To See, Not to See, or to See Poorly: Perceptual Quality and Guess Rate as a Function of Electroencephalography (EEG) Brain Activity in an Orientation Perception Task

Abstract

Brain oscillations are known to modulate detection of visual stimuli, but it is unclear if this is due to increased guess rate or decreased precision of the mental representation. Here we estimated quality and guess rate as a function of electroencephalography (EEG) brain activity using an orientation perception task. Errors on each trial were quantified as the difference between the target orientation and the orientation reported by participants with a response stimulus. Response errors were fitted to standard mixed model by Zhang and Luck (2008) to quantify how participants’ guess rate and standard deviation parameters varied as a function of brain activity. Twenty-four participants were included in the analysis.Within subjects, the power and phase of delta and theta post-target oscillatory activity were found to vary along with performance on the orientation perception task in that greater power and phase coherence in the 2-5 Hz band range was measured in trials with more accurate responses. In addition, the phase of delta and theta correlated with the degree of response error while oscillatory power did not have a relationship with trial-by-trial response errors. Analysis of task-related alpha activity yielded no significant results implying that alpha oscillations do not play an important role in orientation perception at single trial level. Across participants, only the standard deviation parameter correlated with oscillatory power in the high alpha and low beta frequency ranges. These results indicate that post-target power is associated with the precision of mental representations rather than the guess rate, both across trials within subjects and across subjects.

Using occipital ⍺-bursts to modulate behaviour in real-time

“…We found a significant difference between burst and no-burst conditions ( p < .05 ) in a 32 ms time window between 280–312 ms after stimulus presentation. Based on previous literature, this period would correspond to the putative N2 (255 – 360 ms) component (Koivisto & Revonsuo, 2003, 2010; Sheldon & Mathewson, 2021). We reckon that this difference in the ERP might reflect the RT-effect found between burst and no-burst trials at group-level in the main analysis.…”

Rhythms in cognition: The evidence revisited

“…For instance, the notion that rhythms reflect fluctuations in neuronal excitability (Adrian & Matthews, 1934; Bishop, 1932) predicts that behaviour should be rhythmically modulated only when behavioural performance is, in fact, limited by excitability. This is arguably the case for short stimulus durations and tasks like contrast detection or simple feature discrimination but might not be the case for longer stimulus durations (Michail et al, 2021; Sheldon & Mathewson, 2021; both this issue).…”

“…Sheldon and Mathewson (2021, this issue) set out to test whether pre‐stimulus and/or post‐stimulus oscillations affect the precision of visual perception or the likelihood of guessing. They employed an orientation discrimination task in which the participants reproduced the stimulus orientation as precisely as possible and analysed the resulting error distribution with statistical models that yield separate estimates of perceptual precision and guessing.…”

Connecting Covert Attention and Visual Perception to the Spatiotemporal Dynamics of Alpha Band Activity, Cross-Frequency Coupling (CFC), and Functional Connectivity using Multivariate Pattern Analysis (MVPA)

“…Stimuli were presented using a Windows 7 PC running MATLAB R2012b with the Psychophysics toolbox (Version 3; Brainard 1997; Pelli 1997). The code running the task was a modified version of the Orientation Perception Task code from Sheldon and Mathewson (2021). The original version of the code can be found here: https://github.com/APPLabUofA/OrientTask_paper.…”