Human activities have fundamental impacts on the distribution of species through altered land use, but also directly by dispersal of propagules. Rare long-distance dispersal events have a disproportionate importance for the spread of species including invasions. While it is widely accepted that humans may act as vectors of long-distance dispersal, there are few studies that quantify this process. We studied in detail a mechanism of human-mediated dispersal (HMD). For two plant species we measured, over a wide range of distances, how many seeds are carried by humans on shoes. While over half of the seeds fell off within 5 m, seeds were regularly still attached to shoes after 5 km. Semi-mechanistic models were fitted, and these suggested that long-distance dispersal on shoes is facilitated by decreasing seed detachment probability with distance. Mechanistic modelling showed that the primary vector, wind, was less important as an agent of long-distance dispersal, dispersing seeds less than 250 m. Full dispersal kernels were derived by combining the models for primary dispersal by wind and secondary dispersal by humans. These suggest that walking humans can disperse seeds to very long distances, up to at least 10 km, and provide some of the first quantified dispersal kernels for HMD.

Synchronous movement is a key component of social behavior in several species including humans. Recent theories have suggested a link between interpersonal synchrony of brain oscillations and interpersonal movement synchrony. The present study investigated this link. Using transcranial alternating current stimulation (tACS) applied over the left motor cortex, we induced beta band (20 Hz) oscillations in pairs of individuals who both performed a finger-tapping task with the right hand. In-phase or anti-phase oscillations were delivered during a preparatory period prior to movement and while the tapping task was performed. In-phase 20 Hz stimulation enhanced interpersonal movement synchrony, compared with anti-phase or sham stimulation, particularly for the initial taps following the preparatory period. This was confirmed in an analysis comparing real vs pseudo pair surrogate data. No enhancement was observed for stimulation frequencies of 2 Hz (matching the target movement frequency) or 10 Hz (alpha band). Thus, phase-coupling of beta band neural oscillations across two individuals’ (resting) motor cortices supports the interpersonal alignment of sensorimotor processes that regulate rhythmic action initiation, thereby facilitating the establishment of synchronous movement. Phase-locked dual brain stimulation provides a promising method to study causal effects of interpersonal brain synchrony on social, sensorimotor and cognitive processes.

The use of pre-recorded music to ease behavioral and psychological symptoms associated with dementia is popular in health-care contexts in both formal music therapy settings and in non-therapist led interventions. However, further understanding of how non-therapist led interventions compare to therapist led interventions is needed. This paper reviews 28 studies that used pre-recorded music with people with dementia using a critical interpretive synthesis model. Results revealed that pre-recorded music can be effective in reducing a variety of affective and behavioral symptoms, in particular agitation, even where a trained music therapist is not present. However, the results are not universally positive, suggesting the need for further clarification of protocols for music use and closer investigation of variables that influence individual responseto music.

Social networks are ubiquitous in the lives of adolescents. This work systematically reviewed all studies which investigated the relationship between subjective well-being and the social networks of adolescents. Twenty-nine articles (out of 1,204 hits) were included within the review. Offline social networks have a positive association between the mood, self-esteem, and loneliness of adolescents but not body image. Nine of the studies investigating online social networks found a positive association on mood, life satisfaction, and loneliness through support seeking and receiving positive feedback. Fifteen of the studies found a negative association between online social networks and mood, self-esteem, life satisfaction, body image, and overall subjective well-being through high investment, passive use, receiving negative feedback, and social media ostracism. There is a need for intervention programs and education for young people, educators, and parents to address the risks to subjective well-being brought about by online social networks.

Personalized music playlists are increasingly being used in health-care contexts to address the psychological and behavioral symptoms in people with dementia. However, there is little understanding of how people with different mental health histories and symptoms respond differently to music. A factorial experiment was conducted to investigate the influence of depression, anxiety, apathy, and cognitive decline on affective response to music. Ninety-nine people with dementia listened to three music playlists based on personal preferences. Activation of facial action units was measured, and behavioural responses continuously observed. Results demonstrated that people with high levels of depression and with symptoms of Alzheimer's type dementia demonstrated increased levels of sadness when listening to music. People with low depression but high levels of apathy demonstrated the highest behavioral evidence of pleasure during music listening, although behavioral evidence declined with severity of cognitive impairment. It is concluded that as well as accounting for personal preferences, music interventions for people with dementia need to take mental health history and symptoms into account.