Rapid feedback processing in human nucleus accumbens and motor thalamus

Area of Science:

• Neuroscience
• Psychiatry
• Brain Stimulation

Background:

• The nucleus accumbens (NAcc) and thalamus are key in feedback processing models.
• Deep brain stimulation (DBS) treats psychiatric conditions like OCD and Tourette's syndrome (TS).
• The feedback related negativity (FRN) reflects brain activity during feedback evaluation.

Purpose of the Study:

• To investigate neural activity in the NAcc and thalamus during feedback processing in patients undergoing DBS.
• To compare brain responses in patients with psychiatric conditions to healthy participants.
• To explore the neurocognitive effects of DBS on basal ganglia-cortex loops.

Main Methods:

• Recorded scalp EEG and local field potentials (LFP) from externalized electrodes in NAcc or thalamus (VA/VL) in three patients.
• Patients performed a modified time estimation task eliciting feedback processing and FRN.
• Scalp EEG data were also collected from 29 healthy participants (HP) for comparison.

Main Results:

• Both NAcc and thalamus showed differential modulation by positive and negative feedback.
• NAcc exhibited a biphasic response to positive feedback, while the thalamus showed a monophasic response.
• Surface-FRN was similar between patients and HP, indicating preserved feedback processing at the scalp level.

Conclusions:

• The NAcc and thalamus exhibit distinct, feedback-dependent modulations during a time estimation task.
• These findings provide insights into the neurobiological underpinnings of feedback processing in psychiatric disorders.
• DBS targets show specific neural activity patterns relevant to therapeutic modulation.