Visual Attention and Brain Circuits

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Questions and Answers

What role does the frontal eye field (FEF) play in attention?

It completely eliminates distractions.

It lowers the stimulus detection threshold when distractions are present. (correct)

It only guides eye movements without affecting attention.

It increases the stimulus detection threshold.

Which map shows the locations of conspicuous features based on visual salience?

Priority map

Cognitive map

Salience map (correct)

Visual input map

What role does the area MT play in visual processing?

It regulates visual information flow.

It is involved in the speed of motion. (correct)

It enhances visual performance through attention.

It processes color and shape.

What is a key characteristic of neglect syndrome?

Inability to focus on both visual fields equally. Signup and view all the answers

How does the lateral intraparietal area (LIP) facilitate attention?

By creating a priority map based on both bottom-up and top-down inputs. Signup and view all the answers

What is the effect of attention on the V4 neuronal response?

Responses are greater when attention is directed to ‘effective’ stimuli. Signup and view all the answers

Which brain area projects to many cortical areas and regulates visual information flow?

Pulvinar nucleus. Signup and view all the answers

What is the proposed function of the right hemisphere concerning attention?

It attends to both left and right hemifields. Signup and view all the answers

How does stimulation of the frontal eye fields (FEF) affect visual performance?

Lowers the stimulus detection threshold. Signup and view all the answers

What is a potential result of lesions in the parietal cortex?

Development of neglect syndrome. Signup and view all the answers

What was the primary finding of Moore and colleagues' experiment involving FEF?

FEF enhances visual performance through attentional guidance. Signup and view all the answers

What distinguishes the materialist perspective on consciousness?

It posits that consciousness arises from physical processes. Signup and view all the answers

What does the priority map in the parietal lobe take into account?

Cognitive input and the salience of stimuli. Signup and view all the answers

What assumption is made about attention before eye movement occurs?

Attention changes location prior to eye movement. Signup and view all the answers

In which brain region is response enhancement observed as a result of attention?

Posterior parietal cortex. Signup and view all the answers

What effect does distraction have on the FEF's ability to enhance visual performance?

FEF lowers stimulus detection threshold when distractions are present. Signup and view all the answers

What is the primary function of attention as described in the content?

To focus on one aspect of sensory input while ignoring others Signup and view all the answers

What distinguishes the easy problems of consciousness from the hard problem?

Easy problems can be studied scientifically, while hard problems cannot. Signup and view all the answers

What typically happens to brain activity when engaging in a task?

There are decreases in activity in some brain areas Signup and view all the answers

Which of the following accurately describes the resting state of the brain?

Some regions are fairly quiet while others are surprisingly active Signup and view all the answers

Which experimental approach is used to study the neural correlates of consciousness?

fMRI during the presentation of bistable visual images Signup and view all the answers

Which brain areas are active in the default mode network?

Medial prefrontal cortex, posterior cingulate cortex, hippocampus Signup and view all the answers

How does attention affect perception in the brain?

It alters the sensitivity of neurons in various brain areas Signup and view all the answers

What is meant by the term 'neural correlates of consciousness' (NCC)?

The minimal neuronal events associated with specific conscious experiences Signup and view all the answers

What does the internal mentation hypothesis primarily support?

Thinking and remembering, similar to daydreaming Signup and view all the answers

In binocular rivalry experiments, how is visual awareness recorded?

By measuring brain activity in areas specialized for face and place recognition Signup and view all the answers

What is a neural correlate of consciousness as implied in the content?

Heightened activity in sensory processing areas Signup and view all the answers

What challenge is associated with the study of NCC?

Differentiating between awareness and attention in neural studies Signup and view all the answers

What type of attention is characterized by a deliberate direction set by the brain?

Endogenous attention Signup and view all the answers

Why do imagined imagery activate the same visual processes as actual perception?

Due to similar areas of the brain being engaged during both tasks Signup and view all the answers

Which disorder is associated with a limited capacity of attention as mentioned in the content?

Attention-deficit hyperactivity disorder Signup and view all the answers

What is the primary function associated with the shifting of attention?

Changes in brain activity in response to stimuli Signup and view all the answers

What is considered a potential outcome of attention in relation to consciousness?

It can create a greater sense of awareness and behavioral flexibility. Signup and view all the answers

What remains an unresolved aspect of consciousness that is often referred to as the 'hard problem'?

Understanding why experiences occur in specific ways Signup and view all the answers

What type of attention is described as bottom-up and akin to detecting a predator?

Exogenous attention Signup and view all the answers

In imaging studies, what was observed when subjects allocated attention to specific features?

Consequences of attention allocation were revealed Signup and view all the answers

Which approach can demonstrate the brain activity linked to attention to specific visual features?

Subtracting brain responses from multiple tasks Signup and view all the answers

What is the primary effect of attention on sensory information processing?

Focusing on a specific aspect while ignoring others Signup and view all the answers

What does the internal mentation hypothesis primarily focus on?

Supporting thinking and remembering Signup and view all the answers

What happens to brain activity when a person engages in a specific task?

Task-relevant areas become more active while others decrease Signup and view all the answers

Which brain area is NOT part of the default mode network?

Occipital lobe Signup and view all the answers

Which statement best reflects the concept of consciousness in the context provided?

It refers to the awareness of something occurring in the environment Signup and view all the answers

What is indicated by the resting state activity of the brain?

Some areas remain quiet while others are unexpectedly active Signup and view all the answers

How does endogenous attention primarily function?

It is deliberately directed by the brain Signup and view all the answers

What consequence does attention have on neural activity according to imaging studies?

It shifts to high-level cognitive areas Signup and view all the answers

What typically characterizes the relationship between brain areas and attention processing?

Attention enhances activity in task-relevant regions Signup and view all the answers

What is the sentinel hypothesis related to?

Broad environmental monitoring Signup and view all the answers

Which type of attention describes the process similar to detecting a predator?

Exogenous attention Signup and view all the answers

What effect does attention have on visual sensitivity according to the content?

It enhances visual sensitivity Signup and view all the answers

What phrase describes the phenomena that can be answered by scientific methodology in the study of consciousness?

The easy problems of consciousness Signup and view all the answers

What disorder is associated with a limited capacity for attention as mentioned in the content?

Attention-deficit hyperactivity disorder Signup and view all the answers

Which aspect distinguishes the hard problem of consciousness from the easy problems?

The subjective experience itself Signup and view all the answers

What is a challenge faced when interpreting data from studies on neural correlates of consciousness (NCC)?

Defining what constitutes minimal brain activity for consciousness Signup and view all the answers

In binocular rivalry experiments, what variable alternates as perceptions change?

Patterns of neural activity in specific brain regions Signup and view all the answers

What can be inferred from the fact that imagining imagery activates the same visual processes as actual perception?

The brain applies similar mechanisms for actual and imagined perceptions Signup and view all the answers

What potential confound complicates the study of neural correlates of consciousness?

The overlap between attention and awareness Signup and view all the answers

Which approach has been utilized to demonstrate brain activity changes in humans during perceptual awareness?

Functional magnetic resonance imaging (fMRI) Signup and view all the answers

What remains an unresolved issue that complicates the understanding of consciousness?

The 'hard problem' of why experiences are the way they are Signup and view all the answers

What is the role of the pulvinar nucleus in attention?

It projects to many areas of the cortex and regulates visual information flow. Signup and view all the answers

How does attention affect the response of neurons in cortical area V4?

V4 neuronal response is greater when attention is directed to effective stimuli. Signup and view all the answers

What is the primary hypothesis regarding attention's location prior to eye movement?

Attention is assumed to change location before the eye movement occurs. Signup and view all the answers

What effect does stimulation of the frontal eye fields (FEF) have in experimental settings?

It enhances visual performance and lowers stimulus detection thresholds. Signup and view all the answers

What was the key finding of Wurtz, Goldberg, and Robinson's experiments regarding attention and brain activity?

Responses in the posterior parietal cortex are enhanced by attention, speeding visual processing. Signup and view all the answers

In which scenario would attention typically enhance visual processing?

When attention is directed towards effective stimuli that capture focus. Signup and view all the answers

What is one function of the frontal eye fields (FEF) in relation to visual attention?

To direct attention, enhancing visual discrimination in complex environments. Signup and view all the answers

How does the response enhancement in neural activity affect visual processing and reaction times?

It can speed up visual processing and lead to quicker reaction times. Signup and view all the answers

What is the primary role of the lateral intraparietal cortex (area LIP) in attention?

To create a priority map based on cognitive and sensory inputs. Signup and view all the answers

How does neglect syndrome typically manifest in individuals?

Ignoring objects, people, or their own body to one side of the center of gaze. Signup and view all the answers

What distinguishes bottom-up attention from top-down attention?

Bottom-up attention is automatic, while top-down attention is deliberate. Signup and view all the answers

What is the hypothesis regarding brain hemisphere function in relation to attention?

The right hemisphere attends to both right and left hemifields. Signup and view all the answers

What occurs first in the brain when attention effects are evident?

Increased activity in the frontal and parietal areas. Signup and view all the answers

Which phenomenon illustrates the concept of a salience map in attention?

The mapping of visually salient features in a scene. Signup and view all the answers

What characterizes the materialist perspective of consciousness?

Physical processes alone create conscious experience. Signup and view all the answers

What is the relationship between distraction and the frontal eye field (FEF)?

Distraction lowers the detection threshold for the FEF. Signup and view all the answers

Study Notes

Visual Features and Attention

PET imaging shows that visual areas are sensitive to specific features:
- V4, IT, and other areas in the temporal lobe are responsible for attention to color and shape.
- Area MT is responsible for attention to the speed of motion.

Neuronal Responses and Attention

Attention influences neuronal responses in the parietal cortex.
- Enhanced neural activity in the posterior parietal cortex may speed up visual processing and reaction times.

Attention in Visual Cortical Area V4

Neuronal responses in V4 are greater when attention is directed to "effective" stimuli, even if the stimuli are visually the same.

Brain Circuits for Attention

Cortical and subcortical areas guide attention and saccadic eye movements.
- The pulvinar nucleus projects to many areas of the cortex and regulates visual information flow.

Attention and Eye Movements

The frontal eye fields (FEF) are involved in directing attention.
- FEF neurons have motor fields that control eye movements.
- Experiments show that FEF stimulation enhances visual performance and mimics the physiological and behavioral effects of attention.

Direction of Attention with Salience and Priority Maps

Two types of attention:
- Bottom-up attention: salience map identifies conspicuous features.
- Top-down attentional modulation: priority map indicates where attention should be directed based on salience and cognitive input.

A Priority Map in the Parietal Lobe

The lateral intraparietal cortex (LIP) creates a priority map based on bottom-up and top-down inputs.
- LIP guides eye movements and attention.
- Lesions in the parietal cortex are associated with neglect syndrome.

Hemispatial Neglect Syndrome

Neglect syndrome is an attentional disorder where individuals ignore objects and their own body to one side of their gaze.
It is commonly associated with right-sided lesions in the posterior parietal cortex.
This syndrome may be a disruption of the ability to shift attention.

Frontoparietal Attention Network

The frontoparietal network is involved in attention:
- Bottom-up attention: Input from visual areas in the occipital lobe reaches LIP, constructing a salience map, enhancing visual processing, and potentially causing eye movements.
- Top-down attention: Attention effects occur first in frontal and parietal areas.

Consciousness

The nature of human consciousness is problematic even to define.
Two perspectives on mind and body:
- Materialist perspective: consciousness arises from physical processes in the nervous system.
- Dualism: mind and body are distinct entities.

Easy and Hard Problems of Consciousness

"Easy problems" of consciousness: phenomena answerable by scientific methodology, such as the difference between sleep and wakefulness.
"Hard problem" of consciousness: the subjective experience itself and why it is the way it is.

Neural Correlates of Consciousness

The objective is to identify the minimal neuronal events necessary for a specific conscious percept.

Neural Correlates of Alternating Perception in Binocular Rivalry

Binocular rivalry occurs when different images are presented to each eye, causing perceptual awareness to alternate.
- Neural recordings in monkey area IT show changes correlated with perceptions.
- This suggests that neural activity in IT might be a neural correlate of this awareness.

Visual Awareness and Human Brain Activity

fMRI studies using rival images of a face and a house show alternating patterns of brain activity in the FFA (faces) and PPA (places) areas.
Imagining imagery activates the same visual processes as perceiving them.
This suggests that visual awareness involves the same underlying neural processes for both perception and imagination.

Challenges in Studying Neural Correlates of Consciousness (NCC)

Difficulties are encountered in interpreting NCC study data.
- Defining what minimal brain activity constitutes conscious experience is challenging.
- The question arises whether neural activity is a cause of conscious experience, a result of it, or not the NCC.
- Attention may be confounded with awareness.

Resting State Brain Activity

The default mode network (DMN) is active during resting states.
- It encompasses the medial prefrontal cortex, posterior cingulate cortex, posterior parietal cortex, hippocampus, and lateral temporal areas.

Functions of the Default Mode Network

Two hypotheses for the DMN's role:
- Sentinel hypothesis: It broadly monitors the environment.
- Internal mentation hypothesis: It supports thinking and remembering, including daydreaming.

Attention

Attention is the ability to focus on one aspect of sensory input, prioritizing information and ignoring the rest.
Attention has a significant impact on perception.

Types of Attention

Two types of attention:
- Exogenous attention (bottom-up): like an animal detecting a predator.
- Endogenous attention (top-down): deliberately directed by the brain.

Behavioral Consequences of Attention

Attention enhances visual sensitivity and decreases detection and reaction times.

Shifting Attention

fMRI imaging shows that when the location of a cued sector changes, brain activity shifts retinotopically.
PET imaging of attention to visual features (color, shape, speed) shows brain activity associated with attention to a particular feature when subtracting activity during divided attention from activity during selective attention.

Learning Objectives

Understand the resting state of the brain.
Learn about the brain areas involved in attention processing.
Discuss theories of consciousness and its neural correlates.

PET Imaging of Attention to Visual Features

PET imaging assesses the brain areas related to visual features and attention
The temporal lobe: V4, IT, and other visual areas process color and shape focusing attention
Area MT: processes motion speed

Enhanced Neural Responses in Parietal Cortex

Attentional modulation in the posterior parietal cortex increases neural responses, potentially speeding up visual processing and reaction times
The effect of attention on the response of a neuron in the posterior parietal cortex is studied and documented.

Effect of Attention in Visual Cortical Area V4

V4 neuronal responses are stronger when attention is directed to "effective" stimuli, even when visual appearance is the same.

Brain Circuits for Control of Attention

Cortical and subcortical areas guide attention and control saccadic eye movements
The pulvinar nuclues projects to various cortical areas regulating visual information flow
The frontal eye fields play a crucial role in directing attention

Attention & Eye Movements

Frontal eye field neurons (FEF) are motor fields involved in directing attention
FEF stimulation is associated with enhanced visual performance, lowered stimulus detection thresholds, and mimics the physiological and behavioral effects of attention

Direction of Attention with Salience & Priority Maps

Bottom-up attention: saliance map shows locations of notable features, contributing to how certain visual features grab attention.
Top-down attentional modulation from cognitive input: priority map indicates where attention should be directed based on stimulus salience and cognitive processes

A Priority Map in the Parietal Lobe

The lateral intraparietal cortex (area LIP) creates a priority map incorporating both bottom-up and top- down inputs
Area LIP guides eye movements and attention
Parietal lobe lesions are associated with neglect syndrome

Hemispatial Neglect Syndrome

Neglect Syndrome: a disorder where people ignore objects, people, and their own body to one side of their visual field
Usually associated with right-sided lesion in the posterior parietal cortex
Seen as a disruption of attention shifting abilities

Frontoparietal Attention Network

Bottom-up attention: Visual input from the occipital lobe reaches area LIP
Construction of salience map: Enhances visual processing and potentially triggers eye movements
Top-down attention: Attention effects are observed first in frontal and parietal areas
Priority map in LIP and FEF: Enhances visual processing and may cause eye movements

Consciousness

Materialist perspective: Consciousness originates from physical processes
Dualism: Mind and body are separate entities

What is Consciousness?

Easy problems of consciousness: Phenomena easily explained by scientific methods
Hard problem of consciousness: The subjective experience and the reason for its existence

Neural Correlates of Consciousness

Identifying the minimal neuronal events essential for a specific conscious percept
Experimenting with bistable visual images to track changes related to neural activity

Neuronal Correlates of Alternating Perception in Binocular Rivalry

The same image may be perceived differently when seen with each eye
Perceptual awareness alternates between the two images
Neural recordings in the monkey area IT show correlations between changes in neural activity and different perceptions

Visual Awareness & Human Brain Activity

fMRI is used to record human brain activity
Experimenting with rival images of a face and a house, recording in FFA (faces) and PPA (places)
Alternating patterns of brain activity in FFA and PPA were observed

Challenges in the Study of Consciousness

Interpreting NCC study data: Defining the minimal brain activity critical for conscious experience
Conflation of attention and awareness

Resting State Brain Activity

Resting state is fundamental and significant
It involves both monitoring the environment and daydreaming

Default Mode Network

Consistent patterns of brain activity across human subjects
Active brain areas in resting state: medial prefrontal cortex, posterior cingulate cortex, posterior parietal cortex, hippocampus, lateral temporal

Functions of Default Mode Network

Sentinel hypothesis: Broad monitoring of the environment
Internal mentation hypothesis: Supports thinking and remembering, resembling daydreaming

Attention Selectivity

Selective attention: Focused, filtering input
Limited capacity of attention

Attention

Exogenous attention: Bottom-up attention, automatic or triggered by external stimuli
Endogenous attention: Top-down attention, intentional and directed

Behavioral Consequences of Attention

Enhancement of visual sensitivity
Reduction of reaction and detection times
Allocation of attention revealed through imaging studies, animal studies, and fMRI
Shifting attention is observable through neuron activity changes in animal studies

fMRI Imaging of Attention to Location

Subjects view stimuli while the location of cued sectors changes
Brain activity shifts retinotopically
Same-different discrimination task: assessing color, shape, and speed
Selective attention experiment: Attention to one feature versus divided attention experiment: Attention to multiple features.
Subtracting the divided attention data from the selective attention experiment reveals the brain activity related to focusing on a single feature.

Learning Objectives

Understanding the resting state of the brain
Identifying areas involved in processing attention
Discussing the theories of consciousness and neural correlates.

Studying That Suits You

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Description

This quiz explores the mechanisms of visual attention and the respective brain areas involved in processing visual stimuli. It covers regions such as V4, MT, and the parietal cortex, highlighting their role in attention and eye movements. Test your understanding of how neuronal responses are influenced by attention in visual processing.