The Effect of Dual Tasks in Locomotor Path Integration

Abstract

Without landmarks, navigation is based on information about self-velocity, which is transformed to position or orientation by a process called path integration. Simple path integration tasks, such as reaching a previously seen goal by blindfolded locomotion, were often considered to be automatic and not influenced by unrelated cognitive activity. However, we recently showed that reproduction of self-motion without landmark cues exhibits systematic dual-task interference. Since these experiments did not exclude that the dual task only interferes with memory for self-motion, we performed two additional experiments testing generic path integration. We show that locomotor homing and reaching predefined goals by active self-motion are affected systematically by a concurrent mental task. The similarity of the effects we found to those reported for duration estimation led us to the hypothesis that subjective time may be used as a temporal basis of path integration. Alternatively, path integration and duration estimation may be based on similar underlying neuronal mechanisms, for example, coincidence detection in neural oscillators.

Distraction Shrinks Space

“…This result contrasts with previous results showing that path features cause an increase in remembered path length (the feature accumulation effect), and extends results from a pair of studies (Glasauer et al, 2007(Glasauer et al, , 2009) in which a concurrent task caused a shortening of perceived path lengths (the distractor effect). Observation of the distractor effect in the current paradigm suggests that the effect is more general than previously indicated.…”

“…Thus, in the current study, and in those of Glasauer et al (2007Glasauer et al ( , 2009, the anticipation by participants of (potential) upcoming motor responses may have resulted in the engagement of different or additional processes during path encoding, compared to studies showing the feature accumulation effect. For example, there is support for the idea that the anticipation of upcoming movement trajectories results in forward modeling (Wolpert & Ghahramani, 2000;Philbeck, Klatzky, Behrmann, Loomis, & Goodridge, 2001).…”

“…Second, the distractor effect was found in a ratio estimation task in which distance representations must be rescaled and indicated haptically. This suggests that if the distractor effect operates by warping temporal representations, as suggested by Glasauer et al (2007Glasauer et al ( , 2009, these representations are shared between systems that guide motor reproduction and ratio estimation.…”

“…So why did Glasauer et al (2007Glasauer et al ( , 2009) find that concurrent tasks consistently decrease remembered distances? Likewise, why do the various path features described in literature reporting the feature accumulation effect show no evidence of distracting participants from the accumulation of distance cues?…”

Agency, gait and self-consciousness

“…Knoblich and Repp, 2009;Repp and Knoblich, 2007). Furthermore, the study of gait agency opens up the possibility of applying paradigms such as dual tasking to investigate bodily self-consciousness and the sense of agency and related functions of spatial navigation and path integration (Glasauer et al, 2009;Loomis et al, 1993;Wolbers and Hegarty, 2010). This is important as humans may perform many perceptual, motor, and cognitive tasks while walking, potentially causing performance in these tasks to decline or change.…”