Table 2.
Summary of studies.
| Author’s name | n | Age mean (± SD) | Severity of TBI | Time post injury mean (± SD) | Stimuli/task | Physiological measure(s) | Findings | Link with psychological assessment |
|---|---|---|---|---|---|---|---|---|
| Aboulafia-Brakha et al. (2016) | 20 TBI, 22 controls | TBI: 37.4 (±12.6); Controls: 33.4 (± 8.5) | 12 severe, 3, moderate, 5 mild | 18.8 months (±12.01 months) | Verbal reports; Emotion faces on video clips | EDA; SCL | Anger regulation task: Only in the TBI group was mean SCL higher during uninstructed compared to neutral recall. | / |
| Emotion recognition task: No difference between groups was observed | ||||||||
| Amorapanth et al. (2016) | 16 TBI, 10 controls | TBI: 51.9(±15.0); Controls: 38.0 (± 14.4) | / | 5.9 years (± 8.6 years) | Emotional film clips | ECG; HRV | TBI group exhibited lower LFA HRV during amusement films compared to controls. Conversely, the TBI group showed higher LFA HRV during sad films than the control group. | This increase in sympathetic activity for sad films was correlated with self-reported attentional difficulties and impairment in visual attention. |
| de Sousa et al. (2012) | 21 TBI, 25 controls | TBI: 41.2 (±13.1); Controls: 29.0 (±11.1) | Severe | 14.3 years (±10.4 years) | Emotional film clips | EMG; ZM and CM; EDA: SCL | ZM: Greater activity for pleasant films than neutral or unpleasant in controls, little differentiation between the type of films for TBI. Activity increased over time in the control group, especially for pleasant films, this activation decreased in the TBI group, especially for unpleasant films. CM: Greater activation for unpleasant films compared to pleasant and neutral films in controls, no effect valence in TBI. SCL: Lower SCL during unpleasant films in TBI compared to controls. Habituation during unpleasant films and sensitisation during pleasant films only in controls. | |
| de Sousa et al. (2010) | 20 TBI, 22 controls | TBI: 47.4 (±10.0); Controls: 36.1 (± 12.6) | Severe | 13.4 years (± 6.9 years) | IAPS pictures | EMG; ZM and CM; EDA: SCR | ZM: No difference between groups. CM: TBI showed reduced responses to unpleasant pictures. SCR: TBI group exhibited reduced SCR in pleasant, unpleasant, and neutral pictures compared to control participants. | ZM: No significant correlations with emotional or cognitive empathy for both groups. CM: Positive correlations with emotional and cognitive empathy scores for controls during unpleasant pictures. SCR: Positive correlation with cognitive empathy and with emotional empathy (trend toward significance) for TBI during pleasant pictures |
| de Sousa et al. (2011) | 21 TBI, 22 controls | TBI: 48.4 (±8.8) Controls: 36.1 (± 12.6) | Severe | 11.9 years (± 7.8 years) | Facial expressions pictures | EMG: ZM and CM; EDA: SCR and SCL | SCL: Reduced SCL to anger faces in TBI. SCR: Greater SCR to angry faces compared to happy faces in controls, larger SCR to happy faces.in TBI. ZM: No difference between groups. CM: produced greater activity for angry faces compared to happy faces in controls, with no emotional effect in TBI. | SCR: Same SCR to angry and happy faces for TBI and controls with higher emotional empathy level, participants with a lower level of empathy presented higher SCR for happy faces compared to angry faces. ZM: Larger ZM for happy faces than angry for the higher emotional empathy TBI and controls groups. No emotion effect for the low empathy TBI and control group. CM: Group effect with higher CM for TBI group comparing their control counterparts. Emotion effect and group effect in low empathy group: greater CM for angry faces compared to happy faces, inverse pattern in TBI group |
| Fisher et al. (2015) | 19 TBI, 19 controls | TBI:44.89 (±13.76); Controls: 43.95 (±15.15) | Severe | 12.37 years (±7.99 years) | Facial expressions pictures | EDA: SCL | Lower SCL in TBI not emotional effect | |
| Francis et al. (2016) | 30 TBI, 30 controls | TBI: 45,73 (±13,68) Controls: 46,9 (±12,91) | Severe | 14.03 years (± 8.74 years) | Resting state and one session of HRV biofeedback | ECG: HRV | No difference between groups at rest and during the biofeedback session | Positive correlation between HRV and social cognition and emotional empathy, negatively correlation with alexithymia in the TBI group. |
| Kelly et al. (2017) | 21 TBI, 17 controls | TBI: 49.81 (±11.81); Controls: 46.29 (±16.22) | Moderate severe | at least 24 months post-injury. | Cyberball game | EDA: SCL | No difference | No correlation between SCLs and self-reported emotional experience in both groups |
| Krpan et al. (2011) | 18 TBI, 24 controls | TBI: 38.8 (±13.6); Controls: 38.7 (± 17.4) | Moderate–severe | 153 months (±117 months) | Simulated real-world stress test | EDA: SCL, ECG: HR, cortisol | SCL: No significant difference between groups. HR: No significant difference between groups Cortisol: No significant difference between groups | / |
| McDonald et al. (2011) | 18 TBI, 18 controls | TBI: 49.0 (range 31 to63 years); Controls: 35.9 (range 20 to59 years) | Moderate severe | mean time since injury 13.0 (± 7.0 years) | Emotional faces pictures, passive and identification task | EDA: SCR and SCL, ECG: ECD | SCR: No difference between groups SCL: Passive task: increasing of SCL over trials for angry faces and decreasing for happy faces in controls Habituation and no emotion effect in TBI. Identification task: no habituation for either expression for either the control or TBI participants. ECD: Increasing for the identification condition compared to the passive condition in both groups. Identification task: magnitude increasing across repetition higher in controls relative to TBI. Increasing for the happy face across the repetition and decreasing for the angry face in controls, no emotional effect on TBI | No correlation between physiological measures and accuracy in recognizing tasks in both groups |
| Osborne-Crowley et al. (2020) | 30 TBI, 30 controls | TBI: 44.47 (±15.32); Controls: 41.70 (±14.97) | Moderate Severe | 13.63 years (±13.08 years) | Verbal report; Listening stories | EDA: SCL | Greater SCL across the emotional conditions in controls compared to TBI. | |
| (Rushby et al., 2013a) | 17 TBI, 22 controls | TBI: 46.47 (±13.30); Controls: 41.23 (± 14.86) | Severe | 12.59 years (± 8.05 years) | Resting state eyes open, eyes closed | EDA: SCL | Lower SCLs across both conditions in TBI compared to controls | |
| Rushby et al. (2016) | 24 TBI, 24 controls | TBI: 43.3 years (± 14.96); Controls: 42.4 (±14.9) | Severe | 12.63 years (±8.81 years) | Resting state | EDA: SCL | Lower SCL for the TBI compared to controls | |
| Rushby et al. (2013b) | 19 TBI, 25 controls | TBI: 41.5 (±13.8); Controls: 31.0 (±11.1) | Severe | 13.21 years (±10.3 years) | Emotional film clips | EMG: ZM and CM; EDA: SCL, ECG: HR | SCL: Increasing across films repetition in both groups. No emotion effect ZM: No difference between groups CM: Greater activity across all film types in TBI compared to controls. Emotion effect with higher activation for unpleasant films compared to neutral and pleasant films in both groups HR: Increasing across films repetition in controls, deceleration in TBI | SCL: Positive correlation with emotional empathy only in TBI ZM: Larger response in TBI for the low emotional empathy group compared to the higher empathy TBI group. |
| Sánchez-Navarro et al. (2005) | 19 ABI* (14 TBI, 5 ischemic stroke), 23 controls | ABI: 31.63 (±13.05); control: 20.78 (±2.45) | Frontal damage | 24.17 years (±2,01 years) | IPAS pictures | EDA: SCL and SCR; Startle blink, ECG: HR | SCL: No significant difference between groups SCR: Lower responses in TBI than in controls Startle blink: Lower responses in TBI for unpleasant pictures and higher ones to pleasant pictures compared to controls HR: No difference between group | |
| Saunders et al. (2006) | 13 TBI, 24 controls | Adults | Severe | Mean: 6 years 9 months (range 1–17 years). | IAPS pictures, emotional faces pictures | Startle blink | IAPS pictures: Attenuation for pleasant pictures and potentiation for unpleasant ones in controls, attenuation for pleasant and unpleasant pictures in TBI. Slower to reach peak eyeblink response for positive and negative pictures in TBI compared to controls Faces pictures: no emotion and group effects | No correlation between subjective valence ratings and eyeblink peak, latency, or subjective arousal ratings in both groups |
| Soussignan et al. (2005) | 1 TBI, 10 controls | TBI: 30, Controls: 26.4 (±4.87) | Severe | 11 years | IAPS pictures | EMG: ZM and CM; ECG: HR; EDA:SCR | Pictures: SCR: Lower responses for all pictures in TBI. No emotion effect in TBI contrary to controls.ZM and CM: no emotional effect only in TBI Odors: SCL: No valence effect in TBI, greater SCL for unpleasant odors than pleasant or neutral ones in the control group. HR: No group and valence effect ZM and CM: no valence effect on TBI. | |
| Williams and Wood (2012) | 64 TBI, 64 controls | TBI: 32.05 (±12.60); Controls 34.73 (± 12.14) | Moderate to severe | 2.52 years (± 1.422 years) | IAPS pictures acoustic stimulus | Startle blink | Reduce effect of valence in TBI compared to controls | No correlation between with performance on europsychological measures in TBI |
ABI, Acquired brain injury.