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Publication - Dr Casimir Ludwig

    Information Foraging for Perceptual Decisions


    Ludwig, CJH & Evens, DR, 2017, ‘Information Foraging for Perceptual Decisions’. Journal of Experimental Psychology: Human Perception and Performance, vol 43., pp. 245-264


    We tested an information foraging framework to characterise the mechanisms that drive active (visual) sampling behaviour in decision problems that involve multiple sources of information. Experiments 1-3 involved participants making an absolute judgement about the direction of motion of a single random dot motion pattern. In Experiment 4, participants made a relative comparison between two motion patterns that could only be sampled sequentially. Our results show that: (i) Information (about noisy motion information) grows to an asymptotic level that depends on the quality of the information source; (ii) The limited growth is due to unequal weighting of the incoming sensory evidence, with early samples being weighted more heavily; (iii) Little information is lost once a new source of information is being sampled; (iv) The point at which the observer switches from one source to another is governed by online monitoring of his or her degree of (un)certainty about the sampled source. These findings demonstrate that the sampling strategy in perceptual decision-making is under some direct control by ongoing cognitive processing. More specifically, participants are able to track a measure of (un)certainty and use this information to guide their sampling behaviour.

    Full details in the University publications repository