However, since we did not include a non-temporal description task in our study, we cannot rule out the possibility of a more global deficit in the ability to produce specific descriptions underlying our results. Measures of performance on non-temporal description tasks were included in two recent studies of future thinking in patients with medial-temporal lobe damage (Race et al., 2011) and Parkinson’s disease (de Vito et al.,

2012). Both reported that deficits in future thinking could not be accounted for by narrative construction performances. In the current study, patients were required to construct specific events; however, outside of being plausible and lasting less than a day, there were no demands as to the content of these events. This raises the possibility that participants were able to construct simulations based on well-established check details scripts in semantic memory or more generalized memory for routine events, which do not place demands on episodic memory (Cooper, Vargha-Khadem, Gadian, & Maguire, 2011; Maguire, Vargha-Khadem, & Hassabis, 2010). In line with this suggestion, Race et al. (2011) reported that amnesic patients generated a greater number of details, when imagining more frequent and scripted events (a birthday celebration) than less frequent events (winning the lottery),

although future thinking was impaired for both types of future event construction. These results suggest that, if the TBI patients in the present study indeed relied JAK inhibitor on semantic memory when having to construct future events, this should

have improved their performance relative to what would have been observed under conditions controlling for this option. Thus, in the latter case, their deficits would have been even more pronounced than what we observed here. In short, the specific cognitive and neural deficits that may contribute to the reported difficulties in episodic memory and episodic future thinking in TBI patients include reduced Methocarbamol executive functioning, motivational problems, problem with constructing a narrative, and problems with drawing upon relevant schematic/semantic knowledge. The relative contributions of these different factors cannot be decided based on the present findings, and warrant further investigations. The present study holds two main limitations, which should be taken into account when interpreting the findings. Because of the small sample size, conclusions should be drawn only tentatively, and specifically null findings should be interpreted with caution. A second limitation of the study concerns the relatively short time span between the time of the injury and the memory assessment of the TBI participants (between 39 and 117 days after the injury).