The effects of playing violent video games on affect

Are chimpanzees futurists? Effects of motion lines and motion blur on the judgments of global motion direction in chimpanzees (Pan troglodytes).

“…Although previous studies have shown that the length and number of MLs affected the “evocativeness” of motion speed rather than the direction of motion (Hayashi et al, 2012; Miura & Uemura, 2008), the present experiment showed that they also affected the judgment of global motion direction . In particular, the longer the MLs, the stronger the effect of ML direction.…”

“…In humans, the effect of the number of MLs is also inconsistent across studies. Miura and Uemura (2008) reported that the impression of speed increased with increasing the number of MLs, while Hayashi et al (2012), on the contrary, reported no difference in speed judgment between five and eight MLs. Hayashi et al pointed out that in the case of eight MLs, the area of MLs was interpreted as a filled rectangle due to the high density of MLs.…”

“…Hayashi et al pointed out that in the case of eight MLs, the area of MLs was interpreted as a filled rectangle due to the high density of MLs. Indeed, the stimuli used by Miura and Uemura were not as dense with MLs as those of Hayashi et al (2012) further compared speed judgments in the 5-MLs and black rectangle conditions and found that the perceived speed was faster in the 5-MLs condition than in the rectangle condition. The 9/48 condition we used in the present study was similar to the eight-line condition used by Hayashi et al, suggesting that the chimpanzees might have perceived nine MLs as a solid object due to a high density and thus might not have caused a bias toward the directional judgments of the global motion.…”

“…For example, MLs can represent the trajectory of an object’s motion by their shape (cf., Cohn & Maher, 2015). We can also perceive changes in speed (or distance displaced) as well as the direction of motion by manipulating the length and density of the ML (Hayashi et al, 2012; Miura & Uemura, 2008; Satou et al, 2016). In Experiment 2, we examined the effects of manipulating the length and number of ML added to an object on judgments of the global motion direction.…”

“…The length of MLs represents the displacement distance and, thus, the speed (Satou et al, 2016). Humans judge that the longer the MLs, the faster the speed (Hayashi et al, 2012). In addition, studies examining the effect of the speed on the directional judgments of the global motion using random-dot cinematograms in humans showed that within a specific range, the threshold for directional judgments became smaller (i.e., more accurate) as the speed increased (Barton et al, 1996; Snowden & Kavanagh, 2006).…”