Limits...
Neural Differences between Covert and Overt Attention Studied using EEG with Simultaneous Remote Eye Tracking

View Article: PubMed Central - PubMed

ABSTRACT

Research on neural mechanisms of attention has generally instructed subjects to direct attention covertly while maintaining a fixed gaze. This study combined simultaneous eye tracking and electroencephalogram (EEG) to measure neural attention responses during exogenous cueing in overt attention shifts (with saccadic eye movements to a target) and compared these with covert attention shifts (responding manually while maintaining central fixation). EEG analysis of the period preceding the saccade latency showed similar occipital response amplitudes for overt and covert shifts, although response latencies differed. However, a frontal positivity was greater during covert attention shifts, possibly reflecting saccade inhibition to maintain fixation. The results show that combined EEG and eye tracking can be successfully used to study natural overt shifts of attention (applicable to non-verbal infants) and that requiring inhibition of saccades can lead to additional frontal responses. Such data can be used to refine current neural models of attention that have been mainly based on covert shifts.

No MeSH data available.


Related in: MedlinePlus

Wave plot of the occipital response for saccade conditions in the left hemisphere (left) and the right hemisphere (right) of the brain.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120114&req=5

Figure 5: Wave plot of the occipital response for saccade conditions in the left hemisphere (left) and the right hemisphere (right) of the brain.

Mentions: The posterior positivity (Figures 5, 6) peaked around 141 ms after target onset (SD = 26.2) with an average amplitude of 1.42 μV (SD = 2.63 μV). Peak amplitude was significantly affected by number of targets, F(1,330) = 23.59, p < 0.001, d = 0.457, with greater amplitudes for single (M = 2.01, SD = 2.54) than for double targets (M = 0.83, SD = 2.60). No other main effects or interactions were significant. In particular, there was no significant effect of response type on peak amplitude, F(1,330) = 0.62, p = 0.430. Follow up Bayesian analyses were conducted using the lmBF function of the “BayesFactor” Package (Morey and Rouder, 2015) in Core Team, R (2012) using Cauchy priors based on Liang et al. (2012). Comparing a mixed model including response type with a model excluding response type, suggests that it is 6.7 times more likely that there is no effect of response type than that there is one (B10 = 0.149 ± 0.94%).


Neural Differences between Covert and Overt Attention Studied using EEG with Simultaneous Remote Eye Tracking
Wave plot of the occipital response for saccade conditions in the left hemisphere (left) and the right hemisphere (right) of the brain.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120114&req=5

Figure 5: Wave plot of the occipital response for saccade conditions in the left hemisphere (left) and the right hemisphere (right) of the brain.
Mentions: The posterior positivity (Figures 5, 6) peaked around 141 ms after target onset (SD = 26.2) with an average amplitude of 1.42 μV (SD = 2.63 μV). Peak amplitude was significantly affected by number of targets, F(1,330) = 23.59, p < 0.001, d = 0.457, with greater amplitudes for single (M = 2.01, SD = 2.54) than for double targets (M = 0.83, SD = 2.60). No other main effects or interactions were significant. In particular, there was no significant effect of response type on peak amplitude, F(1,330) = 0.62, p = 0.430. Follow up Bayesian analyses were conducted using the lmBF function of the “BayesFactor” Package (Morey and Rouder, 2015) in Core Team, R (2012) using Cauchy priors based on Liang et al. (2012). Comparing a mixed model including response type with a model excluding response type, suggests that it is 6.7 times more likely that there is no effect of response type than that there is one (B10 = 0.149 ± 0.94%).

View Article: PubMed Central - PubMed

ABSTRACT

Research on neural mechanisms of attention has generally instructed subjects to direct attention covertly while maintaining a fixed gaze. This study combined simultaneous eye tracking and electroencephalogram (EEG) to measure neural attention responses during exogenous cueing in overt attention shifts (with saccadic eye movements to a target) and compared these with covert attention shifts (responding manually while maintaining central fixation). EEG analysis of the period preceding the saccade latency showed similar occipital response amplitudes for overt and covert shifts, although response latencies differed. However, a frontal positivity was greater during covert attention shifts, possibly reflecting saccade inhibition to maintain fixation. The results show that combined EEG and eye tracking can be successfully used to study natural overt shifts of attention (applicable to non-verbal infants) and that requiring inhibition of saccades can lead to additional frontal responses. Such data can be used to refine current neural models of attention that have been mainly based on covert shifts.

No MeSH data available.


Related in: MedlinePlus