Related Experiment Video
Updated: Jul 20, 2025
07:54
Detecting Behavioral Deficits in Rats After Traumatic Brain Injury
Published on: January 30, 2018
18.1K
Reduced Sensitivity to Background Reward Underlies Apathy After Traumatic Brain Injury: Insights From an Ecological
Halle Quang1, Campbell Le Heron2, Bernard Balleine1
1University of New South Wales, School of Psychology, Sydney, NSW 2052, Australia.
Neuroscience
|August 3, 2023
Summary
Apathy after traumatic brain injury (TBI) is linked to impaired background reward processing. This study shows individuals with TBI and apathy struggle to adjust decisions when environmental rewards change, unlike those without apathy.
Area of Science:
- Neuroscience
- Psychology
- Clinical Medicine
Background:
- Apathy is a common and debilitating symptom following moderate-to-severe traumatic brain injury (TBI).
- Understanding the neural mechanisms of apathy post-TBI is crucial for developing effective interventions.
- Reward processing, encompassing both immediate gains and broader environmental potential, is implicated in apathy.
Purpose of the Study:
- To investigate the relationship between apathy and reward processing in individuals with moderate-to-severe TBI.
- To examine how disruptions in background reward sensitivity contribute to apathy post-TBI.
Main Methods:
- A computer-based foraging task was administered to 45 individuals with moderate-to-severe TBI (20 with apathy) and 37 matched controls.
- Participants made decisions about leaving depleted reward patches to seek new ones with varying background reward rates.
- Linear mixed effects models were used to analyze patch-leaving times as the primary outcome.
Main Results:
- A significant interaction was found between apathy and background reward sensitivity in TBI participants.
- Apathetic TBI individuals failed to adjust their patch-leaving decisions in response to changes in environmental reward rates.
- While TBI itself reduced sensitivity to foreground rewards, this effect was not modulated by apathy.
Conclusions:
- This study provides the first direct evidence linking disrupted background reward processing to apathy in any brain disorder.
- A novel mechanism for apathy following moderate-to-severe TBI is identified, involving impaired sensitivity to environmental reward potential.
- These findings suggest potential new therapeutic targets for managing apathy after head injury.
