペクトラム障害の基礎的メカニズムとして、事象間の随伴性判断に障害が見られるか、マウスモデルを用いて検討した。道具的条件づけ手続きを用い、レバー押し行動と餌報酬との間の随伴性を操作し、随伴性操作に対する行動の感受性を自閉症モ...自閉症スペクトラム障害の基礎的メカニズムとして、事象間の随伴性判断に障害が見られるか、マウスモデルを用いて検討した。道具的条件づけ手続きを用い、レバー押し行動と餌報酬との間の随伴性を操作し、随伴性操作に対する行動の感受性を自閉症モデル系統のBTBT T+/tfマウスと標準的なC57BL/6マウスにて比較した。実験1・2において、異なる種類の強化子を用いてレバー押しを訓練したが、いずれにおいても、 C57系統に比べ、BTBR系統では 訓練に用いた間欠強化スケジュールでの要求反応比率を上昇させると反応が維持されなくなり、安定した反応率を維持する事が出来なかった。実験3ではFR3での最小限の訓練後、強化子低価値化手続きを用いて、行動に伴う結果表象の有無を検証した。BTBR系統では低価値化の効果が傾向として認められたが、統制群であるC57系統で低価値化効果が見られなかった。いずれの実験においても、実験手続きの更なる改良が必要であることが明らかになった。