[CaBSSem] [Psychat] CABS Seminar Friday at 3:00 pm

Daniel Bub dbub at uvic.ca
Fri Oct 25 12:34:10 PDT 2019


A reminder that our CABS seminar this Friday will feature Thomas Ferguson.


CABSEM Title:  Theta oscillations as possible neural evidence for correspondence effects



CABSEM Abstract:

When people are shown images of handled objects, it is claimed that these images universally elicit affordances. These affordances manifest as correspondence effects – that is, people are quicker to classify an object when the handle direction matches the hand they are using to respond. However, other behavioural work – the spatial coding account – has called into question these claims. This work suggests that it is the specific spatial codes generated by the images that determine whether correspondence effects are present or not. Thus, images of objects do not universally elicit correspondence effects based on graspable properties of the depicted objects. In an extension of these behavioural investigations, I will present data summarizing a recent experiment that examined correspondence effects using electroencephalography. The behavioural data replicate previous findings supporting the spatial coding account when keypress responses are made to the upright/inverted status of the  object.  However, when observers respond to the same images with reach/grasp actions, again to signal whether the object is upright or inverted, evidence suggests that motor effects induced by the handle do indeed affect reaction times.  These data show that top-down influences are crucial determinants of whether spatial or motor codes affect left/right-handed responses.   Both early visual (the P1 and N1 components) and motor (lateralized readiness potential) components were not sensitive to handle alignment, although the P1 and N1 were sensitive to condition. In a surprising twist, frontal theta oscillations emerged as a neural response sensitive to both handle alignment and response condition. I will then discuss the implications of these findings in the broader context of both Simon effects and correspondence effects.



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