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SUMMARY:Perceptual change-of-mind decisions are sensitive to absolute evid
 ence magnitude - Adam Triabhall
DTSTART:20250314T140000Z
DTEND:20250314T150000Z
UID:TALK229447@talks.cam.ac.uk
CONTACT:Adam Triabhall
DESCRIPTION:This week we will discuss and debate a recent paper by Turner 
 and colleagues (2021).\n\nAbstract: “To navigate the world safely\, we o
 ften need to rapidly ‘change our mind’ about decisions. Current models
  assume that initial decisions and change-of-mind decisions draw upon comm
 on sources of sensory evidence. In two-choice scenarios\, this evidence ma
 y be ‘relative’ or ‘absolute’. For example\, when judging which of
  two objects is the brightest\, the luminance difference and luminance rat
 io between the two objects are sources of ‘relative’ evidence\, which 
 are invariant across additive and multiplicative luminance changes. Conver
 sely\, the overall luminance of the two objects combined is a source of 
 ‘absolute’ evidence\, which necessarily varies across symmetric lumina
 nce manipulations. Previous studies have shown that initial decisions are 
 sensitive to both relative and absolute evidence\; however\, it is unknown
  whether change-of-mind decisions are sensitive to absolute evidence. Here
 \, we investigated this question across two experiments. In each experimen
 t participants indicated which of two flickering greyscale squares was bri
 ghtest. Following an initial decision\, the stimuli remained on screen for
  a brief period and participants could change their response. To investiga
 te the effect of absolute evidence\, the overall luminance of the two squa
 res was varied whilst either the luminance difference (Experiment 1) or lu
 minance ratio (Experiment 2) was held constant. In both experiments we fou
 nd that increases in absolute evidence led to faster\, less accurate initi
 al responses and slower changes of mind. Change-of-mind accuracy decreased
  when the luminance difference was held constant\, but remained unchanged 
 when the luminance ratio was fixed. We show that the three existing change
 -of-mind models cannot account for our findings. We then fit three alterna
 tive models\, previously used to account for the effect of absolute eviden
 ce on one-off decisions\, to the data. A leaky competing accumulator model
  best accounted for the changes in behaviour across absolute evidence cond
 itions – suggesting an important role for input-dependent leak in explai
 ning perceptual changes of mind” (Turner et al.\, 2021).\n\nReference: T
 urner\, W.\, Feuerriegel\, D.\, Andrejević\, M.\, Hester\, R.\, & Bode\, 
 S. (2021). Perceptual change-of-mind decisions are sensitive to absolute e
 vidence magnitude. Cognitive Psychology\, 124\, 101358–101358. https://d
 oi.org/10.1016/j.cogpsych.2020.101358
LOCATION:https://cam-ac-uk.zoom.us/j/92612577704?pwd=MUtqMjVQdXNmUTVIYjRkM
 G1NUW9GZz09
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