Neuro: Arousal and Attention

Attention

- More than just sensation and perception; uses stimuli to measure arousal levels

- There can be attentional deficits present in perfectly awake individuals

Attention is a limited resource

What can impair the flexibility of attention?

Extreme arousal (pain, terror, overstimulation)

What are the three characteristics of attention?

Consciousness (alert, arousal)

Awareness (alert, arousal)

Cognitive effort (key piece to attention)

Psychological level

how we process and respond to resources

Neural level

alternations of selective activity; intensity and duration of neural responses

arousal

being awake enough to perceive a stimulus (pain, sound, touch, etc)

Reticular activating system

Cells in the reticular formation can set the pace of activity of cells throughout the brain

Raphe nuclei & locus coeruleus

raphe nuclei

sleep wake cycle; arousal

locus coeruleus

attention

What does damage to reticular activating system cause?

reduced attention, confusion, may lead to a coma

Serotonin

Generalized arousal & sleep wake cycle

origin- raphe nuclei

Norepinephrine

attention (direction of consciousness) & alertness

origin- locus coeruleus and medial reticular zone

Acetylcholine

selection of object of attention, based upon goals & orientation

origin- pedunculopontine nucleus

dopamine

motivation, motor activity, cognition, and executive attention

origin- substantia nigra and ventral tegmental area

Attentional orientation/Orienting Reflex

An individual's immediate response to a novel change in its environment. It is the direction of attention to the novel stimulus.

Sustained attention

- Attending to one stimulus over increasing period of time. Is the ability to sustain alertness (monitor a stimulus) continuously.

- important when a task demands that you cannot "tune out" and must be attentive

ex: in a classroom, operating machinery

Selective (focused) attention

Prioritizing attention to one stimulus over the other(s); conscious

ex: if 2 people are talking, who do you prioritize/tune into more

Filtering process which allows us to hone in on critical information from the vast amount of information that is available (cocktail party effect)

Divided attention

Dividing attention between 2 or more different stimuli.

*attention is a limited resource

Easier to split attention between different modalities than two similar modalities

ex: Talking to someone while driving is easier than listening to 2 people talk at the same time

Involved in dorsal lateral prefrontal cortex

What is orienting?

aligning attention with a source of the sensory signals

3 stages of Attentional shift/ Orienting reflex:

1. disengage from the current stimuli

2. shift attention from current stimuli to a new one

3. attention would be engaged, or focused onto the new target.

Overt

Movement of eye/head towards the novel stimulus. However, prior to this, covert attention shifts to this location

Covert

Attention may shift covertly even without an overt eye/head response.

You can have both covert and overt, or just covert.

3 subsystems of attentional orienting/shift

Posterior attentional systems which is involved in orienting to visual locations

Posterior/superior parietal lobe

Superior colliculus

Thalamic lateral pulvinar nucleus

- frontal eye fields also involved

What happens to human performance over time regarding sustained attention?

Human performance decreases with time due to loss of sensitivity and attention drifting from habituation.

3 subsystems of sustained attention

Reticular activating system

Thalamus

Frontal and inferior parietal regions

What does the width of focus refer to in selective attention?

Focus can be broad or narrow.

broad example- teaching to a whole class

narrow- talking to one individual

What does the direction of focus refer to in selective attention?

Focus can be external or internal.

external example- directing focus to external environment

internal example- directing focus internally

3 subsystems of selective/focused attention

Anterior Attentional System

- Superior colliculus

- Thalamus

- Parietal Lobe

- Medial frontal lobe

- Lateral prefrontal cortex

How are attentional resources allocated?

Attentional resources are allocated depending on the processing needs.

filter theory

bottle neck theory; take in a little information at once

serially process multiple tasks to complete one and then the other

resource capacity

each resource has a limited capacity (visual sys., hearing, tactile, etc) the things we do the most get the most allocation

example: can look at the tv while doing something with my hands and listening to something else other than what im looking at

central resource capacity

Kahneman's attention

one central resource that determines our capacity - as long as resource is not at its capacity, we can be successful

multiple resource

multitasking

- several resources for attention

- depends on type/need

- Success with multitasking as long as resources aren't competing against each other/ Cannot maximize or task becomes unsuccessful based on clients ability

- Cannot use for clients who can only follow one step commands