Decoding a Perceptual Decision Process across Cortex

Abstract

Perceptual decisions arise from the activity of neurons distributed across brain circuits. But, decoding the mechanisms behind this cognitive operation across brain circuits has long posed a difficult problem. We recorded the neuronal activity of diverse cortical areas, while monkeys performed a vibrotactile discrimination task. We find that the encoding of the stimuli during the stimulus periods, working memory, and comparison periods is widely distributed across cortical areas. Notably, during the comparison and postponed decision report periods the activity of frontal brain circuits encode both the result of the sensory evaluation that corresponds to the monkey's possible choices and past information on which the decision is based. These results suggest that frontal lobe circuits are more engaged in the readout of sensory information from working memory, when it is required to be compared with other sensory inputs, than simply engaged in motor responses during this task.

Should Damage to the Machinery of Social Perception Damage Perception?

“…Everything that is known about decision-making in the brain points to awareness as explicitly generated neuronal signals that are received by a decision integrator. A similar point has been made with respect to reportable sensory experience by Romo and colleagues (de Lafuente & Romo, 2005;Hernandez et al, 2010).…”

Coherent delta-band oscillations between cortical areas correlate with decision making

“…1D). We based this selection on the previously described responses of single neurons from these cortical areas associated with different components of the somatosensory discrimination task (7). Examples of the raw simultaneously recorded LFPs during the discrimination task are shown in Fig.…”

“…These studies showed that the neuronal activities distributed across parietal and frontal lobe cortices correlate with processes that lead to decision making (4)(5)(6)(7). However, how these spatially distant, cortical circuits coordinate their activities into a unified functional network during decision making remains poorly understood.…”

“…Here, we examined whether coherent oscillations coordinate the activity of five simultaneously recorded cortical areas in the monkey performing a somatosensory discrimination task (7). We specifically focused on whether coherent delta-band oscillations play a significant functional role in linking cortical circuits during decision making.…”

The neural representation of sensorimotor transformations in a human perceptual decision making network

“…Of course, other regions beyond IPS are also likely to be involved in sensorimotor transformations. A recent examination of activity across the macaque cortex during a delayed vibrotactile comparison task demonstrated that activity during the first sensory input was found beyond primary somatosensory cortex (S1) in ventral premotor (VPC), medial premotor (MPC), and prefrontal cortex (PFC) (Hernandez et al, 2010). Only those regions outside S1 showed activity correlated with sensory comparisons and motor planning during presentation of the second sensory input.…”