Mechanisms of Attention

Question 1

What is the difference between exogenous and endogenous attention? (2 marks)

Answer 1

Both can be categorised under visual location based attention. Exogenous attention is bottom up and is driven by external stimuli within the environment. Endogenous attention has a top down framework and is known as goal driven.

Question 2

Outline an experimental paradigm that was used to identify these types of attention? (3 marks)

Answer 2

Posner’s spatial cueing paradigm was used to direct attention before relevant targets are presented. To test exogenous attention, spatially non-predictive peripheral cues are used, and to test endogenous attention spatially predictive central cues are used. Participants stare at a central fixation point and press a key as soon as they respond to a target stimulus which would be a shape in this case. In this paradigm cues are either classed as valid, invalid or neutral.

Question 3

Outline the major steps in Posner’s model of attentional shift? (3 marks)

Answer 3

Alerting is a general state of arousal elicited by stimuli, showing activation of the locus corelus and frontal cortical areas
Orienting is the shifting of attention to select information in environment, has shown activation of frontal eye fields and superior parietal junction particularly.
Executive attention resolves conflict of competing inputs, Involving the anterior cingulate and insula in particular.

Question 4

Which neurotransmitter’s regulate this model?(2 marks

Answer 4

Regulated by noradrenaline, acetylcholine and dopamine (in order)