Pulling out all the stops to make the distance: Effects of effort and optical information in distance perception responses made by rope pulling.

Human observers perceive distance in remarkably stable and consistent manner across response methods and experimental paradigms. Most empirical work on the problem focused exclusively on geometrical variables, such as angle of declination below the horizon (Ooi, Wu, & He, 2001), with more recent considerations of nonvisual factors, such as effort (Proffitt, 2006). Hajnal, Bunch, and Kelty-Stephen (2014) showed that in addition to the object's physical angle of declination below the horizon, nonvisual variables related to effort were utilized when making distance estimates to objects placed on a sloped ramp.

Going for distance and going for speed: effort and optical variables shape information for distance perception from observation to response.

Visually guided distance perception reflects a relationship of geometrical optical variables with the effort required when traversing the distance. We probed how the representations encoding optical variables might define this relationship. Participants visually judged distances on sloped surfaces and reproduced these distances over flat terrain by walking while blindfolded.

Multiple measures of laterality in Garnett's bushbaby (Otolemur garnettii).

Behavioral laterality, a common measure of hemispheric specialization of the brain, has been examined in multiple tasks across several species of prosimian primates; however, there is inconsistency among findings between and within species that leaves many questions about laterality unanswered. Most studies have employed few measures of laterality, most commonly handedness. This study examined multiple measures of laterality within subjects in 17 captive-born Garnett's bushbabies (Otolemur garnettii) to assess the consistency of lateralized behaviors and to examine possible influences such as age, posture, novelty, and arousal to elucidate the relations between direction and strength of laterality.