Ei-Ichi Izawa

Ei-Ichi Izawa
Keio University | Keidai · Department of Psychology

Ph.D.

About

48
Publications
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Citations

Publications

Publications (48)
Article
Mesotocin (MT) is an avian homologue of oxytocin (OT). Behavioral pharmacological studies in birds have suggested the involvement of OT in socially affiliative behavior. However, investigations of peripheral MT levels associated with social behavior are lacking because non-invasive methods to measure surrogate plasma MT have yet to be established....
Article
Behavioral responses to novelty, including fear and subsequent avoidance of novel stimuli, i.e., neophobia, determine how animals interact with their environment. Neophobia aids in navigating risk and impacts on adaptability and survival. There is variation within and between individuals and species; however, lack of large-scale, comparative studie...
Preprint
Full-text available
Behavioural responses to novelty, including fear and subsequent avoidance of novel stimuli, behaviours referred to as neophobia, determine how animals interact with their environment. Neophobia aids in navigating risk and impacts on adaptability and survival. There is variation within and between individuals and species, however, lack of large-scal...
Article
Altruistic behaviour, such as allogrooming and allofeeding, has been suggested to be crucial for maintenance of cooperative relationship especially between non-kin individuals. Monogamous pair-bond, which is widespread in birds, is a form of cooperation for breeding between a male and a female. Many previous studies reported that altruistic behavio...
Article
Full-text available
Hippocampal “time cells” encode specific moments of temporally organized experiences that may support hippocampal functions for episodic memory. However, little is known about the reorganization of the temporal representation of time cells during changes in temporal structures of episodes. We investigated CA1 neuronal activity during temporal bisec...
Article
Full-text available
In group living species, social interactions often involve two, three, or more individuals. In social interactions involving three or more individuals, each player should adjust its behavior while simultaneously considering multiple social factors (i.e., dominance ranks) associated with all the participants of the current interaction. Despite the i...
Article
Full-text available
The investigation of prosocial behavior is of particular interest from an evolutionary perspective. Comparisons of prosociality across non-human animal species have, however, so far largely focused on primates, and their interpretation is hampered by the diversity of paradigms and procedures used. Here, we present the first systematic comparison of...
Preprint
Full-text available
Interception of a moving target is a fundamental behaviour of predators and requires tight coupling between the sensory and motor systems. In the literature of foraging studies, feedback mechanisms based on current target position are frequently reported. However, there have also been recent reports of animals employing feedforward mechanisms, in w...
Conference Paper
Full-text available
Language discrimination has previously been found in human infants, cotton-top tamarin monkeys, rats, and Java sparrows. This ability might also be relevant for the crow, a social passerine with extensive auditory perceptual skills living in close contact with humans. In this experiment we tested whether crows autonomously pay attention to spoken l...
Article
Full-text available
Allogrooming, where an individual grooms another, has been extensively studied in various social animals to understand its role in the evolution of cooperation/proso-ciality. In existing studies in mammals, allogrooming has been suggested to exhibit not only a hygiene but also a social function. Allopreening, a topic of increasing interest in mamma...
Article
Grasping movement in primates is known to be a visually guided behavior and the aperture of hand opening is adjusted to the target size on the basis of visual information. The analogous behavior can be found in birds, called 'pecking', consisting of head-reaching and bill-grasping. Bill-grasping has been investigated mainly in pigeons and an apertu...
Data
Raw data csv files of the article 'Rapid adjustment of pecking trajectory to prism-induced visual shifts in crows as compared to pigeons' published in Journal of Experimental Biology.
Article
Full-text available
Pecking in birds is analogous to reaching and grasping movements in primates. Earlier studies on visuomotor control in birds, which were conducted mostly in pigeons, suggested that avian pecking is controlled feedforwardly, and is out of the control of visual guidance during movement. However, recent studies using crows suggested a role of vision i...
Article
Birds are an extensively specialized animal group with unique anatomical, physiological and ecological characteristics. Sophisticated social behaviors and remarkable cognitive abilities are present in several avian lineages, driven by their enlarged brains and intricate neural networks. These unique traits could be a result of adaptive evolution un...
Article
Full-text available
The dextrous foraging skills of primates, including humans, are underpinned by flexible vision-guided control of the arms/hands and even tools as body-part extensions. This capacity involves a visuomotor conversion process that transfers the locations of the hands/arms and a target in retinal coordinates into body coordinates to generate a reaching...
Data
Figure S2>Success rates at different position in an array and the order of successive pecks in the control phase.
Data
Figure S3>Grasping onset at different positions in an array and the order of successive pecks in the control phase.
Article
Some group-living animals show conciliatory tendencies towards specific group members afterconflicts, referred to as post-conflict affiliation (PC-affiliation). PC-affiliation with a former opponent and a third-party bystander is classified as ‘reconciliation’ and ‘third-party affiliation’,respectively. PC-affiliation is assumed to be mediated by h...
Article
Full-text available
Early increased sophistication of human tools is thought to be underpinned by adaptive morphology for efficient tool manipulation. Such adaptive specialisation is unknown in nonhuman primates but may have evolved in the New Caledonian crow, which has sophisticated tool manufacture. The straightness of its bill, for example, may be adaptive for enha...
Article
Group living has both benefits and costs to individuals; benefits include efficient acquisition of resources, and costs include stress from social conflicts among group members. Such social challenges result in hierarchical dominance ranking among group members as a solution to avoid escalating conflict that causes different levels of basal stress...
Article
Birds are capable of dexterous sensory-motor activities such as tool use. Reaching is a crucial component of tool use and is a vision-guided behavior in primates, in which arm movement is monitored online in a stable visual frame. However, vision-guided reaching in primates is enabled by anatomical separation of the head and arm; neck reaching in b...
Article
The recognition of individuals is a basic cognitive ability of social animals. A prerequisite for individual recognition is distinct characteristics that can be used to distinguish between other conspecific individuals. Studies of birds have shown that visual information, such as colour patterning, is used in individual recognition. However, in the...
Article
Full-text available
Recognizing other individuals by integrating different sensory modalities is a crucial ability of social animals, including humans. Although cross-modal individual recognition has been demonstrated in mammals, the extent of its use by birds remains unknown. Herein, we report the first evidence of cross-modal recognition of group members by a highly...
Article
Large-billed crows (Corvus macrorhynchos), highly social birds, form stable dominance relationships based on the memory of win/loss outcomes of first encounters and on individual discrimination. This socio-cognitive behaviour predicts the existence of neural mechanisms for integration of social behaviour control and individual discrimination. This...
Article
Full-text available
Exploiting the skills of others enables individuals to reduce the risks and costs of resource innovation. Social corvids are known to possess sophisticated social and physical cognitive abilities. However, their capacity for imitative learning and its inter-individual transmission pattern remains mostly unexamined. Here we demonstrate the large-bil...
Article
In long-range fission-fusion complex societies, individuals are often recognized by audiovocal signals because of long-range propagation. The signature voice system is a well-known mechanism involving both acoustic individuality of a certain call type and discrimination ability. Previous studies on vocal individual recognition of birds have emphasi...
Article
Full-text available
We investigated whether vocal communication in wild Large-billed Crows (Corvus macrorhynchos) is governed by a temporal rule as an evidence for vocal exchange. In order to examine this potential temporal rule, we analyzed the intervals between two single-note ka calls produced sequentially by two crows in gregarious situations. Two different indivi...
Article
In newly hatched chicks, gene expression in the brain has previously been shown to be up-regulated following filial imprinting. By applying cDNA microarrays containing 13,007 expressed sequence tags, we examined the comprehensive gene expression profiling of the intermediate medial mesopallium in the chick cerebrum, which has been shown to play a k...
Article
Using cDNA microarrays, we have identified elsewhere the genes of microtubule-associated proteins as a group up-regulated in newly hatched chick brains after filial imprinting training. Here we show by in situ hybridization that the mRNA for the microtubule-associated protein 2 (MAP2) gene was enriched in the mesopallium and the hippocampus in the...
Article
Jungle crows (Corvus macrorhynchos) flexibly change their social forms depending on their age, time of the day, and the season. In the daytime, paired adults behave territorially and unpaired subadults form small flocks of ten birds, whereas at night hundreds of birds roost together. In the breeding season, pairings remain in their nest all day. Th...
Chapter
Full-text available
A stereotaxic atlas of the telencephalon, diencephalon and mesencephalon of the jungle crow, Corvus macrorynchos, was prepared for use in neuroscientific experiments. The atlas is comprised of 30 frontal plates from the frontal pole to the level of the hypoglossal nucleus and of 21 sagittal plates from the midline level (i.e., 0.5mm to midline) wer...
Article
The effects of bilateral chemical lesions of the ventral striatum (nucleus accumbens and the surrounding areas in the medial striatum) and arcopallium (major descending area of the avian telencephalon) were examined in 1-2-weeks old domestic chicks. Using a Y-maze, we analyzed the lesion effects on the choices that subject chicks made in two tasks...
Article
To identify the neuro-cognitive substrates of valuation and choice, we analysed the neural correlates of anticipated food rewards in the ventral striatum of freely behaving chicks. One-week-old chicks were trained in a color-discrimination task using four color cues (red, yellow, green and blue), each of which was associated with a different food r...
Article
Laterality of foot-use behaviour was examined in jungle crows (Corvus macrorhynchos). Consistency of laterality was also verified in comparison with two different behaviours. One was beak-scratching, and another was food-holding. Significant bias of foot-use laterality was found in 11 of 13 tested subjects for beak-scratching and in 10 of 12 tested...
Article
To reveal the functional roles of the striatum, we examined the effects of excitotoxic lesions to the bilateral medial striatum (mSt) and nucleus accumbens (Ac) in a food reinforcement color discrimination operant task. With a food reward as reinforcement, 1-week-old domestic chicks were trained to peck selectively at red and yellow beads (S+) and...
Article
Effects of bilateral chemical lesion of the hippocampus was examined in 1- to 2-week-old domestic chicks. Chicks were trained and tested in an egocentric spatial task, in which subject chicks should memorize location of a rewarding object in reference to the subject's viewpoint. Two beads were simultaneously presented on a wall, and chicks pecked a...
Article
The archistriatum mediates a neural pathway from the medial part of intermediate hyperstriatum ventrale (in the dorsal pallium) to the lobus parolfactorius (in the medial striatum), thus is possibly involved in memory formation in the domestic chick. To elucidate the functional roles, we examined single neuron activities from archistriatum in uncon...
Article
Full-text available
To understand the animal mind, we have to reconstruct how animals recognize the external world through their own eyes. For the reconstruction to be realistic, explanations must be made both in their proximate causes (brain mechanisms) as well as ultimate causes (evolutionary backgrounds). Here, we review recent advances in the behavioral, psycholog...
Article
Full-text available
Effects of bilateral chemical lesions of the medial basal ganglia [lobus parolfactorius (LPO)] were examined in 7- to 14-d-old domestic chicks. Chicks were trained in a color discrimination task, in which the subject had to peck one of the two colored beads associated with rewards that differed in quantity (amount of food) and/or temporal proximity...
Article
Effects of bilateral chemical lesions of the ventro-medial basal ganglia (lobus parolfactorius, LPO) were examined in 3-9-day-old domestic chicks. In experiment-1, chicks were trained to peck at a blue bead that was associated with drops of water as a reward. Addition of passive avoidance training using a bitter yellow bead resulted in highly selec...
Article
Properties of local synapses were analyzed in lobus parolfactorius (LPO; avian homologue of caudate-nucleus) of quail chicks by using slice preparations in vitro. Field-potential extracellular and whole-cell intracellular recordings revealed excitatory synaptic inputs converging from dorsal and ventral regions within LPO. With exogenous dopamine (1...
Article
Effects of bilateral kainate lesions of telencephalic basal ganglia (lobus parolfactorius, LPO) were examined in domestic chicks. In the imprinting paradigm, where chicks learned to selectively approach a moving object without any explicitly associated reward, both the pre- and post-training lesions were without effects. On the other hand, in the w...
Article
We aimed to reveal what is coded in the basal ganglia of domestic chicks. In the water-reinforced 'go' task, chicks learned to peck selectively at a colored bead in order to obtain a drop of water. Out of 38 units obtained, seven showed excitatory activities specifically during the reward period. In the food-reinforced go/no-go task, chicks learned...
Article
Animals are predisposed to memorize specific features of objects they encounter, and to link them with behavioral outputs in a selective manner. In this study, we examined whether chicks memorize objects by colors, and how they exploit the memorized color cues for selective pecking in 1- to 2-days-old quail chicks (Coturnix japonica). Ball-shaped b...

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