Towards a Dynamic Exploration of Vision, Cognition and Emotion in Alcohol-Use Disorders

Abstract

Visuoperceptive impairments are among the most frequently reported deficits in alcoholuse disorders, but only very few studies have investigated their origin and interactions with other categories of dysfunctions. Besides, these deficits have generally been interpreted in a linear bottom- up perspective, which appears very restrictive with respect to the new models of vision developed in healthy populations. Indeed, new theories highlight the predictive nature of the visual system and demonstrate that it interacts with higher-level cognitive functions to generate top-down predictions. These models notably posit that a fast but coarse visual analysis involving magnocellular pathways helps to compute heuristic guesses regarding the identity and affective value of inputs, which are used to facilitate conscious visual recognition. Building on these new proposals, the present review stresses the need to reconsider visual deficits in alcohol-use disorders as they might have crucial significance for core features of the pathology, such as attentional bias, loss of inhibitory control and emotion decoding impairments. Centrally, we suggest that individuals with severe alcohol-use disorders could present with magnocellular damage and we defend a dynamic explanation of the deficits. Rather than being restricted to high-level processes, deficits could start at early visual stages and then extend and potentially intensify during following steps due to reduced cerebral connectivity and dysfunctional cognitive/emotional regions. A new research agenda is specifically provided to test these hypotheses.

Keywords: Alcohol-use disorders; bottom-up processes; magnocellular pathway; orbitofrontal cortex; parvocellular pathway; top-down processes; visual prediction; visuoperceptive deficits..

Fig. (1)

Paradigm shift between: (A) a classical bottom-up interpretation of the origin and consequences of visual deficits in AUD, and (B) a dynamic explanation combining both bottom-up and top-down mechanisms. Rather than being restricted to strictly bottom-up disturbances starting at the sensory analysis level, the visuoperceptive deficits of IAUD could also be affected by higher-level impairments since emotions, memory, attention and executive functions also influence basic visual processing in a top-down and reciprocal manner. The dashed lines therefore represent the potential multiple origins and directionalities of the deficits.

Fig. (2)

Integrated proposal of visual mechanisms. The incoming visual input reaches early visual areas in a bottom-up fashion. Coarse low SF input from the MC pathway quickly interacts with the slower high SF input of the PC pathway but is also rapidly transmitted to the OFC where a first prediction about the identity and affective value of the stimulus is computed with the contribution of information stored in long-term memory and activations from other affective regions. In parallel, low SF input also reaches the PHC where contextual predictions are initiated. Together, these predictions help to refine the fine-grained analysis performed in the ITC on the basis of high SF cues, facilitating recognition in a top-down manner. In the meantime, attentional and executive processes also modulate these top-down mechanisms by biasing the processing of specific low-level visual features according to the requirement of the task. ITC: inferotemporal cortex; MC: magnocellular; OFC: orbitofrontal cortex; PHC: parahippocampal cortex; PC: parvocellular; SF: spatial frequencies. Figure adapted from the visual and affective prediction models from Bar and colleagues [91, 105, 106].

Fig. (3)

Schematic summary of the proposed two-step research agenda. The first axis focuses on low-level visual properties and basic visual recognition, while the second axis addresses the concurrent role of additional cognitive (attentional, mnemonic, executive) and emotional processes. The lower part of the Figure offers an example of stimuli and task for each part of the research program. These tasks are further described in sections 5.1. and 5.2. of the paper. HSF: high spatial frequency; LSF: low spatial frequency; MC: magnocellular; PC: parvocellular; SF: spatial frequencies.