Biology subjects

Akaishi, R.

Publications and source records attributed to Akaishi, R..

4 recordsLinked to original sources

bioRxiv2025

Investigating the potential for mirror self-recognition in honeybees (Apis mellifera): a preliminary study using the mark test

Mirror self-recognition (MSR) is a key indicator of self-awareness, primarily studied in vertebrates. Investigating MSR in invertebrates such as the western honeybee (Apis mellifera), an insect with advanced cognition, is essential to understanding the evolutionary origins and potential convergent evolution of self-recognition. We conducted two experiments using a classic mark test, applying a paint mark to the clypeus, a body part invisible to the bee without a mirror, and compared head-directed grooming between bees with and without mirror access. In Experiment 1 (n=12), without prior mirror exposure, bees did not increase their total grooming activity, although they did groom for a significantly higher proportion of time while facing the mirror. In Experiment 2 (n=9), bees with prior mirror exposure showed significantly higher total grooming activity than controls, an effect driven by an increase in grooming while facing the mirror. However, the critical test for MSR, a direct comparison of grooming while facing the mirror versus facing away from it, was not significant in either experiments mirror group. Our findings suggest the observed behaviors are not indicative of MSR. Instead, they are better explained by simpler mechanisms, such as an orienting response to a novel stimulus (Exp 1), generalized agitation from a perceived social stimulus (Exp 2), or tactile irritation from the mark itself, an interpretation consistent with findings in other invertebrates. This exploratory research, limited by small sample sizes, provides preliminary yet inconclusive evidence. We discuss our results in the context of key methodological prerequisites for the mark test, such as mark salience, and the broader possibility that MSR-like behaviors reflect a learned perceptual-motor skill rather than an abstract self-concept. Thus, this study contributes not by providing a definitive answer, but by highlighting these critical challenges and establishing a rigorous framework for future investigations designed to disentangle these alternative hypotheses.

animal behavior and cognition↗

bioRxiv2024

Forget and Forgive: A Neurocognitive Mechanism for Increased Cooperation During Group Formation

How do group size changes influence cooperation within groups? To examine this question, we performed a dynamic, network-based prisoners dilemma experiment with fMRI. Across 83 human subjects, we observed increased cooperation as group size increased. However, our computational modeling analysis of behavior and fMRI revealed that group size itself did not increase cooperation. Rather, interaction between (1) subjects stable prosocial tendencies, and (2) dynamic reciprocal strategy weighted by memory confidence, underlies the group size-modulated increase in cooperation because the balance between them shifts toward the prosocial tendency with higher memory demands in the larger groups. We found that memory confidence was encoded in fusiform gyrus and precuneus, whereas its integration with prosocial tendencies was reflected in the left DLPFC and dACC. Therefore, interaction between recall uncertainty during reciprocal interaction (i.e., forgetting) and ones individual prosocial preference is a core pillar of emergent cooperation in more naturalistic and dynamic group formation.

neuroscience↗

bioRxiv2022

Expected Costs of Mental Efforts are Updated When People Exert Effort, not by Prospective Information

To understand why people avoid mental effort, it is crucial to reveal the mechanisms by which we learn and decide about mental effort costs. This study investigated whether mental effort cost learning aligns with temporal-difference (TD) learning or alternative mechanisms. Model-based fMRI analyses showed no correlation between cost prediction errors (CPEs) and activity in the dorsomedial frontal cortex/dorsal anterior cingulate cortex (dmFC/dACC) or striatum at the time of a fully informative effort cue about upcoming effort demands, contradicting the TD hypothesis. Instead, CPEs correlate with dmFC/dACC (positively) and caudate (negatively) activity at effort completion. Furthermore, only activity patterns at effort completion predict subsequent choices. These results show that decision policies are updated retrospectively at effort completion, updating expected costs with prediction error between experienced effort and prior expectations, demonstrating mental effort cost learning is retrospective, and imply that adaptive learning of mental effort cost does not follow canonical TD learning. Significance StatementUnderstanding how people learn about mental effort costs is essential for advancing theories of motivation and cognitive control. However, the algorithms supporting such learning remain unclear. This study addressed this gap and found that temporal-difference learning, commonly used to explain reward learning, could not account for how people learn about effort. Instead, decision policies were updated retrospectively at effort completion, based on a prediction error between experienced effort and prior expectations. These findings reveal that mental effort cost learning is fundamentally retrospective and imply that it relies on mechanisms distinct from canonical temporal-difference learning.

neuroscience↗

bioRxiv2017

Information seeking and simulation: Roles of attention in guiding a goal-directed behavior

We usually actively seek out the information we need. However, it is still debated whether information seeking in decision situation is a purposeful behavior or a random process. We investigated this issue using the decision task involving multiple goal-directed event sequences, in which a contextual cue specifies an associated target and touch to the target delivers the reward. We found that the gaze followed the sequence of contextual cue to the associated target, which was eventually chosen. This fixation sequence from contextual cue to the associated target could be observed even when there were multiple goals and when the focus was shifted from one goal to another. To causally investigate the effects of sequential simulation, we directly manipulated the processing of the contextual cues and found its influence on the final choice of target. Furthermore, past episodes of the sequences influenced both final choices of targets and initial gaze to contextual cues. We interpret the results as suggesting that the internal process of simulating goal-directed event sequence drives information-seeking behavior such as attention/gaze in decision situations.

animal behavior and cognition↗