中部学院大学

Unlike other catarrhine primates, modern humans deliver a helpless newborn who requires prolonged extensive care. Such helpless infancy is associated with fetus-like, rapid postnatal brain growth, which is essential to produce the large human brain. In the debate about its evolution, a key question has been whether it emerged in Homo erectus, whose brain sizes were approximately 20-40% smaller than Homo sapiens. We here show that a type of asymmetric cranial deformity called deformational plagiocephaly can serve as a direct indicator of helpless infancy, regardless of the developmental age of the fossil specimens in question. Because clinical studies have established that such deformation results primarily from an immature state of cranial bones and neck/body muscles, deformational plagiocephaly (or at least its marked condition) must be unique to humans among extant hominids (or more broadly catarrhine primates). Our metric examination based on 1504 cranial specimens (996 great apes and 508 modern humans) supports this working hypothesis. We have found that some cranial fossils of Indonesian H. erectus and Homo floresiensis also display such deformities. These support a deep evolutionary origin of hominin helpless infancy, and imply both elaborate parental childcare and cooperative social behaviours that could likely have accompanied it.

Copers are individuals with a history of ankle sprain who return to daily and sports activities without recurrent instability. However, it is unclear whether copers can use movement strategies comparable to those of healthy individuals without a history of ankle sprain. Understanding these movement strategies may be important for designing effective training programs and avoiding unintended biomechanical adaptations. Therefore, we aimed to compare the kinematics and muscular activities of the lower limbs during half squats and gait between copers and healthy controls. Ten copers (3 females) and 10 controls (4 females) were included in this secondary cross-sectional study. All participants were young, physically active adults who engaged in recreational physical activities for more than 1.5 h per week. We compared mean and peak angles of the thigh, shank, and foot calculated from inertial measurement units, as well as muscle activities of the biceps femoris long head, rectus femoris, gastrocnemius, and tibialis anterior between copers and controls during half squats and gait. During the half squat, copers exhibited lower thigh rotational angles and lower activities of biceps femoris long head, rectus femoris and tibialis anterior across both the descending and ascending phases, accompanied by a higher mean foot angle. In contrast, gait-related group differences were limited to the mean shank angle during the stance phase, with no significant differences observed in other limb angles or muscle activities. These findings suggest that movement strategy alterations in copers are task-dependent and more evident during demanding exercises such as the half squat than during level walking. Identifying such movement characteristics may be important for designing efficient training or rehabilitation programs for individuals with a history of ankle sprain.

The prosocial choice paradigm is a widely used method in studies of prosocial behavior in chimpanzees, but findings produced using this approach have been inconsistent. One potential source of these discrepancies is the lack of control for motor lateralization. The present study examined the influence of motor lateralization on decision-making in four chimpanzees (Pan troglodytes) housed at the Warsaw Zoo. Subjects chose between prosocial (1/1) and selfish (1/0) tokens under three experimental conditions: (a) tokens randomly mixed within the feeder, (b) tokens arranged in single-color stacks on opposite sides, and (c) mixed tokens without a partner (ghost condition). Each individual made 200 decisions per condition over a three-month period. Results indicated that chimpanzees were significantly more likely to choose the prosocial option when token placement minimized lateralization effects through random mixing. In contrast, when tokens were presented in fixed locations, choices were systematically influenced by the physical convenience of reaching, reflecting individual motor preferences. These findings highlight the importance of controlling motor lateralization in studies using the prosocial choice paradigm. Even with motor lateralization controlled, the presence of a partner proved essential for demonstrating prosociality. Prosociality was not detected in the so-called ghost condition, where no partner is present. Future research should increase the number of trials, distribute sessions over time, randomize token placement, and examine the relationship between task-based decisions and broader patterns of social interaction.

Communication support for patients with neurological disorders extends beyond high-technology communication aids. It also includes non-aided and low-technology methods and requires flexible selection and the combined use of these methods depending on the situation. Gaining experience with various communication strategies in a stepwise manner from an early stage enables the smoother introduction of advanced communication devices when necessary. Effective support must be tailored to the disease stage, as communication abilities and needs change over time. In this context, collaboration among multiple professionals is essential. Such interprofessional collaboration enables appropriate assessment, timely intervention, and continuity of care across disease stages. A team-based, continuous support system benefits patients, and caregivers and professionals involved in their care. By sharing knowledge, skills, and responsibilities within a support team, the burden on individual supporters can be reduced, and the quality and consistency of communication support can be enhanced. Looking to the future, further development of emerging technologies such as eye-gaze input systems, personalized speech synthesis, and brain-machine interfaces is highly anticipated. However, careful consideration of their characteristics, limitations, and potential risks is necessary to ensure their safe and effective use in clinical practice.