The Emotional Gatekeeper: A Computational Model of Attentional Selection and Suppression through the Pathway from the Amygdala to the Inhibitory Thalamic Reticular Nucleus
Fig 3
Slow flexible modulation of attention by emotion.
Each simulation is divided into 4 epochs (bottom): two conditioning phases, followed by two testing phases. Each subplot shows the time evolution of key model activities. A, Plan map. B, Salience map for appetitive (positive) stimuli. C, Salience map for aversive (negative) stimuli. D, E, F, Sensory map, including sensory cortex (D), sensory TRN sector (E) and sensory thalamus (F). G, Input to sensory thalamus (stimuli and distractors). H, Reinforcement signals and Conditioned Stimuli (CSs). Amplitudes of CSs are scaled down to 0.5 for visibility (H). In B-G, the y-axis represents the neuron index (neuron #); white indicates zero activity, and dark red/black indicates high activity. In A and H, the y-axis represents activity. In all subplots the x-axis represents time. During the first conditioning phase, CS1 and CS2 are associated with a food reward. During the second conditioning phase, CS3 is associated with an aversive stimulus. During both testing phases, the conditioned stimuli are presented repeatedly in the sequence CS1-CS3-CS2-CS3, with no reinforcement. Elevated activity of a sensory cortical neuron (D) corresponds to attention allocated to the corresponding stimulus (H). Elevated activity in an amygdalar BA principal neuron in a given subpopulation (B and C) represents the affective salience of the corresponding stimulus (H). Elevated activity in a plan cortical neuron (A) indicates that the corresponding behavioral plan is activated. During the testing phases, the rate at which the plan (A) shifts from feed (blue) to fear (red) is dependent on the rate of build-up of the plan cortical expectation violation (EV) signal. Here the cortical expectation violation signal builds up slowly in comparison with Fig 4, allowing each plan (A) to persist for some time despite stimulus-specific violations of expectation. In the bottom-up mode (green arrows), which depends on external stimuli, processing in the salience map (B, C) can (1) determine affective salience, focusing and shifting attention in the sensory map (D-F), and (2) provide evidence in support of plans corresponding to appetitive or aversive stimuli, driving decision-making and switching between the feed (blue plot) and fear (red plot) plan (A).