Age-Related Changes in Smoothness of Gait of Healthy Children and Early Adolescents

Abstract

In this study, we acquired and processed trunk accelerations during level walking in 85 children aged 8-13?years to calculate spatio-temporal parameters and Harmonic Ratio (HR), which is a metrics representative of gait smoothness and step-to-step symmetry. The results show that while spatio-temporal parameters remain unchanged once normalized considering individuals’ anthropometry, significantly higher values of HR for both the antero-posterior and vertical directions were found in participants aged 12–13 with respect to those of 8–9. This indicates an improvement of gait symmetry, which suggests that the gait maturation process is still ongoing for the age ranges tested here.     

Muscarinic receptors activity in the perirhinal cortex and hippocampus has differential involvement in the formation of recognition memory

In this work we probed the effects of post-trial infusions of the muscarinic receptor antagonist scopolamine on object recognition memory formation. Scopolamine was infused bilaterally immediately after the sample phase in the perirhinal cortex or dorsal hippocampus and animals were tested for short-term (90 min) or long-term (24 h) memory. Results showed that scopolamine impaired short-term memory when injected in either the perirhinal cortex or hippocampus. Nevertheless, scopolamine disrupted long-term memory when administrated in the perirhinal cortex but not when applied in the hippocampus. Long-term memory was unaffected when scopolamine was infused 160 min after the sample phase or 90 min before test phase. Our data indicate that short-term recognition memory requires muscarinic receptors signaling in both the perirhinal cortex and hippocampus, whereas long-term recognition memory depends on muscarinic receptors in the perirhinal cortex but not hippocampus. These results support a differential involvement of muscarinic activity in these two medial temporal lobe structures in the formation of recognition memory.     

Multisensory integration affects visuo-spatial working memory

In the present study, we investigate how spatial attention, driven by unisensory and multisensory cues, can bias the access of information into visuo-spatial working memory (VSWM). In a series of four experiments, we compared the effectiveness of spatially-nonpredictive visual, auditory, or audiovisual cues in capturing participants' spatial attention towards a location where to-be-remembered visual stimuli were or were not presented (cued/uncued trials, respectively). The results suggest that the effect of peripheral visual cues in biasing the access of information into VSWM depend on the size of the attentional focus, while auditory cues did not have direct effects in biasing VSWM. Finally, spatially congruent multisensory cues showed an enlarged attentional effect in VSWM as compared to unimodal visual cues, as a likely consequence of multisensory integration. This latter result sheds new light on the interplay between spatial attention and VSWM, pointing to the special role exerted by multisensory (audiovisual) cues.     

The ontogenetic ritualization of bonobo gestures

Great apes communicate with gestures in flexible ways. Based on several lines of evidence, Tomasello and colleagues have posited that many of these gestures are learned via ontogenetic ritualization—a process of mutual anticipation in which particular social behaviors come to function as intentional communicative signals. Recently, Byrne and colleagues have argued that all great ape gestures are basically innate. In the current study, for the first time, we attempted to observe the process of ontogenetic ritualization as it unfolds over time. We focused on one communicative function between bonobo mothers and infants: initiation of “carries” for joint travel. We observed 1,173 carries in ten mother–infant dyads. These were initiated by nine different gesture types, with mothers and infants using many different gestures in ways that reflected their different roles in the carry interaction. There was also a fair amount of variability among the different dyads, including one idiosyncratic gesture used by one infant. This gestural variation could not be attributed to sampling effects alone. These findings suggest that ontogenetic ritualization plays an important role in the origin of at least some great ape gestures.     

Understanding responses to political conflict: interactive effects of the need for closure and salient conflict schemas

Two studies examined the relationship between the need for cognitive closure and preferences for conflict-resolution strategies in 2 different samples of elite political actors. Although research has suggested that high need for closure should be associated with competitiveness, the authors argue that this relationship should be strongest among political actors with a hostile conflict schema, or representation of what a conflict is and how it should be dealt with. The authors provide evidence for this hypothesis using archival survey data on American foreign-policy officials' attitudes toward international conflict at the height of the Cold War (Study 1) and their own data on the relationship between the need for closure and conflict-strategy preferences among samples of activists from 2 political parties in Poland: a centrist party with a reputation for cooperativeness and an extremist party with a reputation for confrontation (Study 2). The broader implications of these findings are discussed.     

Perirhinal cortex muscarinic receptor blockade impairs taste recognition memory formation

The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition memory using attenuation of neophobia as an index. In addition, learned taste aversion in both short- and long-term memory tests was exclusively impaired by scopolamine. These data provide neurochemical support for the theory that cholinergic activity of the perirhinal cortex participates in the formation of the taste memory trace and that it is independent of the NMDA and AMPA receptor activity. These results support the idea that cholinergic neurotransmission in the perirhinal cortex is also essential for acquisition and consolidation of taste recognition memory.     

The positive effect of negative emotions in protracted conflict: The case of anger

Extant research has demonstrated the destructive role that anger plays in the context of intergroup conflict. Among other findings, it has been established that anger elevates public support for aggressive and violent actions towards the outgroup. This finding has been explained by the unique cognitive appraisals, emotional goal, and response tendencies associated with anger, typified by appraised relative strength and high control, motivation to correct perceived wrongdoings, and willingness to engage in risky behavior. In the current work we examine an innovative assumption, according to which the apparent destructive implications of anger are a result of situational range restriction—namely, that anger as a group emotion has been examined almost solely at the escalation stage of conflict. Instead, we propose that the same unique characteristics of anger can bring about constructive political attitudes and support for non-violent policies in the context of systematic efforts to de-escalate a protracted conflict.To test this hypothesis we conducted two studies in which we examined the relationship between anger and the willingness to engage in positive risk-taking and support non-violent policies in the context of political negotiations between adversaries. Results indicate a significant positive relationship, supporting the hypothesis that anger is not an exclusively militant emotion, and its effects are situationally dependent.