The Power of Our Imaginations Combined: Collaborative Imagination’s Role in Facilitating Social Connection

Imagined events and scenarios can influence our perceptions, cognitions, and emotions. It has been found that our imaginations are abundant with social scenarios and can affect how we think of our relationships with others, but can imagining an event together further impact our connection with others? And does the vividness of that imagined event correspond to social connection? In this study, we recruited 126 participants and separated them into pairs of which were then randomly assigned into one of three conditions. Collaborative imagination was found to increase social connection more so than individually imagining a shared social scenario. The vividness of imagined encounters was significantly positively correlated with social connection. Thus, these results suggest that imagining an event together can foster feelings of social closeness and connection, and that the vividness of the imagined event may play a role in these effects, supporting the idea that collaborative imagination may play a role in the development of new relationships. Further research is suggested looking at group impact on collaborative imagination’s role in social connection as well as how episodic-specificity inductions may influence social connection during collaborative imagination

Neuropsychology of Consciousness: Some History and a Few New Trends

Consciousness is a global activity of the nervous system. Its physiological and pathological mechanisms have been studied in relation to the natural sleep-wake cycle and various forms of normal or morbid unconsciousness, mainly in neurophysiology and clinical neurology. Neuropsychology has been more interested in specific higher brain functions, such as perception and memory and their disorders, rather than in consciousness per se. However, neuropsychology has been at the forefront in the identification of conscious and unconscious components in the processing of sensory and mnestic information. The present review describes some historical steps in the formulation of consciousness as a global brain function with arousal and content as principal ingredients, respectively, instantiated in the subcortex and the neocortex. It then reports a few fresh developments in neuropsychology and cognitive neuroscience which emphasize the importance of the hippocampus for thinking and dreaming. Non-neocortical structures may contribute to the contents of consciousness more than previously believed

How do cannabis users mentally travel in time? Evidence from an fMRI study of episodic future thinking

Rationale Episodic future thinking (EFT) is a cognitive function that allows individuals to imagine novel experiences that may happen in the future. Prior studies show that EFT is impaired in different groups of substance users. However, there is no evidence regarding the neurobiological mechanisms of EFT in cannabis users. Objectives We aimed to compare brain activations of regular cannabis users and non-using controls during an EFT fMRI task. Exploratory analyses were also conducted to investigate the association between EFT and cannabis use variables (e.g., duration of use, age onset, frequency of use). Methods Twenty current cannabis users and 22 drug-naïve controls underwent an fMRI scanning session while completing a task involving envisioning future-related events and retrieval of past memories as a control condition. The EFT fMRI task was adapted from the autobiographical interview and composed of 20 auditory cue sentences (10 cues for past and 10 cues for future events). Participants were asked to recall a past or generate a future event, in response to the cues, and then rate their vividness after each response. Results We found that cannabis users compared to non-user controls had lower activation within the cerebellum, medial and superior temporal gyrus, lateral occipital cortex, and occipital fusiform gyrus while envisioning future events. Cannabis users rated the vividness of past events significantly lower than non-users (P < 0.005). There were marginal group differences for rating the vividness of future events (P = 0.052). Significant correlations were also found between the medial and superior temporal gyrus activities and behavioral measures of EFT and episodic memory. Conclusions Cannabis users, compared to drug-naïve controls, have lower brain activation in EFT relevant regions. Thus, any attempts to improve aberrant EFT performance in cannabis users may benefit from EFT training

Building Mental Experiences: From Scenes to Events

Mental events are central to everyday cognition, be it our continuous perception of the world, recalling autobiographical memories, or imagining the future. Little is known about the fine-grained temporal dynamics of these processes. Given the apparent predominance of scene imagery across cognition, in this thesis I used magnetoencephalography to investigate whether and how activity in the hippocampus and ventromedial prefrontal cortex (vmPFC) supports the mental construction of scenes and the events to which they give rise. In the first experiment, participants gradually imagined scenes and also closely matched non-scene arrays; this allowed me to assess whether any brain regions showed preferential responses to scene imagery. The anterior hippocampus and vmPFC were particularly engaged by the construction of scene imagery, with the vmPFC driving hippocampal activity. In the second experiment, I found that certain objects – those that were space-defining – preferentially engaged the vmPFC and superior temporal gyrus during scene construction, providing insight into how objects affect the creation of scene representations. The third experiment involved boundary extension during scene perception, permitting me to examine how single scenes might be prepared for inclusion into events. I observed changes in evoked responses just 12.5-58 ms after scene onset over fronto-temporal sensors, with again the vmPFC exerting a driving influence on other brain regions, including the hippocampus. In the final experiment, participants watched brief movies of events built from a series of scenes or non-scene patterns. A difference in evoked responses between the two event types emerged during the first frame of the movies, the primary source of which was shown to be the hippocampus. The enduring theme of the results across experiments was scene-specific engagement of the hippocampus and vmPFC, with the latter being the driving influence. Overall, this thesis provides insights into the neural dynamics of how scenes are built, made ready for inclusion into unfolding mental episodes, and then linked to produce our seamless experience of the world

The neural and cognitive mechanisms underlying creative thinking

The ability to generate creative ideas and novel solutions is a defining feature of human cognition. However, the cognitive and neural mechanisms that underlie creative cognition are poorly understood. While recent research has highlighted the roles of distinct associative and controlled processes in creative cognition, supported by the default mode and executive control networks, respectively, it remains unclear how exactly creative ideas are produced by the interactions of these processes and networks, or how creative cognition relates to more fundamental processes like executive functions and working memory (WM). The present thesis aims to examine the neurocognitive basis of creative thinking using a combination of behavioral and fMRI experiments. The need for greater computational modeling in neurocognitive creativity research (NCR) is also discussed. The first study examines how the default mode and executive control networks contribute to creative cognition over time. Results are broadly suggestive of distinct generative and evaluative phases in creative thought. A second study explores relationships between multiple forms of creative thinking and multiple forms of inhibition, finding that divergent thinking is related to cognitive inhibition. In a third study, relationships between creative cognition and control over WM are examined, using measures of executive functions. While no relationships were found between divergent thinking and executive functions, a positive relationship was found between WM updating and convergent thinking and verbal fluency. In a review chapter, the case for greater computational modeling in NCR is made. Previous models of creative cognition, and how these might be improved upon, are discussed, with some examples of the model development process. In a final study, relationships are explored between personality measures and evaluations of the novelty, usefulness, and creativity of ideas. A closing chapter summarizes all findings and discusses avenues for future research

“In the mind’s eye” – Exploring the interaction between oculomotor behaviour and memory-related processes in ageing and neurodegeneration

Much of the rich internal world constructed by humans is derived from, and experienced through, visual mental imagery. Despite growing appreciation of visual exploration in guiding imagery-rich construction-based processes, extant theories of memory retrieval and prospection have yet to accommodate the precise role of visual mental imagery and corresponding oculomotor dynamics in the service of past and future-oriented thinking, particularly as we age and in the presence of neurodegenerative syndromes. This thesis comprises three experimental studies investigating these issues. Chapter 2 demonstrates distinct signatures of oculomotor behaviour during visual exploration and memory retrieval in younger and cognitively healthy older adults, as well as patients with Alzheimer’s disease or semantic dementia. In Chapter 3, I further demonstrate age-related changes in eye movement metrics during the endogenous construction of atemporal scenes in the absence of externally cued visual stimuli. Results suggest a shift away from the production of eye movements in older adults as a function of increasing task complexity as cognitive demands exceed working memory capacities. Finally, Chapter 4 expands on the preceding findings in the context of episodic future thinking. The temporal distance and the level of plausibility of hypothetical future events are found to influence participants’ performance by encouraging the elaboration of scenarios that are particularly rich in contextual detail in selected experimental conditions. The work presented in this thesis adds to the extant literature by demonstrating and characterising the relationship between oculomotor behaviour and imagery-rich construction-based processes. Future enquiries exploring the potential and diverse applications of oculomotor metrics to neuropsychological and clinical research will further elucidate the complex adaptive mechanisms supporting cognitive performance in both healthy ageing and neurodegeneration