## 4 Discussion  
This study demonstrates that cognitive remediation using virtual reality impacts specific areas of cognitive functioning differently in older and younger adults. The FAB score increased more in old adults; however, the increase was not sufficient to surpass the performance of younger adults, who evidently started with a higher baseline score. Thus, the intervention appears to restore previously lost skills rather than enhance them from a new baseline. The FAB measures executive functions, which involve a set of operations coordinated by various processes to perform actions flexibly in non-routine contexts. These complex and heterogeneous abilities are predominantly regulated by neuronal mechanisms localized in prefrontal regions [58; 61; 62]. Given the complexity of the subcortical coordination required by these operations, the results should be interpreted from a rehabilitative perspective. Similarly, the Matrix test, despite showing a greater increase in scores among older adults, did not result in older adults achieving better scores than younger adults by the end of the trial. This test assesses different aspects of visual attention, such as speed, detection capacity, and interaction between working memory and visuo-attentive processes [53]. While performance on this test is affected by visual impairment and motor weakness, the role of \"social intelligence\" is minimal; the test tends to deteriorate significantly with age [53]. Therefore, the results are likely influenced by these factors rather than reflecting the specific characteristics of BD related to the impairment of cognitive and affective intelligence. It is important to consider that impairments, which can be exacerbated by microvascular issues common in aging and BD, may contribute to the observed results [27; 28]. Thus, the findings are notable from a rehabilitation perspective. The Babcock Story Recall Test, a neuropsychological measure of episodic memory for immediate and delayed recall [49], revealed that older adults with BD showed nearly double the improvement in scores compared to younger adults. However, this test measures more than just memory performance; it is strongly correlated with movement velocity and both cerebellar and non-cerebular motor control functions [63]. Once again, the interactions between social intelligence and cognitive intelligence appear marginal. A significant heterogeneity in clinical cognitive aging has been observed among individuals with BD. Researchers have proposed three hypotheses to explain these variations in aging [64]. The first hypothesis suggests that different endophenotypes interact with the cognitive aging process in distinct ways, leading to a decline in certain cognitive domains while others remain relatively stable over time. The second hypothesis posits that BD undergoes intrinsic neuroprogression, evolving naturally and progressively toward a state characterized by cognitive impairment. According to this hypothesis, BD would evolve \"naturally\" and progressively towards a disorder characterized by cognitive impairment. According to this view, a severe manic or depressive episode could induce a systemic response that results in a loss of brain connectivity. The third hypothesis considers the risk of vascular dementia, given the documented increase in vascular disorders associated with the progression of BD. These hypotheses are not mutually exclusive; the predominance of any one hypothesis may depend on additional factors such as the effects of medication and overall health conditions, particularly dysmetabolic syndromes [64]. Given these factors, determining which specific intervention might better impact a particular cognitive ability in an older adult sample is challenging. However, if a specific cognitive ability that was deficient improves in younger individuals with bipolar disorder, this may provide more straightforward interpretative insights.