Chapter 14: Attention

Made by @agreyr

Consciousness

The state of being aware that we are conscious and that we can perceive what is going on in our minds and around us

Brain regions implicated in consciousness

Default Mode Network & Claustrum

Default Mode Network

Circuit of brain regions active during quiet introspective thought (frontal, parietal, and temporal regions)

Claustrum

Sheets of neurons in the forebrain (lateral to the basal ganglia)

Elements of consciousness

Theory of mind, mirror recognition, imitation, empathy & emotion, tool use, language, and metacognition

Theory of mind

Understanding others have their own beliefs, knowledge, and desires

Mirror recognition

Ability to recognize the self as depicted in a mirror

Imitation

Ability to copy the actions of others; may be important for empathy and self-awareness

Empathy & emotion

The ability to imagine the feelings of other individuals

Tool use

Ability to employ objects to achieve goals

Language

Use of a system of arbitrary symbols, with specific meanings and strict grammar, to convey information to other individuals

Metacognition

The ability to “think about thinking”

Executive functions

Higher-level cognitive processes that control and organize our thoughts, behaviors, and feelings

Task switching, working memory, inhibition of thoughts/behaviors, thought suppression, and monitoring of ongoing performance (ex: delay of gratification)

Prefrontal cortex responsible for working memory and task switching

Hemispatial Neglect

Individuals ignore stimuli on the left side of their midline; these individuals usually have normal vision, may ignore people and objects; lesions in the frontoparietal attention network

Bálint’s Syndrome

Characterized by bilateral parietal lobe damage; includes oculomotor apraxia, optic ataxia, and simultagnosia

Oculomotor apraxia

Unable to appropriately direct visual gaze horizontally

Optic ataxia

Cannot reach for objects using visual cues

Simultagnosia

Only one object or feature consciously observed at a time

Superior Colliculus

Controls eye movement toward objects of attention; helps direct covert attention

Two major pathways to select and shift attention

Dorsal frontoparietal and right temporoparietal

Dorsal frontoparietal

Top-down, voluntary attention; includes IPS and FEF

Intraparietal sulcus (IPS)

Increased rate of firing of neurons when attention is directed to specific stimuli; can be visual or auditory stimuli; important for steering attention; damage can make voluntary shifts of attention difficult

Frontal eye field (FEF)

Damage results in inability to ignore distractors in periphery; important for gaze being directed at stimuli according to cognitive goals (a top-down process)

Right temporoparietal

Bottom-up, reflexive attention; includes TPJ

Temporoparietal junction (TPJ)

Meeting of the temporal and parietal lobes in right hemisphere; directs attention toward new or unexpected stimuli; stimuli will elicit a spike in the neural activity of this region regardless of location of stimulus in the environment (right vs left visual field); direct input from visual cortex

Measuring attention

When attending to a task, cortical neuron activity becomes synchronized; measured through an EEG, average results over many trials of task completion

Event-Related Potential (ERPs)

Averaged EEG recordings measuring brain responses to repeated presentations of a stimulus

Measuring ERPs

Stimulus presentation —> EEG segments —> averaged ERP waveform

Patterns in shifts of attention

Regarding auditory stimuli, shadowing has a predictable effect on the ERP; two large waves from the auditory cortex, initial positive wave (P1) followed by negative wave (N1)

Differences in ERPs for stimuli attended to, as opposed to stimuli not attended to

Auditory N1 effect

Negative N1 much larger for stimuli attended to; likely measuring the result of selective attention acting on neural mechanisms to enhance the processing of sound stimuli

P3 Effect

The positive wave seen about 300 ms after the stimulus; associated with memory, responses to surprise events, and higher order processing (meaning, language, identity of speaker, etc.)

Shadowing experiments

Participants focus their attention to one of two streams of stimuli (dichotic listening)

Dichotic listening

Focus on one ear and repeat the message

Inattentional blindness

The failure to perceive stimuli that are not actively being attended to

Change blindness

A visual perception phenomenon where people fail to notice a change in a visual scene

Divided attention

The act of processing two or more stimuli at the same time; attention is limited

Attention acts as a spotlight; helps focus our cognitive resources, direct our behavior, and tunes out extraneous information

Perceptual load

Processing demands imposed by the task

When the task is easy: resources left over to process task-irrelevant stimuli

When the task is difficult/complex: no more resources to spare; extra stimuli excluded immediately

Categories of attention

Sustained, voluntary, and reflexive

Sustained attention

Stimulus or location is held in the attentional spotlight for a prolonged period of time; measures basic attentional abilities

Voluntary attention

Voluntary; conscious, top-down; in line with goals; endogenous

Reflexive attention

Involuntary; bottom-up process; mediated by lower levels of the nervous system; exogenous

Feature search

Search for a target based on a unique attribute

Conjunction search

Search for a target on the basis or a combination of features

Binding problem

Question of how the brain understands which individual attributes blend together into a single object, when these different features are processed by different regions in the brain

Selective attention

Process by which we select or focus on one or more stimuli for enhanced processing and analysis

Vigilance

A global level of alertness of the individual

Overt attention

Attention in which the focus coincides with sensory orientation

Covert attention

Attention in which the focus can be directed independently of sensory orientation

Cocktail party effect

Selective enhancement of attention in order to filter out distractions

Attentional bottleneck

Attention acts as a filter so our resources are directed to what is MOST important

Early selection models (when does this bottleneck occur?)

Unattended information is filtered out right away, at the level of sensory input; the meaning is not yet processed and the filter only lets through information based on physical characteristics of the information

Late selection models (when does this bottleneck occur?)

All incoming stimuli are processed for meaning before any selection occurs for attention; no feature-based filtering occurs