L7 Attention and Working Memory (PSYC2050)

Learning Objectives

• The rapid serial visual presentation involves giving the rationale for visual presentation
• It includes describing the attentional blink(AB).
• It evaluates explanations of the AB effect.
• Key results in task switching will be described.
• Task preparation versus disengaging from a prior task will also be described.
• Characteristics of automaticity should be listed
• Situations that produce automatic versus controlled processes should also be listed.
• The central executive of Baddeley and Hitch model should be described
• The involvement in attentional control and the function of working memory should be mentioned
• Baddeley's working memory model and its components should be well outlined.
• Resource models of visual-spatial working memory (VSTM) and related findings are important.
• Experiments for evaluating it, and recent findings about limitations of the model are to be described.

Visual Search

• Focuses on cognitive processes involved in locating a specific item within a visual field.

Is There a Red X in the Display

• Involves identifying the presence of a specific target (red X) among distractors.

Feature Search (Pop-Out)

• The process occurs when a target is identified by a unique feature.
• Feature (disjunctive) search: searches for a red X among black Xs
• The process runs in PARALLEL
• The target shows "pop-out", and an item by item search is not required.

Conjunction Search

• In it, the target is identified by a combination of features
• Search runs serially.
• Search for red X in a background of black Xs and Red Os

Effect on RT of Increases in the Number of Search Items, Treisman & Gelade (1980)

• Feature (disjunctive) search is fast and unaffected by search set size.
• Conjunction search is slower and affected by search set size.
• Target Absent, Conjunction search target is slower
• Slope doubles in serial search when the target is absent.
• A target is found after examining half the items, on average
• When the target is absent, all items are searched (exhaustive search).

Feature Integration Theory (FIT)

• "Automatic" processing of stimulus into elementary features
• Individual feature "maps” give the location of specific features
• Individual maps project onto a single location map
• Activity in individual map can be read without focused attention
• Attention binds features into an object

Two Kinds of Visual Search

• Preattentive search involves: Features, Parallel ('efficient'), Pop-out, Flat slope
• Attentive search involves: Conjunctions, Serial ('inefficient'), No pop-out, Steep slope

Limitations of FIT

• Features don't always pop-out
• Conjunctions can lead to flat search slopes.
• Duncan & Humphreys (1989) showed that two factors neglected by FIT had large effects on RTs:
• Similarity of Ts and Ds
• Heterogeneity of distractors: Search is much easier when distractors are similar to each other.

Guided Search (Jeremy Wolfe)

• Task performance depends on the differences in the quality of guidance.
• Information from the pre-attentive vision guides the deployment of selective attention.

Distinct Search Types

• Wolfe, 1998

The Attentional Blink

• The attentional blink involves searching in TIME
• Concerns limitations in visual attention under time pressure in rapid serial visual presentation(RSVP).
• RSVP = rapid serial visual presentation
• Only one location, but time-pressured
• Letters, digits, words, etc visually displayed, in a single location, one after the other at a rapid rate.
• It normally takes about 100 ms per item
• Ps look out for certain targets; asked at the end of list about items (around 15 items).
• There's quick conceptual processing even at this fast rate of presentation
• Post-target intrusions are common

The Attentional Blink (AB)

• The process involves two-target RSVP
• Ps disregard the digit distractors, and reports the letters.
• There's typically about 15 items per stream
• Example of Lag 4: T2 is the 4th item after T1. i.e. 3 distractors between T1 & T2
• An attentional blink causes:If Ps must detect 2 targets in the RSVP stream, there is a decrement in reporting T2 when it occurs a few hundred ms after T1
• Blink extends out to about T1 +6
• Blink is not typically observed for the T1 + 1 item (Lag-1-sparing)
• T1 & T2 processed as one event when T2 occurs immediately after T1?
• An AB is found if T1 and T2 are defined in the same way (2 digits) or differently (red letter vs. digit)
• Making T1 easier to identify/report reduces the AB
• AB reflects demands of selecting & identifying T1
• AB occurs if Ps have to merely detect T1 without reporting its identity
• AB isn't just a recall problem: Interference is observed when a recognition test of targets is used.
• AB is strongly influenced by whether or not items precede and follow T1 and T2
• Adjacent items serve as pattern masks that curtail processing of the targets
• pattern masks compete with targets to engage perceptual processing It is commonly used to ensure that brief stimuli do not reach awareness
• Ps say they did not see the masked word, but it is processed sufficiently to affect responses in tasks
• Resources for the AB include:
  • Multiple sources
  • Evidence for “resource depletion"
  • Effects of T1 difficulty (more difficult à bigger AB)
• Attentional control mechanisms for selecting targets and rejecting distractors have a role
• The discriminability of targets and distractors are important
• There's debate about the role of distractors in the AB

Attentional Limitations Under Time Pressure

• Under time pressure, effects stress testing of the system to find its limits
• The attentional blink evidence suggests that consolidation of targets in working memory is an operation that can't be done for more than one target (or target-chunk) at a time
• It may be associated with competitive or inhibitory effects for other stimuli

Multiple Choice Example

• In an Attentioanal blink task a more difficult T1 Increases the size of AB

From RSVP to Task Switching

• The attentional blink, as an example, is thought to show a "hard limit" on human cognitive capacities
• Issues of task control are involved
• Research is focused on how people stop responding to RSVP distractors and switch between demands to remember targets and ignore distractors
• Researchers are interested specifically in task control and the task switching paradigm which is called attentional control (also EXECUTIVE control)

Task Switching

• Participants incur a time (and perhaps error) cost when they switch from one simple task to another
• Task switching is an executive control operation with attributes like Contributes to dual task performance
• Task set: involves preparing to perform one task rather than another
• The process Involves selecting, linking, enabling "modules" for task components
• Links to irrelevant modules must be disabled, and Switch costs arise in establishing the appropriate task set & disengaging an inappropriate set

Rogers and Monsell Paradigm

• Rogers and Monsell paradigm deals with basic findings in task switching
• Rogers & Monsell, 1995, AABB paradigm is usually used:
• Consists of Stimuli of digit-letter pair, e.g., G7, B2
  • A Digit task means the right button for odd digit, and left for even
  • B Letter task means right button for vowel, and left for consonant
• There's a Task cue where Stimulus appears in one of 4 boxes.
• Participants will often Perform letter task for top boxes, number task for lower boxes.
• Rogers and Monsell Paradigm may involve:
  • Letter task which involves Vowel (R) or consonant (L)
  • The Digit task involves Odd (R) or even (L)
• Task alternation switches between Letter, and Digit
• Research records accuracy and latency (Reaction Time) for responses for switch vs. non-switch trials

Task Costs

• Task switching costs are not a new thing and provided The basis for Henry Ford’s Highland Park, Michigan plant:
  • It dealt with Model T Ford which was durable and affordable
  • A Moving assembly line, consisting of interchangeable parts
  • The plant involved Workers at specific locations in the line, which is Still the approach used today
• Task switching paradigm
• Arthur T. Jersild (1927) made a block of trials with only a repeated task and another of trials where two tasks alternated at a later time
• This procedure usually goes from AABB, to AAABBB and so on
• Task practice, fatigue, are matched over switch trials and same-task trials
• There are simple responses to digits or letters
• Observers a "switch cost" of up to several hundred ms when the task changes

The Task Switching Phenomenon

• The Phenomenon involves trials that are the Same vs. of different stimuli:
  • Small switch costs if both stimuli and responses different like in letter or digit task
  • High cost incurred when participant changes the task and thus the response selection rule for a common stimulus configuration
• Trivial accounts of switch costs say that Do the Ps occasionally forget what task is next?
  • It shows No. Ps can't see evidence of occasional slow trials and shows Instead a general slowing over the RT distribution

Practice and Task Difficulty Effects

• Practice leads to:
  • Costs are reduced but not eliminated with practice of separate tasks & switching tasks The more difficult Task has traits such as a Switching to or from the easier task incurs a greater cost for example, colour naming to word naming in Stroop
• DISENGAGING from prior task is a major factor and task difficulty may need effort and Concentration to disengage from difficult task

Causes of Task Switching Effects

• Rogers & Monsell, 1995 put an emphasis on Task Set Re-configuration (TSR) prior to the switched task
• It can lead to maintain 2 task sets for different tasks & stimuli
• With different responses for the same stimuli, there will be needed to change the task set when task changes with supported manipulations of preparation time
• Short Cue-digit interval reduces switch time to 2-3 sec

Task-Cuing Paradigm

• Task-cuing paradigm (Sudevan & Taylor, 1987) involves
  • judging Odd-even (task 1) and task2 is greater than/or less than 5 judgments.
  • One must be informed by a cue before the trial and varies Cue to digit interval (400 to 4000 ms)

Preparation vs. Interference from Last Trial

• Can adequate preparation remove the switch cost is always the question
• If not, then there is always a residual cost
• So task preparation is also part of the story since Residual costs are there It's a stimulus is driven function because participants are unable to Do any decision-making for the next trial until the stimulus has been presented and identified
• Deciding on the response for the current stimulus may be changed
• It reduces response associated with the stimulus for the alternative task

Exogenous Effects: Response Congruity

• Rogers & Monsell (R&M) paradigm (AABB)
• Congruity involves Task for: - letter + odd digit, when both right button are congruent - vowel letter + even digit when the two responses: right and left buttons, are incongruent:

Theories of the Switch Cost

• The theories involve Active preparation as the major factor
• The level of interference from prior task is involved
• Whether exogenous factors play a role

Summary of Task Switching Theories

• Disengagement theory: from TSI.
• Allport et al's proactive interference from "task set inertia says that: TS decays and impairs adoption of alternative task set

Endogenous + Exogenous Components

• Includes endogenous component (preparation by participant) which requires time: and a reduced switch cost with preparation time
• The exogenous factors must be triggered by the arrival of a suitable stimulus. For example: Rogers & Monsell

Endogenous only theory

• This theory states the residual cost has because participants do not prepare adequately on every trial

Summary

• Even when motivation, fatigue & practice is addressed, and RTs decrease, a residual switch cost remains
• It is necessary to consider both endogenous + exogenous control

Automacity

• Automatic refers to routine tasks, and involves: Kahneman’s capacity theory: capacity theory: and consumption of resources It comes with performance improvements, a reduction task effort and facilitation of and co-ordination of concurrent tasks
• There's Autonomic every day tasks like in Driving a car and Riding a bicycle
• However, the original demonstration in the lab was by Shiffrin & Schneider (1977) with set targets to be searched for, over an upcoming trial
• Display letters like 'G' and 'M', in "A square that display 4 letters around the middle, as Fixation dot at the centre, during a trial
• During each trial there would be one or zero targets, the remaining are distractors

Shiffrin & Schneider 1977

• There are Key independent variables: Like one which is based on size of memory and another with categorization

Shiffrin & Schneider Key Results

• Isolate how a simple categorical process will make people more quick, efficient and accurate at identifying a singular specific item

Characterising Automatic Processes

• Automatic processes work
  • Without awareness
  • Without conscious deliberation or obligations
  • Without expenditure of resources
  • There's a lack in flexibility and is quite rigid and habitual

Theories of Automaticity

• Logan states that Automaticity is based on learning. It is not all-or-none
• Automaticity is based on Rapid retrieval of relevant information about stimulus

Cautions About Automaticity

• These have created some problems
• Many automatic programs require capacity and face interference if well-practised for long duration

Awareness and Automaticity

• people can have a lack of full awareness and some kind of awareness of automatic
• It's best to always be aware of how you can have a more routine process to have tasks with better additional demands
• Autonomic comes from the situation

Working Memory

• (also called short-term or primary memory) connects Attention and memory for WM is domain of thought
• WM is involved in both, and responses to the for decisions
• It is responsible for environmental input and directing attention

Alan Baddely's Baddeley and Hitch Model involving Visual working/short-term memory

• (WMs) involves keeping items in the short term in WM
• The material in them disappears seconds later, but are continually refreshed
  • There's a Limited capacity with room for about 7 items and it displaces other info with new ones

What is The Central Executive?

• This model also works with long term memory (Ltm) as the "Controller" . It functions by facilitating the various WM functions like the subsidiary WM
• The mental manipulation of info that has been held in the slave system, comes from LTM
• CE has is that can is from Under a lot number and with and:
  • Playing (playing)
  • A and also for LTM

Components of Baddeley's WM Model

• A Phonological short spatial:

The Phonological Loop

• Maintains has and may To may of the

Phonological Loop: 4 Key Effects

• The Key can all":" of "

Phonological Similarity Effect

• is or" and: a:
• " the ":"" and with"" in" a and:
• """ and" "" to"

Irrelevant Speech Effect

• (also or of.
• access short Like

Word length Effect

• Is by of.

Working Memory Model

• For of A
• that of Like For

Visuo-Spatial Sketchpad

• That the that with

Nature of vs-Spatial Sketchpads

• that has into" visual inner

Summary of Baadelay Model

• is that is has of memory, that may be but of
• Visual working deals with buffer