Readings content

What is a proposed model to explain visual search in scenes?

The dual-path model which includes a selective and a non-selective path

According to the dual-path model of visual search in scenes, what is the function of the selective path?

The 'selective' path involves individually selecting candidate objects for recognition

According to the dual-path model of visual search in scenes, what is the function of the 'nonselective' path?

The 'nonselective' path allows information to be extracted from global and/or statistical information

Why do you need to search visually

You need to search because, although you are good at recognizing objects, you cannot recognize multiple objects simultaneously

What process, involved in binding visual features, is described as capacity limited and often attention demanding?

the step of binding visual features together is capacity limited and often attention demanding

What did Buschman and Miller observe in monkeys during visual search that suggested serial processing?

Monkeys searched a circular array of items in the same sequence on every trial, with attentional enhancement rising and falling at successive locations

What role does memory play during visual search?

It prevents perseveration on single salient items. There is also some evidence of inhibition of return, preventing attention from returning to previously visited locations

When does memory aid subsequent visual search?

The degree to which memories aid subsequent search depends on whether it’s faster to retrieve the relevant memory or to repeat the visual search. Memory can speed up common searches, like finding scissors.

How is search proposed to be accomplished, based on eye movement data and the relationship between eye movements and attention?

Search is accomplished by selecting successive small groups of items, whether the eyes move or not

What aspect of real scenes provides scene-based guidance during visual search?

Real scenes aren’t random, elements are arranged in a rule-governed manner e.g. people on horizontal surfaces, chimneys on roofs

What are the 2 types of scene-based guidance?

Semantic and episodic guidance

What oes semantic guidance include?

Knowledge of the probability of an object’s presence in a scene, its probable location given the scene layout, and inter-object relations

What effect do violations of semantic expectations have on object recognition and attention?

They impede object recognition and increase allocation of attention

What is episodic guidance?

Memory for a specific, previously encountered scene that contains information about the specific locations of specific objects

How do classic sources of guidance combine with episodic and semantic sources in naturalistic scenes?

They combine to direct attention efficiently to parts of the scene with the highest probability of containing targets

In naturalistic scenes, compared to knowledge-based factors, what role does guidance of eye movements by bottom-up salience play?

Bottom-up salience plays a minor role compared with more knowledge-based factors

Is a short glimpse of a scene sufficient to guide gaze efficiently?

Yes, it can narrow down search space and efficiently guide gaze, provided enough time is available to apply semantic knowledge to the initial scene representation

According to the dual-path model, where might the raw material for semantic guidance be generated?

In a nonselective pathway that is not subject to the same capacity limits as the selective pathway

In the two-pathway view, where is episodic guidance based?

On the results of selective and nonselective processing

If you are searching for an object that is right in front of your eyes but haven’t found it yet, which visual pathway is primarily contributing to your visual experience at that location?

The nonselective pathway

What kind of information might the nonselective pathway provide?

It would see the global context like the forest

What kind of processing is required for the identification of specific objects or features, such as a tree with green and brown boughs or a bird heading to the right?

The selective path

What would be the consequence of lesioning the hypothestical selective pathway?

The result might be agnostic, someone who could see something throughout the visual field but couldn’t identify objects

What would be the consequence of lesioning the hypothetical nonselective pathway?

This might produce a simultagnosic or Balint’s patient, able to identify the current object of attention but otherwise unable to see

How are the hypothetical selective and nonselective pathways potentially related to the ventral and dorsal streams in the brain?

Lesioning the selective pathway might resemble lesioning the ventral stream (agnostic) and lesioning the nonselective pathway might resemble lesioning the dorsal stream (simultagnosic/Balint's patient) but more research is needed to relate selective/nonselective to what/where

What is the definition of a dual-task decrement?

A reduction in performance when performing 2 tasks together than the same 2 tasks separately

What does a performance operating characteristic (POC) function show?

The relation between the processing performance on 2 tasks when they’re combined. It describes how POC functions can be traced out as the demands of the 2 tasks are varied or as pps vary their commitment of either/both tasks

What is the definition of a conflict effect in the context of attention?

They arise in cases where competing stimuli are present in a display and it’s difficult to ignore which to respond to

What does Broadbent’s model of selective attention propose about the filter?

The selective filter affects the read-out or output of items from the ST store so as to pass them on for further processing. This filter operated on info in sensory memory, which specifies only the physical characteristics of stimuli

According to Broadbent’s filter theory, is selection by filtering pre or post-categorical?

Pre-categorical, meaning the identity of the actual stimulus remains unknown at this stage. It selects aspects of stimulation that possess a common physical attribute

In Broadbent’s model, where do items selected by the filter go?

They are passed on to the limited capacity channel, shown as the P/perceptual system

How is the P/perceptual system assumed to operate in Broadbent’s model

It operates serially, processing selected items one at a time

What is rehearsal in Broadbent’s model and what is its purpose

Rehearsal is when an item selected for read-out from the ST store is passed back from the P system and recirculated into the ST store. This helps prevent info loss from the ST store

In split-span experiments with binaural lists, how did pps perform better?

They performed better when they chose to report the content delivered to one ear and then report the content delivered to the other ear. Performance was also improved if the rate of presentation was slowed down

Why did Broadbent’s theory suggest that switching between input channels (lift-right ears or visual-auditory modalities) affects performance?

Switching between channels takes time. When presentation rates were