Table 1.
Neuroimaging studies included in the present review.
| Study | N | Mean age | Age range | DE | SD | Secondary task | Behavioral results | Contrast condition and main neuroimaging results |
|---|---|---|---|---|---|---|---|---|
| fMRI (Graydon et al., 2004) | 6–3F | – | 22–28 | . | Real world highway presented in a fronto-parallel viewing perspective | Visual event detection task (CEDR—central event detection response, to red colored stimuli | SD + CEDR Task = 611 ms | SD + CEDR vs. SD |
| CEDR Task = 550 ms | Activation of Fronto-parietal regions | |||||||
| t = −2.68, p < 0.05 | ||||||||
| fMRI (Just et al., 2008) | 29–14F | – | 18–25 | . | Steering a vehicle along a curving virtual road using a trackball or mouse in the right hand | Listening and answering to true/false pre-determined questions | SD + Audio Task = 92% (ACC) | SD + Audio Task vs. SD |
| Mean road-maintenance errors: | Activation of the bilateral temporal language areas, left inferior frontal gyrus; | |||||||
| SD = 8.7 (9.7) | Decrease of activation in spatial brain areas | |||||||
| SD + Listening = 12.8 (11.6) | ||||||||
| t(28) = 2.22, p < 0.05 | ||||||||
| The mean root mean squared deviation from the ideal path: | ||||||||
| SD + Listening = 2.64 (0.56) | ||||||||
| SD = 2.48 (0.51) | ||||||||
| t(28) = 2.79, p < 0.01 | ||||||||
| MEG Bowyer et al., 2009 | 28–17F 19 MEG | 36.5 (13.8) | 18–65 | – | Similar to Bowyer et al. (2007) | Listening and answering to pre-determined questions – 1 question = short conversation; multiple questions = long conversation | Results 19 subjects in MEG | SD + Long Conversation Task vs. SD |
| SD + Long Conversation Task: | Decrease of activation in the visual cortex and in the right superior parietal region | |||||||
| RT = 1,043 ms-SE = 65 ms; | ||||||||
| SD = RT = 944 ms-SE = 48 ms | ||||||||
| fMRI (Hsieh et al., 2009) | 10–6F | 36.9 | 19–61 | – | Similar to Bowyer et al. (2007, 2009) | Listening and answering to pre-determined questions in order to carry on short and long conversations | Results in fMRI: | SD + Long Conversation vs. SD |
| SD + Long Conversation: | Activations of language areas (e.g., Wernicke's and Broca's areas) and fronto-parietal areas | |||||||
| RT = 770 ms; | ||||||||
| SD (no conversation) = RT = 726 ms | ||||||||
| MEG (Fort et al., 2010) | 13 M | 25.4 (2.1) | 21–28 | ≥3 year | Driving on single or dual roadways, following traffic light rules, and direction signs, with little traffic and few pedestrians on the roads | Listening to broadcast and answering to 3 pre-determined questions (for half of participants) | SD (traffic lights) + Audio Task | SD + Audio Task vs. SD |
| RT = 430 ms | In both conditions, with traffic light or arrows, sensory visual areas and right fronto-parietal network were activated | |||||||
| SD (traffic lights): RT = 399 ms | With traffic lights: decreases of brain activity in primary visual areas, dorsolateral prefrontal cortex, and right temporo-parietal junction; increase of activation in the posterior parietal cortex. With arrows: decreases of brain activity in occipital visual areas, frontal areas, including the premotor area and left posterior parietal area; increase of activity in the frontopolar cortex | |||||||
| F = 8.167; p = 0.013 | ||||||||
| SD (arrows) + Audio Task | ||||||||
| RT = 875 ms | ||||||||
| SD (arrows): RT = 890 ms | ||||||||
| F = 2.301; p = 0.153 | ||||||||
| fMRI (Uchiyama et al., 2012) | 18–8F | 27.7 (4.3) | – | – | Following a car at the distance of 5 m using a joystick with the right hand. No intersections, other vehicles, or obstacles were included | (1) Sentence comprehension: judge whether the subject of the verb corresponded to the person in the paired words; (2) tone discrimination: judge whether the beep tone in the response phase was high or low | Sentence comprehension accuracy: | SD + Audio Task vs. SD |
| SD + Audio Task: 86.2% | Decrease of activations in the medial prefrontal cortex and left superior occipital gyrus | |||||||
| Audio Task: 88.9% (SD = 12.23) | Car-following performance showed positive correlation with brain activity in the bilateral lateral occipital complex and the right inferior parietal lobule | |||||||
| t(17) = 0.90, p = 0.381 | ||||||||
| Sentence comprehension RT: | ||||||||
| SD + Audio Task: 1,668 ms (320) | ||||||||
| Audio Task: 1,841 ms (300) | ||||||||
| t(17) = 2.77, p < 0.05 | ||||||||
| Car-following performance worse during SD + Audio Task than during SD alone | ||||||||
| fMRI (Schweizer et al., 2013) | 16–7F | 25.8 (1.5) | 20–30 | 7.4 (2.5) | Straight driving, turning left or right at intersection with or without incoming traffic using steering wheel and pedals | Listening and answering to pre-determined questions | SD (Straight Driving) + Audio Task | SD + Audio Task vs. SD |
| Speed: 58.69 (2.34) | Shift in activation from the posterior to the anterior brain during the dual-task condition | |||||||
| SD (Straight Driving) – Speed: 58.57 (3.36) | ||||||||
| SD (Left turn traffic) + Audio Task – Speed: 28.98 (3.76) | ||||||||
| SD (Left turn) – Speed: 26.79 (5.17) | ||||||||
| SD (Left turn traffic) – Speed: 29.35 (4.26) | ||||||||
| fMRI (Chung et al., 2014) | 16 M | 26.6 (2.1) | – | 2.7 (1.5) | Using the wheel and pedals to drive at a constant speed (110 km/h) on a straight road with very few distracting elements, without changing lanes | Listening and answering to questions regarding double-digit carry-over calculation with sums <100 | – | SD + Calculation Task vs. SD |
| Activations of cingulate gyrus and sub-lobar region | ||||||||
| Decrease of activation of regions associated with spatial processing, movement planning and execution | ||||||||
| fMRI (Al-Hashimi et al., 2015) | 31–14F | 38.4 (6.3) | 30–40 | – | Keeping the car within a target box. Right and left turns, and inclining and declining hills formed the tracks, varying from mild to severe | Discrimination sign task (green circles −33% frequency—with a right button press) | Mean accuracy no significant differences | SD + Discrimination Sign Task vs. SD |
| SD + Discrimination Sign Task: 513.9 ms | Activation of the right superior parietal lobule | |||||||
| SD: 530.7 ms | ||||||||
| t(30) = 3.77, p = 0.00042 | ||||||||
| fMRI (Sasai et al., 2016) | 13 M | – | 22–34 | – | Minimizing the deviation from the simulated track centerline | GPS instructions (integrated task) or radio show (split task) | No significant difference in any measures between the integrated and split task conditions | Reduced multivariate functional connectivity during the split task between driving and listening network; higher integration of information content of driving and listening networks during the integrated task |
| fMRI (Choi et al., 2017) | 15 M | 26 (1.4) | – | 2.5 (1.6) | Using the wheel and pedals to drive at a constant speed (80 km/h) on a straight road with very few distracting elements, without changing lanes | Similar to Chung et al. (2014) | Accuracy for SD + Calculation Task | SD + Calculation Task vs. SD |
| 78.5 ± 11.7%; | Inferior frontal gyrus and the superior temporal gyrus enhanced activation | |||||||
| For Calculation Task: 84.8 ± 10.9% | ||||||||
| t-test (PASW Statistics 18), p = 0.196 |
DE, driving experience; SD, simulated driving.