Perception & Attention

Apparent movement

although movement is perceived, nothing is actually moving (Max Wertheimer, stroboscope). The whole is different than the sum of its parts (Gestalt principle).

Attention

Focusing on specific features, objects, or locations or on certain thoughts or activities.

Attentional capture

A rapid shifting of attention, usually caused by a stimulus such as a loud noise, bright light, or sudden movement

Attenuation model of attention (leaky filter)

Treisman, Anne. Proposed selection occurs in two stages, replacing Broadbent’s filter with an attenuator, analyses messages in terms of physical characteristics, language and meaning, determining the strength of what comes through.

Automatic processing

Processing that occurs automatically, without the person’s intending to do it, and that also uses few cognitive resources. Automatic processing is associated with easy or well-practiced tasks.

Bottom-up processing

a way of perceiving and interpreting the world that is driven directly by raw sensory input from the environment

Broadbent’s Filter Model of Attention

Broadbent’s Filter Model of Attention

Central vision

the centre-most region of our visual field = the area where we usually focus our attention.

Change Blindness

Difficulty in detecting changes in similar, but slightly different, scenes that are presented one after another. The changes are often easy to see once attention is directed to them but are usually undetected in the absence of appropriate attention. (Grimes’ study documented the high frequency of this phenomenon).

Change Detection

Detecting differences between pictures or displays that are presented one after another.

Choking (aka cognitive choking)

A decline in performance following increased conscious awareness or intended control of a task.

Continuity errors

In film, changes that occur from one scene to another that do not match, such as when a character reaches for a croissant in one shot, which turns into a pancake in the next shot.

Covert Attention

attention is shifted without moving the eyes, commonly referred to as seeing something “out of the corner of one’s eye.”

Cukur et al

looked at how attention affects the way different types of objects are represented across the brain as a whole. Called this attentional warping - looking for a particular category also increases responses to things related to that category.

Datta and DeYoe

experiment using fMRI found that changes in activation were due to the shifting of attention and not where the eyes were fixed (covert attention).

Deep learning

involves programming that simulates human information processing abilities, including complex pattern recognition for images, language etc. i.e. make sense of an image and describe it in a way that is similar to human abilities.

Default Mode Network (DMN)

Network of structures that are active when a person is not involved in specific tasks.

Dictionary unit

Part of Treisman’s Attenuation model. Contains words, stored in memory, each of which has a threshold for being activated (the lower the threshold the more likely to be detected, even if spoken softly or obscured.

Distraction

Occurs when one stimulus interferes with attention to or the processing of another stimulus

Divided attention

the distribution of attention among two or more task. Involves allocating cognitive resources to multiple tasks simultaneously, i.e. Listening to music while driving.

Egly et al

Same-object advantage occurs when the enhancing effect of attention spreads throughout an object, so that attention to one place on an object results in a facilitation of processing at other places on the object (covert attention).

Endogenous attention

attention that we focus voluntarily on a stimulus of our choice in a sustained, goal-driven manner (e.g. study)

Exogenous attention

attention that is involuntarily directed toward a stimulus in a transient (fleeting) way (e.g. police siren)

Fixation

a pausing of the eyes on places of interest while observing a scene.

Fovea

small area of the retina on which objects in central vision fall - much better detail vision than the peripheral retina

Foveal vision

another name for central vision

Gestalt psychologists

main point is they realised perception based on more than the pattern of light and dark on the retina but determined by specific principles that organize visual information.

Gray and Wedderburn

“Dear Aunt Jane” experiment – participants attention jumped from one ear to the other, inferring they were taking the meaning of the words into account.

Inattentional blindness

occurs when people are unaware of clearly visible stimuli if they are not directing their attention to them - illustrates how we can miss things even if they are clearly visible.

Inattentional deafness

when inattention causes a person to miss an auditory stimulus.

Inverse projection problem

task of determining the object responsible for a particular image on the retina

Likelihood principle

we perceive the object that is most likely to have caused the pattern of stimuli received

Load theory of attention (Lavie, 2008)

proposes that the ability to ignore task-irrelevant stimuli depends on the load of the task the person is carrying out, whereby high-load tasks result in less distraction, but with low-load tasks there is processing capacity available to “notice” the distractor, slowing down the response.

Machine learning

use of algorithms that learn from data they are provided and draw conclusions or make predictions to novel problems based on this data ∴ can accomplish tasks without complete instructions.

MacKay, Donald

experiment that used ambiguous sentences for priming to demonstrate that messages could be selected at a later stage of processing, based primarily on their meaning.

Mind wandering

Thoughts that come from within a person, often unintentionally (also called daydreaming).

Moray, Neville

carried out dichotic listening experiment – participants detected their name being said in the ear they were asked to ignore – challenging Broadbent’s filter model.

Multitasking

phenomenon in which a person attempts to consciously divide attention between multiple tasks while also attempting to switch between those tasks.

Occlusion

process by which something is obscured from view

Overt attention

shifting attention from one place to another by moving the eyes

Perception

sensory information being converted into our conscious experience (i.e. subjective experiences resulting from stimulation of the senses)

Perceptual load

the difficulty of a task

Peripheral vision

everything that surrounds the centre of our visual field =the periphery.

Physical Regularities

regularly occurring physical properties of the environment

Posner et al

experiment with arrows pointing to where a square would appear when focused on a central spot showed that information processing is more effective at the place where (covert) attention is directed.

Pre-cueing

A technique used in cognitive psychology where a cue directs attention to a specific location in the visual field before a target appears

Principle of good continuation

Points that, when connected, result in straight or smoothly curving lines are seen as belonging together, and the lines tend to be seen in such a way as to follow the smoothest path. Also, objects that are overlapped by other objects are perceived as continuing behind the overlapping object.

Principle of good figure (aka principle of simplicity, law of Pragnanz)

Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible.

Principle of similarity

Similar things appear to be grouped together

Principles of perceptual organisation

explain how elements are grouped together to create larger objects

Processing capacity

the amount of information people can handle and sets a limit on their ability to process incoming information

Productivity illusion

The false belief that multitasking makes a person more productive, while actual productivity tends to be slower and lower quality.

Regularities in the environment

certain characteristics of the environment occur that frequently, i.e. e.g. blue is associated with a clear sky, landscapes are often green

Saccadic eye movement

a rapid, jerky movement from one fixation to the next.

Saliency map

map of a scene that indicates the stimulus salience of areas and objects in the scene.

Scene schemas

A person’s knowledge about what is likely to be contained in a particular scene. This knowledge can help guide attention to different areas of the scene. For example, knowledge of what is usually in an office may cause a person to look toward the desk to see the computer.

Schneider & Shiffrin

carried out divide attention experiment demonstrating that practice ca n lead to automatic processing.

Selective attention

The ability to focus on one message and ignore all others

Semantic regularities

the characteristics associated with the functions carried out in different types of scenes (related to scene schemas)

Sensation

information received by our sensory organs

Simons and Chabris

Gorilla costume experiment looking at inattentional blindness. Found that when observers are attending to one sequence of events, they can fail to notice another event, even when it is right in front of them.

Speech Segmentation

ability to tell when one word in a conversation ends and the next one begins (hearing the sounds = BU processing, perceiving individual words = TDP)

Stimulus salience

the physical properties of the stimulus, such as colour, contrast, or movement.

Stroop effect (1935)

An effect originally studied by J. R. Stroop, using a task in which a person is instructed to respond to one aspect of a stimulus, such as the color of ink that a word is printed in, and ignore another aspect, such as the color that the word names. The Stroop effect refers to the fact that people find this task difficult when, for example, the word RED is printed in blue ink.

Task switching (or concept switching)

shifting of attention and cognitive resources from one task to another. Cognitive resources are quickly shifted from task to task - requires disengagement from one to accomplish the other, i.e. texting and driving.

Top-down processing

how the brain uses pre-existing knowledge, past experiences, and expectations to interpret incoming sensory information

Transitional probabilities

the likelihood that one sound will follow another within a word.

Unconscious inference

(Hermann von Helmholtz theory) Process in which our perceptions are the result of unconscious assumptions, or inferences, that we make about the environment

Viewpoint invariance

People’s ability to recognize an object even when it is seen from different viewpoints.

Visual scanning

Movement of the eyes from one location or object to another