Attention

Attention

Focusing our mental resources on certain information, while blocking out irrelevant information

• Can be sustained but it’s more difficult over time

Characteristics of attention

Limited

• Certain amount of attention that can be utilised at any given time

• We can’t attend to all sensory stimuli; we filter relevant components into our awareness

Selective

• We can direct attention to certain stimuli at the exclusion of the other stimuli

Controllable

• Our attention shifts without us being aware of it

Factors that affect attention

Arousal

• EG. Fatigued, can reduce our level of attention

  but mild stress can enhance attention

Task difficulty

• A new or challenging task requires more attentional resources

Anxiety

• Can reduce the cognitive resources available

Skill development

• Through practice in attending to certain stimuli, you can become better at these attentional tasks.

“Cocktail party effect”

Suggests that we tend to direct our attention to stimuli that we deem personally relevant

Selective attention

Focusing our mental resources on one stimuli at the exclusion of the other stimuli

Controlled process

A task that requires a selective attention in order to be completed. Usually the task is difficult or unfamiliar.

Divided attention

Involves the process of simultaneously attending to two or more stimuli or processes

• allows you to distribute your cognitive resources to multiple set of stimuli

• usually from different modalities (verbal, audio, visual)

Automatic process

A task that allows divided attention in order to be completed. Usually the task is easy or well-learned and requires little effort.

Sustained attention

Involves the process of maintaining attention over an extended time.

top-down processing

Cognitive processes including past experiences, prior knowledge and expectations are used to interpret and assign meaning to raw sensory information.

bottom-down processing

Perception begins with raw sensory data, this is then sent to the brain for higher level mental processing. A perception is formed using the raw sensory information. 

Depth perception

Depth perception is the ability to judge distances and see the world in three dimensions.

Pictorial cues

Pictorial cues are so named because artists use them to create depth and distance on two-dimensional surfaces such as paper and canvas.

Depth cues

Depth cues are a source of information from the environment (external cue) or from within the body (internal cue) that aids perception of how far away objects are.

Binocular depth cues

Binocular depth cues require the use of both eyes to send information to the brain to perceive depth.

• Important in determining the distance of objects that are relatively close.

Retinal disparity

Retinal disparity refers to the very slight difference (‘disparity’) in the location of the visual images on the retinas. As our eyes are roughly 6/7 cm apart they have slightly different angles of view.

Type of binocular depth cue

Convergence

Convergence involves the brain interpreting depth, this is detected from changes in tension in the eye muscles when the two eyes turn inwards (towards the nose) to focus on nearby objects.

Monocular depth cues

Monocular depth cues require the use of only one eye to provide information to the brain about depth and distance, but they can also operate with both eyes.

Accomodation

Accommodation is the automatic change of the shape of the lens to focus an object in response to how far away the object is from the viewer.

Gestalt principles

They are a set of principles that explain how we interpret visual information by grouping together smaller parts (that individually lack meaning) to enable us to perceive a whole object.

Perceptual set

Perceptual set is the predisposition, or ‘readiness’, to perceive something in accordance with what we expect it to be.

Perceptual distortion

A perceptual distortion involves an inconsistency, or ‘mismatch’, between a perceptual experience and physical reality.

Visual illusions

Visual illusions are one kind of perceptual distortion which occur when we misinterpret visual information and see stimuli in a way that conflicts with how it is in reality.

• Most illusions occur because they create a perception (the brains interpretation of the visual information) that is inconsistent with the image on the retina. 

Illusions are due to…

• something in our physical external environment makes an image tricky to interpret during perception

  • For example, you may have noticed that the closer the moon is to the horizon line, the bigger it looks. This is something within our physical environment that gives rise to a perceptual visual illusion. (Circles illusion)

• something biological makes an image difficult to interpret

  • For example, have you ever looked at a bright light and then turned it off? Could you still see the image of the bright light, almost like a bright shadow? This is due to our eyes and brain not keeping up with changing reality after intense light and giving rise to a perceptual illusion. (Castle / beach illusion /Ames room) 

• something psychological

  • We may see things in a certain way due to our own application of biased reasoning (as demonstrated by perceptual sets). This can also give rise to perceptual illusions. 

Synaesthesia

Synaesthesia is a perceptual experience in which stimulation of one sense produces additional sensations in another sense. The experience associated with the additional sensations ‘adds’ to the overall perceptual experience without replacing the initial sense.