Effects of all-night driving on selective attention in professional truck drivers : a preliminary functional magnetic resonance study

Fatigue affects multiple aspects of cognitive performance among drivers. However, even after fatigue builds up, some are still able to maintain the level of behavioral performance. To evaluate these adaptations on the neural network level, we utilized functional magnetic resonance imaging (fMRI). Seventeen male professional drivers underwent two fMRI sessions, once while rested and once in a fatigued condition after 10-h of overnight driving. The cognitive task used in the study involved the detection of visual feature conjunctions, namely the shape and the color. There were no significant differences in the task performance between the conditions except for longer reaction times in the fatigued condition. However, we observed substantial differences in the activation patterns during the cognitive task involving selective attention between the conditions. On the global level, we observed a general decrease in activation strength in the fatigued condition, which appeared to be more pronounced in the left hemisphere. On the local level, we observed a (spatially) extended activation of the medial prefrontal regions in the fatigued condition, which reflected increased cognitive control mechanisms compensating for the diminished efficiency of mechanisms involved in meeting task demands

Hippocampal volumes (A) and concentration of metabolities: (B) N-acetylaspartate+N-acetylaspartylglutamate (tNAA), (C) glutamate (Glu) and (D) creatine+phosphocreatine (tCr).

<p>White and black graphs represent control (CONs) and high-fat high carbohydrate diet-treated (OBRs) animals, respectively. The graphs show median values with 25–75% variability range and maximal and minimal values. Decimal indexes indicate statistical significance of intergroup differences (Mann–Whitney U-test).</p

Exemplary proton spectrum with fitted baseline.

<p>Exemplary proton spectrum with fitted baseline.</p

Daily energy intake (A), changes in body weight during the experiment (B), changes in glucose blood levels (C), and changes in blood levels of ketone bodies (D) in controls and HFD-fed rats.

<p>*<i>P</i><0.05, ***<i>P</i><0.01. The “spikes” in levels of ketone bodies were caused by short-lived increases in concentrations of ketone bodies in single animals.</p

Volume of interest placement.

<p>Volume of interest placement.</p

Exemplary parameters of the animal behavior during five-day maze tests performed/repeated at the 9^th month of age.

<p>(A) the total time (seconds) spent in the maze before the reward was reached by the animal on day 1^st, 2^nd, 3^rd, 4^th, and 5^th, (B) the time of walking (seconds) to reach the reward, (C) the time of immobility (seconds), (D) the total walking distance (meters). Abbreviations: White and black graphs characterize control and high-fat high carbohydrate diet-treated animals, respectively. The graphs show median values (squares), 25–75% variability ranges (vertically arranged rectangles), and maximal and minimal values (whiskers). Decimal indexes located below the graphs indicate statistical significance of intergroup differences at a given maze test (Mann–Whitney U-test).</p

Exemplary parcellation of hippocampus: red = hippocampus, yellow = cortex, blue = cerebro-spinal fluid.

<p>Exemplary parcellation of hippocampus: red = hippocampus, yellow = cortex, blue = cerebro-spinal fluid.</p