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Hisashi Murakami

3 papers in the library · 9 citations · publishing 2020-2024

Papers

Information structure of heterogeneous criticality in a fish school.

Scientific reports November 30, 2024 Takayuki Niizato, Kotaro Sakamoto, Yoh-Ichi Mototake et al. 9 citations

Integrated information theory (IIT), which measures consciousness via information integration, can be applied to non-biological systems. In schooling fish (Plecoglossus altivelis), group integrity (Φ) was highest at the critical state. Multiple levels of criticality existed as distinct subgroups within the school, and these fragmented critical subgroups coexisted with the group's overall criticality. The distribution of high-criticality subgroups was uneven across time and space. Fish in high-criticality subgroups were less affected by internal and external stimuli than those in low-criticality subgroups. These results align with prior interpretations of critical phenomena and provide a new view of empirical critical-state dynamics.

Four-Types of IIT-Induced Group Integrity of Plecoglossus altivelis.

Entropy (Basel, Switzerland) June 30, 2020 Takayuki Niizato, Kotaro Sakamoto, Yoh-Ichi Mototake et al.

Integrated information theory (IIT) 3.0, which measures a system's intrinsic cause-effect structure, can classify fish schools by group size and integrity when applied to collective behavior in Plecoglossus altivelis. Using global parameter settings and multiple timescales (from 5/120 to 120/120 seconds), the analysis successfully distinguished schools of different sizes and degrees of group integrity near the fish's reaction time scale. At longer timescales, interaction heterogeneity diminished compared to shorter timescales. The findings also offer two tentative answers to the heap paradox, a longstanding puzzle in collective behavior about how individual actions combine into group-level properties.

Finding continuity and discontinuity in fish schools via integrated information theory.

PloS one January 1, 2020 Takayuki Niizato, Kotaro Sakamoto, Yoh-Ichi Mototake et al.

Integrated information theory (IIT), originally developed to measure consciousness, can reveal a new type of leadership in fish schools that other measures cannot detect. Applying IIT 3.0 to real fish schools (Plecoglossus altivelis) showed a discontinuity in the average integrated information 〈Φ(N)〉 for schools of four or more fish, a transition not observed with mutual information or transfer entropy. This discontinuity correlated with the emergence of leadership, defined not by group behavior but by autonomy or group integrity. Simulations with the Boids model produced different results from real fish, suggesting that IIT captures a unique aspect of collective dynamics.