## 1 Introduction  
The role of caves in the cognitive and cultural development of early human societies has long intrigued archaeologists, anthropologists, and cognitive scientists [1]. These isolated natural environments, often navigable only with artificial light, have been proposed as settings where ancient humans engaged in rituals facilitating altered states of consciousness (ASCs). Such states, potentially induced by sensory deprivation or psychoactive substances [2], may have enabled geometric and figurative hallucinations, possibly enhancing symbolic thinking and contributing to the vivid realism and complexity of Paleolithic cave art [3, 4]. Darkness is one of the unique sensory conditions of caves. The absence of natural light in these environments has been integral to early human spirituality and cognition, shaping rituals, beliefs, and experiences from prehistoric to modern times due to its symbolic ties to mystery, the supernatural, and death [5]. Additionally, caves possess other unique sensory characteristics, such as reverberating acoustics, known to enhance feelings of mystery, romance, sadness, and fear [6], and flickering torchlight impacting perceptions of time, mood, alertness, and divergent thinking [7]. Together, these sensory attributes could have played a crucial role in altering perception, cognition, and emotional states during rituals. From a physiological perspective, it has long been known that prolonged darkness, isolation, and sensory deprivation are known to affect circadian rhythms and perceptual states [8]. In the absence of natural light and time cues, individuals experience desynchronization of biological rhythms, distortions in time perception, and alterations in sleep-wakecycles. Additionally, the confined and low-oxygen atmosphere in caves has been linked to cardiovascular and metabolic responses, which, when combined with isolation, can heighten stress responses and contribute to perceptual and cognitive shifts, facilitating ASCs during prolonged stays [9]. Those hypoxic conditions in deeper cave environments have been hypothesized to contribute to altered consciousness by inducing hallucinations and heightened emotional arousal [10]. Cognitive archaeologists propose that ASCs experienced in cave environments may have thus enabled early humans to perceive and connect with spiritual or transcendent realms, thereby inspiring the creation of figurative art. This connection could manifest through entropic phenomena--geometric patterns originating within the visual system during ASCs--as proposed in [11] or through broader consciousness alterations facilitating multidimensional perception, as proposed in [12]. Such altered perceptions may transcend purely neurological explanations, engaging deeper experiential and symbolic layers that have influenced the form and meaning of the art. Specifically, the rhythmic sounds and flickering torchlight, combined with the disorienting nature of caves and psychophysiological restrictions, could have induced trace-like states--a hypothesis resonating with recent findings in VR studies simulating cave environments [13]. [PERSON] [14] discusses the psychological and perceptual effects of caves on Upper Paleolithic humans, highlighting them as environments that stimulate intense visual and emotional experiences. He suggests that the darkness, complex rock formations, and unpredictable lighting in caves likely enhanced visual hypothesis testing, leading early humans to perceive suggestive shapes as animals or other forms. These perceptions, often accompanied by heightened emotions due to the environment's inherent danger, may have appeared magical or otherworldly. The visual system's tendency to fill in gaps under low-light conditions created a rich setting for imaginative interpretations, contributing to the creation and cultural significance of cave art. This interplay of perception, environment, and emotional arousal positioned caves as potent spaces for symbolic and ritualistic activities.