Limits...
Sustained posterior contralateral activity indicates re-entrant target processing in visual change detection: an EEG study.

Schneider D, Hoffmann S, Wascher E - Front Hum Neurosci (2014)

Bottom Line: The sensory response to the feature changes was reflected in a posterior contralateral positivity at around 100 ms after change presentation and a posterior contralateral negativity in the N1 time window (N1pc).N2pc reflected a subsequent attentional bias in favor of the relevant luminance change.Therefore, this component might reflect the re-processing of information based on sustained short-term memory representations in the visual system until a stable target percept is created that can serve as the perceptual basis for response selection and the initiation of goal-directed behavior.

View Article: PubMed Central - PubMed

Affiliation: Leibniz Research Centre for Working Environment and Human Factors Dortmund, Germany.

ABSTRACT
The present study investigated the neural mechanisms that contribute to the detection of visual feature changes between stimulus displays by means of event-related lateralizations of the electroencephalogram (EEG). Participants were instructed to respond to a luminance change in either of two lateralized stimuli that could randomly occur alone or together with an irrelevant orientation change of the same or contralateral stimulus. Task performance based on response times and accuracy was decreased compared to the remaining stimulus conditions when relevant and irrelevant feature changes were presented contralateral to each other (contralateral distractor condition). The sensory response to the feature changes was reflected in a posterior contralateral positivity at around 100 ms after change presentation and a posterior contralateral negativity in the N1 time window (N1pc). N2pc reflected a subsequent attentional bias in favor of the relevant luminance change. The continuation of the sustained posterior contralateral negativity (SPCN) following N2pc covaried with response times within feature change conditions and revealed a posterior topography comparable to the earlier components associated with sensory and attentional mechanisms. Therefore, this component might reflect the re-processing of information based on sustained short-term memory representations in the visual system until a stable target percept is created that can serve as the perceptual basis for response selection and the initiation of goal-directed behavior.

No MeSH data available.


Related in: MedlinePlus

Scalp topographies of posterior asymmetries for all change conditions. For N1pc, N2pc, and SPCN, the higher negativity contralateral to the relevant luminance change compared to the negativity contralateral to the irrelevant stimulus is plotted on the left hemisphere, while an asymmetry toward the irrelevant stimulus is plotted on the right hemisphere (see LOB condition). The same logic applies to the change-related positivity. The depicted 20 ms time windows correspond to those used for statistical analyses and were oriented at the grand average ERL peaks. Because the LOU condition revealed no distinct ERL peak in the N2 range, a 200–220 ms time window was used to illustrate N2pc scalp topography.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4017132&req=5

Figure 5: Scalp topographies of posterior asymmetries for all change conditions. For N1pc, N2pc, and SPCN, the higher negativity contralateral to the relevant luminance change compared to the negativity contralateral to the irrelevant stimulus is plotted on the left hemisphere, while an asymmetry toward the irrelevant stimulus is plotted on the right hemisphere (see LOB condition). The same logic applies to the change-related positivity. The depicted 20 ms time windows correspond to those used for statistical analyses and were oriented at the grand average ERL peaks. Because the LOU condition revealed no distinct ERL peak in the N2 range, a 200–220 ms time window was used to illustrate N2pc scalp topography.

Mentions: Posterior ERLs revealed a negativity in the N2 time window (N2pc) for both the LUM, t(11) = −3.428, p < 0.01, d = 0.99, and LOB condition, t(11) = −6.017, p < 0.001, d = 1.737. This negativity was larger for the LOB compared to the LUM condition, t(11) = −2.551, p < 0.05, d = 0.736. Furthermore, SPCN was reliably shown in the LUM condition, t(11) = −2.331, p < 0.05, d = 0.673, LOU condition, t(11) = −2.249, p < 0.05, d = 0.649, and LOB condition, t(11) = −3.642, p < 0.01, d = 1.051. The mean amplitude oriented at the SPCN peak in the grand average did not differ as a function of change condition, F(2,22) = 2.459, ε = 0.874, p = 0.117, η2p = 0.183. Yet, while in the LOB condition SPCN was still reliably shown in the 350–400 ms interval, t(11) = −2.904, p < 0.05, d = 0.838, a return to baseline was shown in the LOU, t(11) = 0.205, p = 0.841, d = 0.059, and LUM condition, t(11) = −0.521, p = 0.613, d = 0.15. For further information on the nature of the observed posterior ERLs, Figure 4 displays the posterior activation (PO7/PO8) contralateral and ipsilateral to the feature changes. Figure 5 shows the posterior scalp topographies of the described asymmetries (change-related positivity, N1pc, N2pc, SPCN) in time windows oriented at the peak of these components in the grand average.


Sustained posterior contralateral activity indicates re-entrant target processing in visual change detection: an EEG study.

Schneider D, Hoffmann S, Wascher E - Front Hum Neurosci (2014)

Scalp topographies of posterior asymmetries for all change conditions. For N1pc, N2pc, and SPCN, the higher negativity contralateral to the relevant luminance change compared to the negativity contralateral to the irrelevant stimulus is plotted on the left hemisphere, while an asymmetry toward the irrelevant stimulus is plotted on the right hemisphere (see LOB condition). The same logic applies to the change-related positivity. The depicted 20 ms time windows correspond to those used for statistical analyses and were oriented at the grand average ERL peaks. Because the LOU condition revealed no distinct ERL peak in the N2 range, a 200–220 ms time window was used to illustrate N2pc scalp topography.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4017132&req=5

Figure 5: Scalp topographies of posterior asymmetries for all change conditions. For N1pc, N2pc, and SPCN, the higher negativity contralateral to the relevant luminance change compared to the negativity contralateral to the irrelevant stimulus is plotted on the left hemisphere, while an asymmetry toward the irrelevant stimulus is plotted on the right hemisphere (see LOB condition). The same logic applies to the change-related positivity. The depicted 20 ms time windows correspond to those used for statistical analyses and were oriented at the grand average ERL peaks. Because the LOU condition revealed no distinct ERL peak in the N2 range, a 200–220 ms time window was used to illustrate N2pc scalp topography.
Mentions: Posterior ERLs revealed a negativity in the N2 time window (N2pc) for both the LUM, t(11) = −3.428, p < 0.01, d = 0.99, and LOB condition, t(11) = −6.017, p < 0.001, d = 1.737. This negativity was larger for the LOB compared to the LUM condition, t(11) = −2.551, p < 0.05, d = 0.736. Furthermore, SPCN was reliably shown in the LUM condition, t(11) = −2.331, p < 0.05, d = 0.673, LOU condition, t(11) = −2.249, p < 0.05, d = 0.649, and LOB condition, t(11) = −3.642, p < 0.01, d = 1.051. The mean amplitude oriented at the SPCN peak in the grand average did not differ as a function of change condition, F(2,22) = 2.459, ε = 0.874, p = 0.117, η2p = 0.183. Yet, while in the LOB condition SPCN was still reliably shown in the 350–400 ms interval, t(11) = −2.904, p < 0.05, d = 0.838, a return to baseline was shown in the LOU, t(11) = 0.205, p = 0.841, d = 0.059, and LUM condition, t(11) = −0.521, p = 0.613, d = 0.15. For further information on the nature of the observed posterior ERLs, Figure 4 displays the posterior activation (PO7/PO8) contralateral and ipsilateral to the feature changes. Figure 5 shows the posterior scalp topographies of the described asymmetries (change-related positivity, N1pc, N2pc, SPCN) in time windows oriented at the peak of these components in the grand average.

Bottom Line: The sensory response to the feature changes was reflected in a posterior contralateral positivity at around 100 ms after change presentation and a posterior contralateral negativity in the N1 time window (N1pc).N2pc reflected a subsequent attentional bias in favor of the relevant luminance change.Therefore, this component might reflect the re-processing of information based on sustained short-term memory representations in the visual system until a stable target percept is created that can serve as the perceptual basis for response selection and the initiation of goal-directed behavior.

View Article: PubMed Central - PubMed

Affiliation: Leibniz Research Centre for Working Environment and Human Factors Dortmund, Germany.

ABSTRACT
The present study investigated the neural mechanisms that contribute to the detection of visual feature changes between stimulus displays by means of event-related lateralizations of the electroencephalogram (EEG). Participants were instructed to respond to a luminance change in either of two lateralized stimuli that could randomly occur alone or together with an irrelevant orientation change of the same or contralateral stimulus. Task performance based on response times and accuracy was decreased compared to the remaining stimulus conditions when relevant and irrelevant feature changes were presented contralateral to each other (contralateral distractor condition). The sensory response to the feature changes was reflected in a posterior contralateral positivity at around 100 ms after change presentation and a posterior contralateral negativity in the N1 time window (N1pc). N2pc reflected a subsequent attentional bias in favor of the relevant luminance change. The continuation of the sustained posterior contralateral negativity (SPCN) following N2pc covaried with response times within feature change conditions and revealed a posterior topography comparable to the earlier components associated with sensory and attentional mechanisms. Therefore, this component might reflect the re-processing of information based on sustained short-term memory representations in the visual system until a stable target percept is created that can serve as the perceptual basis for response selection and the initiation of goal-directed behavior.

No MeSH data available.


Related in: MedlinePlus