Lecture 7 - Attention and Neural Mechanisms

A set of vocabulary flashcards covering the concepts, neural mechanisms, and research studies related to selective, voluntary, and reflexive attention from the lecture notes.

Selective Attention

The allocation of attention among many relevant inputs, thoughts and actions, while simultaneously ignoring irrelevant and distracting ones.

Goal-driven control

Top-down control driven by current goals and shaped by learning and experience.

Stimulus-driven control

Bottom-up control, reflexively driven by environmental sensory input.

Voluntary Attention

Also known as endogenous attention; a top-down and goal-driven process where goals, expectation, and rewards guide focus to achieve goals.

Reflexive Attention

Involuntary, bottom-up, and stimulus-driven attention guided by a stimulus in the environment to rapidly attend to changes.

Overt Attention

The purposeful allocation of attention to a stimulus.

Covert Attention

The discrete, unintentional allocation of attention to a stimulus.

Hermann von Helmholtz

Researcher who found that while keeping eyes fixated in the center of a screen, one could covertly attend to any location on the screen and perceive letters.

The cocktail party effect

A term designated by Cherry ($1953$) for selective auditory attention, often studied using a dichotic listening task.

Early Selection

The theory that a stimulus can be selected for further processing or ignored as irrelevant before perpetual analysis occurs.

Late Selection

The theory that perceptual systems first process all stimuli equally, and selection happens afterwards.

ERPs

Consistent patterns of EEG activity triggered by a stimulus, defined by polarity, latency, scalp location, and sensitivity to experimental manipulations.

P1

The first positive deflection in an ERP, occurring $60-70\text{ms}$ post-stimulus onset, generated by neural activity in the visual cortex.

N1

The first negative deflection in an ERP, occurring approximately $180\text{ms}$ post-stimulus onset.

Heinze et al. ($1994$)

Researchers who combined ERPs and PET scans to find that $P1$ effects seem to originate from the extrastriate cortex.

Tootell et al. ($1998$)

Researchers who used fMRI to link retinotopic maps to selective attention, finding activation in extrastriate areas ($V2$, $V3$, $V3a$) that was absent when ignoring stimuli.

Biased Computational Model

A model suggesting that stimuli compete to control a visual neuron's firing when they fall within its receptive field, with attention favoring one stimulus.

LGN (Lateral Geniculate Nucleus)

A subcortical structure where selective processing increases activity; its relay neurons gate signals heading into the $V1$.

McAlonan et al. ($2008$)

Found that $LGN$ relay neurons pass info to the $V1$, and $TRN$ neurons receive input from the $V1$ to feed back into the $LGN$, gating signals.

Pop out search

A visual search task where a specific stimulus (e.g., a red X in a field of red Os) is immediately and effortlessly noticed.

Conjunction Search

A visual search task where a stimulus shares features with others (e.g., same color or same shape), making it more difficult to find.

Feature integration theory

Suggests the visual system processes simple features in parallel but requires spatial attention to bind features together to identify an object.

Spatial Attention

The act of orienting towards a specific stimulus in a specific location.

Feature Attention

The act of orienting towards a stimulus based on specific features like color or shape.

Schoenfield et al. ($2007$)

A study using MEG and fMRI found that $V4$ tracks color (feature attention) while $MT$ and $V5$ track motion (spatial attention).

Dorsal Attention Network

A bilateral network of frontal and parietal regions (FEF, SEF, IPS, SPL) active during directed attentional control and eye movements.

Ventral Attention Network

A right-lateralized network (ventral frontal lobe and TPJ) that drives reflexive attention to unexpected, unattended, or novel stimuli.

Unilateral spatial neglect

A condition caused by damage to the attention network in one hemisphere, resulting in a deficit of attention to the opposite side of space.

Balint’s Syndrome

A condition resulting from bilateral lesions in the occipital and parietal lobes, characterized by severe deficits in visual attention and awareness.

Simultanagnosia

A symptom of Balint’s Syndrome involving difficulty perceiving the visual field as a single, whole scene.

Ocular apraxia

A deficit in making eye movements to scan the visual field, associated with Balint’s Syndrome.

Optic ataxia

Difficulty in making visually guided hand movements, associated with Balint’s Syndrome.