| 1. |
- Jimenez, Mikel, et al.
(author)
-
The Level of Processing Modulates Visual Awareness : Evidence from Behavioral and Electrophysiological Measures
- 2021
-
In: Journal of cognitive neuroscience. - : MIT Press - Journals. - 0898-929X .- 1530-8898. ; 33:7, s. 1295-1310
-
Journal article (peer-reviewed)abstract
- The level of processing hypothesis (LoP) proposes that the transition from unaware to aware visual perception is graded for low-level (i.e., energy, features) stimulus whereas dichotomous for high-level (i.e., letters, words, meaning) stimulus. In this study, we explore the behavioral patterns and neural correlates associated with different depths (i.e., low vs. high) of stimulus processing. The low-level stimulus condition consisted of identifying the color (i.e., blue/blueish vs. red/reddish) of the target, and the high-level stimulus condition consisted of identifying stimulus category (animal vs. object). Behavioral results showed that the levels of processing manipulation produced significant differences in both the awareness rating distributions and accuracy performances between tasks, the low-level task producing more intermediate subjective ratings and linearly increasing accuracy performances and the high-level task producing less intermediate ratings and a more nonlinear pattern for accuracies. The electrophysiological recordings revealed two correlates of visual awareness, an enhanced posterior negativity in the N200 time window (visual awareness negativity [VAN]), and an enhanced positivity in the P3 time window (late positivity [LP]). The analyses showed a double dissociation between awareness and the level of processing hypothesis manipulation: Awareness modulated VAN amplitudes only in the low-level color task, whereas LP amplitude modulations were observed only in the higher level category task. These findings are compatible with a two-stage microgenesis model of conscious perception, where an early elementary phenomenal sensation of the stimulus (i.e., the subjective perception of color) would be indexed by VAN, whereas stimulus' higher level properties (i.e., the category of the target) would be reflected in the LP in a later latency range.
|
|
| 2. |
- Lundqvist, Mikael, et al.
(author)
-
Preservation and Changes in Oscillatory Dynamics across the Cortical Hierarchy
- 2020
-
In: Journal of cognitive neuroscience. - : MIT Press - Journals. - 0898-929X .- 1530-8898. ; 32:10, s. 2024-2035
-
Journal article (peer-reviewed)abstract
- Theta (2-8 Hz), alpha (8-12 Hz), beta (12-35 Hz), and gamma (>35 Hz) rhythms are ubiquitous in the cortex. However, there is little understanding of whether they have similar properties and functions in different cortical areas because they have rarely been compared across them. We record neuronal spikes and local field potentials simultaneously at several levels of the cortical hierarchy in monkeys. Theta, alpha, beta, and gamma oscillations had similar relationships to spiking activity in visual, parietal, and prefrontal cortices. However, the frequencies in all bands increased up the cortical hierarchy. These results suggest that these rhythms have similar inhibitory and excitatory functions across the cortex. We discuss how the increase in frequencies up the cortical hierarchy may help sculpt cortical flow and processing.
|
|
| 3. |
- Nobre, Alexandre P, et al.
(author)
-
Effects of Temporal Expectations on the Perception of Motion Gestalts
- 2021
-
In: Journal of Cognitive Neuroscience. - : MIT Press - Journals. - 1530-8898 .- 0898-929X. ; 33:5, s. 853-871
-
Journal article (peer-reviewed)abstract
- Gestalt psychology has traditionally ignored the role of attention in perception, leading to the view that autonomous processes create perceptual configurations that are then attended. More recent research, however, has shown that spatial attention influences a form of Gestalt perception: the coherence of random-dot kinematograms (RDKs). Using ERPs, we investigated whether temporal expectations exert analogous attentional effects on the perception of coherence level in RDKs. Participants were presented fixed-length sequences of RDKs and reported the coherence level of a target RDK. The target was indicated immediately after its appearance by a postcue. Target expectancy increased as the sequence progressed until target presentation; afterward, remaining RDKs were perceived without target expectancy. Expectancy influenced the amplitudes of ERP components P1 and N2. Crucially, expectancy interacted with coherence level at N2, but not at P1. Specifically, P1 amplitudes decreased linearly as a function of RDK coherence irrespective of expectancy, whereas N2 exhibited a quadratic dependence on coherence: larger amplitudes for RDKs with intermediate coherence levels, and only when they were expected. These results suggest that expectancy at early processing stages is an unspecific, general readiness for perception. At later stages, expectancy becomes stimulus specific and nonlinearly related to Gestalt coherence.
|
|
| 4. |
- Samrani, George, et al.
(author)
-
Encoding-related Brain Activity Predicts Subsequent Trial-level Control of Proactive Interference in Working Memory
- 2024
-
In: Journal of cognitive neuroscience. - : MIT Press. - 0898-929X .- 1530-8898. ; 36:5, s. 828-835
-
Journal article (peer-reviewed)abstract
- Proactive interference (PI) appears when familiar information interferes with newly acquired information and is a major cause of forgetting in working memory. It has been proposed that encoding of item-context associations might help mitigate familiarity-based PI. Here, we investigate whether encoding-related brain activation could predict subsequent level of PI at retrieval using trial-specific parametric modulation. Participants were scanned with event-related fMRI while performing a 2-back working memory task with embedded 3-back lures designed to induce PI. We found that the ability to control interference in working memory was modulated by level of activation in the left inferior frontal gyrus, left hippocampus, and bilateral caudate nucleus during encoding. These results provide insight to the processes underlying control of PI in working memory and suggests that encoding of temporal context details support subsequent interference control.
|
|
| 5. |
- Samrani, George, et al.
(author)
-
Encoding-related Brain Activity Predicts Subsequent Trial-level Control of Proactive Interference in Working Memory
- 2024
-
In: Journal of cognitive neuroscience. - : MIT Press. - 0898-929X .- 1530-8898. ; 36:5, s. 828-835
-
Journal article (peer-reviewed)abstract
- Proactive interference (PI) appears when familiar information interferes with newly acquired information and is a major cause of forgetting in working memory. It has been proposed that encoding of item–context associations might help mitigate familiarity-based PI. Here, we investigate whether encoding-related brain activation could predict subsequent level of PI at retrieval using trial-specific parametric modulation. Participants were scanned with event-related fMRI while performing a 2-back working memory task with embedded 3-back lures designed to induce PI. We found that the ability to control interference in working memory was modulated by level of activation in the left inferior frontal gyrus, left hippocampus, and bilateral caudate nucleus during encoding. These results provide insight to the processes underlying control of PI in working memory and suggest that encoding of temporal context details support subsequent interference control.
|
|
| 6. |
- Skagerlund, Kenny, et al.
(author)
-
Investigating the Neural Correlates of the Affect Heuristic Using Functional Magnetic Resonance Imaging
- 2021
-
In: Journal of cognitive neuroscience. - : MIT PRESS. - 0898-929X .- 1530-8898. ; 33:11, s. 2265-2278
-
Journal article (peer-reviewed)abstract
- This study investigated the neural correlates of the so-called affect heuristic, which refers to the phenomenon whereby individuals tend to rely on affective states rather than rational deliberation of utility and probabilities during judgments of risk and utility of a given event or scenario. The study sought to explore whether there are shared regional activations during both judgments of relative risk and relative benefit of various scenarios, thus being a potential candidate of the affect heuristic. Using functional magnetic resonance imaging, we developed a novel risk perception task, based on a preexisting behavioral task assessing the affect heuristic. A whole-brain voxel-wise analysis of a sample of participants (n = 42) during the risk and benefit conditions revealed overlapping clusters in the left insula, left inferior frontal gyrus, and left medial frontal gyrus across conditions. Extraction of parameter estimates of these clusters revealed that activity of these regions during both tasks was inversely correlated with a behavioral measure assessing the inclination to use the affect heuristic. More activity in these areas during risk judgments reflect individuals ability to disregard momentary affective impulses. The insula may be involved in integrating viscero-somatosensory information and forming a representation of the current emotional state of the body, whereas activity in the left inferior frontal gyrus and medial frontal gyrus indicates that executive processes may be involved in inhibiting the impulse of making judgments in favor of deliberate risk evaluations.
|
|
| 7. |
- Trübutschek, Darinka, et al.
(author)
-
EEGManyPipelines : A Large-scale, Grassroots Multi-analyst Study of Electroencephalography Analysis Practices in the Wild
- 2024
-
In: Journal of Cognitive Neuroscience. - : MIT Press. - 0898-929X .- 1530-8898. ; 36:2, s. 217-224
-
Journal article (peer-reviewed)abstract
- The ongoing reproducibility crisis in psychology and cognitive neuroscience has sparked increasing calls to re-evaluate and reshape scientific culture and practices. Heeding those calls, we have recently launched the EEGManyPipelines project as a means to assess the robustness of EEG research in naturalistic conditions and experiment with an alternative model of conducting scientific research. One hundred sixty-eight analyst teams, encompassing 396 individual researchers from 37 countries, independently analyzed the same unpublished, representative EEG data set to test the same set of predefined hypotheses and then provided their analysis pipelines and reported outcomes. Here, we lay out how large-scale scientific projects can be set up in a grassroots, community-driven manner without a central organizing laboratory. We explain our recruitment strategy, our guidance for analysts, the eventual outputs of this project, and how it might have a lasting impact on the field.
|
|
