Impaired Decision Making is Associated with Poor Inhibition Control in Nonpathological Lottery Gamblers.

Previous studies by questionnaires have demonstrated that lottery gamblers who have not meet the criteria of pathological gambler show greater gambling acceptability. However, few empirical evidence of whether such nonpathological lottery gamblers (NPLGs) display the same impairments of decision making with pathological gamblers has been found so far. In present study, NPLGs and matched controls (MCs) were asked to perform the Iowa Gambling Task (IGT) and inter-temporal choice task (ICT). We found that compared to MCs, NPLGs displayed much lower IGT scores, net gains and proportions of advantageous decks in the IGT task and much higher percentages of trials during which smaller-but-sooner rewards were chosen in the ICT. These findings indicate that NPLGs display much more risky and impulsive decision makings, just like pathological gamblers in the previous studies. Next, the Go/NoGo task was employed to explore the role of response inhibition in the impairment of decision making in NPLGs. We found that NPLGs did show much higher commission errors compared to MCs. Moreover, IGT scores, net gain and proportions of advantageous decks were significantly negatively correlated with commission errors, which indicates that poor response inhibition might be involved in the impairments of decision making in NPLGs. To our knowledge, we provided the first empirical evidence of impairment of decision making and its cognitive mechanisms in NPLGs.

Neural substrate of initiation of cross-modal working memory retrieval.

Cross-modal working memory requires integrating stimuli from different modalities and it is associated with co-activation of distributed networks in the brain. However, how brain initiates cross-modal working memory retrieval remains not clear yet. In the present study, we developed a cued matching task, in which the necessity for cross-modal/unimodal memory retrieval and its initiation time were controlled by a task cue appeared in the delay period. Using functional magnetic resonance imaging (fMRI), significantly larger brain activations were observed in the left lateral prefrontal cortex (l-LPFC), left superior parietal lobe (l-SPL), and thalamus in the cued cross-modal matching trials (CCMT) compared to those in the cued unimodal matching trials (CUMT). However, no significant differences in the brain activations prior to task cue were observed for sensory stimulation in the l-LPFC and l-SPL areas. Although thalamus displayed differential responses to the sensory stimulation between two conditions, the differential responses were not the same with responses to the task cues. These results revealed that the frontoparietal-thalamus network participated in the initiation of cross-modal working memory retrieval. Secondly, the l-SPL and thalamus showed differential activations between maintenance and working memory retrieval, which might be associated with the enhanced demand for cognitive resources.