Human biological and nonbiological point-light movements: Creation and validation of the dataset

Abstract

Human action perception is so powerful that people can identify movement efficiently in the absence of pictorial information, such as in point-light displays. Interest is growing in this type of stimulus for research in neuroscience. This interest stems from the advantage of separating the component of pure human action kinematics from other pictorial information, such as facial expression and muscle contraction. Although several groups have previously developed datasets of human point-light actions, due to the lack of datasets composed of daily actions with short durations, we developed 20 biological and 40 control (scrambled) point-light movements by using the technique of recording people wearing reflector patches. The videos are about 1 s long. Subsequently, we performed a judgment task in which 100 participants (50 male and 50 female) evaluated each video according to three categories: human action resemblance, performed action, and gender of actor. We present the mean scores of each evaluation for each video, and further propose a selection of the most suitable videos to be used as human point-light action displays and scrambled point-light displays for control. Finally, we discuss our findings on the gender attributions of the pointlight displays.

Distinct cerebellar regions for body motion discrimination

“…A key component of daily social interactions is the ability to perceive other individuals’ body movements, in order to understand their actions but also their intentions and emotions. While we can identify actions, intentions and emotions of others even if this information is conveyed by only a handful of briefly presented points (typically used for biological motion experiments, Thornton et al ., 2014 ; Lapenta et al ., 2017 ), there are many pathological conditions in which this ability can be profoundly deteriorated (such as in autism spectrum disorder, Kaiser & Pelphrey, 2012 ; see also Urgesi et al ., 2014 ). Cortical areas traditionally associated to biological motion processing are the ventral premotor cortex ( Saygin et al ., 2004 ; van Kemenade et al ., 2012 ; Avenanti et al ., 2013 ; Borgomaneri et al ., 2015 ), the posterior parietal cortex ( Battelli et al ., 2003 ) and the posterior superior temporal sulcus (pSTS) ( Grossman et al ., 2000 , 2005 ; Sokolov et al ., 2018 ).…”

Reading point-light walkers and amorphous—A TMS study.

“…The four categories of stimuli were previously developed by our group. Specifically, PLDs were created and validated as described in Lapenta et al (2017), we selected the PLb and PLnb previously evaluated as more suitable to compose each category. Further, for composing PLs condition we presented the male and female athletes standing still wearing the reflector patches.…”

“…In order to eliminate possible influences of facial expression, we edit the videos to cover actor's faces with a black mask (see Figure 1 for stimuli examples of each condition). Technical approach for video recording and editing followed the same procedure as described in Lapenta et al (2017). All stimuli are approximately 1,000 ms long and were presented upright.…”

“…Herein we aimed to compare motor activation during observation of real movements (RM), point-light biological movements (PLb); point-light amorphous (non-biological shape) movements (PLnb) and static point-lights human shaped (PLs). Our PL stimuli were provided from a database previously developed and validated by our group (Lapenta et al, 2017). To compose RM category we used our videos from the same actors performing the same actions as selected for PLb.…”

“…To compose RM category we used our videos from the same actors performing the same actions as selected for PLb. For the PLs category we filmed the actors standing still wearing the reflector patches and edited the videos following the same procedure as in Lapenta et al (2017). With this strategy we aim to achieve the following goals: (a) evaluate if human actions with and without pictorial information result in comparable motor facilitation clarifying the adequacy of PLb in motor observation research; (b) identify if motor facilitation differs during PLb and PLnb observation, verifying the suitability of PLnb as control condition; (c) identify if motor facilitation differs between PLb and PLs observation, clarifying if human shape alone, without movement inference, promote motor circuitry recruitment.…”