scholarly journals Brain States: Top-Down Influences in Sensory Processing

Neuron ◽  
2007 ◽  
Vol 54 (5) ◽  
pp. 677-696 ◽  
Author(s):  
Charles D. Gilbert ◽  
Mariano Sigman
Keyword(s):  
Sensory Processing ◽  
Top Down ◽  
Brain States

Multi-scale predictions distinctively modulate tone perception in schizophrenia patients with auditory verbal hallucinations

2020 ◽  
Author(s):  
Fuyin Yang ◽  
Hao Zhu ◽  
Lingfang Yu ◽  
Weihong Lu ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Sensory Processing ◽  
Source Monitoring ◽  
Weighting Function ◽  
Sensitivity Index ◽  
Healthy Controls ◽  
Top Down ◽  
Bottom Up ◽  
Multiple Timescales ◽  
Temporal Characteristics ◽  
Auditory Verbal Hallucinations

AbstractsAuditory verbal hallucinations (AVHs) are one of the most pronounced symptoms that manifest the underlying mechanisms of deficits in schizophrenia. Cognitive models postulate that malfunctioned source monitoring incorrectly weights the top-down prediction and bottom-up sensory processing and causes hallucinations. Here, we investigate the featural-temporal characteristics of source monitoring in AVHs. Schizophrenia patients with and without AVHs, and healthy controls identified target tones in noise at the end of tone sequences. Predictions of different timescales were manipulated by either an alternating pattern in the preceding tone sequences, or a repetition between the target tone and the tone immediately before. The sensitivity index, d’, was obtained to assess the modulation of predictions on tone identification. We found that patients with AVHs showed higher d’ when the target tones conformed to the long-term regularity of alternating pattern in the preceding tone sequence than that when the targets were inconsistent with the pattern. Whereas, the short-term regularity of repetitions modulated the tone identification in patients without AVHs. Predictions did not influence tone identification in healthy controls. These findings suggest that malfunctioned source monitoring in AVHs heavily weights predictions to form incorrect perception. The weighting function in source monitoring can extend to the process of basic tonal features, and predictions at multiple timescales differentially modulate perception in different clinical populations. These collaboratively reveal the featural and temporal characteristics of weighting function in source monitoring of AVHs and suggest that the malfunctioned interaction between top-down and bottom-up processes might underlie the development of auditory hallucinations.HighlightsMalfunctioned source monitoring incorrectly weights the top-down prediction and bottom-up sensory processing underlie pathogenesis of auditory verbal hallucinations in schizophrenia.The weighting function in top-down predictions and bottom-up sensory processing can extend to tonal features.Predictions at multiple timescales differentially modulate perception in different clinical schizophrenia populations.

scholarly journals Top-down inputs drive neuronal network rewiring and context-enhanced sensory processing in olfaction

2019 ◽  
Vol 15 (1) ◽  
pp. e1006611 ◽  
Author(s):  
Wayne Adams ◽  
James N. Graham ◽  
Xuchen Han ◽  
Hermann Riecke
Keyword(s):  
Neuronal Network ◽  
Sensory Processing ◽  
Top Down ◽  
Network Rewiring

scholarly journals Top-down control of visual sensory processing during an ocular motor response inhibition task

2010 ◽  
pp. no-no ◽  
Author(s):  
Brett A. Clementz ◽  
Yuan Gao ◽  
Jennifer E. McDowell ◽  
Stephan Moratti ◽  
Sarah K. Keedy ◽  
...  
Keyword(s):  
Sensory Processing ◽  
Response Inhibition ◽  
Motor Response ◽  
Ocular Motor ◽  
Top Down ◽  
Motor Response Inhibition

scholarly journals Spatiotemporal context modulates encoding and retrieval of overlapping events

2021 ◽  
Author(s):  
Devyn E Smith ◽  
Isabelle L Moore ◽  
Nicole M Long
Keyword(s):  
Human Subjects ◽  
Top Down ◽  
Past Event ◽  
The Past ◽  
Automatic Retrieval ◽  
Selective Interference ◽  
Brain States ◽  
Present Event ◽  
Temporal Overlap

Overlap between events can lead to interference due to a tradeoff between encoding the present event and retrieving the past event. Temporal context information -- 'when' something occurred, a defining feature of episodic memory -- can cue retrieval of a past event. However, the influence of temporal overlap, or proximity in time, on the mechanisms of interference are unclear. Here, by identifying brain states using scalp electroencephalography (EEG) from male and female human subjects, we show the extent to which temporal overlap promotes interference and induces retrieval. In this experiment, subjects were explicitly directed to either encode the present event or retrieve a past, overlapping event while perceptual input was held constant. We find that the degree of temporal overlap between events leads to selective interference. Specifically, greater temporal overlap between two events leads to impaired memory for the past event selectively when the top-down goal is to encode the present event. Using pattern classification analyses to measure neural evidence for a retrieval state, we find that greater temporal overlap leads to automatic retrieval of a past event, independent of top-down goals. Critically, the retrieval evidence we observe likely reflects a general retrieval mode, rather than retrieval success or effort. Collectively, our findings provide insight into the role of temporal overlap on interference and memory formation.

scholarly journals Local cortical desynchronization and pupil-linked arousal differentially shape brain states for optimal sensory performance

2019 ◽  
Author(s):  
Leonhard Waschke ◽  
Sarah Tune ◽  
Jonas Obleser
Keyword(s):  
Sensory Processing ◽  
Closed Loop ◽  
Perceptual Processing ◽  
Sensory Cortex ◽  
Single Trial ◽  
Response Sensitivity ◽  
Independent States ◽  
Brain States ◽  
Evoked Activity ◽  
And Performance

AbstractInstantaneous brain states have consequences for our sensation, perception, and behaviour. Fluctuations in arousal and neural desynchronization likely pose perceptually relevant states. However, their relationship and their relative impact on perception is unclear. We here show that, at the single-trial level in humans, local desynchronization in sensory cortex (expressed as time-series entropy) versus pupil-linked arousal differentially impact perceptual processing. While we recorded electroencephalography (EEG) and pupillometry data, stimuli of a demanding auditory discrimination task were presented into states of high or low desynchronization of auditory cortex via a real-time closed-loop setup. Desynchronization and arousal distinctly influenced stimulus-evoked activity and shaped behaviour displaying an inverted u-shaped relationship: States of intermediate desynchronization elicited minimal response bias and fastest responses, while states of intermediate arousal gave rise to highest response sensitivity. Our results speak to a model in which independent states of local desynchronization and global arousal jointly optimise sensory processing and performance.

scholarly journals Accumulation of sensory evidence is impaired in Parkinson’s disease with visual hallucinations

2017 ◽  
Author(s):  
Claire O’Callaghan ◽  
Julie M. Hall ◽  
Alessandro Tomassini ◽  
Alana J. Muller ◽  
Ishan C. Walpola ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Sensory Processing ◽  
Sensory Input ◽  
Decision Time ◽  
Visual Hallucinations ◽  
Top Down ◽  
Evidence Accumulation ◽  
Sensory Evidence ◽  
Response Output

AbstractModels of hallucinations across disorders emphasise an imbalance between sensory input and top-down influences over perception. However, the psychological and mechanistic correlates of this imbalance remain underspecified. Visual hallucinations in Parkinson’s disease (PD) are associated with impairments in lower level visual processes and attention, accompanied by over activity and connectivity in higher-order association brain networks. PD therefore provides an attractive framework to explore the relative contributions of bottom-up versus top-down disturbances in hallucinations. Here, we characterised sensory processing in PD patients with and without visual hallucinations, and in healthy controls, by fitting a hierarchical drift diffusion model (hDDM) to an attentional task. The hDDM uses Bayesian estimates to decompose reaction time and response output into parameters reflecting drift rates of evidence accumulation, decision thresholds and non-decision time. We observed slower drift rates in PD patients with hallucinations, which were insensitive to changes in task demand. In contrast, wider decision boundaries and shorter non-decision times relative to controls were found in PD regardless of hallucinator status. Inefficient and less flexible sensory evidence accumulation emerge as unique features of PD hallucinators. We integrate these results with current models of hallucinations, suggesting that slow and inefficient sensory input in PD is less informative, and may therefore be down-weighted leading to an over reliance on top-down influences. Our findings provide a novel computational framework to better specify the impairments in dynamic sensory processing that are a risk factor for visual hallucinations.

scholarly journals Local cortical desynchronization and pupil-linked arousal differentially shape brain states for optimal sensory performance

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Leonhard Waschke ◽  
Sarah Tune ◽  
Jonas Obleser
Keyword(s):  
Sensory Processing ◽  
Closed Loop ◽  
Perceptual Processing ◽  
Sensory Cortex ◽  
Single Trial ◽  
Response Sensitivity ◽  
Independent States ◽  
Brain States ◽  
Evoked Activity ◽  
And Performance

Instantaneous brain states have consequences for our sensation, perception, and behaviour. Fluctuations in arousal and neural desynchronization likely pose perceptually relevant states. However, their relationship and their relative impact on perception is unclear. We here show that, at the single-trial level in humans, local desynchronization in sensory cortex (expressed as time-series entropy) versus pupil-linked arousal differentially impact perceptual processing. While we recorded electroencephalography (EEG) and pupillometry data, stimuli of a demanding auditory discrimination task were presented into states of high or low desynchronization of auditory cortex via a real-time closed-loop setup. Desynchronization and arousal distinctly influenced stimulus-evoked activity and shaped behaviour displaying an inverted u-shaped relationship: States of intermediate desynchronization elicited minimal response bias and fastest responses, while states of intermediate arousal gave rise to highest response sensitivity. Our results speak to a model in which independent states of local desynchronization and global arousal jointly optimise sensory processing and performance.

Representation of affect in sensory cortex

2016 ◽  
Vol 39 ◽  
Author(s):  
Vladimir Miskovic ◽  
Karl Kuntzelman ◽  
Junichi Chikazoe ◽  
Adam K. Anderson
Keyword(s):  
Sensory Processing ◽  
Iterative Process ◽  
Empirical Support ◽  
External World ◽  
Sensory Cortex ◽  
Top Down ◽  
Bottom Up ◽  
Affective Influences ◽  
Affective Dimensions ◽  
Physical Dimensions

AbstractContemporary neuroscience suggests that perception is perhaps best understood as a dynamically iterative process that does not honor cleanly segregated “bottom-up” or “top-down” streams. We argue that there is substantial empirical support for the idea that affective influences infiltrate the earliest reaches of sensory processing and even that primitive internal affective dimensions (e.g., goodness-to-badness) are represented alongside physical dimensions of the external world.

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