Synchronous beta rhythms of frontoparietal networks support only behaviorally relevant representations

Categorization has been associated with distributed networks of the primate brain, including the prefrontal cortex (PFC) and posterior parietal cortex (PPC). Although category-selective spiking in PFC and PPC has been established, the frequency-dependent dynamic interactions of frontoparietal networks are largely unexplored. We trained monkeys to perform a delayed-match-to-spatial-category task while recording spikes and local field potentials from the PFC and PPC with multiple electrodes. We found category-selective beta- and delta-band synchrony between and within the areas. However, in addition to the categories, delta synchrony and spiking activity also reflected irrelevant stimulus dimensions. By contrast, beta synchrony only conveyed information about the task-relevant categories. Further, category-selective PFC neurons were synchronized with PPC beta oscillations, while neurons that carried irrelevant information were not. These results suggest that long-range beta-band synchrony could act as a filter that only supports neural representations of the variables relevant to the task at hand.

Download Full-text

Distinct oscillatory frequencies underlie excitability of human occipital and parietal cortex

10.1101/082693 ◽

2016 ◽

Cited By ~ 3

Author(s):

Jason Samaha ◽

Olivia Gosseries ◽

Bradley R. Postle

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Cortical Excitability ◽

Neural Correlates ◽

Cortical Inhibition ◽

Alpha Band ◽

Beta Band ◽

Time Frequency ◽

Posterior Parietal ◽

Near Threshold

AbstractMagnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes, but neural correlates of phosphene perception preceding and succeeding stimulation of both areas are unknown. Using near-threshold TMS with concurrent electroencephalography (EEG) recordings, we uncover oscillatory brain dynamics that covary, on single trials, with the perception of phosphenes following occipital and parietal TMS. Prestimulus power and phase predominantly in the alpha-band (8-13 Hz) predicted occipital TMS phosphenes, whereas higher frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (~5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception using near-threshold visual stimuli and speak to the possible early onset of visual consciousness. The differential pattern of prestimulus predictors of phosphene perception suggest that distinct frequencies reflect cortical excitability within different cortical regions, and that the alpha-band rhythm, long thought of as a general index of cortical inhibition, may not reflect excitability of posterior parietal cortex.Significance statementAlpha-band oscillations are thought to reflect cortical excitability and are therefor suggested to play an important role in gating information transmission across cortex. We directly probe cortical excitability in human occipital and parietal cortex and observed that whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes, which were manifest in both early and late patterns of evoked activity, shedding light on the neural correlates of consciousness. Our findings prompt revision of the notion that alpha activity reflects inhibition across all of cortex and suggests instead that excitability in different regions is reflected in distinct frequency bands.

Download Full-text

Stereomotion Processing in the Nonhuman Primate Brain

Cerebral Cortex ◽

10.1093/cercor/bhaa055 ◽

2020 ◽

Vol 30 (8) ◽

pp. 4528-4543 ◽

Cited By ~ 2

Author(s):

Yseult Héjja-Brichard ◽

Samy Rima ◽

Emilie Rapha ◽

Jean-Baptiste Durand ◽

Benoit R Cottereau

Keyword(s):

Posterior Parietal Cortex ◽

Binocular Disparity ◽

Primate Species ◽

Functional Magnetic Resonance ◽

Experimental Protocol ◽

Cortical Areas ◽

Primate Brain ◽

Posterior Parietal ◽

Random Dot Patterns ◽

Human Neuroimaging

Abstract The cortical areas that process disparity-defined motion-in-depth (i.e., cyclopean stereomotion [CSM]) were characterized with functional magnetic resonance imaging (fMRI) in two awake, behaving macaques. The experimental protocol was similar to previous human neuroimaging studies. We contrasted the responses to dynamic random-dot patterns that continuously changed their binocular disparity over time with those to a control condition that shared the same properties, except that the temporal frames were shuffled. A whole-brain voxel-wise analysis revealed that in all four cortical hemispheres, three areas showed consistent sensitivity to CSM. Two of them were localized respectively in the lower bank of the superior temporal sulcus (CSMSTS) and on the neighboring infero-temporal gyrus (CSMITG). The third area was situated in the posterior parietal cortex (CSMPPC). Additional regions of interest-based analyses within retinotopic areas defined in both animals indicated weaker but significant responses to CSM within the MT cluster (most notably in areas MSTv and FST). Altogether, our results are in agreement with previous findings in both human and macaque and suggest that the cortical areas that process CSM are relatively well preserved between the two primate species.

Download Full-text

Stereomotion processing in the non-human primate brain

10.1101/638155 ◽

2019 ◽

Cited By ~ 1

Author(s):

Yseult Héjja-Brichard ◽

Samy Rima ◽

Emilie Rapha ◽

Jean-Baptiste Durand ◽

Benoit R. Cottereau

Keyword(s):

Posterior Parietal Cortex ◽

Binocular Disparity ◽

Primate Species ◽

Functional Magnetic Resonance ◽

Experimental Protocol ◽

Primate Brain ◽

Posterior Parietal ◽

Random Dot Patterns ◽

Human Neuroimaging ◽

Human Primate

AbstractThe cortical areas that process disparity-defined motion-in-depth (i.e. cyclopean stereomotion) were characterised with functional magnetic resonance imaging in two awake, behaving macaques. The experimental protocol was similar to previous human neuroimaging studies. We contrasted the responses to dynamic random-dot patterns that continuously changed their binocular disparity over time with those to a control condition that shared the same properties, except that the temporal frames were shuffled. A whole-brain voxel-wise analysis revealed that in all four cortical hemispheres, three areas showed consistent sensitivity to cyclopean stereomotion. Two of them were localised respectively in the lower bank of the superior temporal sulcus (CSMSTS) and on the neighbouring infero-temporal gyrus (CSMITG). The third area was situated in the posterior parietal cortex (CSMPPC). Additional ROIs-based analyses within retinotopic areas defined in both animals indicated weaker but significant responses to cyclopean stereomotion within the MT cluster (most notably in areas MSTv and FST). Altogether, our results are in agreement with previous findings in both human and macaque and suggest that the cortical networks that process cyclopean stereomotion is relatively well preserved between the two primate species.

Download Full-text

Posterior parietal cortex mediates encoding processes in change blindness

PsycEXTRA Dataset ◽

10.1037/e520562012-977 ◽

2009 ◽

Author(s):

Philip Tseng ◽

Cassidy Sterling ◽

Adam Cooper ◽

Bruce Bridgeman ◽

Neil G. Muggleton ◽

...

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Change Blindness ◽

Posterior Parietal

Download Full-text

The Grasp Cell Hypothesis: Near-miss effect points to common neurological machinery in posterior parietal cortex for controllable objects and concepts

10.31234/osf.io/4awrz ◽

2018 ◽

Author(s):

Imogen M Kruse

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Near Miss ◽

Illusion Of Control ◽

Gambling Behaviour ◽

Drug Seeking ◽

Spatial Influence ◽

Reward Probability ◽

Posterior Parietal ◽

Action Value

The near-miss effect in gambling behaviour occurs when an outcome which is close to a win outcome invigorates gambling behaviour notwithstanding lack of associated reward. In this paper I postulate that the processing of concepts which are deemed controllable is rooted in neurological machinery located in the posterior parietal cortex specialised for the processing of objects which are immediately actionable or controllable because they are within reach. I theorise that the use of a common machinery facilitates spatial influence on the perception of concepts such that the win outcome which is 'almost complete' is perceived as being 'almost within reach'. The perceived realisability of the win increases subjective reward probability and the associated expected action value which impacts decision-making and behaviour. This novel hypothesis is the first to offer a neurological model which can comprehensively explain many empirical findings associated with the near-miss effect as well as other gambling phenomena such as the ‘illusion of control’. Furthermore, when extended to other compulsive behaviours such as drug addiction, the model can offer an explanation for continued drug-seeking following devaluation and for the increase in cravings in response to perceived opportunity to self-administer, neither of which can be explained by simple reinforcement models alone. This paper therefore provides an innovative and unifying perspective for the study and treatment of behavioural and substance addictions.

Download Full-text