Effects of Material and Non-Material Rewards on Remembering to Do Things for Others

Learning without contingencies: A loss of synergy between memory and reward circuits in schizophrenia

Motivational deficits in schizophrenia may interact with foundational cognitive processes including learning and memory to induce impaired cognitive proficiency. If such a loss of synergy exists, it is likely to be underpinned by a loss of synchrony between the brains learning and reward sub-networks. Moreover, this loss should be observed even during tasks devoid of explicit reward contingencies given that such tasks are better models of real world performance than those with artificial contingencies. Here we applied undirected functional connectivity (uFC) analyses to fMRI data acquired while participants engaged in an associative learning task without contingencies or feedback. uFC was estimated and inter-group differences (between schizophrenia patients and controls, n = 54 total, n = 28 patients) were assessed within and between reward (VTA and NAcc) and learning/memory (Basal Ganglia, DPFC, Hippocampus, Parahippocampus, Occipital Lobe) sub-networks. The task paradigm itself alternated between Encoding, Consolidation, and Retrieval conditions, and uFC differences were quantified for each of the conditions. Significantly reduced uFC dominated the connectivity profiles of patients across all conditions. More pertinent to our motivations, these reductions were observed within and across classes of sub-networks (reward-related and learning/memory related). We suggest that disrupted functional connectivity between reward and learning sub-networks may drive many of the performance deficits that characterize schizophrenia. Thus, cognitive deficits in schizophrenia may in fact be underpinned by a loss of synergy between reward-sensitivity and cognitive processes.

The deficient cue monitoring and the facilitating effect of prosocial intention on prospective memory in patients with schizophrenia spectrum disorders

The study aimed to investigate the cognitive processing of prospective memory (PM) in patients with schizophrenia spectrum disorders (SSDs) by using an eye-tracking paradigm. In addition, the facilitating effects of prosocial intention (the desire to help others) on PM in SSDs were also examined. In phase 1, 26 patients (group1) and 25 healthy controls (HCs) were compared in an eye-tracking PM paradigm in terms of the PM accuracy and eye-tracking indices. In phase 2, 21 more patients (group2) were recruited, and a prosocial intention was introduced in the eye-tracking PM paradigm. Their PM accuracy and eye-tracking indices were compared with those in group1. The PM cue monitoring was indicated by the total fixation counts and fixation time on distractor words. In phase 1, group1 showed lower PM accuracy, fewer fixation counts and less fixation time on distractor words than HCs. In phase 2, group2 (with prosocial intention) performed significantly better than group1 (with typical instruction) on both PM accuracy and fixation time on distractor words. In both groups of SSDs, the PM accuracy was significantly correlated with both the fixation counts and the fixation time of distractor words. After controlling for the cue monitoring indices, the difference in PM accuracy remained significant between group1 and HCs but disappeared between group1 and group2. The cue monitoring deficit contributes to the PM impairment in SSDs. The facilitating effect of prosocial intention disappears after the control of cue monitoring, also indicating its critical role in PM.

Prosocial motivation can promote the time-based prospective memory of school-age children

In real life, we are often motivated to plan things to be performed at specific times in the future. Some of these intended actions help other individuals, and thus involve time-based prospective memory (TBPM) under prosocial motivational conditions. Children's social development is very rapid, and they have relatively stable prosocial motivation during school age. Few studies have paid attention to this issue. This study focuses on three aspects of this issue: (1) the impact of prosocial motivation on the TBPM of school-age children, (2) whether there are sex differences in this effect, and, for the first time, (3) the processing mechanism by which prosocial motivation affects TBPM in school-age children in the framework of the motivation cognitive model. A total of 112 elementary school students, aged between 8 and 12, participated in the experiment, using a 2 (group: prosocial motivation, control) × 2 (sex: boy, girl) between-subjects design. The results showed that prosocial motivation can significantly reduce children's time difference of TBPM. However, we found no sex differences in the effect of prosocial motivation on TBPM in the above two indicators. With regard to the processing mechanism, we found that the prosocial motivation group paid more attention to external time information throughout the experiment. However, their internal attention and the effectiveness of attention did not improve. These results partially support the motivation cognitive model. Overall, this study found that prosocial motivation relies mainly on external attention to improve the TBPM performance of school-age children.

The Impact of Error-Consequence Severity on Cue Processing in Importance-Biased Prospective Memory

Prospective memory (PM) enables people to remember to complete important tasks in the future. Failing to do so can result in consequences of varying severity. Here, we investigated how PM error-consequence severity impacts the neural processing of relevant cues for triggering PM and the ramification of that processing on the associated prospective task performance. Participants role-played a cafeteria worker serving lunches to fictitious students and had to remember to deliver an alternative lunch to students (as PM cues) who would otherwise experience a moderate or severe aversive reaction. Scalp-recorded, event-related potential (ERP) measures showed that the early-latency frontal positivity, reflecting the perception-based neural responses to previously learned stimuli, did not differ between the severe versus moderate PM cues. In contrast, the longer-latency parietal positivity, thought to reflect full PM cue recognition and post-retrieval processes, was elicited earlier by the severe than the moderate PM cues. This faster instantiation of the parietal positivity to the severe-consequence PM cues was then followed by faster and more accurate behavioral responses. These findings indicate how the relative importance of a PM can be neurally instantiated in the form of enhanced and faster PM-cue recognition and processing and culminate into better PM.

Event versus activity-based cues and motivation in school-related prospective memory tasks

Prospective memory (PM), the ability to remember an intention in the future, is essential to children's everyday lives. We explored age differences (6- to 7- vs. 10- to 11-year-olds) in PM depending on the nature of the task and the children's motivation. Children performed event-based PM tasks (in which the cue was presented during the ongoing activity) and activity-based PM tasks (in which the cue consisted of finishing the ongoing activity). Additionally, the children were assigned to either a reward condition or a no-reward condition. The results showed better performance in event than in activity based tasks, with older children outperforming younger children in both. There was a marginal effect of reward for PM accuracy. These patterns suggest that the cue detection process and children's motivation play a role in PM performance during development.

Social importance enhances prospective memory: evidence from an event-based task

Prospective memory performance can be enhanced by task importance, for example by promising a reward. Typically, this comes at costs in the ongoing task. However, previous research has suggested that social importance (e.g., providing a social motive) can enhance prospective memory performance without additional monitoring costs in activity-based and time-based tasks. The aim of the present study was to investigate the influence of social importance in an event-based task. We compared four conditions: social importance, promising a reward, both social importance and promising a reward, and standard prospective memory instructions (control condition). The results showed enhanced prospective memory performance for all importance conditions compared to the control condition. Although ongoing task performance was slowed in all conditions with a prospective memory task when compared to a baseline condition with no prospective memory task, additional costs occurred only when both the social importance and reward were present simultaneously. Alone, neither social importance nor promising a reward produced an additional slowing when compared to the cost in the standard (control) condition. Thus, social importance and reward can enhance event-based prospective memory at no additional cost.