Lecture 7/8 - Attention

Awareness Test

Selective and Divided Attention

Lectures Overview:

• Focus on Selective and Divided Attention

• Dr. Tom Beesley (t.beesley@lancaster.ac.uk)

Objectives of the Lectures

• Understand early vs. late selection accounts of attention: Explore the two main theories that explain how attention is allocated during information processing.

• Explore attention as a limited resource and factors affecting multitasking: Analyze how cognitive load affects the ability to perform multiple tasks simultaneously.

• Examine interactions between selective and divided attention (Lavie’s Load Theory): Investigate how selective attention operates under varying perceptual loads and its influence on distractions.

• Understand parallel vs. serial processes in visual search: Differentiate between the two types of processes in how we search for visual information.

Defining Attention

William James (1890) famously defined attention as "the taking into possession of the mind" of one object from several possibilities, underscoring its role in focalization and concentration. Attention is a foundational cognitive resource that supports perception and cognition.

Selective Attention

Function:

• The primary function of selective attention is to filter information for efficient cognitive processing. This ensures that relevant stimuli are prioritized while distractions are minimized, enhancing our ability to process information accurately.

The Cocktail Party Problem

• Cherry (1953) Findings: His research revealed that effective filtering of audio streams requires distinct physical differences in stimulus characteristics, such as voice or gender. Moreover, minimal information is retained from the stream that is not being attended to, demonstrating the limits of selective attention.

Input Processing Stages

• Filtering Process:

  • Pre-attentive Stage: This initial stage involves the identification of simple physical characteristics (e.g., voice pitch, gender, or location) that can be processed in parallel and require little cognitive effort.

  • Attentive Stage: This stage involves processing more complex properties and meanings in a serial manner, which requires focused cognitive effort.

Broadbent’s Filter Theory

• Stages of Processing:

  • Parallel Stage: Initial sensory processing occurs based on physical features, where inherent stimuli are sorted.

  • Serial Stage: The attended stream is further processed for semantic content, but evidence now challenges this model as it shows unattended stimuli can sometimes be processed semantically.

Late Selection Theory

• Deutsch & Deutsch (1963) proposed that all sensory information undergoes semantic processing; selection takes place just before the response is made. This theory effectively explains phenomena such as slips of attention and how special stimuli can capture attention even when not prioritized.

Selection in Space

• Attention can narrow focus, effectively reducing cognitive processing for unattended information. This has implications for how we navigate complex environments and manage competing information sources.

Serial vs. Parallel Search

• Serial Search: Increased distractors lead to heightened search difficulty, as searching becomes reliant on processing each potential distractor one after the other.

• Parallel Search: Targets defined by specific features (like color or shape) can stand out, allowing the observer to process multiple stimuli simultaneously.

Feature Searches vs. Conjunction Searches

• Feature Searches: These are tasks where the target can be identified by a single unique feature (e.g., a red item among blue items) and are processed in parallel.

• Conjunction Searches: These require serial processing as multiple features must be combined (e.g., identifying a red circle among blue squares and red squares), making these more challenging. A aprticular combination of features

Feature Integration Theory (FIT) - Anne Treisman

• FIT posits that early selection occurs for basic perceptual features. However, when features must be combined (binding), attentional resources must be focused serially.

• ausitory attention = serial stage and semnatic processing

• visual attnetion = serial stage and binding complex features

Predictions of FIT

• Limited serial searches result in poorer binding of features, as evidenced by errors in feature binding.

Illusory Conjunctions

• These errors in feature binding support FIT, indicating that automatic feature extraction is separate from object recognition, which relies on the effective binding of features.

• These errors in binding features support Triesman’s Feature Integration Theory.

• Feature extraction occurs automatically and in parallel; object recognition requires feature binding.

• (Accurate) binding of features requires slow serial attentional processing of stimuli.

• If this is not allowed, then errors in binding will occur and will be based on features extracted automatically during early perceptual processing

Divided Attention (Multitasking)

• Attention is notably a limited resource. Key factors influencing performance include:

  • Task Similarity: Similar tasks compete for the same cognitive resources, leading to greater interference.

  • Practice: Familiarity can improve performance despite concurrent tasks.

  • Task Difficulty: More difficult tasks interfere more significantly with the capacity to divide attention.

  • Secondary tasks - The use of secondary tasks to “load” attentional/cognitive capacity isa very effective methodology

  • Can provide insights into what processes are operating

  • Contrasting primary and secondary task types

  • Provides evidence for role of effortful and automatic processes.

Task Similarity and Performance

• Insights from Segal & Fusella (1970) suggest that the similarity of tasks can profoundly impact performance on concurrent activities, leading to increased errors or diminished efficiency.

Lavie’s Load Theory

• Concept: This theory posits that attentional selection is critically determined by the perceptual load of the tasks at hand.

  • High Perceptual Load: When tasks demand significant cognitive resources, the ability to process distractions diminishes, allowing for more focused attention on pertinent stimuli.

  • Low Load: In lower-load situations, distractions become significantly more salient as cognitive resources are available for additional processing.

Results of Load Theory Experiments

• Low Load: Feature identification tasks reveal that more interference may occur from distractors during these tasks due to excess cognitive capacity.

  • High Load: Conjunction tasks require more effort for attention allocation and significantly reduce attention to distractions.

Implicit Learning and Selective Attention

• Research by Rowland & Shanks (2006) indicates that individuals can learn from unattended information, especially under low load conditions, highlighting the potential for implicit learning in everyday contexts.

Conclusions from Research

• Passive learning is feasible when perceptual processing demands are low, which provides valuable insights into attentional mechanisms and how they operate across various contexts.