Chasing vs. stalking: interrupting the perception of animacy

Area of Science:

• Cognitive Psychology
• Neuroscience
• Visual Perception

Background:

• Visual perception encompasses physical features and higher-level properties like animacy and goal-directedness.
• Perceiving animacy is dynamic, as agents' goal-directed behaviors change over time.
• The visual system must maintain and update representations of animate behavior during motion.

Purpose of the Study:

• To investigate how the visual system perceives and updates animacy, specifically chasing behavior.
• To determine the role of temporal dynamics and motion patterns in the detection of chasing.

Main Methods:

• Participants controlled a 'sheep' shape, attempting to avoid a 'wolf' shape that mimicked distractors.
• The wolf's pursuit was manipulated with periods of static, jiggling, or random motion.
• Detection of chasing was assessed by the participant's ability to avoid capture.

Main Results:

• Detection of chasing was significantly impaired only when the wolf's motion was random and temporally chunked.
• The character and temporal grouping of pursuit, not merely its duration, determined chasing detection.
• Intermittent random motion disrupted the perception of goal-directed chasing.

Conclusions:

• The visual system relies on specific temporal dynamics and motion patterns to interpret chasing.
• Temporally extended random motion can lead the visual system to reject interpretations of chasing.
• Understanding these dynamics is key to how the brain constructs or rejects perceptions of animacy.