Neural and computational processes of accelerated perceptual awareness and decisions: A 7T fMRI Study

Rapidly detecting salient information in our environments is critical for survival. Visual processing in subcortical areas like the pulvinar and amygdala have been shown to facilitate unconscious processing of salient stimuli. It is unknown, however, if and how these areas might interact with cortical networks to facilitate faster conscious perception of salient stimuli. Here we investigated these neural processes using 7T functional Magnetic Resonance Imaging (fMRI) in concert with computational modelling while participants (n = 32) engaged in a breaking continuous flash suppression paradigm (bCFS) in which fearful and neutral faces are initially suppressed from conscious perception but then eventually breakthrough into awareness. We found that participants reported faster breakthrough times for fearful faces compared to neutral faces. Drift-diffusion modelling suggested that perceptual evidence was accumulated at a faster rate for fearful faces compared to neutral faces. For both neutral and fearful faces, faster response times coincided with greater activity in the amygdala (specifically within its subregions, including superficial, basolateral and amygdalo-striatal transition area) and the insula. Faster rates of evidence accumulation coincided with greater activity in frontoparietal regions and the occipital lobe, as well as the amygdala. Overall, our findings suggest that hastened perceptual awareness of salient stimuli recruits the amygdala and, more specifically, is driven by accelerated evidence accumulation in fronto-parietal and visual areas. In sum, we have uncovered and mapped distinct neural computations that accelerate perceptual awareness of visually suppressed faces.

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Effects of Symbol Structure on Visual Information Processing

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128302700503 ◽

1983 ◽

Vol 27 (5) ◽

pp. 354-354

Author(s):

Bruce W. Hamill ◽

Robert A. Virzi

Keyword(s):

Information Processing ◽

Visual Processing ◽

Visual Information ◽

Context Effects ◽

Response Times ◽

Search Time ◽

Visual Information Processing ◽

Array Size ◽

Serial Search ◽

Feature Structure

This investigation addresses the problem of attention in the processing of symbolic information from visual displays. Its scope includes the nature of attentive processes, the structural properties of stimuli that influence visual information processing mechanisms, and the manner in which these factors interact in perception. Our purpose is to determine the effects of configural feature structure on visual information processing. It is known that for stimuli comprising separable features, one can distinguish between conditions in which only one relevant feature differs among stimuli in the array being searched and conditions in which conjunctions of two (or more) features differ: Since the visual process of conjoining separable features is additive, this fact is reflected in search time as a function of array size, with feature conditions yielding flat curves associated with parallel search (no increase in search time across array sizes) and conjunction conditions yielding linearly increasing curves associated with serial search. We studied configural-feature stimuli within this framework to determine the nature of visual processing for such stimuli as a function of their feature structure. Response times of subjects searching for particular targets among structured arrays of distractors were measured in a speeded visual search task. Two different sets of stimulus materials were studied in array sizes of up to 32 stimuli, using both tachistoscope and microcomputer-based CRT presentation for each. Our results with configural stimuli indicate serial search in all of the conditions, with the slope of the response-time-by-array-size function being steeper for conjunction conditions than for feature conditions. However, for each of the two sets of stimuli we studied, there was one configuration that stood apart from the others in its set in that it yielded significantly faster response times, and in that conjunction conditions involving these particular stimuli tended to cluster with the feature conditions rather than with the other conjunction conditions. In addition to these major effects of particular targets, context effects also appeared in our results as effects of the various distractor sets used; certain of these context effects appear to be reversible. The effects of distractor sets on target search were studied in considerable detail. We have found interesting differences in visual processing between stimuli comprising separable features and those comprising configural features. We have also been able to characterize the effects we have found with configural-feature stimuli as being related to the specific feature structure of the target stimulus in the context of the specific feature structure of distractor stimuli. These findings have strong implications for the design of symbology that can enhance visual performance in the use of automated displays.

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Should I stay or should I go? Evidence accumulation drives decision making in human drivers

10.31234/osf.io/p8dxn ◽

2020 ◽

Author(s):

Arkady Zgonnikov ◽

David Abbink ◽

Gustav Markkula

Keyword(s):

Decision Making ◽

Cognitive Processes ◽

Cognitive Process ◽

Response Times ◽

Process Models ◽

Cognitive Mechanisms ◽

Naturalistic Decision Making ◽

Dynamic Constraints ◽

Evidence Accumulation ◽

Out Of Sample

Laboratory studies of abstract, highly controlled tasks point towards noisy evidence accumulation as a key mechanism governing decision making. Yet it is unclear whether the cognitive processes implicated in simple, isolated decisions in the lab are as paramount to decisions that are ingrained in more complex behaviors, such as driving. Here we aim to address the gap between modern cognitive models of decision making and studies of naturalistic decision making in drivers, which so far have provided only limited insight into the underlying cognitive processes. We investigate drivers' decision making during unprotected left turns, and model the cognitive process driving these decisions. Our model builds on the classical drift-diffusion model, and emphasizes, first, the drift rate linked to the relevant perceptual quantities dynamically sampled from the environment, and, second, collapsing decision boundaries reflecting the dynamic constraints imposed on the decision maker’s response by the environment. We show that the model explains the observed decision outcomes and response times, as well as substantial individual differences in those. Through cross-validation, we demonstrate that the model not only explains the data, but also generalizes to out-of-sample conditions, effectively providing a way to predict human drivers’ behavior in real time. Our results reveal the cognitive mechanisms of gap acceptance decisions in human drivers, and exemplify how simple cognitive process models can help us to understand human behavior in complex real-world tasks.

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C-19 An fMRI Study of Age-Associated Changes in Basic Visual Discrimination

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acz034.181 ◽

2019 ◽

Vol 34 (6) ◽

pp. 1048-1048

Author(s):

T Seider ◽

E Porges ◽

A Woods ◽

R Cohen

Keyword(s):

Visual Processing ◽

Visual Discrimination ◽

Community Sample ◽

Visual Assessment ◽

Brain Regions ◽

Brain Response ◽

Match To Sample ◽

Fmri Study ◽

Perceptual Skill ◽

Cluster Level

Abstract Objective The study was conducted to determine age-associated changes in functional brain response, measured with fMRI, during visual discrimination with regard to three elementary components of visual perception: shape, location, and velocity. A secondary aim was to validate the method used to isolate the hypothesized brain regions associated with these perceptual functions. Method Items from the Visual Assessment Battery (VAB), a simultaneous match-to-sample task, assessed visual discrimination in 40 healthy adults during fMRI. Participants were aged 51-91 and recruited from a larger community sample for a study on normal aging. The tasks were designed to isolate neural recruitment during discrimination of either location, shape, or velocity by using tasks that were identical aside from the perceptual skill required to complete them. Results The Location task uniquely activated the dorsal visual processing stream, the Shape task the ventral stream, and the Velocity task V5/MT. Greater age was associated with greater neural recruitment, particularly in frontal areas (uncorrected voxel-level p < .001, family-wise error cluster-level p□.05). Conclusions Results validated the specialization of brain regions for spatial, perceptual, and movement discriminations and the use of the VAB to assess functioning localized to these regions. Anterior neural recruitment during visual discrimination increases with age.

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Visual hallucinations in Alzheimer's disease do not seem to be associated with chronic hypoperfusion of to visual processing areas V2 and V3 but may be associated with reduced cholinergic input to these areas

Alzheimer s Research & Therapy ◽

10.1186/s13195-019-0519-7 ◽

2019 ◽

Vol 11 (1) ◽

Cited By ~ 2

Author(s):

Lindsey Isla Sinclair ◽

Amit Kumar ◽

Taher Darreh-Shori ◽

Seth Love

Keyword(s):

Microvessel Density ◽

Visual Processing ◽

Occipital Lobe ◽

Occipital Cortex ◽

Cholinergic Innervation ◽

Density Level ◽

Post Mortem ◽

Visual Hallucinations ◽

Metabolic Demand ◽

Cell Content

Abstract Background Up to 20% of patients with AD experience hallucinations. The pathological substrate is not known. Visual hallucinations (VH) are more common in dementia with Lewy bodies (DLB). In autopsy studies, up to 60% of patients with AD have concomitant Lewy body pathology. Decreased perfusion of the occipital lobe has been implicated in DLB patients with VH, and post-mortem studies point to both decreased cholinergic activity and reduced oxygenation of the occipital cortex in DLB. Methods We used biochemical methods to assess microvessel density (level of von Willebrand factor, a marker of endothelial cell content), ante-mortem oxygenation (vascular endothelial growth factor, a marker of tissue hypoxia; myelin-associated glycoprotein to proteolipid protein-1 ratio, a measure of tissue oxygenation relative to metabolic demand), cholinergic innervation (acetylcholinesterase and choline acetyltransferase), butyrylcholinesterase and insoluble α-synuclein content in the BA18 and BA19 occipital cortex obtained post-mortem from 23 AD patients who had experienced visual hallucinations, 19 AD patients without hallucinations, 19 DLB patients, and 36 controls. The cohorts were matched for age, gender and post-mortem interval. Results There was no evidence of reduced microvessel density, hypoperfusion or reduction in ChAT activity in AD with visual hallucinations. Acetylcholinesterase activity was reduced in both BA18 and BA19, in all 3 dementia groups, and the concentration was also reduced in BA19 in the DLB and AD without visual hallucinations groups. Insoluble α-synuclein was raised in the DLB group in both areas but not in AD either with or without visual hallucinations. Conclusions Our results suggest that visual hallucinations in AD are associated with cholinergic denervation rather than chronic hypoperfusion or α-synuclein accumulation in visual processing areas of the occipital cortex.

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The neural mechanism of aesthetic judgments of dynamic landscapes: an fMRI study

Scientific Reports ◽

10.1038/s41598-020-77658-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Xueru Zhao ◽

Junjing Wang ◽

Jinhui Li ◽

Guang Luo ◽

Ting Li ◽

...

Keyword(s):

Visual Processing ◽

Occipital Lobe ◽

Neural Mechanism ◽

Aesthetic Judgment ◽

Neural Mechanisms ◽

Middle Temporal Gyrus ◽

Dynamic Stimuli ◽

Dynamic Landscapes ◽

The Aesthetic ◽

Aesthetic Judgments

AbstractMost previous neuroaesthetics research has been limited to considering the aesthetic judgment of static stimuli, with few studies examining the aesthetic judgment of dynamic stimuli. The present study explored the neural mechanisms underlying aesthetic judgment of dynamic landscapes, and compared the neural mechanisms between the aesthetic judgments of dynamic landscapes and static ones. Participants were scanned while they performed aesthetic judgments on dynamic landscapes and matched static ones. The results revealed regions of occipital lobe, frontal lobe, supplementary motor area, cingulate cortex and insula were commonly activated both in the aesthetic judgments of dynamic and static landscapes. Furthermore, compared to static landscapes, stronger activations of middle temporal gyrus (MT/V5), and hippocampus were found in the aesthetic judgments of dynamic landscapes. This study provided neural evidence that visual processing related regions, emotion-related regions were more active when viewing dynamic landscapes than static ones, which also indicated that dynamic stimuli were more beautiful than static ones.

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MODULATION OF AUDITORY AND VISUAL PROCESSING BY DELTA-9-TETRAHYDROCANNABINOL AND CANNABIDIOL: AN FMRI STUDY

Schizophrenia Research ◽

10.1016/j.schres.2010.02.898 ◽

2010 ◽

Vol 117 (2-3) ◽

pp. 476-477

Author(s):

Toby T. Winton-Brown ◽

Paul Allen ◽

Sagnik Bhattacharrya ◽

Stefan J. Borgwardt ◽

Fusar-Poli Paolo ◽

...

Keyword(s):

Visual Processing ◽

Fmri Study

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Object-Selective Cortex Exhibits Performance-Independent Repetition Suppression

Journal of Neurophysiology ◽

10.1152/jn.00500.2005 ◽

2006 ◽

Vol 95 (2) ◽

pp. 995-1007 ◽

Cited By ~ 100

Author(s):

Rory Sayres ◽

Kalanit Grill-Spector

Keyword(s):

Response Time ◽

Response Times ◽

Recognition Performance ◽

Region Of Interest ◽

Stimulus Presentation ◽

Repetition Suppression ◽

Fmri Study ◽

Bold Responses ◽

Cortical Regions ◽

Time Required

Object-selective cortical regions exhibit a decreased response when an object stimulus is repeated [repetition suppression (RS)]. RS is often associated with priming: reduced response times and increased accuracy for repeated stimuli. It is unknown whether RS reflects stimulus-specific repetition, the associated changes in response time, or the combination of the two. To address this question, we performed a rapid event-related functional MRI (fMRI) study in which we measured BOLD signal in object-selective cortex, as well as object recognition performance, while we manipulated stimulus repetition. Our design allowed us to examine separately the roles of response time and repetition in explaining RS. We found that repetition played a robust role in explaining RS: repeated trials produced weaker BOLD responses than nonrepeated trials, even when comparing trials with matched response times. In contrast, response time played a weak role in explaining RS when repetition was controlled for: it explained BOLD responses only for one region of interest (ROI) and one experimental condition. Thus repetition suppression seems to be mostly driven by repetition rather than performance changes. We further examined whether RS reflects processes occurring at the same time as recognition or after recognition by manipulating stimulus presentation duration. In one experiment, durations were longer than required for recognition (2 s), whereas in a second experiment, durations were close to the minimum time required for recognition (85–101 ms). We found significant RS for brief presentations (albeit with a reduced magnitude), which again persisted when controlling for performance. This suggests a substantial amount of RS occurs during recognition.

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Dissecting the impact of depression on decision-making

Psychological Medicine ◽

10.1017/s0033291719001570 ◽

2019 ◽

Vol 50 (10) ◽

pp. 1613-1622 ◽

Cited By ~ 1

Author(s):

Victoria M. Lawlor ◽

Christian A. Webb ◽

Thomas V. Wiecki ◽

Michael J. Frank ◽

Madhukar Trivedi ◽

...

Keyword(s):

Decision Making ◽

Cognitive Deficits ◽

Response Times ◽

Major Depressive ◽

Evidence Accumulation ◽

Two Samples ◽

Sensorimotor Deficit ◽

The Impact ◽

To Receive ◽

Trial Participants

AbstractBackgroundCognitive deficits in depressed adults may reflect impaired decision-making. To investigate this possibility, we analyzed data from unmedicated adults with Major Depressive Disorder (MDD) and healthy controls as they performed a probabilistic reward task. The Hierarchical Drift Diffusion Model (HDDM) was used to quantify decision-making mechanisms recruited by the task, to determine if any such mechanism was disrupted by depression.MethodsData came from two samples (Study 1: 258 MDD, 36 controls; Study 2: 23 MDD, 25 controls). On each trial, participants indicated which of two similar stimuli was presented; correct identifications were rewarded. Quantile-probability plots and the HDDM quantified the impact of MDD on response times (RT), speed of evidence accumulation (drift rate), and the width of decision thresholds, among other parameters.ResultsRTs were more positively skewed in depressed v. healthy adults, and the HDDM revealed that drift rates were reduced—and decision thresholds were wider—in the MDD groups. This pattern suggests that depressed adults accumulated the evidence needed to make decisions more slowly than controls did.ConclusionsDepressed adults responded slower than controls in both studies, and poorer performance led the MDD group to receive fewer rewards than controls in Study 1. These results did not reflect a sensorimotor deficit but were instead due to sluggish evidence accumulation. Thus, slowed decision-making—not slowed perception or response execution—caused the performance deficit in MDD. If these results generalize to other tasks, they may help explain the broad cognitive deficits seen in depression.

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Invisible Adaptation: The Effect of Awareness on the Strength of the Motion Aftereffect

Perception ◽

10.1177/0301006620936853 ◽

2020 ◽

Vol 49 (8) ◽

pp. 835-857

Author(s):

Daphne Roumani ◽

Konstantinos Moutoussis

Keyword(s):

Visual Processing ◽

Discrimination Task ◽

Motion Aftereffect ◽

Stimulus Strength ◽

Perceptual Awareness ◽

Physical Stimulus ◽

Adaptation Stimulus ◽

Unconscious Processing ◽

Total Absence ◽

Direction Discrimination

The ability to process information despite the lack of perceptual awareness is one of the most fascinating aspects of the visual system. Such unconscious processing is often investigated using adaptation, where any presence of the former can be traced by its footprint on aftereffects following the latter. We have investigated the mechanisms of the motion aftereffect (MAE) using random dot displays of varying motion coherence as well as crowding to modulate both the physical as well as the perceptual strength of the adaptation stimulus. Perceptual strength was quantitatively measured as the performance in a forced-choice direction-discrimination task. A motion-nulling technique was used to quantitatively measure the strength of the MAE. We show that the strength of the dynamic MAE is independently influenced by both the physical stimulus strength as well as the subjective perceptual strength, with the effect of the former being more prominent than that of the latter. We further show that the MAE still persists under conditions of subthreshold perception. Our results suggest that perceptual awareness can influence the strength of visual processing, but the latter is not fully dependent on the former and can still take place at its partial or even total absence.

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Amygdala activation and symptom dimensions in obsessive–compulsive disorder

The British Journal of Psychiatry ◽

10.1192/bjp.bp.112.123364 ◽

2014 ◽

Vol 204 (1) ◽

pp. 61-68 ◽

Cited By ~ 48

Author(s):

Esther Via ◽

Narcís Cardoner ◽

Jesús Pujol ◽

Pino Alonso ◽

Marina López-Solà ◽

...

Keyword(s):

Obsessive Compulsive Disorder ◽

Obsessive Compulsive ◽

Cross Sectional ◽

Symptom Dimensions ◽

Compulsive Disorder ◽

Amygdala Activation ◽

Fearful Faces ◽

Fmri Study ◽

Fear And Anxiety ◽

Emotional Face

BackgroundDespite knowledge of amygdala involvement in fear and anxiety, its contribution to the pathophysiology of obsessive–compulsive disorder (OCD) remains controversial. In the context of neuroimaging studies, it seems likely that the heterogeneity of the disorder might have contributed to a lack of consistent findings.AimsTo assess the influence of OCD symptom dimensions on amygdala responses to a well-validated emotional face-matching paradigm.MethodCross-sectional functional magnetic resonance imaging (fMRI) study of 67 patients with OCD and 67 age-, gender- and education-level matched healthy controls.ResultsThe severity of aggression/checking and sexual/religious symptom dimensions were significantly associated with heightened amygdala activation in those with OCD when responding to fearful faces, whereas no such correlations were seen for other symptom dimensions.ConclusionsAmygdala functional alterations in OCD appear to be specifically modulated by symptom dimensions whose origins may be more closely linked to putative amygdala-centric processes, such as abnormal fear processing.

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